[C-reactive protein level and rate of detection of autoantibodies to beta(1)-adrenoreceptors in patients with supraventricular tachyarrhythmias].

In order to assess concentration of C-reactive protein (CRP) and prevalence of autoantibodies against beta(1)-adrenoreceptors (abeta(1)-AR) in patients with cardiac supraventricular arrhythmias we studied 53 patients with arrhythmias and 20 healthy control subjects. Patients with idiopathic arrhythmias (atrial fibrillation or flutter and atrial tachycardia, n=35) comprised group I. Group II was formed of 15 patients with supraventricular arrhythmias and dilated cardiomyopathy (DCM) or chronic myocarditis. Patients of group III (n=23) had supraventricular arrhythmias and arterial hypertension (AH). CRP concentration was determined by recently developed well standardized high sensitivity method. abeta(1)-AR were detected in blood serum by direct immunoassay. Synthetic fragment containing 26 amino acids of abeta(1)-AR second loop was used as antigen. Patients with supraventricular arrhythmias and DCM or chronic myocarditis had higher median CRP (8.0 mg/1) than patients with idiopathic arrhythmias (0.78 mg/l), with supraventricular arrhythmias and AH (1.57 mg/l), or control group (0.6 mg/l). Groups I, II and III showed similar prevalence of ab1-AR (51.4, 40.0, 52.2%, respectively), that was significantly higher than in control subjects (10%) (p<0.005). These results provide evidence of the possible presence of autoimmune and/or inflammatory processes that may be involved in the genesis of supraventricular arrhythmias.

[Cardiac sympathetic innervation in patients with ventricular arrhythmias: an assessment by 123I-metaiodobenzylguanidine scintigraphy].

The aim of this study was to determine the state of sympathetic innervation in patients with ventricular arrhythmias (VA) using 123I-metaiodobenzylguanidine 123I -MIBG) scintigraphy. Fifty six patients (26 men and 30 women, mean age 37.4+/-11,6) underwent single-photon emission computed tomography (SPECT) imaging and planner scintigraphy after injection of 123I-MIBG (activity 148 MBq). They form three groups. Thirty patients with idiopathic VA (IVA) were included in group I: 14 patients with ventricular extrasystoles (VE) and 16 - with ventricular tachycardias (VT). Group II was formed by 17 patients (with dilated cardiomyopathy, n=7 and chronic myocarditis, n=10), 6 of them had VE and 11 - VT. The control group III was formed by 9 healthy subjects with structurally normal heart without VA. We analyzed early (30 minutes) and delayed (4 hours) images after 123I-MIBG administration. The global sympathetic activity (SA) was assessed by heart/mediastinum ratio and washout rate. Regional SA was assessed by extent and severity of defect. In group I 25 of 30 patients (83.3%) had regional SA abnormalities significantly different from controls (p<0.001). At the same time global uptake of 123I-MIBG in this group was not affected. In group II regional SA abnormalities were revealed in all patients (100%) and global reduction of 123I-MIBG uptake - in 14 patients (82.4%). Regional and global SA abnormalities in group II were different from controls (p<0.0001) and patients with IVA (p<0.001). There was no difference in SA abnormalities between patients with VE and VT. Our results suggest that patients with different VA have abnormalities of sympathetic innervation, including patients with structurally normal heart.

[Spectral parameters of heart rate variability and frequency of detection of autoantibodies to beta(1)-adrenoreceptors in patients with tachyarrhythmias: idiopathic and at the background of primary myocardial diseases].

In order to assess parameters of heart rate variability (HRV) and prevalence of autoantibodies against the beta(1)-adrenoreceptors in patients with cardiac arrhythmias we studied 42 patients with arrhythmias and 20 healthy control subjects. Thirty one patients with idiopathic arrhythmias were included in group I: with paroxysmal atrial fibrillation or flutter (n=13), paroxysmal atrial tachycardia (n=2) and paroxysmal ventricular tachycardia (n=16). Group II was formed of 11 patients with paroxysmal ventricular tachycardia and dilated cardiomyopathy or chronic myocarditis. ab1-AR were determined in blood serum by direct immunoassay. Synthetic fragment containing 26 amino acids of ab1-AR second loop was used as antigen. Groups I (54.8%) and II (63.6%) showed similar prevalence of ab1-AR, which was significantly higher than in control subjects (10%) (p<0.005). HRV parameters in I group were lower in ab1-AR-positive compared with ab1-AR-negative patients. At the same time HRV parameters in ab1-AR-positive patients were significantly different from those in controls (p<0.05). In group II HRV parameters of ab1-AR-positive and ab1-AR-negative patients were significantly lower than in control subjects (p<0.05). We suppose, that ab1-AR could participate in dysfunction of chronotropic heart regulation and contribute to development of arrhythmias in patients with structurally normal hearts.