Diastolic dysfunction
Encyclopedia
Diastolic heart failure or diastolic dysfunction refers to decline in performance of one or both ventricles of the heart during the time
phase of diastole
. Diastole is that phase of the cardiac cycle
when the heart is not contracting to propel blood out (systole
) to the body, brain and lungs but instead is relaxed and filling with incoming blood that is being returned from the body through the inferior vena cava
(IVC) from the lungs through the pulmonary veins and from the brain through the superior vena cava
(SVC).
mass
loads forward 60-80 times per minute in an unobstructed cascade from the lungs, into the pulmonary veins, then into the left atrium
, through the mitral valve
, and finally into the left ventricle
. When the left ventricle
cannot be normally filled due to deterioration of preload, compliance and/or E/A ratio
during diastole
, the pressurized cascade begins to fail and incrementally reverses. Eventually blood then regurgitates back into the left atrium
in a backward pathologic spiral gradient towards the lungs.
This process then creates a second type of high blood pressure known as pulmonary hypertension
or PH. Unchecked PH can lead to pulmonary edema
.
Physiologically this process results in a higher than normal mismatch pressure gradient of blood within both the large and alveolar vessels of the lungs. Diastolic dysfunction paired with pulmonary hypertension
is a significant negative prognostic indicator of heart failure with normal ejection fraction. As a result of
hydrostatic forces, this pressure mismatch leads to leaking of fluid (i.e. transudate
) from the pulmonary blood vessels into the air-spaces (alveoli) of the lungs.
The result of this hydrostatic mismatch is sometimes pulmonary edema
, a dreaded condition characterized by difficulty breathing, inadequate oxygenation
of blood, and, if severe and untreated, death. Pulmonary edema developed as a result of diastolic dysfunction is not fully imparted by failing pump systolic
function of the left ventricle and may be insidious in nature or sudden depending upon the pathophysiology
involved.
The pressure gradient reversal inherent to diastolic dysfunction may further result from the left and/or right ventricle's pathologic inability to readily accept blood entering the ventricles from the atria. Pressure mismatches then may cause or impart pathologic geometric deformational changes of individual heart chambers leading to a gradual loss of optimal valvular coaptation and subsequent regurgitant (sagging/leaking) valvular heart disease.
, as opposed to systolic heart failure, which sometimes presents with eccentric hypertrophy
.
Diastolic dysfunction is characterized by elevated diastolic pressure in the left ventricle despite essentially normal/physiologic end diastolic volume or EDV. Histologic evidence supporting diastolic dysfunction demonstrates hypertrophy of the cardiomyocytes, increased interstitial Collagen
deposition and/or infiltration of the myocardium. These influences collectively lead to a downhill spiral in distensibility of the myocardium. The ventricle then behaves as a balloon made from abnormally thick rubber. (An old tire does not ride nearly as comfortably as a new tire) Despite filling with high pressure, the volume cannot expand adequately.
If the heart cannot readily fill with blood following contraction, one of two things must follow; either the cardiac output becomes diminished or compensation ensues to increase the ventricular diastolic pressure to higher levels. When the left ventricular diastolic pressure is elevated, venous pressure in the lungs must also become elevated to maintain forward flow. Increased pulmonary venous pressure results in alveolar edema causing the patient to be short of breath. Phrased differently, left ventricular stiffness makes it more difficult for blood to enter from the left atrium. As a result, pressure rises in the atrium and is transmitted back to the pulmonary venous system thereby increasing its hydrostatic pressure and thus promoting pulmonary edema
.
It is important to note that a normal heart that is overfilled with blood may demonstrate increased stiffness and decreased Compliance characteristics. This is loosely analogous to a balloon that is over-filled with air (except that the multichambered balloon is filled with viscous blood, not gas). Blowing more air (or blood) into the balloon becomes difficult because the balloon acts stiff and non-compliant at a filling volume it wasn't designed to hold. It may be misguided to classify the volume overloaded heart as having diastolic dysfunction if it is behaving in a stiff and non-compliant manner. The term diastolic dysfunction should not be applied to the dilated heart. Dilated (remodeled) hearts have increased volume for the amount of diastolic pressure and therefore have increased (not decreased) distensibility. The term diastolic dysfunction is sometimes erroneously applied in this circumstance when increased fluid volume retention causes the heart to be over-filled.
