Value of the 12-lead electrocardiogram at hospital admission in the diagnosis of pulmonary embolism.

In 49 consecutive patients (27 men and 22 women, age range 44 to 86 years) presenting with acute symptoms and with subsequently proven pulmonary embolism, and without previous lung disease, the 12-lead electrocardiograms obtained at hospital admission were reviewed in a blinded fashion to identify electrocardiographic features suggestive of right ventricular overload. Pulmonary embolism was considered probable in 37 patients (76%), from the presence of > or = 3 of the following abnormalities: (1) incomplete or complete right bundle branch block (n = 33); which was associated with ST-segment elevation (n = 17) and positive T wave (n = 3) in lead V1; (2) S waves in leads I and aVL of > 1.5 mm (n = 36); (3) a shift in the transition zone in the precordial leads to V5 (n = 25); (4) Q waves in leads III and aVF, but not in lead II (n = 24); (5) right-axis deviation, with a frontal QRS axis of > 90 degrees (n = 16), or an indeterminate axis (n = 15); (6) a low-voltage QRS complex of < 5 mm in the limb leads (n = 10); and (7) T-wave inversion in leads III and aVF (n = 16) or leads V1 to V4 (n = 13), which occurred more often in patients with symptoms for > 7 days. In the 12 patients with normal electrocardiograms at admission, serial electrocardiograms revealed diagnostic features of embolism in an additional 3 patients. Two-dimensional Doppler echocardiography at admission revealed tricuspid valve regurgitation and an increased right ventricular end-diastolic diameter in all cases.(ABSTRACT TRUNCATED AT 250 WORDS)