A 36-year-old man with Duchenne muscular dystrophy is bedridden and ventilator-dependent, requiring G-tube feeding:

• Sinus rhythm, 76/min
• Tall R waves in the right precordial leads (V1-V3)
• Deep Q waves in I and the left chest leads
• These QRS findings are frequently found in ECGs of patients with progressive muscular dystrophy

The echocardiogram of this patient demonstrated akinesia of the basal inferior region of the left ventricle. The tall R waves in the right precordial leads in muscular dystrophy are the result of loss of posteriorly directed forces caused by degenerative changes and scarring in the posterobasal portion of the left ventricle and the posterior papillary muscle. The abnormally deep Q waves in the left leads reflect lateral extension of these changes.