Pacemaker syndrome
Encyclopedia
Pacemaker syndrome is a disease that represents the clinical consequences of suboptimal atrioventricular
(AV) synchrony or AV dyssynchrony, regardless of the pacing mode, after the pacemaker plantation.
It is an iatrogenic disease—an adverse effect resulting from medical treatment—that is often underdiagnosed. In general, the symptoms of the syndrome
are a combination of decreased cardiac output
, loss of atrial contribution to ventricular
filling, loss of total peripheral resistance
response, and nonphysiologic pressure waves.
Individuals with a low heart rate prior to pacemaker implantation are more at risk of developing pacemaker syndrome. Normally the first chamber of the heart (atrium) contracts as the second chamber (ventricle) is relaxed, allowing the ventricle to fill before it contracts and pumps blood out of the heart. When the timing between the two chambers goes out of synchronization, less blood is delivered on each beat. Patients who develop pacemaker syndrome may require adjustment of the pacemaker timing, or another lead fitted to regulate the timing of the chambers separately.
of pacemaker
syndrome
. Most of the signs and symptoms of pacemaker syndrome are nonspecific, and many are prevalent in the elderly population at baseline. In the lab, pacemaker interrogation plays a crucial role in determining if the pacemaker mode had any contribution to symptoms.
Symptoms commonly documented in patients history, classified according to etiology
:
In particular, the examiner should look for the following in the physical examination
, as these are frequent findings at the time of admission:
is poorly understood. However several risk factors
are associated with pacemaker syndrome.
timing of atrial and ventricular
contractions, or sometimes called AV dyssynchrony, leads to different mechanisms of symptom
s production. This altered ventricular contraction will decrease cardiac output
, and in turn will lead to systemic hypotensive reflex response with varying symptoms.
compliance, which may be caused by diseases such as hypertensive cardiomyopathy
, hypertrophic cardiomyopathy
, restrictive cardiomyopathy
, and aging, can result in loss of atrial contraction and significantly reduces cardiac output
. Because in such cases the atrias are required to provide 50% of cardiac output
, which normally provides only 15% - 25% of cardiac output
.
can cause pulsation in the neck and abdomen
, headache
, cough
, and jaw pain.
pacing is associated with elevated right
and left atrial
pressures, as well as elevated pulmonary venous
and pulmonary arterial
pressures, which can lead to symptom
atic pulmonary
and hepatic
congestion.
syndrome
exhibit increased plasma levels of ANP
. That's due to increase in left atrial
pressure and left ventricular
filling pressure, which is due to decreased cardiac output
caused by dyssynchrony in atrial and ventricular
contraction. ANP
and BNP
are potent arterial
and venous
vasodilators
that can override carotid
and aortic
baroreceptor reflex
es attempting to compensate for decreased blood pressure
. Usually patients with cannon a waves
have higher plasma levels of ANP
than those without cannon a waves
.
. VA conduction, sometimes referred to as retrograde conduction, leads to delayed, nonphysiologic timing of atrial contraction in relation to ventricular
contraction
. Nevertheless, many conditions other than VA conduction promote AV dyssynchrony.
This will further decrease blood pressure
, and secondary increase in ANP
and BNP
.
, AV synchrony should be optimized to prevent the occurrence of pacemaker
syndrome
. Where patients with optimized AV synchrony have shown great results of implantation
and very low incidence
of pacemaker syndrome than those with suboptimal AV synchronization.
are used to treat pacemaker syndrome directly because treatment consists of upgrading or reprogramming the pacemaker.
intervention is needed. After consulting an electrophysiologist, possibly an additional pacemaker
lead placement is needed, which eventually relieve some of the symptoms.
are at higher risk of developing fatal complications
that calls for the patients to be carefully monitored in the ICU
. Complications include atrial fibrillation
, thrombo-embolic events, and heart failure.
of pacemaker syndrome has ranged from 2% to 83%. The wide range of reported incidence is likely attributable to two factors which are the criteria used to define pacemaker syndrome and the therapy used to resolve that diagnosis.
Atrioventricular node
The atrioventricular node is a part of the electrical control system of the heart that coordinates heart rate. It electrically connects atrial and ventricular chambers...
(AV) synchrony or AV dyssynchrony, regardless of the pacing mode, after the pacemaker plantation.
