Myotonic dystrophy and cardiac disorders

Myotonic dystrophy (MD) is a multisystem disease affecting numerous organs and systems. Cardiac involvement is frequent. Sudden death, due to fatal cardiac rhythm and conduction disturbances occurs in 30% of patients with MD. The aim of this study was to assess the possibilities and methods of early detection of myocardial and conduction system disturbances. ECG, 24-hr Holter monitoring, echocardiography and electrophysiologic studies of the conduction system (electrophysiologic study) were carried out in 45 patients. Analysis of late ventricular potentials was done in 36 patients. Genetic studies revealed multiplication of CTG triplets in all patients. Cardiological abnormalities were detected in 89% of our patients. Disturbances of intraventricular conduction with prolongation of HV interval were most frequent (72%). Electrophysiologic study was the most sensitive method for detecting heart involvement in MD (positive findings in 87% patients). Abnormal findings were also discovered by Holter monitoring (64%), ECG (58%), analysis of late ventricular potentials (55%) and by echocardiography in 46% patients. The results of this study indicate a high rate of cardiac involvement in MD.

[The role of echocardiography in the evaluation of cardiac damage in Lyme disease]

Lyme disease is an infectious, multisystem disease involving the skin, heart, joints, and nervous system. With its ability to assess cardiac anatomy, chamber sizes and myocardial and valvular function, echocardiography is a powerful noninvasive tool to investigate possible cardiac involvement in this disorder. We studied by echocardiography 15 patients, (6 women and 9 men, mean age 28.5 years, range 17 to 42) with clinical and electrocardiographic changes compatible with acute myocarditis or myopericarditis. 14 patients (pts) had transitory complete heart block and one patient had ventricular extrasystolic arhythmia. A first patient group (n = 6) who had a tick bite (Lyme antibody titers were found in three patents) was compared with a group (n = 9) without such confirmation. In first group two pts had small pericardial effusion and two pts had a nonspecific, discrete and small myocardial fibrosis after 3-6 months echocardiographic follow-up. Chambers sizes and indexes of left ventricular systolic and diastolic function were normal. Similar findings were found in the other group. We concluded that echocardiographic findings is not specific for Lyme disease, but echocardiography is an excellent tool for assessing the presence and degree of cardiac dysfunction and therefore provides essential information for the management of these patients.

[Hemorheologic changes in diabetes mellitus]

78 diabetics and a healthy control group of 100 were evaluated according to their haemorrheological parameters (whole blood viscosity, plasma viscosity, aggregability and rigidity of erythrocytes). Diabetics were divided according to type of diabetes, quality of metabolic control and expression of microangiopathy. Hyperviscosity was noted in both groups of diabetics as compared to the control group. Changes in patients with IDDM were more pronounced in erythrocyte rigidity, while in patients with NIDDM they were more expressed in cell aggregability. These changes were present even before the clinical onset of the late complications of diabetes, although they were more expressed in patients with complications. Changes in patients with good metabolic control, were less expressed in comparison to those with poor metabolic control. The conclusion is that metabolic derangements in diabetes have an important influence on haemorrheological properties. Thus, reducing blood viscosity in these patients, may be a promising approach to improving microcirculation and delaying the progression of microangiopathy.