Prevalence of Helicobacter Pylori infection in patients with Idiopathic Arrhytmias

Chronic Helicobacter Pylori (HP) gastric infections can stimulate autoimmune responses and can be associated with coronary heart disease. Silent autoimmune cardiomyopathy may be the cause of "idiopathic" arrhythmias (IA). The purpose of this study was to evaluate the prevalence of HP infection and that of HP strains which express the cytotoxin-associated gene A (CagA) and vacuolating cytotoxin-associated gene A (VacA) in patients (pts) with IA. 54 pts (40 males and 14 females, mean age 44 + 17 years) affected by IA, 23 pts with supraventricular (SVA) and 31 pts with ventricular (VA), were evaluated. HP infection was determined by 13C-urea breath test. The presence of the cytotoxins CagA and VacA, in HP-positive pts, was evaluated through Western blot analysis. Gastrointestinal (GI) Symptoms (bloating, pyrosis, epigastric pain, belching, halitosis and nausea) were also assessed. 23 out of 54 IA pts (42%), 16 males and 7 females, (mean age 48 + 14 years), 11 out of 23 (48%) with SVA and 12 out of 31 (39%) with VA, resulted infected by HP. CagA and VacA cytotoxins were found in 65% (15 out of 23) and 74% (17 out of 23) of pts, respectively. HP positive pts did not show any significant difference in the incidence of the GI symptoms when compared to non infected pts, excluding belching that was markedly more prevalent in infected pts (83 vs 42%, p<0.002). The prevalence of HP infection in pts with IA is similar to that reported in the literature in normal controls. The prevalence of HP strains able to produce CagA and VacA cytotoxins is much higher in infected arrhythmic pts, as compared to that reported in HP positive controls (28%). Further investigations are needed to evaluate the pathogenic role of HP cytotoxic strains in the development of immune-mediated IA and cardiomyopathy