It is an iatrogenic disease—an adverse effect resulting from medical treatment—that is often underdiagnosed. In general, the symptoms of the syndrome
Syndrome
In medicine and psychology, a syndrome is the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one or more features alerts the physician to the possible presence of the others...
are a combination of decreased cardiac output
Cardiac output
Cardiac output is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute. CO may be measured in many ways, for example dm3/min...
, loss of atrial contribution to ventricular
Ventricle (heart)
In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
filling, loss of total peripheral resistance
Total peripheral resistance
Vasculature throughout the entire body can be thought of as two separate circuits - one is the systemic circulation, while the other is the pulmonary circulation. Total peripheral resistance is the sum of the resistance of all peripheral vasculature in the systemic circulation...
response, and nonphysiologic pressure waves.
Individuals with a low heart rate prior to pacemaker implantation are more at risk of developing pacemaker syndrome. Normally the first chamber of the heart (atrium) contracts as the second chamber (ventricle) is relaxed, allowing the ventricle to fill before it contracts and pumps blood out of the heart. When the timing between the two chambers goes out of synchronization, less blood is delivered on each beat. Patients who develop pacemaker syndrome may require adjustment of the pacemaker timing, or another lead fitted to regulate the timing of the chambers separately.
Signs and symptoms
No specific set of criteria has been developed for diagnosisDiagnosis
Diagnosis is the identification of the nature and cause of anything. Diagnosis is used in many different disciplines with variations in the use of logics, analytics, and experience to determine the cause and effect relationships...
of pacemaker
Pacemaker
An artificial pacemaker is a medical device that uses electrical impulses to regulate the beating of the heart.Pacemaker may also refer to:-Medicine:...
syndrome
Syndrome
In medicine and psychology, a syndrome is the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one or more features alerts the physician to the possible presence of the others...
. Most of the signs and symptoms of pacemaker syndrome are nonspecific, and many are prevalent in the elderly population at baseline. In the lab, pacemaker interrogation plays a crucial role in determining if the pacemaker mode had any contribution to symptoms.
Symptoms commonly documented in patients history, classified according to etiology
Etiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....
:
- Neurological - DizzinessDizzinessDizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....
, near syncopeSyncope (medicine)Syncope , the medical term for fainting, is precisely defined as a transient loss of consciousness and postural tone characterized by rapid onset, short duration, and spontaneous recovery due to global cerebral hypoperfusion that most often results from hypotension.Many forms of syncope are...
, and confusionConFusionConFusion is an annual science fiction convention organized by the Stilyagi Air Corps and its parent organization, the Ann Arbor Science Fiction Association. Commonly, it is held the third weekend of January. It is the oldest science fiction convention in Michigan, a regional, general SF con...
. - Heart failure - DyspneaDyspneaDyspnea , shortness of breath , or air hunger, is the subjective symptom of breathlessness.It is a normal symptom of heavy exertion but becomes pathological if it occurs in unexpected situations...
, orthopnea, paroxysmal nocturnal dyspnea, and edemaEdemaEdema or oedema ; both words from the Greek , oídēma "swelling"), formerly known as dropsy or hydropsy, is an abnormal accumulation of fluid beneath the skin or in one or more cavities of the body that produces swelling...
. - HypotensionHypotensionIn physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...
- SeizureSeizureAn epileptic seizure, occasionally referred to as a fit, is defined as a transient symptom of "abnormal excessive or synchronous neuronal activity in the brain". The outward effect can be as dramatic as a wild thrashing movement or as mild as a brief loss of awareness...
, mental status change, diaphoresisDiaphoresisDiaphoresis is excessive sweating commonly associated with shock and other medical emergency conditions.Diaphoretic is the state of perspiring profusely, or something that has the power to cause increased perspiration....
, and signs of orthostasis and shock. - Low cardiac outputCardiac outputCardiac output is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute. CO may be measured in many ways, for example dm3/min...
- Fatigue, weaknessWeaknessWeakness is a symptom represented, medically, by a number of different conditions, including: lack of muscle strength, malaise, dizziness, or fatigue. The causes are many and can be divided into conditions that have true or perceived muscle weakness. True muscle weakness is a primary symptom of a...
