Can Cardiorespiratory Fitness Impact Arrhythmia?

For obese individuals with atrial fibrillation (AF), the chances of arrhythmia recurrence are reduced with high levels of cardiorespiratory fitness (ie, exercise capacity). Furthermore, increasing the level of exercise as part of the treatment continues to lower the risk.

“While weight loss is important for heart disease in patients, especially those with arrhythmia, our study shows it’s beneficial to have high cardiorespiratory fitness and continue to improve on that,” said Prashanthan Sanders, MBBS, PhD, senior author of the study and director of the Centre for Heart Rhythm Disorders at the University of Adelaide in Adelaide, Australia.
____________________________________________________________________________________________________________________________________________________________

RELATED CONTENT
Lone Atrial Fibrillation in a Young Man
Warfarin and Atrial Fibrillation
____________________________________________________________________________________________________________________________________________________________

AF affects 1% of the population in the United States and is considered the most common type of arrhythmia. Both a high body mass index and low physical activity are considered risk factors for AF.

In the study, 308 AF patients with a BMI >27 (overweight) were divided into 3 baseline groups: low, adequate, and high cardiorespiratory fitness. The participants were followed for 4 years to measure the impact of the fitness level on arrhythmia recurrence. They were also offered a physician-led program to produce weight loss and increase exercise activity.

At the 4-year follow-up, 17% of the low cardiorespiratory group, 76% of the adequate group, and 84% of the high group were free for arrhythmia. Those who increased their cardiorespiratory fitness levels throughout the study measured further risk reduction.

Researchers calculated that for every increase in metabolic equivalent (ie, the amount of oxygen consumed at rest), there was a 20% reduction in the risk for arrhythmia recurrence.

The complete study is available in the June issue of the Journal of American College of Cardiology.

Reference:

Pathak RK, Elliott A, Middeldorp ME, et al. Impact of CARDIOrespiratory FITness on arrhythmia recurrence in obese individuals with atrial fibrillation: the CARDIO-FIT study. J Am Coll Cardiol. 2015 Jun 20 [epub ahead of print] doi: 10.1016/j.jacc.2015.06.488