[Syncope as a misinterpreted leading symptom of pulmonary embolism].

One or several syncopes were the reason for hospitalization in 31 of 155 in-patients with proven pulmonary embolism. In all of them there were at least two further pointers to acute pulmonary embolism: all had tachypnoea, 28 had dyspnoea, 25 had sinus tachycardia (more than 100 beats/min), 24 had congested neck veins and 16 had deep leg-vein thrombosis. In 21 patients the ECG had signs of right heart strain, in 15 of 20 in whom it was measured the arterial oxygen partial pressure was below 70 mm Hg. In 23 patients the chest X-ray was largely unremarkable despite dyspnoea. In 23 patients there had been a massive embolus and 16 patients had died. Although syncope is only rarely caused by pulmonary embolism, its ominous significance in this connection should stimulate a search for further diagnostic pointers to such an occurrence.