Cardiorespiratory changes in progressive muscular dystrophy.

Incipient cardiac failure was detected in 56 per cent of cases of pseudohypertrophic muscular dystrophy, 50per cent oflimb girdle type ofmyopathies, and2 of the 3 cases with 'unclassifled' variety. 'Myopathic pattern' in the electrocardiogram was seen in 82 per cent of the cases of pseudohypertrophic muscular dystrophy who showed abnormal haemodynamics. This suggests that this pattern is due to myocardial damage. Thus the electrocardiogram can be used as a simple and safe procedure for the detection of dystrophic heart disease. Though 'myopathic pattern' is seen only in pseudohypertrophic muscular dystrophy the haemodynamic evidence of dystrophic heart disease is seen in other myopathies as well. Pulmonary ventilatory function tests revealed restrictive changes in 57 per cent of cases of myopathy when muscles of the chest wall were involved. This abnormality in pulmonary function tests had no apparent haemodynamic effect.