Cardiac tamponade

Definition

Cardiac tamponade is a clinical syndrome associated with a sharp disruption of cardiac function and systemic hemodynamics due to the rapid accumulation of fluid in the pericardial cavity and an increase in intrapericardial pressure. Cardiac tamponade can be manifested by chest discomfort, excruciating dyspnea, tachycardia, tachypnea, paradoxical pulse, arterial hypotension, swelling of the jugular veins, syncope, and shock. Diagnosis of cardiac tamponade is based on the data of physical examination, echocardiography, ECG, chest X-ray, and right heart catheterization. In cardiac tamponade, urgent pericardial puncture is indicated, sometimes – pericardiotomy or subtotal pericardiectomy.

General information

Cardiac tamponade is a critical condition caused by increased fluid accumulation in the pericardial cavity, highintrapericardial pressure, and impaired diastolic ventricular filling, leading to a acute decrease in cardiac output. According to clinical manifestations, cardiac tamponade can be acute and chronic. Acute cardiac tamponade is characterized by rapid and rapid development of symptoms and unpredictable course. In cardiology, cardiac tamponade is a dangerous complication leading to severe disorders of central hemodynamics and metabolic and microcirculatory disorders, contributing to the development of acute heart failure, shock, and cardiac arrest.

Causes of cardiac tamponade

Cardiac tamponade may occur when the pericardial cavity is filled with various types of effusion (blood, pus, exudate, transudate, lymph). Most often, acute cardiac tamponade occurs in hemopericardium—bleeding into the pericardial cavity that develops in open and closed injuries of the chest and heart as a result of medical procedures (myocardial biopsy, cardiac probing, central venous catheter placement) and surgical operations, in aortic aneurysm dissection, spontaneous rupture of the heart in patients with myocardial infarction, and during anticoagulant treatment.

Cardiac tamponade can complicate the course of pericarditis (tuberculous, purulent, acute idiopathic), malignant tumors of the heart and lungs, chronic renal failure, systemic lupus erythematosus, myxedema, and others.

Hemodynamics in cardiac tamponade.

Hemodynamic disorders in cardiac tamponade depend less on the volume than on the fluid inflow rate and the degree of pericardial distensibility. Normally, the pericardial cavity contains approximately 20-40 ml of fluid, and intrapericardial pressure is about 0 mmHg. Due to the pericardium’s adaptive ability, slow accumulation of up to 1000-2000 ml of effusion usually leads to insignificant pressure changes.

If even a small amount (more than 100-200 ml) of exudate suddenly inflows into the pericardial cavity, a sharp rise in intrapericardial pressure may occur, leading to compression of the heart and intrapericardially located areas of the superior and inferior vena cava. Blood flow into the ventricles is obstructed, leading to decreased filling during diastole, stroke volume, and cardiac output.

The increased central venous pressure (CVP), increased HR, and increased peripheral resistance characteristic of cardiac tamponade are a compensatory mechanism to maintain adequate cardiac filling and ejection. Cardiac tamponade with low intrapericardial pressure may occur with decreased intravascular volume (hypovolemia) in dehydrated patients in critical condition.

Symptoms of cardiac tamponade

Clinical manifestations of cardiac tamponade are caused by a sharp decrease in the pumping function of the heart and cardiac output. Complaints presented by patients with cardiac tamponade are usually nonspecific: heaviness in the chest, increasing dyspnea, a sense of “fear of death”, weakness, and profuse cold sweat. When examining the patient, cyanosis of the skin, psychomotor agitation, tachycardia, rapid shallow breathing, pronounced paradoxical pulse, arterial hypotension, and muffled heart tones can be noted. In acute cardiac tamponade, activation of the sympathoadrenal system for several hours can maintain BP and improve venous return.

The clinical picture of severe acute cardiac tamponade, caused, for example, by rupture of the myocardium or aorta, may manifest itself with the development of sudden syncope and hemorrhagic collapse, requiring urgent surgical intervention, without which the patient dies.

With gradual development (chronic course), cardiac tamponade’s clinical symptoms are similar to those of heart failure: patients are bothered by dyspnea on exertion and in the supine position (orthopnea), weakness, loss of appetite, swollen jugular veins, right subcostal pain, hepatomegaly, and ascites. Decompensation of congestion in systemic circulation in chronic cardiac tamponade leads to shock development.