, dyspnea on exertion, lethargy, and lightheadedness. - Hemodynamic - PulsationPulseIn medicine, one's pulse represents the tactile arterial palpation of the heartbeat by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed against a bone, such as at the neck , at the wrist , behind the knee , on the inside of the elbow , and near the...
in the neck and abdomenAbdomenIn vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
, chokingChokingChoking is the mechanical obstruction of the flow of air from the environment into the lungs. Choking prevents breathing, and can be partial or complete, with partial choking allowing some, although inadequate, flow of air into the lungs. Prolonged or complete choking results in asphyxia which...
sensation, jawJawThe jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of...
pain, right upper quadrant (RUQ) pain, chestChestThe chest is a part of the anatomy of humans and various other animals. It is sometimes referred to as the thorax or the bosom.-Chest anatomy - Humans and other hominids:...
colds, and headacheHeadacheA headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
. - Heart rateHeart rateHeart rate is the number of heartbeats per unit of time, typically expressed as beats per minute . Heart rate can vary as the body's need to absorb oxygen and excrete carbon dioxide changes, such as during exercise or sleep....
related - Palpitations associated with arrhythmias
In particular, the examiner should look for the following in the physical examination
Physical examination
Physical examination or clinical examination is the process by which a doctor investigates the body of a patient for signs of disease. It generally follows the taking of the medical history — an account of the symptoms as experienced by the patient...
, as these are frequent findings at the time of admission:
- Vital signsVital signsVital signs are measures of various physiological statistics, often taken by health professionals, in order to assess the most basic body functions. Vital signs are an essential part of a case presentation. The act of taking vital signs normally entails recording body temperature, pulse rate ,...
may reveal hypotensionHypotensionIn physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...
, tachycardiaTachycardiaTachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...
, tachypneaTachypneaTachypnea means rapid breathing. Any rate between 12-20 breaths per minute is normal. Tachypnea is a respiration rate greater than 20 breaths per minute. - Distinction from other breathing terms :...
, or low oxygen saturationOxygen saturationOxygen saturation or dissolved oxygen is a relative measure of the amount of oxygen that is dissolved or carried in a given medium. It can be measured with a dissolved oxygen probe such as an oxygen sensor or an optode in liquid media, usually water.It has particular significance in medicine and...
. - Pulse amplitude may vary, and blood pressureBlood pressureBlood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
may fluctuate. - Look for neck veinVeinIn the circulatory system, veins are blood vessels that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart...
distensionDistensionDistension generally refers to an enlargement or ballooning effect:* Gastric distension - bloating of the stomach when air is pumped into it, as in a medical procedure* Abdominal distension - abdominal bloating, a symptom of several medical conditions...
and cannon wavesCannon A wavesCannon A waves, or cannon atrial waves, are waves seen occasionally in the jugular vein of humans with severe cardiac arrhythmia. When the atria and ventricles contract simultaneously, the blood will be pushed against the AV valve, and a very large pressure wave runs up the vein...
in the neck veins. - Lungs may exhibit crackles.
- Cardiac examination may reveal regurgitantRegurgitation (circulation)Regurgitation is blood flow in the opposite direction from normal, as the backward flowing of blood into the heart or between heart chambers. Can be categorized by:...
murmursMurmursMurmurs is the first full-length release by Caroline. It was released on Temporary Residence Limited.-Track listing:# Bicycle – 3:46# Pink & Black – 4:41# Sunrise – 4:02# Where's My Love? – 4:22# Everylittlething – 3:19# All I Need – 3:20...
and variability of heart soundsHeart soundsHeart sounds, or heartbeats, are the noises generated by the beating heart and the resultant flow of blood through it...
. - LiverLiverThe liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
may be pulsatile, and the RUQ may be tenderTendernessTenderness can mean:* a tendency to express warm, compassionate, or affectionate feelings* delicate or intimate physical contact* tenderness – pain or discomfort when an affected area is touched-Other:...
to palpationPalpationPalpation is used as part of a physical examination in which an object is felt to determine its size, shape, firmness, or location...
. AscitesAscitesAscites is a gastroenterological term for an accumulation of fluid in the peritoneal cavity.The medical condition is also known as peritoneal cavity fluid, peritoneal fluid excess, hydroperitoneum or more archaically as abdominal dropsy. Although most commonly due to cirrhosis and severe liver...
may be present in severe cases. - The lower extremities may be edematous.
