Comparative study of mitral annular calcification (MAC) with cardiac arrhythmias in dialysis patients.

Cardiac arrhythmias and myocardial malfunction are very frequent in uremic patients. The pathogenesis and etiology of arrhythmias are very complex and still unknown. The sedimentation of calcium salt in myocardial structures is one of the reasons for emergence of cardiac arrhythmias (AV conduction defects, ectopic arrhythmias). The appearance of mitral annular calcification (MAC), as the expression of the speed up process of atherosclerosis, was noted in younger uremic patients especially during hemodialysis. The aim of our research was to compare the incidence of MAC and cardiac arrhythmias in patients on hemodialysis. Our study included 40 patients, 24 male and 16 female, in the age between 20 and 60. Patients were mostly from Zagreb and the Counties of Zagreb (35%), Karlovac (10%), Slavonski Brod (7.5%), Varazdin (5%) and Pozega (5%). All 40 patients received 24 hours of Holter monitoring and 2-D echocardiography of M-mode. The patients were divided in two groups: I MAC+ (N = 23) and II MAC- (N = 17). Frequency of cardiac arrhythmias in group I was: atrial fibrillation N = 0; conduction defects N = 2 (1%); ventricularectopy Lown grade 3-5 N = 15 (65%); supraventricular ectopy N = 8 (34%), while the frequency of cardiac arrhythmias in group II was: atrial fibrillation N = 0; conduction defects N = 0; ventricular ectopy Lown grade 3-5 N = 6 (35%), supraventricular ectopy N = 6 (35%). During statistical processing the significant connection of MAC+ and frequency of cardiac arrhythmias was noticed. For both groups we have not noticed statistical significance in cardiac arrhythmia compared to electrolytes, risk factors PTH, and age. The time of hemodialysis treatment is one of possible factors for incidence of cardiac arrhythmias influenced by MAC. We noticed statistically significant (p < 0.05) difference of rhythm disorders between group I and group II especially for the ventricular ectopic activity, the frequency of which was higher in group I than in group II. MAC has probably significant role in dialysis patients for the development of cardiac arrhythmias within the framework of series of complicated multifactorial patogenetic mechanisms.