In connection with a life-threatening condition, in all cases of cardiac tamponade, emergency evacuation of the pericardial fluid is indicated by performing pericardial puncture (pericardiocentesis) or surgical intervention (with traumatic and postoperative genesis of tamponade). To provide hemodynamic support for cardiac tampon infusion therapy (intravenous plasma, nootropic drugs) is performed.
Puncture of the pericardium is performed under the mandatory control of echocardiography or fluoroscopy, with constant monitoring of blood pressure, heart rate, CVP. The pronounced clinical effect of pericardiocentesis with cardiac tamponade is already noticeable when aspirating 25-50 ml of fluid from the pericardial cavity. After removal of the effusion into the pericardial cavity, antibiotics, hormonal drugs, sclerosing agents may be administered as indicated. To prevent re-accumulation of effusion in the pericardial cavity, drainage is established for a 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 repeated cardiac tamponade, preference is given to surgical treatment (pericardiotomy, Subtotal pericardiectomy), providing a more complete drainage of the pericardial cavity. Emergency surgery for vital reasons is performed with tamponade due to rupture of the heart or aorta.
With pericardiotomy, a hole is made in the pericardial wall for drainage of its cavity and an 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.
Heart tamponade is a critical condition caused by the increasing accumulation of fluid in the pericardial cavity, a significant increase in intrapericardial pressure, a violation of the ventricular diastolic filling, leading to a sharp decrease in cardiac output. According to the clinical manifestations of cardiac tamponade can be acute and chronic. For acute tamponade of the heart is characterized by rapid and rapid development of symptoms and unpredictability of the course. In cardiology, cardiac tamponade is a dangerous complication leading to severe disturbances of central hemodynamics, metabolic and microcirculatory disorders, contributing to the development of acute heart failure, shock and cardiac arrest.
Cardiac tamponade is a clinical syndrome associated with severe impairment of heart function and systemic hemodynamics due to the rapid accumulation of fluid in the pericardial cavity and the rise in intrapericardial pressure. Heart tamponade can manifest discomfort in the chest, painful dyspnea, tachycardia, tachypnea, paradoxical pulse, arterial hypotension, jugular vein swelling, fainting, shock. The diagnosis of cardiac tamponade is based on physical examination, echoCG, ECG, chest X-ray, right heart catheterization. With cardiac tamponade, an urgent puncture of the pericardium is shown, sometimes – pericardiotomy, subtotal pericardiectomy.
Causes of heart tamponade
Cardiac tamponade can develop with accumulation in the pericardial cavity of a different effusion type (blood, pus, exudate, transudate, lymph), as well as gas.
The most common acute tamponade of the heart occurs with hemopericardium – bleeding into the pericardial cavity, which develops with open and closed injuries of the chest and heart; due to medical procedures (myocardial biopsy, cardiac sounding, central venous catheter installation) and surgery; with stratification of the aortic aneurysm, spontaneous rupture of the heart in patients with myocardial infarction, during treatment with anticoagulants.
Heart tamponade may complicate the course of pericarditis (tuberculosis, purulent, acute idiopathic), malignant heart and lung tumors, chronic renal failure, systemic lupus erythematosus, myxedema, etc.
Hemodynamics with cardiac tamponade
Hemodynamic disturbances during cardiac tamponade depend not so much on volume, as on the rate of fluid intake and the degree of pericardial distensibility. Normally, about 20-40 ml of fluid are contained in the pericardial cavity, intrapericardial pressure is about 0 mm Hg. Due to the adaptive capacity of the pericardium, the slow accumulation of effusion up to 1000-2000 ml usually leads to a slight change in the intrapericardial pressure.
If even a small amount (more than 100-200 ml) of exudate suddenly enters the pericardial cavity, a sharp rise in intrapericardial pressure can occur, leading to compression of the heart and intrapericardially located sections of the upper and lower hollow veins. There is an obstacle to the flow of blood into the ventricles, which leads to a decrease in their filling during diastole, a decrease in stroke volume and cardiac output.