- Neurologic examination may reveal confusionConFusionConFusion is an annual science fiction convention organized by the Stilyagi Air Corps and its parent organization, the Ann Arbor Science Fiction Association. Commonly, it is held the third weekend of January. It is the oldest science fiction convention in Michigan, a regional, general SF con...
, dizzinessDizzinessDizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....
, or altered mental status.
Causes
The etiologyEtiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....
is poorly understood. However several risk factors
Risk factors
A risk factor is a concept in finance theory such as the CAPM, APT and other theories that use pricing kernels. In these models, the rate of return of an asset is a random variable whose realization in any time period is a linear combination of other random variables plus a disturbance term or...
are associated with pacemaker syndrome.
Risk factors
- In the preimplantationImplant (medicine)An implant is a medical device manufactured to replace a missing biological structure, support a damaged biological structure, or enhance an existing biological structure. Medical implants are man-made devices, in contrast to a transplant, which is a transplanted biomedical tissue...
period, two variables are predicted to predispose to the syndrome. First is low sinus rate, and second is a higher programmed lower rate limit. In postimplantationImplant (medicine)An implant is a medical device manufactured to replace a missing biological structure, support a damaged biological structure, or enhance an existing biological structure. Medical implants are man-made devices, in contrast to a transplant, which is a transplanted biomedical tissue...
, an increased percentage of ventricularVentricle (heart)In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
paced beats is the only variable that significantly predicts development of pacemaker syndrome. - Patients with intact VA conductionVA conductionVA conduction, also named Ventriculoatrial conduction and sometimes referred to as Retrograde conduction, is the conduction backward phenomena in the heart, where the conduction comes from the ventricles or from the AV node into and through the atria.Retrograde VA conduction results in many...
are at greater risk for developing pacemaker syndrome. Around 90% of patients with preserved AV conduction have intact VA conductionVA conductionVA conduction, also named Ventriculoatrial conduction and sometimes referred to as Retrograde conduction, is the conduction backward phenomena in the heart, where the conduction comes from the ventricles or from the AV node into and through the atria.Retrograde VA conduction results in many...
, and about 30-40% of patients with complete AV blockAtrioventricular blockAn atrioventricular block involves the impairment of the conduction between the atria and ventricles of the heart.The causes of pathological AV block are varied and include ischaemia, infarction, fibrosis or drugs. Certain AV blocks can also be found as normal variants, such as in athletes or...
have preserved VA conductionVA conductionVA conduction, also named Ventriculoatrial conduction and sometimes referred to as Retrograde conduction, is the conduction backward phenomena in the heart, where the conduction comes from the ventricles or from the AV node into and through the atria.Retrograde VA conduction results in many...
. Intact VA conductionVA conductionVA conduction, also named Ventriculoatrial conduction and sometimes referred to as Retrograde conduction, is the conduction backward phenomena in the heart, where the conduction comes from the ventricles or from the AV node into and through the atria.Retrograde VA conduction results in many...
may not be apparent at the time of pacemaker implantation or even may develop at any time after implantation. - Patients with noncompliant ventriclesVentricle (heart)In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
and diastolic dysfunction are particularly sensitive to loss of atrial contribution to ventricular filling, where that highly increase the chance of developing the syndrome. This includes patients with cardiomyopathyCardiomyopathyCardiomyopathy, which literally means "heart muscle disease," is the deterioration of the function of the myocardium for any reason. People with cardiomyopathy are often at risk of arrhythmia or sudden cardiac death or both. Cardiomyopathy can often go undetected, making it especially dangerous to...
(hypertensive, hypertrophicHypertrophic cardiomyopathyHypertrophic cardiomyopathy is a disease of the myocardium in which a portion of the myocardium is hypertrophied without any obvious cause...
, restrictiveRestrictive cardiomyopathyRestrictive cardiomyopathy is a form of cardiomyopathy in which the walls are rigid, and the heart is restricted from stretching and filling with blood properly....
) and elderly individuals. - Other factors correlated with development of pacemaker syndrome include decreased stroke volumeStroke volumeIn cardiovascular physiology, stroke volume is the volume of blood pumped from one ventricle of the heart with each beat. SV is calculated using measurements of ventricle volumes from an echocardiogram and subtracting the volume of the blood in the ventricle at the end of a beat from the volume...
, decreased cardiac outputCardiac outputCardiac output is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute. CO may be measured in many ways, for example dm3/min...
