Heart Rate Response In Patients Research Articles

Lack of Effects of Renin-Angiotensin-Aldosterone System Activity and Beta-Adrenoceptor Pathway Polymorphisms on the Response to Bisoprolol in Hypertension.

PurposeThis study examined the effects of plasma renin activity (PRA), angiotensin II (Ang II) and aldosterone (PAC) concentrations as well as common polymorphisms in the β1-Adrenoceptor gene (ADRB1) and the G-protein α-Subunit (Gαs) protein gene the G protein α-Subunit 1 gene (GNAS) on the blood pressure (BP) and heart rate (HR) response to bisoprolol in Chinese patients with hypertension.MethodsPatients with sitting clinic systolic BP (SBP) 140–169 mmHg and/or diastolic BP (DBP) 90–109 mmHg after placebo run-in were treated with open-label bisoprolol 2.5 mg daily for 6 weeks. Patients diagnosed as having primary aldosteronism or renal artery stenosis were excluded. PRA, Ang II and PAC concentrations were measured after the placebo run-in and after 6 weeks of treatment. The Ser49Gly and Arg389Gly polymorphisms in ADRB1 and the c.393C > T polymorphism in GNAS were genotyped by the TaqMan® assay.ResultsIn 99 patients who completed the study, baseline PAC levels were significantly associated with baseline DBP and plasma potassium on univariate but not on multivariate linear regression analysis. PRA, Ang II, and PAC concentrations at baseline were not associated with changes in BP with bisoprolol treatment, but the values were all significantly reduced (PRA −0.141 ± 0.595 ng/mL/h, Ang II −2.390 ± 5.171 pmol/L and aldosterone −51.86 ± 119.1 pg/mL; all P < 0.05) following 6 weeks of bisoprolol treatment. There were no significant differences in BP or HR responses in patients with baseline PRA above or below the PRA cut-point of 0.65 ng/mL/h or the median value of 0.9 ng/ml/hour. There were no significant associations of the ADRB1 and GNAS polymorphisms with the clinic and ambulatory BP and HR responses to bisoprolol.ConclusionBaseline PRA, PAC and Ang II concentrations showed no significant association with the BP response to bisoprolol treatment, but all these parameters were reduced after 6 weeks of treatment with bisoprolol. The two common polymorphisms in ADRB1 and the c.393C > T polymorphism in GNAS had no significant association with the BP and HR response to bisoprolol in these patients.

Cardiovascular Autonomic Regulation, ETCO2 and the Heart Rate Response to the Tilt Table Test in Patients with Orthostatic Intolerance.

Chronic orthostatic intolerance (COI) is defined by changes in heart rate (HR), blood pressure (BP), respiration, symptoms of cerebral hypoperfusion and sympathetic overactivation. Postural tachycardia syndrome (POTS) is the most common form of COI in young adults and is defined by an orthostatic increase in heart rate (HR) of ≥ 30bpm in the absence of orthostatic hypotension. However, some patients referred for evaluation of COI symptoms do not meet the orthostatic HR response criterion of POTS despite debilitating symptoms. Such patients are ill defined, posing diagnostic and therapeutic challenges. This study explored the relationship among cardiovascular autonomic control, the orthostatic HR response, EtCO2 and the severity of orthostatic symptoms and fatigue in patients referred for evaluation of COI. Patients (N = 108) performed standardized testing protocol of the Autonomic Reflex Screen and completed the Composite Autonomic Symptom Score (COMPASS-31) and the Fatigue Severity Scale (FSS). Greater severity of COI was associated with younger age, larger phase IV amplitude in the Valsalva maneuver and lower adrenal baroreflex sensitivity. Greater fatigue severity was associated with a larger reduction in ETCO2 during 10min of head-up tilt (HUT) and reduced low-frequency (LF) power of heart rate variability. This study suggests that hemodynamic changes associated with the baroreflex response and changes in EtCO2 show a stronger association with the severity of orthostatic symptoms and fatigue than the overall orthostatic HR response in patients with COI.