Normally, at the end of diastole, the pressure in the right atrium and ventricle is about 7 and 5 mm Hg. Art. respectively, in the left atrium and ventricle – up to 14 and 12 mm Hg. Art. Heart tamponade develops when intrapericardial pressure becomes equal to the final diastolic pressure (KDD) in the ventricles.
An increase in central venous pressure (CVP) characteristic of cardiac tamponade, an increase in heart rate and an increase in peripheral resistance is a compensatory mechanism aimed at maintaining an adequate filling of the heart and its release. Low intrapericardial pressure cardiac tamponade may occur when intravascular volume (hypovolemia) decreases in dehydrated critically ill patients.
Heart Tamponade Symptoms
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 not specific: heaviness in the chest, increase in shortness of breath, feeling of “fear of death”, severe weakness, and abundant cold sweat.
On examination of the patient, cyanosis of the skin, psychomotor agitation, tachycardia, rapid shallow breathing, marked paradoxical pulse, arterial hypotension, and deaf heart sounds are noted. In acute cardiac tamponade, due to the powerful activation of the sympathoadrenal system, blood pressure can be maintained for several hours and an improvement in venous return can be observed.
The clinical picture of a severe acute cardiac tamponade, caused, for example, by a myocardial or aortic rupture, may be manifested by the development of sudden syncope and hemorrhagic collapse, requiring urgent surgical intervention, without which the patient dies.
With the gradual development (chronic course), the clinical symptoms of cardiac tamponade are similar to manifestations of heart failure: patients experience shortness of breath with exertion and lying (orthopnea), weakness, loss of appetite, swelling of the jugular veins, pain in the right hypochondrium, hepatomegaly, ascites. Decompensation of stagnation in the systemic circulation in chronic cardiac tamponade leads to the development of a shock.
Diagnosis of heart tamponade
It is possible to suggest the presence of cardiac tamponade with simultaneous development of dyspnea, tachycardia or tachypnea, increased CVP, low blood pressure, and paradoxical pulse in the patient with no signs of left ventricular failure. Paradoxical pulse is not a characteristic symptom of cardiac tamponade and may also accompany COPD, an acute attack of bronchial asthma, pulmonary embolism, myocardial infarction of the right ventricle, constrictive pericarditis. Paradoxical pulses may be absent in patients with cardiac tamponade with acute or chronic aortic insufficiency, DMPP, severe hypotension, local myocardial compression (for example, massive blood clots).
Echocardiography with cardiac tamponade has the highest diagnostic value, as it allows to detect even a small amount of effusion in the pericardial cavity, as well as the presence of a diastolic collapse of the right heart chambers and a change in blood flow velocity through the tricuspid and mitral valves during inspiration. A transesophageal echocardiography is performed when there are signs of tamponade after heart surgery, and when it is difficult to detect a pericardial effusion.
ECG manifestations of cardiac tamponade are usually non-specific (low amplitude of the QRS complex, flattened or negative T waves, with a large amount of effusion – complete electrical alternation of the P and T teeth and QRS complex). A chest x-ray with cardiac tampon often reveals an enlarged heart shadow with a weakened pulse, the absence of venous congestion in the lungs.
Catheterization of the right heart can confirm the diagnosis of cardiac tamponade and assess the severity of hemodynamic disorders. Pulsed dopplerography with cardiac tampon shows the dependence of blood flow through the heart valves on respiratory excursions (decrease in transmitral blood flow during inspiration> 25%, decrease in transtricuspid blood flow during expiration> 40%). Cardiac tamponade must be differentiated from constrictive pericarditis and severe myocardial insufficiency.
Prognosis and prevention of cardiac tamponade
Timely undiagnosed cardiac tamponade is fatal. The situation is unpredictable in the development of hemopericardium and cardiac tamponade in the event of a significant injury or rupture of the heart, aortic aneurysm dissection.
With early diagnosis and the provision of necessary medical assistance for cardiac tampon, the closest prognosis is usually favorable, distant – depends on the etiology of the disease.
Prevention of cardiac tamponade includes the timely treatment of pericarditis, adherence to the technique of invasive procedures, monitoring of the state of the blood coagulation system during anticoagulant therapy, the treatment of associated diseases.