, and decreased left atrialLeft atriumThe left atrium is one of the four chambers in the human heart. It receives oxygenated blood from the pulmonary veins, and pumps it into the left ventricle, via the mitral valve.-Foramen ovale:...
total emptying fraction associated with ventricularVentricle (heart)In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
pacing.
Pathophysiology
The loss of physiologicPhysiology
Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...
timing of atrial and ventricular
Ventricle (heart)
In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
contractions, or sometimes called AV dyssynchrony, leads to different mechanisms of symptom
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...
s production. This altered ventricular contraction will decrease cardiac output
Cardiac output
Cardiac output is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute. CO may be measured in many ways, for example dm3/min...
, and in turn will lead to systemic hypotensive reflex response with varying symptoms.
Loss of atrial contraction
Inappropriate pacing in patients with decreased ventricularVentricle (heart)
In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
compliance, which may be caused by diseases such as hypertensive cardiomyopathy
Hypertensive heart disease
Hypertensive heart disease is any of a number of complications of arterial hypertension that affects the heart.-Symptoms:* Fatigue* Cardiomegaly* Irregular pulse* Swelling of feet* Weight gain* Nausea* Shortness of breath...
, hypertrophic cardiomyopathy
Hypertrophic cardiomyopathy
Hypertrophic cardiomyopathy is a disease of the myocardium in which a portion of the myocardium is hypertrophied without any obvious cause...
, restrictive cardiomyopathy
Restrictive cardiomyopathy
Restrictive cardiomyopathy is a form of cardiomyopathy in which the walls are rigid, and the heart is restricted from stretching and filling with blood properly....
, and aging, can result in loss of atrial contraction and significantly reduces cardiac output
Cardiac output
Cardiac output is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute. CO may be measured in many ways, for example dm3/min...
. Because in such cases the atrias are required to provide 50% of cardiac output
Cardiac output
Cardiac output is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute. CO may be measured in many ways, for example dm3/min...
, which normally provides only 15% - 25% of cardiac output
Cardiac output
Cardiac output is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute. CO may be measured in many ways, for example dm3/min...
.
Cannon A waves
Atrial contraction against a closed tricuspid valveTricuspid valve
The tricuspid valve, or right atrioventricular valve, is on the right dorsal side of the mammalian heart, between the right atrium and the right ventricle. The normal tricuspid valve usually has three leaflets and three papillary muscles. They are connected to the papillary muscles by the chordae...
can cause pulsation in the neck and abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
, headache
Headache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
, cough
Cough
A cough is a sudden and often repetitively occurring reflex which helps to clear the large breathing passages from secretions, irritants, foreign particles and microbes...
, and jaw pain.
Increased atrial pressure
VentricularVentricle (heart)
In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
pacing is associated with elevated right
Right atrium
The right atrium is one of four chambers in the hearts of mammals and archosaurs...
and left atrial
Left atrium
The left atrium is one of the four chambers in the human heart. It receives oxygenated blood from the pulmonary veins, and pumps it into the left ventricle, via the mitral valve.-Foramen ovale:...
pressures, as well as elevated pulmonary venous
Pulmonary vein
The pulmonary veins are large blood vessels that carry blood from the lungs to the left atrium of the heart. In humans there are four pulmonary veins, two from each lung...
and pulmonary arterial
Pulmonary artery
The pulmonary arteries carry deoxygenated blood from the heart to the lungs. They are the only arteries that carry deoxygenated blood....
pressures, which can lead to symptom
Symptom
A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...
atic pulmonary
Pulmonary edema
Pulmonary edema , or oedema , is fluid accumulation in the air spaces and parenchyma of the lungs. It leads to impaired gas exchange and may cause respiratory failure...
and hepatic
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
congestion.
Increased production of natriuretic peptides
Patients with pacemakerArtificial pacemaker
A pacemaker is a medical device that uses electrical impulses, delivered by electrodes contacting the heart muscles, to regulate the beating of the heart...
syndrome
Syndrome
In medicine and psychology, a syndrome is the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one or more features alerts the physician to the possible presence of the others...
exhibit increased plasma levels of ANP
Atrial natriuretic peptide
Atrial natriuretic peptide , atrial natriuretic factor , atrial natriuretic hormone , or atriopeptin, is a powerful vasodilator, and a protein hormone secreted by heart muscle cells. It is involved in the homeostatic control of body water, sodium, potassium and fat...