Renal Functional Reserve Is Related to the Nondipping Phenotype and to the Exercise Heart Rate Response in Patients with Essential Hypertension and Preserved Renal Function

Background: Renal functional reserve (RFR), defined as the difference between stress and resting glomerular filtration rate (GFR), may constitute a diagnostic tool to identify patients at higher risk of developing acute kidney injury or chronic kidney disease. Blunted RFR has been demonstrated in early stages of hypertension and has been attributed to impaired vascular reactivity due to an overactive sympathetic nervous system (SNS). Objective: The purpose of this study was to investigate whether RFR correlates with other phenotypes expressing overactivity of the SNS in patients with essential hypertension and preserved renal function. Methods: Thirty-six patients with untreated essential hypertension and a GFR >60 mL/min/1.73 m² were enrolled. The following parameters were measured: RFR, 24-h ambulatory blood pressure (BP) profile, a treadmill stress test, and an echocardiographic examination. Urine and venous samples were obtained at specific time points for the determination of clinical parameters, and both resting and stress GFR were calculated by using endogenous creatinine clearance for the measurement of RFR after an acute oral protein load (1 g/kg). Results: Twenty-one patients had a RFR <30 mL/min/1.73 m² and 15 had a RFR above this cutoff. A nondipping pattern of 24-h BP was significantly more frequent in patients with low RFR (57.1 vs. 25.0%, p < 0.05 for systolic BP and 52.3 vs. 10.0%, p < 0.02 for diastolic BP). Moreover, patients with lower RFR values showed a blunted heart rate (HR) response to exercise during treadmill test (r = 0.439, p < 0.05). None of the echocardiographic parameters differed between the two groups of patients. Conclusions: In hypertensive patients with preserved GFR, reduced RFR is related to nondipping BP phenotype as well as to attenuated exercise HR response. Overactivity of the SNS may be a common pathway. Since loss of RFR may represent a risk factor for acute or chronic kidney injury, hypertensive patients with blunted RFR might need a more careful renal follow-up.

P4982Blunted heart rate reserve as an imaging-independent prognostic predictor during dipyridamole-echocardiography test

Abstract Background A blunted heart rate (HR) response during dipyridamole myocardial perfusion imaging have been associated with a poor outcome. Aim To assess the value of HR response in patients undergoing high dose dipyridamole stress echocardiography (SE). Methods We retrospectively selected a consecutive sample of 1,622 patients (none with pacemakers or atrial fibrillation), mean age 66±12 years, 431 (27%) on beta-blockers. All underwent high dose (0.84 mg/kg) dipyridamole SE for known or suspected coronary artery disease and/or heart failure from January 1988 to January 2018 in our Cardiology Division. HR (with 12-lead ECG) was obtained each minute and recorded at rest and peak stress. HR reserve (HRR) was calculated as the peak/rest HR ratio. All patients were followed-up. The composite end-point was made of all cause-death, non-fatal myocardial infarction and late (&gt;3 months) symptoms-driven myocardial revascularizations. Results SE was positive for regional wall motion abnormalities (RWMA) in 192 patients (12%). HR increased (rest=70±11 beats/min vs stress= 92±17 beats/min, p&lt;0.0001). During a median follow-up time of 904 days, 462 events occurred: 73 deaths, 57 non-fatal myocardial infarctions, 332 myocardial revascularizations. Receiver operating curve analysis identified a HRR ≤1.27 as the best cutoff. At multivariate analysis a reduced HRR was a significant predictor of hard events (Hazard Ratio, HR=2.02, 95% Confidence Intervals, CI, 1.38–2.95, P&lt;0.0001), additive to ischemic regional wall motion abnormalities (HR=2.11, 95% CI 1.28–3.48, P=0.004), resting RWMA (HR =1.88, 95% CI 1.31–2.72, P&lt;0.001), age (HR =1.06, 95% CI 1.04–1.08, P&lt;0.001) and beta-blockers at the time of testing (HR =1.55, 95% CI 1.06–2.29, P=0.03). Five-year hard event-free survival increased from 6% to 26% from the highest to the lowest HRR quartile: see figure. Survival curve Conclusion A blunted HRR is a useful non-imaging predictor of adverse events during high dose dipyridamole-SE. It is additive over resting or inducible regional wall motion abnormalities, and unmasks a prognostically meaningful autonomic unbalance. Chronotropic incompetence during dipyridamole SE is a negative prognostic finding, equally important than RWMA.

