Abstract
Intermittent or transient right bundle branch block (RBBB) can occur in various clinical situations but is rarely described in acute pulmonary embolism. We present a unique case involving a 57-year-old male who experienced a syncopal episode during transit. He displayed signs of a transient right bundle branch block (RBBB) and S1Q3T3 on the initial EMS ECG, which reverted to normal ECG later. This case highlights the significance of recognizing transient RBBB and S1Q3T3 patterns as potential markers of acute PE. Anticoagulation therapy is the mainstay of PE treatment, but other modalities like thrombolysis and surgical embolectomy can be used in selected cases.