Cardiac tamponade
Encyclopedia
Cardiac tamponade, also known as pericardial tamponade, is an emergency
condition in which fluid accumulates in the pericardium
(the sac in which the heart
is enclosed).
Cardiac tamponade occurs when the pericardial space fills up with fluid faster than the pericardial sac can stretch. If the amount of fluid increases slowly (such as in hypothyroidism) the pericardial sac can expand to contain a liter or more of fluid prior to tamponade occurring. If the fluid occurs rapidly (as may occur after trauma or myocardial rupture) as little as 100 ml can cause tamponade.
Causes of increased pericardial effusion include hypothyroidism
, physical trauma
(either penetrating trauma involving the pericardium or blunt chest trauma), pericarditis (inflammation of the pericardium), iatrogenic trauma (during an invasive procedure), and myocardial rupture.
Cardiac tamponade is caused by a large or uncontrolled pericardial effusion
, i.e. the buildup of fluid inside the pericardium. This commonly occurs as a result of chest trauma (both blunt and penetrating), but can also be caused by myocardial rupture
, cancer
, uraemia, pericarditis
, or cardiac surgery, and rarely occurs during retrograde aortic dissection
, or whilst the patient is taking anticoagulant therapy. The effusion can occur rapidly (as in the case of trauma or myocardial rupture), or over a more gradual period of time (as in cancer). The fluid involved is often blood
, but pus
is also found in some circumstances.
Myocardial rupture is a somewhat uncommon cause of pericardial tamponade. It typically happens in the subacute setting after a myocardial infarction
(heart attack), in which the infarcted muscle of the heart thins out and tears. Myocardial rupture is more likely to happen in elderly individuals without any previous cardiac history who suffer from their first heart attack and are not revascularized either with thrombolytic therapy or with percutaneous coronary intervention
or with coronary artery bypass graft surgery.
One of the most common settings for cardiac tamponade is in the first 24 to 48 hours after heart surgery. After heart surgery, chest tube
s are placed to drain blood. These chest tubes, however, are prone to clot formation. When a chest tube becomes occluded or clogged, the blood that should be drained can accumulate around the heart, leading to tamponade. Nurses will frequently milk clots from the tubes, or strip the tubes, but even with these efforts chest tubes can become clogged. Thus, after heart surgery it is critical to be on the watch for chest tube clogging.
If fluid continues to accumulate, then with each successive diastolic period, less and less blood enters the ventricles, as the increasing pressure presses on the heart and forces the septum
to bend into the left ventricle
, leading to decreased stroke volume. This causes obstructive shock
to develop, and if left untreated then cardiac arrest may occur (in which case the presenting rhythm is likely to be pulseless electrical activity
).
, including tension pneumothorax, and acute heart failure. In a trauma patient presenting with PEA (pulseless electrical activity) in the absence of hypovolemia and tension pneumothorax, the most likely diagnosis is cardiac tamponade.
Symptoms of classical cardiac tamponade include three signs, known as Beck's triad. Hypotension
occurs because of decreased stroke volume, jugular-venous distension due to impaired venous return to the heart, and muffled heart sounds
due to fluid inside the pericardium.
Other signs of tamponade include pulsus paradoxus
(a drop of at least 10mmHg in arterial blood pressure on inspiration), and ST segment
changes on the electrocardiogram
, which may also show low voltage QRS complex
es, as well as general signs & symptoms of shock (such as tachycardia
, breathlessness and decreasing level of consciousness
).
Tamponade can often be diagnosed radiographically, if time allows. Echocardiography
, which is the diagnostic test of choice**, often demonstrates an enlarged pericardium or collapsed ventricles, and a chest x-ray of a large cardiac tamponade will show a large, globular heart.
, and monitoring. There is little care that can be provided pre-hospital other than general treatment for shock. A number of the Helicopter Emergency Medical Services (HEMS) in the UK, which have doctor/paramedic teams, have performed an emergency thoracotomy
to release clotting in the pericardium
caused by a penetrating chest injury.