Although the term diastolic heart failure is often used when there are signs and symptoms of heart failure with normal LV systolic function, this is not always appropriate. Diastolic function is determined by relative EDV in relation to EDP and is therefore independent of LV systolic function. Leftward shift of the end-diastolic pressure-volume relationship (ie. decreased LV distensibility) can occur both in those with normal and those with decreased LV systolic function. Likewise, heart failure may occur in those with dilated LV and normal systolic function. This is often seen in valvular heart disease and high output failure. Neither of these situations constitutes a diastolic heart abnormality.
imaging is an earlier mathematical attempt to divide systolic vs. diastolic heart failure.
No one single echocardiographic parameter can make the diagnosis of diastolic heart failure. Multiple echo parameters have been proposed including mitral inflow velocity patterns, pulmonary vein flow patterns, E:A reversal, tissue Doppler measurements, and M-mode echo measurements (ie. left atrial size). Algorithms have been developed which combine multiple echocardiographic parameters to diagnose diastolic heart failure.
There are four basic Echocardiographic patterns of diastolic heart failure, graded I to IV.
Grade III and IV diastolic dysfunction are called restrictive filling dynamics. These are both severe forms of diastolic dysfunction and patients tend to have advanced heart failure symptoms.
Imaged volumetric definition of systolic heart performance is commonly accepted as ejection fraction
. Volumetric definition of the heart in systole
was first described by Adolph Fick as cardiac output
. Fick may be readily and inexpensively inverted to cardiac input
and Injection fraction
to mathematically describe Diastole
. Decline of Injection fraction paired with decline of E/A ratio
seems a stronger argument in support of mathematical definition of diastolic heart failure.
- see above). When this chronic condition is well tolerated by an individual, no specific treatment may be indicated. Rather, therapy should be directed at the root cause of the stiff left ventricle with things like high blood pressure and diabetes treated appropriately. Conversely, and as noted above, diastolic dysfunction tends to be better tolerated if the atrium is able to pump blood into the ventricles in a coordinated fashion. This does not occur in atrial fibrillation
where there is no coordinated atrial activity. Hence, atrial fibrillation should be treated aggressively in people with diastolic dysfunction. In the same light, and also as noted above, if the atrial fibrillation persists and is leading to a rapid heart rate, treatment must be given to slow down that rate. The use of a self-expanding device that attaches to the external surface of the left ventricle has been suggested yet still awaits FDA approval. When the heart muscle squeezes, energy is loaded into the device, which absorbs this energy, and releases it to the left ventricle in the diastolic phase, which help retain muscle elasticity
At this date, the role of specific treatments for diastolic dysfunction per se is unclear. There is some evidence that calcium channel blocker
drugs may be of benefit in reducing ventricular stiffness in some cases. Likewise, treatment with angiotensin converting enzyme inhibitors such as enalapril
, ramipril
, and many others, may be of benefit due to their effect on ventricular remodeling
.
A major treatment consideration in people with diastolic dysfunction is when pulmonary edema
develops. Unlike treatment of pulmonary edema occurring the setting of systolic
dysfunction (where the primary problem is poor ventricular pumping as opposed to poor filling), the treatment of pulmonary edema complicating diastolic dysfunction emphasizes heart rate control (i.e. lowering it). Diuretics are often given as well. The role of afterload reduction in this setting is unknown.
in 2006, evidence was presented to suggest that the prognosis in diastolic dysfunction is the same as that in systolic dysfunction
Time
Time is a part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify rates of change such as the motions of objects....
phase of diastole
Diastole
Diastole is the period of time when the heart fills with blood after systole . Ventricular diastole is the period during which the ventricles are relaxing, while atrial diastole is the period during which the atria are relaxing...
. Diastole is that phase of the cardiac cycle
Cardiac cycle
The cardiac cycle is a term referring to all or any of the events related to the flow or blood pressure that occurs from the beginning of one heartbeat to the beginning of the next. The frequency of the cardiac cycle is described by the heart rate. Each beat of the heart involves five major stages...
when the heart is not contracting to propel blood out (systole
Systole (medicine)
Systole is the contraction of the heart. Used alone, it usually means the contraction of the left ventricle.In all mammals, the heart has 4 chambers. The left and right ventricles pump together. The atria and ventricles pump in sequence...
