Cardiac tamponade is clinically defined as the accumulation of fluid such as blood in the pericardial sac which alters cardiac filling. Cardiac tamponade will usually present with hypotension, muffling of heart sounds, and accentuated neck veins. Because cardiac tamponade is a medical emergency, immediate attempts to evacuate the blood from the pericardium is of utmost priority to avoid mortality and further morbidity.
The following symptomatology are observable in patients with cardiac tamponade:
Patients presenting with low blood pressure while in cardiac tamponade are unable to exhibit the Kussmaul sign, jugular venous distention, and pulsus paradoxus due to the hypovolemic state of the system. This type of cardiac tamponade is clinically referred to as low pressure tamponade occurring in 20% of all cardiac tamponade cases .
The following diagnostic modalities and tests are being implored among patients with cardiac tamponade:
Patients with cardiac tamponade are always treated as a medical emergency. Patients are immediately attached for oxygen inhalation upon admission in the emergency room. Isotonic crystalloids are used to resuscitate the volume loss while the lower extremities are elevated. Inotropic agents like dobutamine is incorporated in the fluids to assists the pumping of the heart. Inpatients are subjected to pericardiocentesis and attached to a close drainage system to drain the reaccumulating fluids. Balloon pericardiotomy may also be instituted to restore the pericardial window. In extreme cases, an open thoracotomy with pericardiotomy is performed to directly drain the fluid and correct any anatomic defects .
Cardiac tamponade is a medical emergency. The failure to evacuate the pericardial fluid immediately can result into death. Effusion that gradually accumulates and does not reach a total volume of 150 ml may be averted when the underlying causes is immediately addressed. Penetrating injuries to the chest wall causing cardiac tamponade carry a grim prognosis.
In the United States, the incidence of cardiac tamponade is estimated to be 2 cases per 10,000 population. Cardiac tamponade is more common in males than females with a ratio of 7:3 in children and 1.25:1 in adults. Traumatic causes and HIV infection are common causation in cardiac tamponade among young adults while renal failure and malignancies are more common in the elderly group.
The basic pathophysiology of cardiac tamponade starts with the accumulation of fluid in the space between the pericardium and the heart. The common fluid accumulation in the pericardial space is usually hemorrhagic, chylous, serous, or serosanguinous in nature. The initial phase of the pericardial effusion increases the filling pressure of the heart ventricles making the ventricles physiologically stiffer. The continuous accumulation of fluid in the pericardial space increase the pericardial pressure beyond the ventricular filling pressure reducing the cardiac output significantly .
The progressive loss in functional cardiac output due to the cardiac tamponade diminishes the systemic venous return and consequently results in the collapse of the right atrium and right ventricles. Pericardial effusion as low as 150 ml accumulation can already greatly impede the cardiac output and function . Although pericardial stretching with time can make the myocardium adaptive to this kind of restrictive insults, making the heart function normally and physiologically despite the presence of pericardial effusion.
Chest trauma is one of the leading cause of cardiac tamponade, thus; the prudent use of seatbelts during driving greatly prevents the occurrence of accidental blunt trauma to the chest. Mild septicemia must be promptly treated to avoid the untoward complication of a bacterial or viral pericardial effusion. Patients with history of recurrent effusion in the pericardial space will benefit from the use of sclerosing agents to obliterate the potential space.
Cardiac tamponade occurs when the blood or fluids starts to build up between the myocardium and the pericardium that causes compression of the heart. The restrictive cardiac condition in cardiac tamponade limits the blood flow that is being pumped by the heart. Cardiac tamponade is a life-threatening condition that could be reversed rapidly with prompt and proper therapeutic interventions.