The patient is a 44-year-old male who developed back pain during the night. He has a history of hypertension and smokes cigarettes. Because the discomfort did not abate, he was seen in the emergency room where the below ECG was performed.
The ECG shows which of the following?
The correct answer is: D. Left atrial abnormality.
The ECG shows sinus rhythm with a heart rate of approximately 100 beats per minute. The QRS is narrow and the axis is normal. Q waves are present in the inferior leads with ST elevation and ST depression in aVL confirming acute inferior infarction. Lateral T wave changes are present (lead I, V5, V6) indicating lateral wall ischemia. Lead V1 and V3 are reversed giving the picture of poor R wave progression suggestive of anterior infarction. The P wave in V1 (inverted at V3) shows prominent left atrial component (likely high left atrial pressure) indicating left atrial abnormality. The patient was found to have 100% right coronary artery obstruction as well as high grade very distal left anterior descending artery obstruction. Angioplasty of the right coronary artery was performed.
Jin L, Weisse AB, Hernandez F, Jordan T. Significance of electrocardiographic isolated abnormal terminal P-wave force (left atrial abnormality). An echocardiographic and clinical correlation. Arch Intern Med 1988;148:1545-9.