Resting Heart Rate as a Cardiovascular Risk Factor in Hypertensive Patients: An Update

Reference ranges for ambulatory heart rate measurements in a middle-aged population

BACKGROUND

Elevated heart rate (HR) predicts cardiovascular disease and mortality, but there are no established normal limits for ambulatory HR. We used data from the Swedish CArdioPulmonary Imaging Study to determine reference ranges for ambulatory HR in a middle-aged population. We also studied clinical correlates of ambulatory HR.

METHODS

A 24-hour ECG was registered in 5809 atrial fibrillation-free individuals, aged 50-65 years. A healthy subset (n=3942) was used to establish reference values (excluding persons with beta-blockers, cardiovascular disease, hypertension, heart failure, anaemia, diabetes, sleep apnoea or chronic obstructive pulmonary disease).Minimum HR was defined as the lowest 1-minute HR. Reference ranges are reported as means±SDs and 2.5th-97.5th percentiles. Clinical correlates of ambulatory HR were analysed with multivariable linear regression.

RESULTS

The average mean and minimum HRs were 73±9 and 48±7 beats per minute (bpm) in men and 76±8 and 51±7 bpm in women; the reference range for mean ambulatory HR was 57-90 bpm in men and 61-92 bpm in women. Average daytime and night-time HRs are also reported. Clinical correlates, including age, sex, height, body mass index, physical activity, smoking, alcohol intake, diabetes, hypertension, haemoglobin level, use of beta-blockers, estimated glomerular filtration rate, per cent of predicted forced expiratory volume in 1 s and coronary artery calcium score, explained <15% of the interindividual differences in HR.

CONCLUSION

Ambulatory HR varies widely in healthy middle-aged individuals, a finding with relevance for the management of patients with a perception of tachycardia. Differences in ambulatory HR between individuals are largely independent of common clinical correlates.

Blood pressure screening in Mata Sector, a rural area of Rwanda

In rural sub-Saharan Africa, knowledge of non-communicable diseases such as high blood pressure (BP) is rather limited. This report provides information about a BP screening in Mata Sector, a rural region in Southern Province of Rwanda. Community-based, house-to-house screening was performed between February and July 2020 on more than 7000 inhabitants. The screening was conducted by a local team composed by 20 community health care workers, five community health care supervisors, and one nurse with hypertension surveillance training. BP and heart rate were recorded after 5 min of resting, using a validated automated oscillometric OMRON M6 IT-HEM-7322-E monitor with Intelli Wrap Cuff (HEM-FL31-E) technology. The mean of the second and third value was retained. BP was normal (<140/90 mm Hg) in 6340 (88%) and elevated in 863 (12%) participants with 95% of unawareness. Grade 1 (140-159/90-99 mm Hg) hypertensive BP readings were detected in 697 (81%), grade 2 (160-179/100-109 mm Hg) in 134 (16%), and grade 3 (≥180/≥110 mm Hg) in 32 (3.7%) individuals. The prevalence of hypertensive readings was significantly age-dependent. Additionally, a slightly greater proportion of participants with high BP (14% versus 11%) had a body mass index (BMI) ≥ 25.0 kg/m2. Also resting heart rate was higher in individuals with high BP (82 versus 77 beats/min). Although individuals identified with occasionally elevated BP values need further confirmatory measurements to establish the diagnosis of hypertension, these data suggest that high BP represents a noteworthy and preventable reason of concern within sub-Saharan Africa.

The clinical value of β-blockers in patients with stable angina

Stable angina, one manifestation of chronic coronary syndrome (CCS), is characterised by intermittent episodes of insufficient blood supply to the myocardium, provoking symptoms of myocardial ischaemia, particularly chest pain. These attacks usually occur during exercise or stress. Anti-ischaemic drugs are the mainstay of pharmacologic management of CCS with symptoms of angina. β-blockers reduce heart rate and myocardial contractility, thus reducing myocardial oxygen consumption. These drugs have been shown to ameliorate the frequency of anginal attacks and to improve exercise capacity in these patients. Current management guidelines include β-blockers as a first-line management option for most patients with CCS and symptoms of myocardial ischaemia, alongside dihydropyridine calcium channel blockers (CCB). The presence of comorbid angina and heart failure is a strong indication for starting with a β-blocker. β-blockers are also useful in the management of angina symptoms accompanied by a high heart rate, hypertension (with or without a renin-angiotensin-aldosterone-system [RAS] blocker or CCB), or microvascular angina (with a RAS blocker and a statin). A β-blocker is not suitable for a patient with low heart rate (<50 bpm), although use of a β-blocker may be supported by a pacemaker if the β-blocker is strongly indicated) and should be used at a low dose only in patients with low blood pressure.