. That's due to increase in left atrial
Left atrium
The left atrium is one of the four chambers in the human heart. It receives oxygenated blood from the pulmonary veins, and pumps it into the left ventricle, via the mitral valve.-Foramen ovale:...
pressure and left ventricular
Left ventricle
The left ventricle is one of four chambers in the human heart. It receives oxygenated blood from the left atrium via the mitral valve, and pumps it into the aorta via the aortic valve.-Shape:...
filling pressure, which is due to decreased cardiac output
Cardiac output
Cardiac output is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute. CO may be measured in many ways, for example dm3/min...
caused by dyssynchrony in atrial and ventricular
Ventricle (heart)
In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
contraction. ANP
Atrial natriuretic peptide
Atrial natriuretic peptide , atrial natriuretic factor , atrial natriuretic hormone , or atriopeptin, is a powerful vasodilator, and a protein hormone secreted by heart muscle cells. It is involved in the homeostatic control of body water, sodium, potassium and fat...
and BNP
Brain natriuretic peptide
Brain natriuretic peptide , now known as B-type natriuretic peptide or GC-B, is a 32 amino acid polypeptide secreted by the ventricles of the heart in response to excessive stretching of heart muscle cells...
are potent arterial
Artery
Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries....
and venous
Vein
In the circulatory system, veins are blood vessels that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart...
vasodilators
Vasodilation
Vasodilation refers to the widening of blood vessels resulting from relaxation of smooth muscle cells within the vessel walls, particularly in the large arteries, smaller arterioles and large veins. The process is essentially the opposite of vasoconstriction, or the narrowing of blood vessels. When...
that can override carotid
Common carotid artery
In human anatomy, the common carotid artery is an artery that supplies the head and neck with oxygenated blood; it divides in the neck to form the external and internal carotid arteries. - Structure :...
and aortic
Aorta
The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...
baroreceptor reflex
Baroreflex
The baroreflex or baroreceptor reflex is one of the body's homeostatic mechanisms for maintaining blood pressure. It provides a negative feedback loop in which an elevated blood pressure reflexively causes heart rate to decrease therefore causing blood pressure to decrease; likewise, decreased...
es attempting to compensate for decreased blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
. Usually patients with cannon a waves
Cannon A waves
Cannon A waves, or cannon atrial waves, are waves seen occasionally in the jugular vein of humans with severe cardiac arrhythmia. When the atria and ventricles contract simultaneously, the blood will be pushed against the AV valve, and a very large pressure wave runs up the vein...
have higher plasma levels of ANP
Atrial natriuretic peptide
Atrial natriuretic peptide , atrial natriuretic factor , atrial natriuretic hormone , or atriopeptin, is a powerful vasodilator, and a protein hormone secreted by heart muscle cells. It is involved in the homeostatic control of body water, sodium, potassium and fat...
than those without cannon a waves
Cannon A waves
Cannon A waves, or cannon atrial waves, are waves seen occasionally in the jugular vein of humans with severe cardiac arrhythmia. When the atria and ventricles contract simultaneously, the blood will be pushed against the AV valve, and a very large pressure wave runs up the vein...
.
VA conduction
A major cause of AV dyssynchrony is VA conductionVA conduction
VA conduction, also named Ventriculoatrial conduction and sometimes referred to as Retrograde conduction, is the conduction backward phenomena in the heart, where the conduction comes from the ventricles or from the AV node into and through the atria.Retrograde VA conduction results in many...
. VA conduction, sometimes referred to as retrograde conduction, leads to delayed, nonphysiologic timing of atrial contraction in relation to ventricular
Ventricle (heart)
In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
contraction
Muscle contraction
Muscle fiber generates tension through the action of actin and myosin cross-bridge cycling. While under tension, the muscle may lengthen, shorten, or remain the same...
. Nevertheless, many conditions other than VA conduction promote AV dyssynchrony.
This will further decrease blood pressure
Blood pressure
Blood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
, and secondary increase in ANP
Atrial natriuretic peptide
Atrial natriuretic peptide , atrial natriuretic factor , atrial natriuretic hormone , or atriopeptin, is a powerful vasodilator, and a protein hormone secreted by heart muscle cells. It is involved in the homeostatic control of body water, sodium, potassium and fat...
and BNP
Brain natriuretic peptide
Brain natriuretic peptide , now known as B-type natriuretic peptide or GC-B, is a 32 amino acid polypeptide secreted by the ventricles of the heart in response to excessive stretching of heart muscle cells...
