Background

In patients with acute myocardial infarction, altered cardiac repolarisation has been linked to ventricular fibrillation and major adverse cardiac events. Treatment of sleep disordered breathing early after acute myocardial infarction may normalise the ventricular ectopic substrate. Therefore, the aim of this ancillary analysis was to assess the effect of adaptive servoventilation (ASV) on cardiac repolarisation.
Methods

This analysis included 42 participants from the prospective multicentre randomised trial TEAM-ASV I. 22 were randomised to early treatment with ASV in addition to standard care, and 20 to standard care only. Cardiac repolarisation was assessed by means of T-peak-to-end- (TpTec) and QTc- intervals and TpTe/QT-ratios derived from 12-lead ECG before and 4 and 12 weeks after percutaneous coronary intervention.
Results

The population was predominantly male (79%), obese (mean±sd body mass index 31±6 kg·m−2), had severe sleep disordered breathing with an apnoea–hypopnoea index of 34±18 events·h−1 and ASV was initiated within 2.6±1 days. After 4 weeks, QTc significantly decreased in the ASV group compared to the control group (−5.8% versus −1.2%, p=0.041). A similar trend was observed with respect to TpTec (−18.0% versus −6.8%, p=0.119) and TpTe/QT (−17.6% versus −6.6%, p=0.252). After 12 weeks, the decrease in repolarisation times was similar between the groups. (QTc −7.6% versus −4.5%, p=0.400; TpTec −19.3% versus −18.8%, p=0.400; TpTe/QT −9.7 versus −13.0, p=0.652).
Conclusion

In patients with first acute myocardial infarction and sleep disordered breathing, early treatment with ASV reduced cardiac repolarisation after 4 weeks, but not after 12 weeks. Thus, ASV may contribute to preventing ventricular arrhythmias in the vulnerable early phase after acute myocardial infarction.