) to the body, brain and lungs but instead is relaxed and filling with incoming blood that is being returned from the body through the inferior vena cava
Inferior vena cava
The inferior vena cava , also known as the posterior vena cava, is the large vein that carries de-oxygenated blood from the lower half of the body into the right atrium of the heart....
(IVC) from the lungs through the pulmonary veins and from the brain through the superior vena cava
Superior vena cava
The superior vena cava is truly superior, a large diameter, yet short, vein that carries deoxygenated blood from the upper half of the body to the heart's right atrium...
(SVC).
Significance of diastolic dysfunction
Diastolic dysfunction may be divided into left/systemic/body and right/pulmonary/lungs. In optimal left sided performance of the heart, bloodBlood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
loads forward 60-80 times per minute in an unobstructed cascade from the lungs, into the pulmonary veins, then into the left atrium
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:...
, through the mitral valve
Mitral valve
The mitral valve is a dual-flap valve in the heart that lies between the left atrium and the left ventricle...
, and finally into the left ventricle
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:...
. When the left ventricle
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:...
cannot be normally filled due to deterioration of preload, compliance and/or E/A ratio
E/A ratio
The E/A ratio is the ratio between early and late ventricular filling velocity.The early diastolic one is caused by accumulation of blood in the atria during previous systole, and second, a late one created by atrial contraction .In a young and compliant heart, early ventricular filling accounts...
during diastole
Diastole
Diastole is the period of time when the heart fills with blood after systole . Ventricular diastole is the period during which the ventricles are relaxing, while atrial diastole is the period during which the atria are relaxing...
, the pressurized cascade begins to fail and incrementally reverses. Eventually blood then regurgitates back into the left atrium
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:...
in a backward pathologic spiral gradient towards the lungs.
This process then creates a second type of high blood pressure known as pulmonary hypertension
Pulmonary hypertension
In medicine, pulmonary hypertension is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion...
or PH. Unchecked PH can lead to pulmonary edema
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...
.
Physiologically this process results in a higher than normal mismatch pressure gradient of blood within both the large and alveolar vessels of the lungs. Diastolic dysfunction paired with pulmonary hypertension
Pulmonary hypertension
In medicine, pulmonary hypertension is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion...
is a significant negative prognostic indicator of heart failure with normal ejection fraction. As a result of
hydrostatic forces, this pressure mismatch leads to leaking of fluid (i.e. transudate
Transudate
Transudate is extravascular fluid with low protein content and a low specific gravity .This is in contrast to transudate where the extracellular fluid is an ultrafiltrate of blood plasma and thus larger molecules such as proteins and cell debris are absent....
) from the pulmonary blood vessels into the air-spaces (alveoli) of the lungs.
The result of this hydrostatic mismatch is sometimes pulmonary edema
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...
, a dreaded condition characterized by difficulty breathing, inadequate oxygenation
Oxygenation (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...
of blood, and, if severe and untreated, death. Pulmonary edema developed as a result of diastolic dysfunction is not fully imparted by failing pump systolic
Systole (medicine)
Systole is the contraction of the heart. Used alone, it usually means the contraction of the left ventricle.In all mammals, the heart has 4 chambers. The left and right ventricles pump together. The atria and ventricles pump in sequence...
function of the left ventricle and may be insidious in nature or sudden depending upon the pathophysiology
Pathophysiology
Pathophysiology is the study of the changes of normal mechanical, physical, and biochemical functions, either caused by a disease, or resulting from an abnormal syndrome...
involved.
The pressure gradient reversal inherent to diastolic dysfunction may further result from the left and/or right ventricle's pathologic inability to readily accept blood entering the ventricles from the atria. Pressure mismatches then may cause or impart pathologic geometric deformational changes of individual heart chambers leading to a gradual loss of optimal valvular coaptation and subsequent regurgitant (sagging/leaking) valvular heart disease.
Pathophysiology
Diastolic heart failure sometimes presents with concentric hypertrophyConcentric hypertrophy
Concentric hypertrophy is a hypertrophic growth of a hollow organ without overall enlargement, in which the walls of the organ are thickened and its capacity or volume is diminished....
, as opposed to systolic heart failure, which sometimes presents with eccentric hypertrophy
Eccentric hypertrophy
Eccentric hypertrophy is a type of left ventricular hypertrophy where the growth of the walls of a hollow organ, especially the heart, in which the overall size and volume are enlarged....
