Predicting the outcome of acute pulmonary embolism by dynamic changes of the QRS complex in lead V1

Electrocardiography can provide useful prognostic information in acute pulmonary embolism (APE). Several abnormal QRS changes in lead V1, including notched or fragmented QRS, incomplete or complete right bundle branch block (IRBBB or CRBBB) and the QR sign, which are associated with APE, are of prognostic significance. To illustrate this, we describe lead V1 QRS changes in combination with the clinical state of six APE patients. The dynamic ECG changes suggest that a change from a diminution of the S wave amplitude to notched S wave, next to RBBB and then to the QR sign indicate worsening of the patients' condition, and vice versa. Also, a diminution of the S wave amplitude in lead V1 associated with a final R' wave in the right precordial accessory leads indicates the possibility of hidden RBBB. Understanding dynamic QRS changes in APE may aid in risk stratification.