Cholinesterase inhibition reduces arrhythmias in asymptomatic Chagas disease.

INTRODUCTION: Parasympathetic dysfunction may play a role in the genesis of arrhythmias in Chagas disease. AIM: This study evaluates the acute effects of pyridostigmine (PYR), a reversible cholinesterase inhibitor, on the occurrence of arrhythmias in patients with Chagas cardiac disease. METHOD: Following a double-blind, randomized, placebo-controlled, cross-over protocol, 17 patients (age 50±2 years) with Chagas cardiac disease type B underwent 24-hour Holter recordings after oral administration of either pyridostigmine bromide (45 mg, 3 times/day) or placebo (PLA). RESULTS: Pyridostigmine reduced the 24-hours incidence (median [25%-75%]) of premature ventricular beats-PLA: 2998 (1920-4870), PYR: 2359 (940-3253), P=.044; ventricular couplets-PLA: 84 (15-159), PYR: 33 (6-94), P=.046. Although the total number of nonsustained ventricular tachycardia in the entire group was not different (P=.19) between PLA (1 [0-8]) and PYR (0 [0-4]), there were fewer episodes under PYR in 72% of the patients presenting this type of arrhythmia (P=.033). CONCLUSION: Acute administration of pyridostigmine reduced the incidence of nonsustained ventricular arrhythmias in patients with Chagas cardiac disease. Further studies that address the use of pyridostigmine by patients with Chagas cardiac disease under a more prolonged follow-up are warranted.

Impact of the Use of Benznidazole Followed by Antioxidant Supplementation in the Prevalence of Ventricular Arrhythmias in Patients With Chronic Chagas Disease: Pilot Study.

Patients with chronic Chagas disease have a higher prevalence of premature ventricular contraction (PVC) because of immunoinflammatory response magnified by the increased oxidative stress. Thus, the sequential treatment with benznidazole (BZN) and antioxidants can reduce the prevalence of PVC. We wish to establish whether the etiological treatment of Chagas disease followed by supplementation with the antioxidant vitamins E and C decreases the prevalence of PVC in these patients. A sample of 41 patients with chronic Chagas disease at different stages of the heart disease was selected for the treatment against the causative agent using BZN (5 mg·kg·d, minimum dose 300 mg daily) for 2 months followed by supplementation with antioxidants such as vitamins E (800 UI/d) and C (500 mg/d) for 6 months. The prevalence of PVC was observed by conducting 24-hour Holter. To evaluate the oxidative status of the patients, serum markers of oxidative stress like glutathione peroxidase, superoxide dismutase, catalase, glutathione reductase, and glutathione S-transferase were measured, and also reduced glutathione, vitamin E, and markers of tissue damage like thiobarbituric acid reactive substances and protein carbonyl. A decrease in the prevalence of PVC in patients with advanced Chagas heart disease was observed (5391 vs. 1185, P = 0.0068). This reduction was followed by decrease of serum markers of oxidative stress. In patients with a lower degree of cardiac damage, the reduction on prevalence of PVC was not significant. The etiological treatment with BZN followed by supplementation with antioxidant vitamins E and C reduces episodes of PVC in patients with severe Chagas heart disease.