Exercise-test-related heart rate variability and mortality: The Finnish cardiovascular study

Abstract

Decreased heart rate variability (HRV) at rest associates with worse prognosis, while a recent study found that greater HRV during an exercise treadmill test was linked to increased risk of death. As a part of the Finnish Cardiovascular Study (FINCAVAS), we evaluated the prognostic power of HRV during bicycle ergometer test in 1876 patients. During the follow-up (mean±SD 47.5±12.8 months) period, there were 101 (5.4%) deaths. Cox regression analysis was performed during four periods (pre-exercise, first and last minute of exercise, and first 2 min of recovery). During the pre-exercise period, greater HRV was clearly linked to better prognosis. During the first minute of exercise, a single HRV parameter was associated with decreased risk. None of the HRV parameters were connected to mortality at peak exercise or during the recovery phase. In conclusion, HRV does not have prognostic value during the physical exertion in an exercise test. However, our results support previous studies, where decreased HRV at rest has been associated with worse prognosis.