A woman in her 60s was admitted with increasing shortness of breath. The ECG showed: Sinus tachycardia (109/min) Right axis deviation Incomplete right bundle branch block (QRS < 120 ms) T-wave inversions in aVR, III, and V1–V5 This ECG pattern is classic for acute pulmonary embolism and reflects right heart strain. T-wave inversions may also be seen in leads II and aVF, although not in this case. Many associate pulmonary embolism with the S1Q3T3 pattern : S wave in lead I Q w
