Relationship between heart rate recovery, P-R and Q-T intervals among young healthy students of Bayero University Kano, Nigeria

Abstract

Background: Heart rate recovery (HRR) is a measure of the number of heart beats a person drops from the peak end of exercise to a  specific time after cessation of exercise. Although it has been reported that abnormally low HRR is linked to a higher risk of some  cardiovascular diseases, data is scanty on the relationship between HRR, cardiac conductivity and risk of arrhythmia. This study therefore,  assessed the correlation between HRR, P-R and Q-T interval in young healthy individuals.

Method: A total of 46 young healthy  participants matched for age and with normal BMI, were recruited into the study. They were subjected to 3 minutes of moderate exercise  and their heart rates were recorded at the peak end of the exercise and 1 and 2 minutes from the cessation of the exercise. The latter  values were subtracted from the peak heart rate to obtain the HRR in 1 (HRR-1) and 2 minutes (HRR-2). P-R and Q-T intervals of the  participants were measured using 12-LEAD ECG. Data were analyzed with IBM SPSS version 25.0 and relationships between HRR, P-R and  Q-T intervals were assessed using Pearson’s correlation.

Results: Q-T interval was found to be negatively correlated with HRR-1 (r =  -0.314, p = 0.03) and HRR-2 (r = -0.380, p = 0.001) but no significant correlation was found between PR, HRR-1 and HRR-2.

Conclusion:  HRR-1 and HRR-2 are negatively correlated with Q-T interval indicating that low heart rate recovery is associated with the risk of having  prolonged Q-T, cardiac arrhythmia and sudden cardiac death.