Prompt diagnosis and treatment is the key to survival with tamponade. Some pre-hospital providers will have facilities to provide pericardiocentesis
, which can be life-saving. If the patient has already suffered a cardiac arrest
, pericardiocentesis alone cannot ensure survival, and so rapid evacuation to a hospital is usually the more appropriate course of action.
is left in place during resuscitation following initial drainage so that the procedure can be performed again if the need arises. If facilities are available, an emergency pericardial window may be performed instead, during which the pericardium is cut open to allow fluid to drain. Following stabilization of the patient, surgery is provided to seal the source of the bleed and mend the pericardium.
If aggressive treatment is offered immediately and no complications arise (shock, AMI or arrhythmia, heart failure, aneurysm, carditis, embolism, or rupture), or they are dealt with quickly and fully contained, then adequate survival is still a distinct possibility.
Medical emergency
A medical emergency is an injury or illness that is acute and poses an immediate risk to a person's life or long term health. These emergencies may require assistance from another person, who should ideally be suitably qualified to do so, although some of these emergencies can be dealt with by the...
condition in which fluid accumulates in the pericardium
Pericardium
The pericardium is a double-walled sac that contains the heart and the roots of the great vessels.-Layers:...
(the sac in which the heart
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
is enclosed).
Cardiac tamponade occurs when the pericardial space fills up with fluid faster than the pericardial sac can stretch. If the amount of fluid increases slowly (such as in hypothyroidism) the pericardial sac can expand to contain a liter or more of fluid prior to tamponade occurring. If the fluid occurs rapidly (as may occur after trauma or myocardial rupture) as little as 100 ml can cause tamponade.
Causes of increased pericardial effusion include hypothyroidism
Hypothyroidism
Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone.Iodine deficiency is the most common cause of hypothyroidism worldwide but it can be caused by other causes such as several conditions of the thyroid gland or, less commonly, the pituitary gland or...
, physical trauma
Physical trauma
Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...
(either penetrating trauma involving the pericardium or blunt chest trauma), pericarditis (inflammation of the pericardium), iatrogenic trauma (during an invasive procedure), and myocardial rupture.
Cardiac tamponade is caused by a large or uncontrolled pericardial effusion
Pericardial effusion
Pericardial effusion is an abnormal accumulation of fluid in the pericardial cavity. Because of the limited amount of space in the pericardial cavity, fluid accumulation will lead to an increased intrapericardial pressure and this can negatively affect heart function...
, i.e. the buildup of fluid inside the pericardium. This commonly occurs as a result of chest trauma (both blunt and penetrating), but can also be caused by myocardial rupture
Myocardial rupture
Myocardial rupture is a laceration or tearing of the walls of the ventricles or atria of the heart, of the interatrial or interventricular septum, of the papillary muscles or chordae tendineae or of one of the valves of the heart...
, cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
, uraemia, pericarditis
Pericarditis
Pericarditis is an inflammation of the pericardium . A characteristic chest pain is often present.The causes of pericarditis are varied, including viral infections of the pericardium, idiopathic causes, uremic pericarditis, bacterial infections of the precardium Pericarditis is an inflammation of...
, or cardiac surgery, and rarely occurs during retrograde aortic dissection
Aortic dissection
Aortic dissection occurs when a tear in the inner wall of the aorta causes blood to flow between the layers of the wall of the aorta and force the layers apart. The dissection typically extends anterograde, but can extend retrograde from the site of the intimal tear. Aortic dissection is a medical...
, or whilst the patient is taking anticoagulant therapy. The effusion can occur rapidly (as in the case of trauma or myocardial rupture), or over a more gradual period of time (as in cancer). The fluid involved is often blood
Blood
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....
, but pus
Pus
Pus is a viscous exudate, typically whitish-yellow, yellow, or yellow-brown, formed at the site of inflammatory during infection. An accumulation of pus in an enclosed tissue space is known as an abscess, whereas a visible collection of pus within or beneath the epidermis is known as a pustule or...
is also found in some circumstances.
Myocardial rupture is a somewhat uncommon cause of pericardial tamponade. It typically happens in the subacute setting after a myocardial infarction
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
(heart attack), in which the infarcted muscle of the heart thins out and tears. Myocardial rupture is more likely to happen in elderly individuals without any previous cardiac history who suffer from their first heart attack and are not revascularized either with thrombolytic therapy or with percutaneous coronary intervention
Percutaneous coronary intervention
Percutaneous coronary intervention , commonly known as coronary angioplasty or simply angioplasty, is one therapeutic procedure used to treat the stenotic coronary arteries of the heart found in coronary heart disease. These stenotic segments are due to the build up of cholesterol-laden plaques...
or with coronary artery bypass graft surgery.
