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 ye ars) presenting with acute symptoms and with subsequently proven pulmo nary embolism, and without previous lung disease, the 12-lead electroc ardiograms obtained at hospital admission were reviewed in a blinded f ashion to identify electrocardiographic features suggestive of right v entricular overload. Pulmonary embolism was considered probable in 37 patients (76%), from the presence of greater than or equal to 3 of the following abnormalities: (1) incomplete or complete right bundle bran ch block (n = 33); which was associated with ST-segment elevation (n = 17) and positive T wave (n = 3) in lead V-1; (2) S waves in leads I a nd aVL of >1.5 mm (n = 36); (3) a shift in the transition zone in the precordial leads to V-5 (n = 25); (4) Q waves in leads III and aVF, bu t not in lead II (n = 24); (5) right-axis deviation, with a frontal QR S 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 V-1 to V-4 ( n = 13), Which occurred more often in patients with symptoms for >7 da ys. In the 12 patients with normal electrocardiograms at admission, se rial electrocardiograms revealed diagnostic features of embolism in an additional 3 patients. Two-dimensional Doppler echocardiography at ad mission revealed tricuspid valve regurgitation and an increased right ventricular end-diastolic diameter in all cases. There was no signific ant difference in the echocardiographically derived peak right ventric ular systolic pressure (55 +/- 13 vs 54 +/- 10 mm Hg) or the right ven tricular end-diastolic diameter (41 +/- 7 vs 37 +/- 6 mm) between pati ents with and without abnormal electrocardiograms, respectively. In su bdividing the patients with abnormal electrocardiograms into 3 groups depending on the number of electrocardiographic abnormalities (greater than or equal to 7 abnormalities, 5 to 6 abnormalities, 3 to 4 abnorm alities), there was no significant difference between any of the subgr oups in right ventricular systolic pressure or end-diastolic diameter.