CARDIAC AND RESPIRATORY INVOLVEMENT IN ADVANCED-STAGE DUCHENNE MUSCULAR-DYSTROPHY

This study aimed to describe myocardial involvement, respiratory impai rment and pulmonary blood flow abnormalities in advanced-stage Duchenn e muscular dystrophy (DMD). Twenty-one wheelchair-bound patients, aged from 10 to 24 yr, underwent electrocardiographic and echocardiographi c examination, conventional spirometry, diurnal arterial blood gas ana lysis, and nocturnal polysomnography (SaO(2) monitoring). Diagnosis wa s confirmed by neurological examination, dystrophin analysis at protei n and DNA level. Patients were classified into two groups: group A nor moxemic (14 cases) and group B with nocturnal hypoxemia (seven cases). Group A was further split into two subgroups, one without, and one wi th, left ventricular dilation (A1 = nine patients, end diastolic volum e (EDV) = 51 ml m(-2), ejection fraction (EF) = 56 per cent; A2 = five patients, EDV = 112 ml m(2), EF = 32 per cent; P < 0.05). Left ventri cular regional wall motion abnormalities were found in 55, 40, and 43 per cent of groups A1, A2, and B patients respectively. Analysis of pu lsed Doppler pulmonary data highlighted a significant reduction in cor rected time to peak velocity in group B patients, when compared with c ontrol, A1, and A2 groups respectively. In group A, we observed a dire ct correlation between ejection fraction and corrected time-to-peak ve locity. Two patterns of cardiac involvement may be recognized in advan ced-stage DMD; left ventricular wall motion abnormalities and dilated cardiomyopathy. Doppler data which could suggest pulmonary hypertensio n may be observed in patients with dilated cardiomyopathy, and in pati ents with nocturnal hypoxemia. Therefore, in the management of advance d-stage DMD, a careful diagnosis of the heart-lung relationship should be performed, and both conventional treatment of heart failure and ve ntilatory therapy are necessary to improve the quality of life and sur vival in these patients.