Diagnosis of cardiac tamponade

Cardiac tamponade can be suspected if the patient has simultaneous dyspnea, tachycardia or tachypnea, increased CVP, low BP, and paradoxical pulse in the absence of signs of left ventricular failure. Paradoxical pulse is not a characteristic symptom of cardiac tamponade and may also accompany COPD, acute bronchial asthma attack, pulmonary embolism, right ventricular myocardial infarction, and constrictive pericarditis. Paradoxical pulse may be absent in patients with cardiac tamponade in acute or chronic aortic insufficiency, ventricle septal defect, severe hypotension, and local compression of the myocardium (e.g., massive blood clots).

Echocardiography has the highest diagnostic value in cardiac tamponade, as it allows the detection of even a small volume of effusion in the pericardial cavity, as well as the presence of diastolic collapse of the right heart chambers and changes in blood flow velocity through the tricuspid and mitral valves on inspiration. Transesophageal echocardiography is performed when there are signs of tamponade after cardiac surgery when it is difficult to detect pericardial effusion.

ECG manifestations of cardiac tamponade are usually nonspecific (low amplitude of QRS complex, flattened or negative T waves, and, in case of a large volume of effusion, complete electrical alternation of P and T waves and QRS complex). Chest radiography in cardiac tamponade often reveals an enlarged heart shadow with weakened pulsation and absence of venous stasis in the lungs.

Right heart catheterization allows the confirmation of the diagnosis of cardiac tamponade and the severity of hemodynamic disorders. Doppler ultrasonography in cardiac tamponade shows the dependence of blood flow through the heart valves on respiratory excursions (decrease in transmitral blood flow on inhalation >25%, decrease in transtricuspidblood flow on exhalation >40%). Cardiac tamponade should be differentiated from constrictive pericarditis and severe myocardial insufficiency.

Treatment for cardiac tamponade

Due to life-threatening conditions in all cases of cardiac tamponade, urgent evacuation of pericardial fluid by pericardial puncture (pericardiocentesis) or surgical intervention (in traumatic and postoperative genesis of tamponade) is indicated. Infusion therapy is performed to provide hemodynamic support in cardiac tamponade.

Pericardial puncture is performed under mandatory control of echo or fluoroscopy, with continuous monitoring of BP, HR, and CVP. A pronounced clinical effect of pericardiocentesis in cardiac tamponade is noticeable at aspiration of 25-50 ml of fluid from the pericardial cavity. After removal of the effusion in the pericardial cavity, antibiotics, hormonal drugs, and sclerosing agents can be introduced according to the indications. Drainage is installed to prevent recurrent accumulation of effusion in the pericardial cavity and ensure the constant outflow of fluid. Further treatment of the underlying disease is carried out to prevent the development of recurrent cardiac tamponade.

At high risk of recurrent cardiac tamponade, preference is given to surgical treatment (fenestration, subtotal pericardiectomy), providing more complete drainage of the pericardial cavity. Emergency surgery for vital indications is performed in case of tamponade due to rupture of the heart or aorta.

In fenestration, a hole is made in the pericardial wall to drain the pericardial cavity, and the internal surface is inspected to detect traumatic hemopericardium or tumor foci. Subtotal pericardiectomy is a radical method of treating cardiac tamponade in chronic exudative pericarditis, scarring, and calcification of the pericardium.

All these treatment options are available in more than 60 hospitals worldwide (https://doctor.global/results/procedures/pericardiocentesis). For example, Pericardiocentesis can be done in 7 clinics across India for an approximate price of $1,9 K (https://doctor.global/results/asia/india/all-cities/all-specializations/procedures/pericardiocentesis). 

Prognosis and prevention of cardiac tamponade

Untimely diagnosed cardiac tamponade is fatal. The situation is unpredictable in the development of hemopericardium and cardiac tamponade in case of significant trauma or rupture of the heart and aortic aneurysm dissection. In the case of early diagnosis and the provision of necessary therapeutic assistance in cardiac tamponade, the immediate prognosis is usually favorable. Still, the long-term prognosis depends on the etiology of the disease.

Prevention of cardiac tamponade includes timely treatment of pericarditis, compliance with the technique of invasive procedures, monitoring of the blood coagulation system during anticoagulant therapy, and therapy of concomitant diseases.