Syncope in a 67-year-old man

D. Luke Glancy, MD, and Ghiath M. Mikdadi, MD

A 67-year-old man with an unremarkable medical history except for high blood pressure came to the emergency department because of a syncopal episode. He denied dyspnea and chest pain. An electrocardiogram was recorded. The rhythm on the electrocardiogram is sinus tachycardia with frequent premature atrial complexes-the 2nd, 5th, 9th, 13th, and 16th P waves. A P-wave axis of +70° and slightly tall P waves in leads II (2.5 mm) and V 2 (1.5 mm) suggest the possibility of right atrial enlargement. The QRS axis is markedly rightward (+175°), and the QRS duration is normal (0.09 seconds). Precordial R-wave development is markedly delayed, a so-called clockwise rotation of the QRS complex, with the S wave larger than the R wave in each of the precordial leads. Inverted T waves are found across the precordium and in leads III and aVF, where they are accompanied by small q waves; lead II shows neither q's nor inverted T's. All of these findings suggest acute cor pulmonale, which is usually due to pulmonary embolism.