.
Prevention
At the time of pacemaker implantationImplant (medicine)
An implant is a medical device manufactured to replace a missing biological structure, support a damaged biological structure, or enhance an existing biological structure. Medical implants are man-made devices, in contrast to a transplant, which is a transplanted biomedical tissue...
, AV synchrony should be optimized to prevent the occurrence of pacemaker
Pacemaker
An artificial pacemaker is a medical device that uses electrical impulses to regulate the beating of the heart.Pacemaker may also refer to:-Medicine:...
syndrome
Syndrome
In medicine and psychology, a syndrome is the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one or more features alerts the physician to the possible presence of the others...
. Where patients with optimized AV synchrony have shown great results of implantation
Implant (medicine)
An implant is a medical device manufactured to replace a missing biological structure, support a damaged biological structure, or enhance an existing biological structure. Medical implants are man-made devices, in contrast to a transplant, which is a transplanted biomedical tissue...
and very low incidence
Incidence (epidemiology)
Incidence is a measure of the risk of developing some new condition within a specified period of time. Although sometimes loosely expressed simply as the number of new cases during some time period, it is better expressed as a proportion or a rate with a denominator.Incidence proportion is the...
of pacemaker syndrome than those with suboptimal AV synchronization.
Diet
Diet alone cannot treat pacemaker syndrome, but an appropriate diet to the patient, in addition to the other treatment regimens mentioned, can improve the patient's symptoms. Several cases mentioned below:- For patients with heart failure, low-salt dietLow sodium dietA low sodium diet is a diet that includes no more than 1,500 to 2,400 mgs of sodium per day. People who follow a vigorous or moderate exercise schedule are usually advised to limit their sodium intake to 3,000 mg per day and those with moderate to severe heart failure are usually advised to...
is indicated. - For patients with autonomicAutonomic nervous systemThe autonomic nervous system is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness, and controls visceral functions. The ANS affects heart rate, digestion, respiration rate, salivation, perspiration, diameter of the pupils,...
insufficiency, a high-salt dietDiet (nutrition)In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...
may be appropriate. - For patients with dehydrationDehydrationIn physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...
, oralOral administrationOral administration is a route of administration where a substance is taken through the mouth.-Terminology:Per os is an adverbial phrase meaning literally from Latin "by mouth" or "by way of the mouth." The expression is used in medicine to describe a treatment that is taken orally. The...
fluid rehydrationFluid replacementFluid replacement or fluid resuscitation is the medical practice of replenishing bodily fluid lost through sweating, bleeding, fluid shifts or other pathologic processes. Fluids can be replaced via oral administration , intravenous administration, rectally, or hypodermoclysis, the direct injection...
is needed.
Medication
No specific drugsDRUGS
Destroy Rebuild Until God Shows are an American post-hardcore band formed in 2010. They released their debut self-titled album on February 22, 2011.- Formation :...
are used to treat pacemaker syndrome directly because treatment consists of upgrading or reprogramming the pacemaker.
Medical Care
- For some patients who are ventricularlyVentricle (heart)In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
paced, usually the addition of an atrial lead and optimizing the AV synchrony usually resolves symptoms. - In patients with other pacing modes, other than ventricular pacing, symptoms usually resolve after adjusting and reprogramming of pacemakerPacemakerAn artificial pacemaker is a medical device that uses electrical impulses to regulate the beating of the heart.Pacemaker may also refer to:-Medicine:...
parameters, such as tuning the AV delay, changing the postventricularVentricle (heart)In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
atrial refractory periodRefractory periodIn physiology, a refractory period is a period of time during which an organ or cell is incapable of repeating a particular action, or the amount of time it takes for an excitable membrane to be ready for a second stimulus once it returns to its resting state following an excitation...
, the sensing level, and pacing threshold voltageThreshold voltageThe threshold voltage of a MOSFET is usually defined as the gate voltage where an inversion layer forms at the interface between the insulating layer and the substrate of the transistor. The purpose of the inversion layer's forming is to allow the flow of electrons through the gate-source junction...