One of the most common settings for cardiac tamponade is in the first 24 to 48 hours after heart surgery. After heart surgery, chest tube
Chest tube
A chest tube is a flexible plastic tube that is inserted through the side of the chest into the pleural space. It is used to remove air or fluid , or pus from the intrathoracic space...
s are placed to drain blood. These chest tubes, however, are prone to clot formation. When a chest tube becomes occluded or clogged, the blood that should be drained can accumulate around the heart, leading to tamponade. Nurses will frequently milk clots from the tubes, or strip the tubes, but even with these efforts chest tubes can become clogged. Thus, after heart surgery it is critical to be on the watch for chest tube clogging.
Pathophysiology
The outer layer is made of fibrous tissue which does not easily stretch, and so once fluid begins to enter the pericardial space, pressure starts to increase.If fluid continues to accumulate, then with each successive diastolic period, less and less blood enters the ventricles, as the increasing pressure presses on the heart and forces the septum
Interventricular septum
Interventricular septum , abbreviated IVS, is the stout wall separating the lower chambers of the heart from one another....
to bend 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:...
, leading to decreased stroke volume. This causes obstructive shock
Obstructive shock
Obstructive shock is a form of shock associated with physical obstruction of the great vessels or the heart itself. Pulmonary embolism and cardiac tamponade are considered forms of obstructive shock....
to develop, and if left untreated then cardiac arrest may occur (in which case the presenting rhythm is likely to be pulseless electrical activity
Pulseless electrical activity
Pulseless electrical activity or PEA refers a cardiac arrest situation in which a heart rhythm is observed on the electrocardiogram that should be producing a pulse, but is not...
).
Assessment findings
Assessment findings with cardiac tamponade include tachycardia, distant or muffled heart sounds,jugular vein distention,and a falling BP, accompanied by paradoxical pulse(a drop in inspiratory BP by greater than 10 mmHg)Diagnosis
Initial diagnosis can be challenging, as there are a number of differential diagnosesDifferential diagnosis
A differential diagnosis is a systematic diagnostic method used to identify the presence of an entity where multiple alternatives are possible , and may also refer to any of the included candidate alternatives A differential diagnosis (sometimes abbreviated DDx, ddx, DD, D/Dx, or ΔΔ) is a...
, including tension pneumothorax, and acute heart failure. In a trauma patient presenting with PEA (pulseless electrical activity) in the absence of hypovolemia and tension pneumothorax, the most likely diagnosis is cardiac tamponade.
Symptoms of classical cardiac tamponade include three signs, known as Beck's triad. Hypotension
Hypotension
In 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...
occurs because of decreased stroke volume, jugular-venous distension due to impaired venous return to the heart, and muffled heart sounds
Heart sounds
Heart sounds, or heartbeats, are the noises generated by the beating heart and the resultant flow of blood through it...
due to fluid inside the pericardium.
Other signs of tamponade include pulsus paradoxus
Pulsus paradoxus
In medicine, a pulsus paradoxus , also paradoxic pulse or paradoxical pulse, is defined as an exaggeration of the normal variation during the inspiratory phase of respiration, in which the blood pressure declines as one inhales and increases as one exhales...
(a drop of at least 10mmHg in arterial blood pressure on inspiration), and ST segment
ST segment
In electrocardiography, the ST segment connects the QRS complex and the T wave and has a duration of 0.08 to 0.12 sec .It starts at the J point and ends at the beginning of the T wave...
changes on the electrocardiogram
Electrocardiogram
Electrocardiography is a transthoracic interpretation of the electrical activity of the heart over a period of time, as detected by electrodes attached to the outer surface of the skin and recorded by a device external to the body...
, which may also show low voltage QRS complex
QRS complex
The QRS complex is a name for the combination of three of the graphical deflections seen on a typical electrocardiogram . It is usually the central and most visually obvious part of the tracing. It corresponds to the depolarization of the right and left ventricles of the human heart...
es, as well as general signs & symptoms of shock (such as tachycardia
Tachycardia
Tachycardia 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...
, breathlessness and decreasing level of consciousness
Glasgow Coma Scale
Glasgow Coma Scale or GCS is a neurological scale that aims to give a reliable, objective way of recording the conscious state of a person for initial as well as subsequent assessment...
