Heart Rate Variability In Hypertensive Patients Research Articles

Left ventricular hypertrophy and sinus variability in arterial hypertension

Previous studies on heart rate variability (HRV) in systemic hypertension have yielded conflicting results. We sought to assess changes in HRV in hypertensive patients with or without left ventricular hypertrophy (LVH). In total, 112 patients with sinus rhythm hypertension, mean age 56 ± 10 years, without diabetes mellitus, symptomatic coronary artery disease or systolic dysfunction, were recruited prospectively. Echocardiographic examination allowed them to be subdivided into 3 groups: normal geometry (71), concentric remodeling (23) and LVH (18). HRV time and frequency domain measurements were obtained from 24-hour Holter ECG recordings in all patients and in 40 control subjects. In comparison with control subjects, the 3 hypertensive groups exhibited a significant decrease in SDNN and total frequency power, the two indices of overall HRV; a significant decrease in pNN50 and power at high frequency, indices of HRV reflecting parasympathetic tone, and a significant decrease in SDANN and power at low frequency, indices reflecting sympathetic modulation of HRV. Comparisons between the three hypertensive groups showed that patients with LVH had significantly ( P < 0.05) lower low frequency power (5.5 ± 1.0 Ln m2) than patients with normal left ventricular geometry. (5.9 ± 0.8 Ln m2) or a concentric remodeling (5.9 ± 0.9 Ln m2). Evaluation of HRV in hypertensive patients shows a constant decrease in parasympathetic indices and a more marked reduction in sympathetic parameters in the presence of LVH.

Heart rate variability in patients with atrial fibrillation and hypertension.

Atrial fibrillation (AF) and hypertension are independently associated with impaired autonomic function determined using heart rate variability (HRV). As these conditions frequently co-exist, we sought to determine whether AF would worsen HRV in hypertensive patients. We studied HRV in AF (and hypertension) (n=61) and hypertension control group (n=33). The AF (and hypertension) group was subdivided into permanent AF (n=30) and paroxysmal AF (n=31) and re-studied. Time-domain, frequency-domain and nonlinear measures of HRV were determined. Permanent AF group (n=30) was followed up after 8weeks following optimisation of their heart rate and blood pressure (BP). Time-domain and nonlinear indices of HRV were higher in AF (and hypertension) group compared to hypertensive controls (P≤.01). Time-domain and nonlinear indices of HRV were higher in permanent AF group compared to paroxysmal AF (P≤.001). Permanent AF was an independent predictor of HRV on multivariable analysis (P=.006). Optimisation of heart rate and BP had no significant impact on HRV in permanent AF. AF, independent of hypertension, is characterised with marked HRV and is possibly related to vagal tone. HRV is higher in permanent AF compared to paroxysmal AF suggesting evident autonomic influence in the pathophysiology of permanent AF. Modulation of autonomic influence on cardiovascular system should be explored in future studies.

P-207: The effects of Ramadan Fasting on heart rate variability in hypertensive patients

Background Ramadan fasting is one of the five fundamental rituals of Islam. Heart rate variability (HRV) is an independent predictor of increased mortality of patients with myocardial infarction and congestive heart failure. The effects of fasting on the HRV are not known. Aim: To study the effects of Ramadan fasting on HRV in hypertensive patients. Methods Our study is a prospective study that includes a total of 20 hypertensive patients, with sinus rhythm and without coronary artery disease, between July and October 2014. HRV was determined twice by ambulatory 24-hour Holter recordings at fasting in the middle of Ramadan and two months after Ramadan. Informed consent was obtained from each study subject prior to participation in study. Mean values of continuous variables were compared by using the Student t-test. Results The mean age of patients was 55,2 ± 4,4 years with 8 women and 12 men. The mean BMI was 27,9 ± 4,4. When two groups compared, statistically significant differences were found in terms of heart rate (during Ramadan 70,5 ± 9,4, post-Ramadan 76,3 ± 9,7, p = 0.001), SDNN (during Ramadan 51,6 ± 13,7, post-Ramadan 52,2 ± 16,4, p = 0.000), SDNNI (during Ramadan 105,5 ± 44,4, post-Ramadan 131,7 ± 48,7, p = 0.001) RMSSD (during Ramadan 38,1 ± 14,4, post-Ramadan 39,9 ± 18,5, p = 0.02), T power (during Ramadan 2327,5 ± 1151, post-Ramadan 2597,5 ± 1678,3, p = 0.001), LF (during Ramadan 539,9 ± 301, post-Ramadan 591,2 ± 476,3, p = 0.001), HF (during Ramadan 276 ± 173,2, post-Ramadan 304 ± 325,3, p = 0.015) and LF/HF (during Ramadan 2,9 ± 2,3, post-Ramadan 3,6 ± 3,5, p = 0.000) values. Conclusions In our study, HRV parameters were found to be decreased in Ramadan month compared to after Ramadan in hypertensive patients. So we think that Ramadan fasting enhances the activity of the sympathetic system in hypertensive patients.

Effects of cigarette smoke on Holter ECG recordings in patients with arterial hypertension. Part 1: Time domain parameters of heart rate variability

This report was intended to evaluate the effect of cigarette smoke on heart rate variability (HRV) in patients with arterial hypertension (AH). 223 individuals were qalified to the studies. The following groups of patients not suffering from other disease which may affect HRV were delineated: 1 – patients with AH (n=145); 2 – patients without AH (n=48). In group 1 the following patient groups were studied: A – active smokers (n=42), B – non-smokers exposed to cigarette smoke (n=30), C – non-smokers not exposed to tobacco smoke (n=34), D – former smokers (n=26). A time domain HRV analysis was carried out. Group 1 versus group 2 manifested significantly lower mean values of most parameters in the HRV time domain analysis. Subgroups A, B and D versus subgroup C also exhibited significantly lower mean values of most parameters in the HRV time domain analysis. Active cigarette smoking and passive exposure to tobacco smoke represented independent risk factors for a decreased HRV. Conclusions: Active and passive exposure to cigarette smoke decreases HRV in hypertensive patients.