Heartbeat tracking task performance, an indicator of interoceptive accuracy, is associated with improvement of exercise tolerance in patients undergoing home-based cardiac rehabilitation

AIMS: Interoception is the sensing function of physiological conditions and is crucial in self-regulation and decision-making. We examined the association of heartbeat tracking task performance, an indicator of interoceptive accuracy, with the degree of improvement in exercise tolerance in patients undergoing home-based cardiac rehabilitation. METHODS AND RESULTS: Participants underwent baseline peak oxygen uptake (VO(2)) measurements and a heartbeat tracking task. The heartbeat tracking task score varies between 0 and 1, with higher scores indicating a better heartbeat perception. After 6 months of home-based exercise training, peak VO(2) was measured again, and the percentage change (%Δ peak VO(2)) relative to the peak VO(2) at baseline was calculated. Univariate regression analysis was performed to examine the association between %Δ peak VO(2) and the heartbeat tracking task score. Multiple regression analysis was performed to determine the predictors of %Δ peak VO(2). Of 120 participants, 100 patients (age 65.9 ± 11.9 years; 86% male) were included. There was a significant positive association between %Δ peak VO(2) and the heartbeat tracking task score at baseline (R(2) = 0.236, P < 0.001). In multiple regression analysis, the percentage of measured peak VO(2) to the predicted value (%predicted peak VO(2)) (β = −0.248, P = 0.002), exercise adherence (β = 0.364, P < 0.001), and heartbeat tracking task score at baseline (β = 0.372, P < 0.001) were significantly associated with %Δ peak VO(2). CONCLUSIONS: Heartbeat tracking task performance, an indicator of interoceptive accuracy, at baseline is associated with the degree of improvement in exercise tolerance.