Prognostic Significance of Incidental Nonsustained Ventricular Tachycardia Detected on Pacemaker Interrogation

Symptomatic sustained ventricular tachycardia is a life threatening arrhythmia requiring prompt treatment. However, the risk associated with asymptomatic nonsustained ventricular tachycardia (NSVT) detected on routine permanent pacemaker (PPM) interrogation in patients with known cardiac conduction disease is unknown. Our aim is to determine if asymptomatic NSVT detected on PPM interrogation is associated with increased mortality. As part of a prospective observational cohort study, 582 patients with long-term pacemakers were recruited at a tertiary cardiac centre, and followed for 4 ± 1.96 years (mean ± standard deviation). At each subsequent pacemaker check, any symptoms and ventricular high-rate episodes were recorded. We excluded 17 patients due to incomplete data. In the remaining 565 patients (57% male, age 74.5 ± 19.2 years, left ventricular ejection fraction 50.0 ± 11.3%), NSVT was found in 125 (22.1%) patients with a higher prevalence in males (65% vs 54%; p = 0.033). Those with NSVT were more likely to have had coronary artery disease (p = 0) or previous myocardial infarction (p = 0.015). After correction for baseline variables, NSVT had no impact on survival (n = 52 [42%] vs n = 162 [37%]; log-rank p = 0.331, hazard ratio: 0.927, 95% confidence interval: 0.678 to 1.268, p = 0.697). In conclusion, asymptomatic NSVT identified on PPM interrogation does not appear to be associated with increased mortality, thus whether treatment to suppress this arrhythmia is of benefit remains unproven.