Usefulness of Blunted Heart Rate Reserve as an Imaging-Independent Prognostic Predictor During Dipyridamole Stress Echocardiography

A blunted heart rate (HR) response during dipyridamole myocardial perfusion imaging has been associated with a poor outcome. To assess the value of HR response in patients who underwent high-dose dipyridamole stress echocardiography (SE), we retrospectively selected a sample of 3,059 patients (none with pacemakers or atrial fibrillation; mean age 66 ± 11 years). All underwent high-dose (0.84 mg/kg) dipyridamole SE for evaluation of known or suspected coronary artery disease and/or heart failure in 2 laboratories of Pisa-IFC and Lucca. HR (with 12-lead ECG) was obtained each minute and recorded at rest and peak stress. HR reserve (HRR) was calculated as the peak/rest HR ratio. All patients were followed up. Patients were randomly divided into the modeling and validation group of equal size. During a median follow-up time of 1,004 days, 321 hard events occurred: 231 deaths and 90 nonfatal myocardial infarctions. HRR ≤ 1.22 identified by receiver operating characteristic analysis in the modeling group was an independent predictor of infarction-free survival in the modeling (hazard ratio 1.83, 95% confidence interval [CI] 1.30 to 2.60, p = 0.001), in the validation (hazard ratio 1.47, 95% CI 1.08 to 2.01, p = 0.02), and in the overall group (hazard ratio 1.60, 95% CI 1.27 to 2.02, p <0.0001), either off- or on-β blockers. Five-year event rate increased from 8% to 24 % from the highest (≥1.41) to the lowest (≤1.14) HRR quartile. In conclusion, blunted HRR is a useful nonimaging predictor of adverse events during high-dose dipyridamole SE, independent of inducible ischemia, and beta-blocker therapy.

The effects of rehabilitation and features of heart rate response in patients with chronic thromboembolic pulmonary hypertension

The effects of rehabilitation and features of heart rate response in patients with chronic thromboembolic pulmonary hypertension

Haemodynamic effects of pharmacologic stress with adenosine in patients with left ventricular systolic dysfunction

BackgroundIn patients with heart failure, downregulation of adenosine receptor gene expression and impaired adenosine-related signal transduction may result in a diminished response to adenosine. This may have implications for cardiac stress testing. We evaluated the haemodynamic response to intravenous adenosine in patients with left ventricular systolic dysfunction (LVSD) undergoing stress cardiovascular magnetic resonance imaging (CMR). Methods and resultsWe retrospectively examined 497 consecutive patients referred for clinical stress CMR. Blood pressure and heart rate responses with intravenous adenosine were compared in patients with normal, mild-moderately impaired and severely impaired LV systolic function (ejection fraction [EF] > 55%, 36–55% and < 35%, respectively).Following 2 min of adenosine infusion, there was a significant difference between the groups in the heart rate change from baseline, with a diminished heart rate response in patients with LVSD (p < 0.001). An increase in the dose of adenosine (up to 210 μg/kg/min) was required to achieve a sufficient haemodynamic response in more patients with severe LVSD (41%) than those with mild-moderately impaired and normal LV systolic function (24% and 19%, respectively, p < 0.001). Even with increased doses of adenosine in subjects with severe LVSD, peak haemodynamic response remained blunted. With multivariate analysis age (p < 0.001) and LVEF (p = 0.031) were independent predictors of heart rate response to adenosine. ConclusionPatients with reduced LVEF referred for stress CMR may have a blunted heart rate response to adenosine. Further study is warranted to determine whether this may be associated with reduced diagnostic accuracy and also the potential utility of further dose increases or alternative stressors.

Arterial blood pressure and heart rate response in patients with acute ischemic stroke - Correlation with the severity of cardiovascular autonomic dysfunction

