TITLE:
Exploring the Role of Heart Rate Variability: A Study on Chronic Heart Failure Follow-Up in Two Major Hospitals in Sub-Saharan Africa
AUTHORS:
Valérie Ndobo, Hilary Mongo, Christian Ngongang Ouankou, Pierre Mintom, Jean Tinmou Bekouti, Nelly Ateba, Guillaume Ebene Manon, Sylvie Ndongo, Jérôme Boombhi
KEYWORDS:
Chronic Heart Failure, Sinus Variability, Adherence, Cameroon
JOURNAL NAME:
World Journal of Cardiovascular Diseases,
Vol.15 No.11,
November
3,
2025
ABSTRACT: Introduction: Heart rate variability (HRV), defined as fluctuations in the time intervals between successive heartbeats, was generated by the sinoatrial node and modulated by the autonomic nervous system (ANS). HRV emerged as a prognostic marker in chronic heart failure (CHF), particularly for mortality risk assessment in Western countries. This study aimed to evaluate the utility of HRV measurement in the follow-up of CHF patients in a sub-Saharan African context. Methods: We conducted a cross-sectional, descriptive, and analytical study during six months, in the cardiology departments of the Yaoundé General Hospital (HGY) and the Yaoundé Central Hospital (HCY). Eligible participants were adults with a confirmed diagnosis of CHF based on clinical, echocardiographic and electrocardiographic criteria, who had been on treatment for at least three months and provided informed consent. Exclusion criteria included atrial disease, non-sinus rhythm (atrial fibrillation, atrial flutter), loss to follow-up, and death. Consecutive sampling was applied. HRV recordings were obtained twice at a two-month interval using a Polar H10® heart rate monitor connected via Bluetooth to the Elite HRV application installed on an iPhone 12 Pro Max. SDNN was the standard deviation of all normal-to-normal (NN) intervals, and RMSSD was Root Mean Square of Successive Differences. HF (High Frequency, 0.15 - 0.40 Hz) corresponds to respiratory sinus arrhythmia; R-R intervals were recorded at rest for 5 minutes. Treatment adherence was assessed and its relationship to HRV was explored. Data were entered using CS Pro® 7.0 and analyzed with SPSS® 23. Results: Thirty-one patients were included, with a median age of 64 years; women accounted for 54.8% of the sample. The most prevalent cardiovascular risk factors were dyslipidemia (38.7%) and alcohol consumption (34.6%). The leading etiologies of CHF were hypertensive cardiomyopathy and dilated cardiomyopathy, each representing 54.8% of cases. Left ventricular failure was present in 74.2%, and 61.3% had a left ventricular ejection fraction (LVEF) 2; p = 0.040]. Factors associated with HRV impairment found a borderline association with BMI: overweight/obese patients tended to have higher odds of HRV impairment (OR = 1.7, 95% CI: 0.4 - 7.4, p = 0.052); age ≤ 60 years (OR = 0.8, 95% CI: 0.4 - 8.1, p Conclusion: This study confirms the potential of HRV as a complementary tool for the follow-up of CHF patients. HRV indices, particularly regarding young age, good weight and combined with treatment adherence assessment, may provide a cost-effective, non-invasive method to improve CHF management in resource-limited settings.