.
Diastolic dysfunction is characterized by elevated diastolic pressure in the left ventricle despite essentially normal/physiologic end diastolic volume or EDV. Histologic evidence supporting diastolic dysfunction demonstrates hypertrophy of the cardiomyocytes, increased interstitial Collagen
Collagen
Collagen is a group of naturally occurring proteins found in animals, especially in the flesh and connective tissues of mammals. It is the main component of connective tissue, and is the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content...
deposition and/or infiltration of the myocardium. These influences collectively lead to a downhill spiral in distensibility of the myocardium. The ventricle then behaves as a balloon made from abnormally thick rubber. (An old tire does not ride nearly as comfortably as a new tire) Despite filling with high pressure, the volume cannot expand adequately.
If the heart cannot readily fill with blood following contraction, one of two things must follow; either the cardiac output becomes diminished or compensation ensues to increase the ventricular diastolic pressure to higher levels. When the left ventricular diastolic pressure is elevated, venous pressure in the lungs must also become elevated to maintain forward flow. Increased pulmonary venous pressure results in alveolar edema causing the patient to be short of breath. Phrased differently, left ventricular stiffness makes it more difficult for blood to enter from the left atrium. As a result, pressure rises in the atrium and is transmitted back to the pulmonary venous system thereby increasing its hydrostatic pressure and thus promoting pulmonary edema
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...
.
It is important to note that a normal heart that is overfilled with blood may demonstrate increased stiffness and decreased Compliance characteristics. This is loosely analogous to a balloon that is over-filled with air (except that the multichambered balloon is filled with viscous blood, not gas). Blowing more air (or blood) into the balloon becomes difficult because the balloon acts stiff and non-compliant at a filling volume it wasn't designed to hold. It may be misguided to classify the volume overloaded heart as having diastolic dysfunction if it is behaving in a stiff and non-compliant manner. The term diastolic dysfunction should not be applied to the dilated heart. Dilated (remodeled) hearts have increased volume for the amount of diastolic pressure and therefore have increased (not decreased) distensibility. The term diastolic dysfunction is sometimes erroneously applied in this circumstance when increased fluid volume retention causes the heart to be over-filled.
Although the term diastolic heart failure is often used when there are signs and symptoms of heart failure with normal LV systolic function, this is not always appropriate. Diastolic function is determined by relative EDV in relation to EDP and is therefore independent of LV systolic function. Leftward shift of the end-diastolic pressure-volume relationship (ie. decreased LV distensibility) can occur both in those with normal and those with decreased LV systolic function. Likewise, heart failure may occur in those with dilated LV and normal systolic function. This is often seen in valvular heart disease and high output failure. Neither of these situations constitutes a diastolic heart abnormality.
Risk factors and causes
Any condition or process that leads to stiffening of the left ventricle can lead to diastolic dysfunction. Causes of left ventricular stiffening include:- high blood pressure (i.e. hypertensionHypertensionHypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
, where, as a result of left ventricular muscle hypertrophyHypertrophyHypertrophy is the increase in the volume of an organ or tissue due to the enlargement of its component cells. It should be distinguished from hyperplasia, in which the cells remain approximately the same size but increase in number...
to deal with the high pressure, the left ventricle has become stiff) - aortic stenosis of any cause (here as with hypertension, the ventricular muscle has hypertrophied and thence become stiff, as a result of the increased pressure load placed on it by the stenosis)
- scarred heart muscle (e.g. occurring after a heart attack) (scars are relatively stiff)
- diabetes (stiffening occurs presumably as a result of glycosylationGlycosylationGlycosylation is the reaction in which a carbohydrate, i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule . In biology glycosylation refers to the enzymatic process that attaches glycans to proteins, lipids, or other organic molecules...
of heart muscle) - severe systolic dysfunction that has led to ventricular dilation (i.e when the ventricle has been stretched to a certain point, any further attempt to stretch it more, as by blood trying to enter it from the left atrium, meets with increased resistance - it has become stiff
- reversible stiffening as can occur during periods of cardiac ischemiaIschemiaIn medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...
