[HR AND DURATION OF ECG ELEMENTS OF AN ADULT DURING PHYSICAL EXERCISES]

Area of Science:

• Cardiology
• Exercise Physiology
• Biomedical Engineering

Background:

• Understanding the impact of physical exercise on cardiac electrophysiology is crucial for assessing cardiovascular health.
• Electrocardiogram (ECG) parameters, including heart rate (HR) and interval durations (PP, PT, TP), provide insights into myocardial function.
• Previous research has explored exercise-induced cardiac adaptations, but specific effects on ECG intervals in young, healthy females warrant further investigation.

Purpose of the Study:

• To investigate the changes in heart rate (HR) and the duration of PP, PT, and TP intervals of the electrocardiogram (ECG) before and after physical exercise (PE) in healthy young girls.
• To determine the relationship between pre-exercise ECG values and post-exercise alterations in cardiac electrical activity.

Main Methods:

• The study involved 21 healthy young girls (mean age 18.1 ± 0.7 years).
• Electrocardiograms (ECG) were recorded using the II standard lead for 300 cardiocycles.
• Physical exercise was performed at a power of 1 W/kg.

Main Results:

• Heart rate (HR) and the duration of the PT interval (depolarization and repolarization) remained largely unchanged after physical exercise.
• A significant decrease in the duration of the TP segment (isopotential state of the myocardium) was observed post-exercise.
• Longer PP intervals were shortened by 60%, and shorter PP intervals were shortened by 30% after exercise.

Conclusions:

• Physical exercise induces specific changes in ECG intervals, notably affecting the TP segment and PP intervals, in healthy young women.
• The variability of the PP interval is influenced by the TP segment under resting conditions and by the PT interval during exercise.
• These findings highlight exercise-induced modifications in myocardial electrical activity and timing relevant to cardiovascular assessment in this demographic.