Prognostic Value of Nighttime Double Product in Nondialysis Chronic Kidney Disease With Hypertension

BACKGROUND

Both nighttime systolic blood pressure and pulse rate are associated with adverse outcomes in patients with chronic kidney disease (CKD). However, nighttime double product (DP), which is the product of nighttime systolic blood pressure and pulse rate, has not yet been investigated in this context. The present study aimed to explore the prognostic value of nighttime DP for adverse outcomes in patients with CKD and hypertension.

METHODS AND RESULTS

This retrospective cohort study included a total of 1434 patients with nondialysis CKD complicated by hypertension. The patients were enrolled in Zhuhai and Guangzhou, China, with a median follow-up of 23.8 months. Patient enrollment for the high or low nighttime DP group was performed on the basis of the cutoff value determined by time-dependent receiver operator characteristic curve analysis. The primary end point was a composite of major cardiovascular and cerebrovascular events, and the secondary end point was all-cause death and composite renal end point. The 24-hour circadian DP rhythm was established via multiple-component cosinor analysis. Cox regression was used to explore the association between nighttime DP and adverse outcomes. The DP of nondialysis patients with CKD and hypertension showed a diurnal rhythm, which varied with renal function. After adjustment, high nighttime DP was associated with a higher risk for major cardiovascular and cerebrovascular events (hazard ratio [HR], 5.823 [95% CI, 2.382-14.233]), all-cause death (HR, 4.978 [95% CI, 2.205-11.240]), and composite renal event (HR, 1.661 [95% CI, 1.128-2.447]), compared with low nighttime DP. These associations were independent of nighttime systolic blood pressure and PR.

CONCLUSIONS

The present cohort study demonstrated that DP had diurnal fluctuations and nighttime DP was an important prognostic factor in nondialysis patients with CKD and hypertension, outperforming traditional risk factors, including systolic blood pressure and pulse rate.

High blood pressure with elevated resting heart rate: a high risk "Sympathetic" clinical phenotype

Epidemiological studies have unequivocally shown that elevated heart rate values measured at rest have an adverse prognostic impact in the hypertensive patient, being associated with an increased risk of cardiovascular events and complications. In recent years new data have been collected on this issue, strengthening the clinical relevance of elevated heart rate as a specific hypertensive phenotype. The present paper will review old and new data on the prognostic importance of resting tachycardia in the hypertensive patient. It will also examine the role of the sympathetic nervous system in the development of this alteration as well as its therapeutic implications. The different approaches to dynamically assess heart rate values in the clinical setting will be finally discussed.

Effects of Near-Infrared Light on Well-Being and Health in Human Subjects with Mild Sleep-Related Complaints: A Double-Blind, Randomized, Placebo-Controlled Study

Modern urban human activities are largely restricted to the indoors, deprived of direct sunlight containing visible and near-infrared (NIR) wavelengths at high irradiance levels. Therapeutic exposure to doses of red and NIR, known as photobiomodulation (PBM), has been effective for a broad range of conditions. In a double-blind, randomized, placebo-controlled study, we aimed to assess the effects of a PBM home set-up on various aspects of well-being, health, sleep, and circadian rhythms in healthy human subjects with mild sleep complaints. The effects of three NIR light (850 nm) doses (1, 4, or 6.5 J·cm^-2) were examined against the placebo. Exposure was presented five days per week between 9:30 am and 12:30 pm for four consecutive weeks. The study was conducted in both summer and winter to include seasonal variation. The results showed PBM treatment only at 6.5 J·cm^-2 to have consistent positive benefits on well-being and health, specifically improving mood, reducing drowsiness, reducing IFN-γ, and resting heart rate. This was only observed in winter. No significant effects on sleep or circadian rhythms were noted. This study provides further evidence that adequate exposure to NIR, especially during low sunlight conditions, such as in the winter, can be beneficial for human health and wellness.

Comparative efficacy of ivabradine and beta-blockers in the treatment of tachycardia in patients after COVID-19

Aim. To assess the changes of heart rate (HR), exercise tolerance and quality of life in patients after coronavirus disease 2019 (COVID-19) during treatment with ivabradine monotherapy or in combination with beta-blockers (BB) compared with BB monotherapy.