).
Tamponade can often be diagnosed radiographically, if time allows. Echocardiography
Echocardiography
An echocardiogram, often referred to in the medical community as a cardiac ECHO or simply an ECHO, is a sonogram of the heart . Also known as a cardiac ultrasound, it uses standard ultrasound techniques to image two-dimensional slices of the heart...
, which is the diagnostic test of choice**, often demonstrates an enlarged pericardium or collapsed ventricles, and a chest x-ray of a large cardiac tamponade will show a large, globular heart.
Pre-hospital care
Initial treatment given will usually be supportive in nature, for example administration of oxygenOxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
, and monitoring. There is little care that can be provided pre-hospital other than general treatment for shock. A number of the Helicopter Emergency Medical Services (HEMS) in the UK, which have doctor/paramedic teams, have performed an emergency thoracotomy
Thoracotomy
Thoracotomy is an incision into the pleural space of the chest. It is performed by a surgeon, and, rarely, by emergency physicians, to gain access to the thoracic organs, most commonly the heart, the lungs, the esophagus or thoracic aorta, or for access to the anterior spine such as is necessary...
to release clotting in the pericardium
Pericardium
The pericardium is a double-walled sac that contains the heart and the roots of the great vessels.-Layers:...
caused by a penetrating chest injury.
Prompt diagnosis and treatment is the key to survival with tamponade. Some pre-hospital providers will have facilities to provide pericardiocentesis
Pericardiocentesis
In medicine, pericardiocentesis is a procedure where fluid is aspirated from the pericardium .-Position:The patient undergoing pericardiocentesis is positioned supine with the head of the bed raised to a 30- to 60-degree angle.This places the heart in proximity to the chest wall for easier...
, which can be life-saving. If the patient has already suffered a cardiac arrest
Cardiac arrest
Cardiac arrest, is the cessation of normal circulation of the blood due to failure of the heart to contract effectively...
, pericardiocentesis alone cannot ensure survival, and so rapid evacuation to a hospital is usually the more appropriate course of action.
Hospital management
Initial management in hospital is by pericardiocentesis. This involves the insertion of a needle through the skin and into the pericardium and aspirating fluid under ultrasound guidance preferably. This can be done laterally through the intercostal spaces, usually the fifth, or as a subxiphoid approach. Often, a cannulaCannula
A cannula or canula is a tube that can be inserted into the body, often for the delivery or removal of fluid or for the gathering of data...
is left in place during resuscitation following initial drainage so that the procedure can be performed again if the need arises. If facilities are available, an emergency pericardial window may be performed instead, during which the pericardium is cut open to allow fluid to drain. Following stabilization of the patient, surgery is provided to seal the source of the bleed and mend the pericardium.
If aggressive treatment is offered immediately and no complications arise (shock, AMI or arrhythmia, heart failure, aneurysm, carditis, embolism, or rupture), or they are dealt with quickly and fully contained, then adequate survival is still a distinct possibility.
See also
- Pericardial effusionPericardial effusionPericardial effusion is an abnormal accumulation of fluid in the pericardial cavity. Because of the limited amount of space in the pericardial cavity, fluid accumulation will lead to an increased intrapericardial pressure and this can negatively affect heart function...
- TamponadeTamponadeTamponade is the closure or blockage as if by a tampon especially to stop bleeding.Tamponade is a useful method of stopping a hemorrhage...
- Emergency medicineEmergency medicineEmergency medicine is a medical specialty in which physicians care for patients with acute illnesses or injuries which require immediate medical attention. While not usually providing long-term or continuing care, emergency medicine physicians diagnose a variety of illnesses and undertake acute...
- Pulmonary contusionPulmonary contusionA pulmonary contusion is a contusion of the lung, caused by chest trauma. As a result of damage to capillaries, blood and other fluids accumulate in the lung tissue. The excess fluid interferes with gas exchange, potentially leading to inadequate oxygen levels...
- Commotio cordisCommotio cordisCommotio cordis is a disruption of heart rhythm that occurs as a result of a blow to the area directly over the heart , at a critical time during the cycle of a heart beat. It is a form of ventricular fibrillation, not mechanical damage to the heart muscle or surrounding organs, and not the result...