Comparative Study Of Diurnal Variations In Electrocardiographic Intervals Of Non-Athletes And Athletes In Zaria, Nigeria

There is paucity of information on the diurnal variation in electrocardiogram (ECG) parameters of normal individuals, especially those subjected to physical exertion. The aim of the study was to determine changes in patterns of ECG intervals of normal young adults with variations in hours of the day, and to compare the changes between athletes and non-athletes. The study investigated resting ECG values from 30 athletes (20 males and 10 females) and compared with those obtained from 26 non-athletes (16 males and 10 females) in the same laboratory. ECG recordings were performed according to the recommendation of Society for Cardiological Science and Technology, 2006. Recordings were made at 07:00 h, 12:00 h and 17:00 h daily for two days consecutively for all the subjects. Intervals considered included P-wave duration, PR interval, QRS interval, QT interval and the corrected QT interval (QTc). [Data were subjected to statistical analysis using the Student’s t-test and were expressed as mean±SEM]. The results of the study revealed that values of all the measured parameters for all the subjects were all within normal range, and a significant (P < 0.05) diurnal variation. The results also indicated that there was a higher (P < 0.05) range of ECG interval variations in males than females, and in athletes compared to non-athletes, In conclusion, the study showed that the ECG intervals exhibited diurnal variation and that exercise exerted effects on diurnal variations of ECG intervals in man.