It is known that pulmonary embolism is accompanied by quite complex pathophysiological changes in cardovascular system. From cardiovascular point of view, the diagnosis of pulmonary thromboembolism may be easily based on echocardiographic signs of right ventricular hypokinesia. Physiologic abnormalities caused by venous emboli are related to the cross-sectional area of occluded pulmonary arterial bed. Recent studies has demonstrated, that in patents with massive pulnonary thromboembolism and signs of pulmonary hypertension, increase of right ventricular afterload can lead to both right ventricular failure and reduction of left ventricular preload. Despite development of pulmonary hypertension in acute massive pulmonary thromboembolism, there are no signs of right ventricular hypertrophy. The main ECG changes include right ventricular overloadl Previous Normal ECG is of special importance. Documentation of serious increase of pulmonary arterial pressure by Doppler echocardiography will assist to link right ventricular pressure overload and dysfunctional with embolia. Transesophageal echocardiography had the similar diagnostic value as transhoracic one, but especially is helpful in bedside diagnosis in patients with signs of shock secondary to pulmonary thromboembolism.