Cardiac tamponade is a medical emergency condition where a large amount of a fluid (e.g. pericardial effusion) accumulates in the pericardial space in a relatively short time. This may lead to an elevated intrapericardial pressure (>15 mm Hg), which prevents proper filling of heart cavities. Instead of reducing the filling of both ventricles equally, the septum of the heart will bend into either the left or right ventricle. The end result is hemodynamic compromise, low stroke volume and shock.
Cardiac tamponade can happen acutely, such as from a stab wound, from surgery, or from the heart muscle rupturing. Heart rupture will usually happen (though it is very uncommon) around the site of myocardial infarction.
Chronic cardiac tamponade is a slower process, where up to two litres of fluid can enter the pericardial space over a period of time. The pericardium will stretch to accommodate the extra fluid leading in turn to reduced ventricular filling.
- Malignancy: metastasis to the pericardium.
- Pericarditis: infections, radiation, connective tissue diseases, uremia or idiopathic pericarditis.
- Post-coronary intervention
- Post-cardiovascular surgery
- Post-myocardial infarction (Dressler's syndrome)
Symptoms and signs
The signs and symptoms can appear very similar to congestive heart failure, with dyspnea, cough, hypotension and tachycardia. There usually is a history of sudden onset attributable to trauma, particularly in younger patients.
Examination of the patient may reveal pulsus paradoxus and distention of the jugular veins. The jugular veins may show loss of the normal y-descent. On auscaltation, the heart sounds may sound muffled on auscultation as the accumulated fluid dampen the normal heart sounds transmitted through the chest wall.
1. EKG shows low QRS voltage or electrical alternans.
2. Chest x-ray shows cardiac enlargement with the characteristic "water bottle" appearance in some cases.
3. Echocardiography is the investigation of choice, showing the effusion and its hemodynamic consequences in terms of chamber dimensions.
4. Catheterization can be used to confirm the diagnosis and measure the diastolic pressures.
1. Immediate pericardiocentesis
Needle evacuation of the fluid and lowering of the pressure, and then treatment of the underlying cause.
2. Volume expansion
Volume expansion in cases with shock, until pericardiocentesis can be performed.
Anterior and posterior pericardiectomy may be needed in cases that reacculmate.
4. Percutaneous balloon pericardiotomy
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