Diagnosis
Meaningful criteria suggesting diastolic dysfunction or diastolic heart failure remains imprecise. This has made it difficult to conduct clinical trials of treatments for diastolic heart failure. This problem is compounded by the fact that systolic and diastolic heart failure is a common coexisting presentation in many ischemic and nonischemic etiologies of HF. Narrowly defined, Diastolic Dysfunction has often been described as heart failure with normal systolic function (LVEF>60%) Chagasic heart disease may represent an optimal academic model of diastolic heart failure that spares systolic function. A patient is defined as having diastolic [vagal] dysfunction if they have signs and symptoms of heart failure but the left ventricular ejection fraction is normal. A second approach is to use an elevated BNP level in the presence of normal EF to diagnose diastolic heart failure. Concordance of both volumetric and biochemical measurements/markers lends to even stronger terminology regarding scientific/mathematical expression of diastolic heart failure. These are both probably too broad a definition for diastolic heart failure and this group of patients is more precisely described as heart failure with normal systolic function. Echocardiography can be used to diagnose diastolic dysfunction but is a limited modality unless boosted by stress imaging. MUGAMuga
The Muga is a river in Catalonia which rises in the Alberes mountains of the eastern Pyrenees and enters the sea at the Gulf of Roses.The river is 58 km long with its source below the summit of Montnegre...
imaging is an earlier mathematical attempt to divide systolic vs. diastolic heart failure.
No one single echocardiographic parameter can make the diagnosis of diastolic heart failure. Multiple echo parameters have been proposed including mitral inflow velocity patterns, pulmonary vein flow patterns, E:A reversal, tissue Doppler measurements, and M-mode echo measurements (ie. left atrial size). Algorithms have been developed which combine multiple echocardiographic parameters to diagnose diastolic heart failure.
There are four basic Echocardiographic patterns of diastolic heart failure, graded I to IV.
- The mildest form is called an abnormal relaxation pattern or grade I diastolic dysfunction. On the mitral inflow Doppler echocardiogram, there is reversal of the normal E/A ratioE/A ratioThe E/A ratio is the ratio between early and late ventricular filling velocity.The early diastolic one is caused by accumulation of blood in the atria during previous systole, and second, a late one created by atrial contraction .In a young and compliant heart, early ventricular filling accounts...
. This pattern may develop normally with age in some patients and many grade I patients will not have any clinical signs or symptoms of heart failure. - Grade II diastolic dysfunction is called pseudonormal filling dynamics. This is considered moderate diastolic dysfunction and is associated with elevated left atrial filling pressures. These patients more commonly have symptoms of heart failure and many have left atrial enlargement due to the elevated pressures in the left heart.
Grade III and IV diastolic dysfunction are called restrictive filling dynamics. These are both severe forms of diastolic dysfunction and patients tend to have advanced heart failure symptoms.
- Class III diastolic dysfunction patients will demonstrate reversal of their diastolic abnormalities on echocardiogram when they perform the Valsalva maneuver and are called reversible restrictive diastolic dysfunction.
- Class IV diastolic dysfunction patients will not demonstrate reversibility of their echocardiogram abnormalities and are therefore called fixed restrictive diastolic dysfunction. The presence of either class III and IV diastolic dysfunction is associated with a significantly worse prognosis. These patients will have left atrial enlargement and many will have a reduced left ventricular ejection fraction indicating a combination of systolic and diastolic dysfunction.
Imaged volumetric definition of systolic heart performance is commonly accepted as ejection fraction
Ejection fraction
In cardiovascular physiology, ejection fraction is the fraction of Blood pumped out of the Right Ventricle of the heart to the Pulmonary Circulation and Left Ventricle of the heart to the Systemic Circulation with each Heart beat or Cardiac cycle...
. Volumetric definition of the heart in systole
Systole (medicine)
Systole is the contraction of the heart. Used alone, it usually means the contraction of the left ventricle.In all mammals, the heart has 4 chambers. The left and right ventricles pump together. The atria and ventricles pump in sequence...
was first described by Adolph Fick as 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...
. Fick may be readily and inexpensively inverted to cardiac input
Cardiac input
Cardiac input is the inverse operation of cardiac output .Cardiac output implies ejection fraction.Ejection fraction is an easily understood and inexpensively imaged mathematical model of systole....
and Injection fraction
Injection fraction
Injection fraction, or end diastolic volume divided by end systolic volume of the ventricles or IF=EDV/ESV, is the inverse mathematical operation of the Myocardium derived Ejection Fraction. "Ejection Fraction" is historically and mathematically derived from Cardiac Output first posited by Adolph...
to mathematically describe Diastole
Diastole
Diastole is the period of time when the heart fills with blood after systole . Ventricular diastole is the period during which the ventricles are relaxing, while atrial diastole is the period during which the atria are relaxing...