. The optimal values of these parameters for each individual differ. So, achieving the optimal values is by experimenting with successive reprogramming and measurement of relevantRelevantRelevant may refer to:* Relevant operator, a concept in physics, see renormalization group* Relevant, Ain, a commune of the Ain département in France* Relevant Magazine, an American religious publication...
parameters, such as blood pressureBlood pressureBlood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
, cardiac outputCardiac outputCardiac output is the volume of blood being pumped by the heart, in particular by a left or right ventricle in the time interval of one minute. CO may be measured in many ways, for example dm3/min...
, and total peripheral resistanceTotal peripheral resistanceVasculature throughout the entire body can be thought of as two separate circuits - one is the systemic circulation, while the other is the pulmonary circulation. Total peripheral resistance is the sum of the resistance of all peripheral vasculature in the systemic circulation...
, as well as observations of symptomatology. - In rare instances, using hysteresisHysteresisHysteresis is the dependence of a system not just on its current environment but also on its past. This dependence arises because the system can be in more than one internal state. To predict its future evolution, either its internal state or its history must be known. If a given input alternately...
to help maintain AV synchrony can help alleviate symptoms in ventricularlyVentricle (heart)In the heart, a ventricle is one of two large chambers that collect and expel blood received from an atrium towards the peripheral beds within the body and lungs. The Atria primes the Pump...
inhibited paced (VVI) patients providing they have intact sinus node function. Hysteresis reduces the amount of time spent in pacing mode, which can relieve symptoms, particularly when the pacing mode is generating AV dyssynchrony. - If symptoms persist after all these treatment modalities, replacing the pacemakerPacemakerAn artificial pacemaker is a medical device that uses electrical impulses to regulate the beating of the heart.Pacemaker may also refer to:-Medicine:...
itself is sometimes beneficial and can alleviate symptoms. - Medical care includes supportive treatment, in case any of the following complications happen, medical team should be ready. Possible complications include heart failure, hypotensionHypotensionIn physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...
, tachycardiaTachycardiaTachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...
, tachypneaTachypneaTachypnea means rapid breathing. Any rate between 12-20 breaths per minute is normal. Tachypnea is a respiration rate greater than 20 breaths per minute. - Distinction from other breathing terms :...
, and oxygenationOxygenation (medical)Oxygenation occurs when oxygen molecules enter the tissues of the body. For example, blood is oxygenated in the lungs, where oxygen molecules travel from the air and into the blood...
deficit.
Surgical Care
Sometimes surgicalSurgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
intervention is needed. After consulting an electrophysiologist, possibly an additional pacemaker
Pacemaker
An artificial pacemaker is a medical device that uses electrical impulses to regulate the beating of the heart.Pacemaker may also refer to:-Medicine:...
lead placement is needed, which eventually relieve some of the symptoms.
Complications
Studies have shown that patients with Pacemaker syndrome and/or with sick sinus syndromeSick sinus syndrome
Sick sinus syndrome, also called sinus node dysfunction, is a group of abnormal heart rhythms presumably caused by a malfunction of the sinus node, the heart's primary pacemaker...
are at higher risk of developing fatal complications
Complication (medicine)
Complication, in medicine, is an unfavorable evolution of a disease, a health condition or a medical treatment. The disease can become worse in its severity or show a higher number of signs, symptoms or new pathological changes, become widespread throughout the body or affect other organ systems. A...
that calls for the patients to be carefully monitored in the ICU
Intensive Care Unit
thumb|220px|ICU roomAn intensive-care unit , critical-care unit , intensive-therapy unit/intensive-treatment unit is a specialized department in a hospital that provides intensive-care medicine...
. Complications include atrial fibrillation
Atrial fibrillation
Atrial fibrillation is the most common cardiac arrhythmia . It is a common cause of irregular heart beat, identified clinically by taking a pulse. Chaotic electrical activity in the two upper chambers of the heart result in the muscle fibrillating , instead of achieving coordinated contraction...
, thrombo-embolic events, and heart failure.
Epidemiology
The reported incidenceIncidence
Incidence may refer to:* Incidence , a measure of the risk of developing some new condition within a specified period of time* Incidence , the binary relations describing how subsets meet...
of pacemaker syndrome has ranged from 2% to 83%. The wide range of reported incidence is likely attributable to two factors which are the criteria used to define pacemaker syndrome and the therapy used to resolve that diagnosis.