Noninvasive assessment of left ventricular function in myotonic muscular dystrophy.

Abstract

Myotonic muscular dystrophy is a diffuse systemic disorder, which is inherited as an autosomal dominant trait, with appearance in both sexes, generally late onset of symptoms, and slowly progressive evolution. The clinical picture may include involvement of skeletal and cardiac muscle, cataracts, premature frontal baldness, bone changes, testicular atrophy, other mild endocrine abnormalities, and mental deterioration.Evidence of cardiac disease in patients with myotonic dystrophy is usually found in the electrocardiogram, the most common alterations being P and ST and T wave abnormalities, first degree atrioventricular block, left axis deviation, atrial flutter and fibrillation, bundle-branch block, and premature atrial and ventricular contractions

Doppler Echocardiographic Assessment of Left Ventricular Diastolic Function in Myotonic Dystrophy

“…In 24% of patients we have shown Dopp ler abnormalities that conformed to a pattern of impaired left ventricular relaxation. These findings are supported bv previous M-mode échocardiographie studies [8,9] that showed reduced maximal diastolic endocardial velocity and decreases in the left ventricular peak diastolic length ening rate in patients with myotonic dystrophy and with out clinically apparent heart failure. On the contrary, a recent study [14] showed a Doppler pattern of abnormal relaxation (early to atrial peak velocity ratio < 1 and timevelocity integral of early velocity curve to atrial curve ratio <1.5) in only 3 of 42 unselected patients with myo tonic dystrophy and in only 1 patient diastolic dysfunc tion was related to a myocardial dystrophic disease.…”

“…Most studies, however, demonstrated that demonstrate impairment of diastolic performance [2,12]; others [8,9] showed abnormalities in left ventricular relaxation. Recently, a study assessing the relation be tween the severity of cardiac involvement and the myo tonic dystrophy genotype [14] reported that Doppler echocardiographic indexes of left ventricular tilling are normal in patients with myotonic dystrophy.…”

“…The hallmark of heart involvement in myotonic dys trophy is derangement of the conducting system [1][2][3][4][5][6], Clinically overt primary myocardial impairment is rare [7], but subclinical myocardial dysfunction has been sug gested [8][9][10][11]. Most studies, however, demonstrated that demonstrate impairment of diastolic performance [2,12]; others [8,9] showed abnormalities in left ventricular relaxation.…”

Early detection of biventricular involvement in myotonic dystrophy by tissue Doppler

“…Cardiac involvement is usually characterized by conduction system abnormalities with prolonged PR interval, frequent bradyarrhythmias and increased risk of sudden death [2][3][4]. Despite some controversial results [5,6], it is known that patients with myotonic dystrophy may develop a specific cardiomyopathy and symptoms of heart failure [7,8], while only subclinical left ventricular (LV) diastolic dysfunction is detectable in the early stages of disease [9][10][11][12]. In this view, and because of a very variable phenotypic expression of the International Journal of Cardiology 118 (2007) 227 -232 www.elsevier.com/locate/ijcard disease, the detection of early markers of cardiac involvement may be crucial for an appropriate management of patients affected by MD [13].…”

Ambulatory Electrocardiographic Monitoring in Myotonic Dystrophy (Steinert&rsquo;s Disease)

“…Cardiac manifestations reflect selective disturbances of conduction system [2,3,5,7,9,11,13] rather than myo cardium [3,5,13,14,17]. The most com mon electrocardiographic abnormalities are sinus bradycardia, prolongation of P-R in terval and intraventricular conduction dis turbances; high-degree atrioventricular block and severe arrhythmias may also oc cur, which could be responsible for syncope and sudden death [4,10,15,16].…”