Electrocardiogram patterns during hemodynamic instability in patients with acute pulmonary embolism.

Background: We have previously described new electrocardiogram (ECG) findings for massive pulmonary embolism, namely ST-segment elevation in lead aVR with ST-segment depression in leads I and V-4-V-6. However, the ECG patterns of patients with acute pulmonary embolism during hemodynamic instability are not fully described. Methods: We compared the differences between the ECG at baseline and after deterioration during hemodynamic instability in twenty patients with acute pulmonary embolism. Results: Compared with the ECG at baseline, three ischemic ECG patterns were found during clinical deterioration with hemodynamic instability: ST-segment elevation in lead aVR with concomitant ST-segment depression in leads I and V-4-V-6, ST-segment elevation in leads V-1-V-3/V-4, and ST-segment elevation in leads III and/or V-1/V-2 with concomitant ST-segment depression in leads V-4/V-5-V-6. Ischemic ECG patterns with concomitant S1Q3 and/or abnormal QRS morphology in lead V-1 were more common (90%) during hemodynamic instability than at baseline (5%) (P = 0.001). Conclusions: Hemodynamic instability in acute pulmonary embolism is reflected by signs of myocardial ischemia combined with the right ventricular strain pattern in the 12-lead ECG