Material and methods. This randomized comparative study included 90 patients discharged from a university hospital after an acute COVID-19. The main group (n=60) received, in addition to standard therapy, ivabradine monotherapy or in combination with BB, while the control one (n=30) — standard therapy in combination with BB. The follow-up period lasted 24 weeks. Statistical processing was performed using the STATISTICA 8.0 program. The level of statistical significance was p<0,05.

Results. There was a significant decrease in heart rate, an increase in physical activity, as well as an improvement in the quality of life in both groups. In the ivabradine group, significantly lower heart rates (71,2±4,1 vs 73,9±5,1 bpm (p=0,015)), significantly higher increase in physical activity (80 (60; 135) vs 65 m (40; 100) (p=0,017)) and quality of life (35 (27; 45) vs 30 (26; 36) points (p=0,03)) was revealed.

Conclusion. It has been shown that ivabradine and beta-blockers can be used in post-COVID-19 tachycardia. Ivabradine monotherapy or in combination with beta-blockers causes a more pronounced decrease in heart rate compared to beta-blocker monotherapy, accompanied by a significant improvement in exercise tolerance and quality of life in this category of patients.

Effect of Probiotics Supplementation on Heart Rate: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Background and Aims

Probiotics consumption lowers the risk of cardiovascular disease, but whether it affects heart rate (HR) remains controversial. Therefore, our study aimed to assess the chronotropic effects of probiotics on heartbeat via a meta-analysis of randomized clinical trials.

Methods

Relevant studies were identified by searching PubMed, Cochrane library, and Clinical Trials databases up to October 2021. Either a fixed-effects or a random-effects model was used to calculate the pooled effect sizes and 95% confidence intervals (CIs).

Results

This meta-analysis included 13 studies involving 16 interventional trial arms and 931 participants according to inclusion criteria. The overall pooled estimate showed that probiotics supplementation had a slight, but no significant reduction of 0.28 bpm (95% CI: −1.17, 0.60) on HR. Relatively high heterogeneity was observed among included trials (I² = 80.8%, P heterogeneity < 0.001). Subgroup analysis displayed that probiotics supplementation significantly reduced HR by 2.94 bpm (95% CI: −5.06, −0.82) among participants with baseline HR ≥ 75 bpm, by 1.17 bpm (95% CI: −2.34, −0.00) with probiotics dose ≥1 × 10¹⁰ CFU/day, and by 1.43 bpm (95% CI: −2.69, −0.17) with multiple-strain intervention. Meta-regression analysis showed that baseline HR was a major potential effect modifier of probiotics supplementation on lowering HR.

Conclusion

Hitherto, the overall evidence in the literature was insufficient to support the notion that probiotics supplementation has a class effect on HR reduction. However, in subgroup analysis, probiotics reduced HR significantly in those who had higher baseline HR, received a higher dose or multiple strains of probiotics.

Accuracy of the oscillometric method for the measurement of heart rate at rest and during mild exercise

OBJECTIVE

Whether oscillometric devices provide accurate measurements of heart rate (HR) is not known. Our aim was to determine the accuracy of an oscillometric device for the measurement of HR during rest and exercise.

METHODS

The Microlife WatchBP O3, a monitor previously validated for blood pressure measurement, was tested in 36 individuals from the general population (mean age, 72.9 years; 18 men). HR was measured at rest and during stress testing on a cycle ergometer in order to increase HR by 15% or more. HR was computed from the oscillometric waves recorded during the deflation phase of the blood pressure measurement and was compared with HR measured by pulse palpation by two observers.

RESULTS

At rest, the mean device-observer HR difference was 0.9 ± 2.1 bpm. During exercise, the average HR increase was 20.3% and the mean device-observer difference was 0.6 ± 2.6 bpm. The device-observer HR differences were all included within ±6 bpm both at rest and during exercise. Kappa statistics showed a very good agreement between device and observers both at rest (kappa scores, 0.82-0.88) and during exercise (kappa scores, 0.81 and 0.86). The device-observer HR differences were unrelated to the level of HR or to pulse pressure.

CONCLUSION

The present study shows that the oscillometric technique is able to provide reliable HR measurements during rest and mild exercise. Whether evaluation of HR performance should be included during validation testing of automatic monitors should be established by regulatory bodies.