The correct interpretation includes normal sinus rhythm, biatrial enlargement, and right-axis deviation. Other findings include a prolonged QT interval and ST-T wave abnormalities in inferior and anterior distributions.
A P wave for every QRS complex and a QRS complex for every P wave, with a consistent PR interval and a rate > 60 and < 100 beats/min, indicates normal sinus rhythm. Biatrial enlargement is evidenced by a notched P wave in lead I, a tall P wave in lead II, and a biphasic P wave in V1. Right-axis deviation is defined by an R-wave axis between 90° and 180°. Biatrial enlargement and right-axis deviation suggest a pulmonary disease pattern.
A normal QTc interval is generally 350 to 440 ms; the patient’s QTc interval (477 ms) meets the criteria for prolonged QT. There are ST- and T-wave inversions in leads II, III, and aVF, consistent with inferior ischemia, with ST depressions in leads V3 and V4, which could suggest anterior ischemia. Such findings are also seen in a pulmonary disease pattern.
Further workup included a chest x-ray, laboratory testing, and an echocardiogram. The last revealed right lower lobe consolidation and a diffuse, dilated cardiomyopathy with mild mitral and tricuspid regurgitation.