Sleep-related breathing disorders in patients with implanted cardioverter-defibrillators

Sleep-related breathing disorders are more common in patients with cardiovascular diseases compared to general population. There are contradictory data on the role of these disorders for the risk of ventricular tachycardia (VT) and ventricular fibrillation (VF). Objective. To determine the incidence, severity and structure of sleep-related breathing disorders in patients with implanted car-dioverter-defibrillators (ICD), as well as to assess the role of these disorders in recurrent VT and VF. Material and methods. The study included 67 patients (aged 34—83 years, median 65, 54 (81%) men) with body mass index >25 kg/m². Three-chamber (n=22, 33%), two-chamber (n=42, 62.5%) or single-chamber (n=3, 4.5%) ICD were implanted in all patients for primary (35 (52%) patients) or secondary (32 (48%) patients) prevention of SCD. Coronary artery disease and post-infarc-tion cardiac sclerosis were the most common causes of ventricular arrhythmias (44 (65.5%) patients). Fifty (75%) patients had signs of chronic heart failure NYHA class 2—3. All patients underwent cardiorespiratory monitoring (CRM). We analyzed ICD data con-sidering parameters characterizing recurrences of sustained VT and VF, as well as methods for their correction. Results. According to CRM data, sleep-related breathing disorders were diagnosed in 64 (95.5%) patients (mild — 23 (34.5%) cases, moderate — 22 (33%) cases, severe — 19 (28%) cases). There were obstructive disorders in all cases, but 19 (28.5%) patients had concomitant episodes of central apnea (apnea-hypopnea index >5 events/hour). Long-term analysis of ICD data (median 40 months) did not reveal significant differences between patients with moderate-to-severe respiratory disorders (n=41) and those without disorders or mild disturbances (n=26) regarding sustained ventricular arrhythmia recurrences, their daily distribution, the need for electrical discharges for VT and VF, as well as tendency to electric storm. Conclusion. Moderate-to-severe obstructive sleep-related breathing disorders are detected in 61% of patients with ICD. Episodes of central apnea additionally occur in 28.5% of patients. Moderate-to-severe obstructive sleep-related breathing disorders in patients with ICD are not accompanied by higher risk of VT and VF recurrences.