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 V4 -V6 . 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 V4 -V6 , ST-segment elevation in leads V1 -V3 /V4 , and ST-segment elevation in leads III and/or V1 /V2 with concomitant ST-segment depression in leads V4 /V5 -V6 . Ischemic ECG patterns with concomitant S1Q3 and/or abnormal QRS morphology in lead V1 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.