It’s a Boy: Duchenne Muscular Dystrophy

Report:

Sinus tachycardia 144/min

Axis +90o

Rs in V1 consistent with Erb-Duchenne (pseudohypertrophic) muscular dystrophy[!xe "Duchenne (pseudohypertrophic) muscular dystrophy" \b \i!]

Comment:

The characteristic feature of Duchenne dystrophy is the dominant R wave in lead V1. It has been related to fibrosis and hypertrophy of the posterobasal portion of the left ventricle. Tall right precordial R waves are often associated with Q waves in limb or left precordial leads; the Q waves seen here are, however, within normal limits. The ECG presentation of Duchenne dystrophy is thus indistinguishable from posterolateral myocardial infarction128.

Not all the patients with Duchenne dystrophy develop the characteristic ECG pattern. Below (172a) is an example from a 15 year old dying from respiratory muscle involvement. Early transition with prominent R in V2 is suggestive, but far from typical of anything in particular.

Yet another example is shown in Fig 172b, about to die in four days at the age of 21, with LAD -45o, presumably fibrosis involving the anterior superior division of the left bundle branch. The appearance is the same as any LAHB, except for much smaller than usual voltages.

Fig 172c exhausts my collection. It’s an 11 year old with fairly typical tracing, suspected by the reporting Cardiologist of having inferior infarction or hypertrophic cardiomyopathy, with advice the patient needs investigating. Not this one.