. Decline of Injection fraction paired with decline of E/A ratio
E/A ratio
The E/A ratio is the ratio between early and late ventricular filling velocity.The early diastolic one is caused by accumulation of blood in the atria during previous systole, and second, a late one created by atrial contraction .In a young and compliant heart, early ventricular filling accounts...
seems a stronger argument in support of mathematical definition of diastolic heart failure.
Treatment
Generally, diastolic dysfunction is chronic process (except during acute ischemiaIschemia
In medicine, ischemia is a restriction in blood supply, generally due to factors in the blood vessels, with resultant damage or dysfunction of tissue. It may also be spelled ischaemia or ischæmia...
- see above). When this chronic condition is well tolerated by an individual, no specific treatment may be indicated. Rather, therapy should be directed at the root cause of the stiff left ventricle with things like high blood pressure and diabetes treated appropriately. Conversely, and as noted above, diastolic dysfunction tends to be better tolerated if the atrium is able to pump blood into the ventricles in a coordinated fashion. This does not occur in 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...
where there is no coordinated atrial activity. Hence, atrial fibrillation should be treated aggressively in people with diastolic dysfunction. In the same light, and also as noted above, if the atrial fibrillation persists and is leading to a rapid heart rate, treatment must be given to slow down that rate. The use of a self-expanding device that attaches to the external surface of the left ventricle has been suggested yet still awaits FDA approval. When the heart muscle squeezes, energy is loaded into the device, which absorbs this energy, and releases it to the left ventricle in the diastolic phase, which help retain muscle elasticity
At this date, the role of specific treatments for diastolic dysfunction per se is unclear. There is some evidence that calcium channel blocker
Calcium channel blocker
A calcium channel blocker is a chemical that disrupts the movement of calcium through calcium channels.CCB drugs devised to target neurons are used as antiepileptics. However, the most widespread clinical usage of calcium channel blockers is to decrease blood pressure in patients with...
drugs may be of benefit in reducing ventricular stiffness in some cases. Likewise, treatment with angiotensin converting enzyme inhibitors such as enalapril
Enalapril
Enalapril is an angiotensin converting enzyme inhibitor used in the treatment of hypertension and some types of chronic heart failure. ACE raises blood pressure by constricting blood vessels. ACE inhibitors like enalapril prevent this effect. Enalapril has been shown to lower the death rate in...
, ramipril
Ramipril
Ramipril is an angiotensin-converting enzyme inhibitor, used to treat high blood pressure and congestive heart failure.-Mechanism of action:ACE inhibitors lower the...
, and many others, may be of benefit due to their effect on ventricular remodeling
Ventricular remodeling
Ventricular remodeling refers to the changes in size, shape, and function of the heart after injury to the ventricles. The injury is typically due to acute myocardial infarction , but may be from a number of causes that result in increased pressure or volume overload on the heart...
.
A major treatment consideration in people with diastolic dysfunction is when pulmonary edema
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...
develops. Unlike treatment of pulmonary edema occurring the setting of systolic
Systole (medicine)
Systole is the contraction of the heart. Used alone, it usually means the contraction of the left ventricle.In all mammals, the heart has 4 chambers. The left and right ventricles pump together. The atria and ventricles pump in sequence...
dysfunction (where the primary problem is poor ventricular pumping as opposed to poor filling), the treatment of pulmonary edema complicating diastolic dysfunction emphasizes heart rate control (i.e. lowering it). Diuretics are often given as well. The role of afterload reduction in this setting is unknown.
Prognosis
Until recently, it was generally assumed that the prognosis for individuals with diastolic dysfunction and associated, intermittent pulmonary edema was better than those with systolic dysfunction. In fact, in two studies appearing in the New England Journal of MedicineNew England Journal of Medicine
The New England Journal of Medicine is an English-language peer-reviewed medical journal published by the Massachusetts Medical Society. It describes itself as the oldest continuously published medical journal in the world.-History:...
in 2006, evidence was presented to suggest that the prognosis in diastolic dysfunction is the same as that in systolic dysfunction