P-wave durations in patients experiencing atrial fibrillation during exercise testing

Area of Science:

• Cardiology
• Electrophysiology
• Exercise Physiology

Background:

• Sympathoadrenal activity during exercise may precipitate arrhythmias like atrial fibrillation (AF).
• Prolonged intraatrial and interatrial conduction times, assessed by maximum P-wave duration (P max) and P-wave dispersion (PWD), characterize atria prone to fibrillation.

Purpose of the Study:

• To investigate elevated P max and PWD in patients experiencing AF during exercise testing.
• To evaluate the efficacy of beta-blockade in managing exercise-induced AF.

Main Methods:

• Compared 22 patients with exercise-induced AF to 41 controls without AF.
• Measured P max, PWD, workload, and ejection fraction.
• Assessed changes in P max, PWD, and AF prevalence after 2 weeks of beta-blocker treatment.

Main Results:

• Patients with AF exhibited significantly higher P max (p = 0.001) and PWD (p = 0.001) than controls.
• AF development during exercise correlated positively with P max (r = 0.87), PWD (r = 0.83), and workload (r = 0.34).
• Beta-blocker treatment reduced P max, PWD, and the incidence of exercise-induced AF.

Conclusions:

• Elevated P max and PWD are significant indicators of AF risk during exercise.
• Beta-blocker therapy effectively reduces P-wave abnormalities and exercise-induced AF recurrence.