Purpose: To report a case of severe and fatal cardiac complication following pericardiotomy to relieve a malignant tamponade. Right ventricular (RV) failure was responsible for major hypoxemia and for a persistent shunt through a patent foramen ovale. In the absence of pulmonary embolism and coronary occlusion, possible pathophysiologic mechanisms are discussed.
Clinical features: This 53-yr-old patient presented with oropharyngeal carcinoma previously treated by chemotherapy. One month later, he showed clinical and echocardiographic signs of cardiac tamponade. He had a circumferential pericardial effusion with complete end-diastolic collapse of the right cavities. After an emergent pericardiotomy, he rapidly presented severe hypoxemia. Transesophageal echocardiography showed an akinetic and dilated right ventricle, paradoxical septal wall motion and a normal left ventricular function. A contrast study revealed a right-to-left shunt. No residual pericardial effusion was detectable. Pulmonary angiography excluded a pulmonary embolism and the coronary angiogram was normal. Troponin Ic was elevated postoperatively and peaked on day two (3.78 micro g x L(-1)). The patient died of refractory shock with persistent intracardiac shunt and RV akinesia on day nine.
Conclusion: Although pulmonary embolism or thrombus of a coronary vessel are the most common causes of prolonged RV failure after pericardiotomy, other mechanisms may be invoked. The possibility is raised that a rapid increase in RV tension may induce the development of muscular injury and impair coronary blood flow, despite a normal coronary angiogram. These could result in a stunned myocardium and opening of a patent foramen ovale. We hypothesize that gradual decompression of a chronic pericardial effusion might be beneficial in patients at risk.