This 68-year-old man with severe obstructive lung disease and pulmonary hypertension is admitted to the medical intensive care unit with extensive pneumonia:

• Multifocal atrial tachycardia, rate 140/min, with occasional aberrantly conducted QRS complexes (right bundle branch block pattern)
• Right ventricular hypertrophy

The patient had a several-year history of clinical and echocardiographic findings of pulmonary hypertension and right ventricular hypertrophy. He had been on home oxygen because of hypoxemia. Prior to the present admission, he had been in sinus rhythm. The ECG shows typical findings of multifocal atrial tachycardia and right ventricular hypertrophy, and the T wave changes are secondary to RVH and hypoxemia.