Title : Resolution of bigeminy PVCs and desaturation following cardiac rehabilitation in alcoholic cardiomyopathy and heart failure: A case report
Abstract:
Background and Aim: Patients with non-ischemic cardiomyopathy (NICM), atrial fibrillation (AF), and congestive heart failure (CHF) often experience reduced exercise tolerance and impaired quality of life. Premature ventricular complexes (PVCs) and oxygen desaturation are frequently observed during exercise testing. Exercise-induced Premature ventricular contractions (EI-PVCs) are correlated with a higher risk of all-cause death or cardiovascular events in the long term. Patients with heart failure who had large desaturation during exercise and a short 6-minute walk Distance have the highest incidence of major adverse cardiovascular events, including rehospitalization for heart failure or cardiovascular death. However, there are few reports on improved exercise tolerance and cardiac arrhythmia after cardiac rehabilitation.
Methods: A 50-year-old male with a history of alcoholic cardiomyopathy (Ejection fraction 21%), non-valvular AF, and congestive heart failure was in an outpatient cardiac rehabilitation program.
Result: His initial 6-minute walk test (6MWT) distance was 310 m, with exercise-induced desaturation (SpO? 93–94%) without EKG monitoring. Second, visit continuous bigeminy PVCs on ECG and SpO? 94–95% during 6MWT. He started with short-duration walking (5–10 min) and gradually progressed to 30 minutes of continuous exercise. He was followed up and received an update on his Individualized Treatment Plan (ITP) once a month for five visits. After progressive exercise training, his exercise tolerance improved, with a 6-minute walk test (6MWT) distance increasing from 310 m to 430 m. The patient's left ventricular ejection fraction improved significantly from 21% to 54%. Bigeminy PVCs progressively decreased and were absent by the final visit. Oxygen desaturation was resolved, with SpO? stabilizing at 98% post-exercise. The patient tolerated moderate-intensity jogging for 30 minutes without significant arrhythmia.
Discussion: The 6MWT is a valuable and widely used tool for assessing exercise tolerance and functional status in patients with heart failure. In this case, the initial six-minute walk test (6MWT) revealed exercise-induced desaturation. To ensure patient safety, he was instructed to reduce his walking speed to a normal pace, which led to an improvement in SpO? to 95%. Although the instructor may terminate testing based on the appearance of the patient or if oxygen saturation falls <80%, a threshold commonly applied in patients with COPD who often have a lower baseline oxygen level. The specific termination criteria for exercise testing in patients with heart conditions remain undefined; oxygen desaturation during the 6MWT warrants careful consideration.
In a hospital setting, the six-minute walk test (6MWT) is not only used to assess functional capacity but also helps guide the prescription of appropriate exercise intensity and duration. This allows for the development of a safe and individualized home-based exercise program. Systematic reviews have demonstrated that home-based cardiac rehabilitation (HBCR) is a safe and effective approach, while also facilitating continued follow-up by making treatment more accessible and less burdensome for patients.
Conclusion: Cardiac rehabilitation contributed to the resolution of exercise-induced bigeminy PVCs and desaturation in this patient. The progressive approach, which included warm-up, gradual intensity adjustment, and monitoring of ECG changes, contributed to patient safety and enhanced cardiovascular function in high-risk cardiac patients.