Background and purpose: Despite numerous studies, the mechanisms of blood pressure and heart rate regulation in cerebrovascular diseases remain not completely understood. The aim of the study was to determine the changes in blood pressure (BP) and heart rate (HR) in patients with an acute hemispheric ischemic stroke and to seek a relation to the severity of the cardiovascular autonomic dysfunction. Methods: 20 healthy volunteers and 50 patients with an acute hemispheric ischemic stroke participated in the study. The values of BP and HR were registered. Cardiovascular autonomous disorders were examined with Ewing battery tests. Patients were divided into two groups according to the severity of the autonomous disorders. Results: Elevated BP values at admission were observed in 56% of our patients, and significantly higher values of systolic blood pressure (SBP) (p <0,001), diastolic blood pressure (DBP) (p = 0,001), and mean arterial pressure (p <0,001), as well as of the heart rate (p = 0,027) were found, compared to the control group. The most significantly increased values of the indicators were reported in patients with a stroke in the territory of the right middle cerebral artery with an involvement of the insular cortex. The results of the t-test performed, showed correlation only between the systolic blood pressure and the severity of the autonomic dysfunction, the values being significantly higher in patients with severe autonomic disorders (t = -2,14; p = 0.036). Conclusion: A variability in BP and HR with a tendency to increase was observed in patients with an acute hemispheric ischemic stroke (ICS) compared to controls, with the highest values reported in patients with ICS in the territory of right middle cerebral artery (TRMCA) with the involvement of the insular cortex (IC). A positive correlation was found between the values of systolic blood pressure (SBP) and the severity of autonomic dysfunction (AD).

Impaired Heart Rate Response to Exercise in Diabetes and Its Long-term Significance

ObjectiveTo investigate the effect of diabetes mellitus on exercise heart rate and the role of impaired heart rate in excess mortality in diabetes. Patients and MethodsPatients without cardiovascular disease who underwent exercise testing from September 1, 1993, through December 31, 2010, were included. Mortality was determined from Mayo Clinic records and the Minnesota Death Index. Multivariate linear regression was used to compare heart rate responses in patients with vs without diabetes. Cox regression was used to determine the effect of abnormal heart rate recovery and abnormal chronotropic index on survival. ResultsA total of 21,396 patients (65.4% men) with a mean ± SD age of 51±11 years, including 1200 patients with diabetes (5.4%), were included. Patients with diabetes had a higher resting heart rate (81±14 vs 77±13 beats/min), lower peak heart rate (154±20 vs 165±19 beats/min), heart rate reserve (73±19 vs 88±19 beats/min), chronotropic index (0.86±0.22 vs 0.99±0.20), and heart rate recovery (15±8 vs 19±9 beats/min) vs patients without diabetes. There were 1362 deaths (6.4%) during a mean ± SD follow-up of 11.9±4.9 years. Adjusting for age, sex, and heart rate–lowering drug use, a chronotropic index less than 0.8 contributed significantly to risk in patients with diabetes (hazard ratio [HR], 2.21; 95% CI, 1.62-3.00; P<.001) and patients without diabetes (HR, 1.94; 95% CI, 1.71-2.20; P<.001), as did abnormal heart rate recovery (patients with diabetes: HR, 2.21; 95% CI, 1.60-5.05; P<.001; patients without diabetes: HR, 1.75; 95% CI, 1.55-1.97). ConclusionsPatients with diabetes exhibit abnormal heart rate responses to exercise, which are independently predictive of reduced long-term survival in patients with diabetes as in patients without diabetes.

Effect of beta-blocker therapy on heart rate response in patients with hypertension and newly diagnosed untreated obstructive sleep apnea syndrome

BackgroundBeta1-receptor antagonists (BBs) are commonly administered in the treatment of cardiovascular disease (CVD). The reported benefits of BB use in CVD patients with concomitant obstructive sleep apnea (OSA) may be limited by their impact on apnea-induced bradycardias. Therefore the aim of the study was to test the influence of BBs on periapneic heart rate (HR) fluctuations in hypertensive patients with newly-detected and untreated OSA. MethodsWe studied 88 hypertensive patients (56 on BBs and 32 BB naive) with newly-diagnosed moderate-to-severe OSA who were free of major pulmonary comorbidities and did not require antiarrhythmic therapy. ECGs recorded during sleep were investigated for heart rate (HR) responses to apneas allowing to compare extreme HR accelerations and decelerations between the groups. ResultsAverage sleep-time HR was comparable in BB-naive (BB−) and BB-treated (BB+) patients. Direct comparisons showed that HR decelerations were also similar in the two subgroups (53.8±9.6 vs. 54.4±7.8bpm; P=0.78, for BB− and BB+, respectively) however, BBs blunted the OSA-induced HR accelerations (82.3±12.2 vs. 74.3±10.0; P=0.003). After adjusting for baseline HR and magnitude of desaturations, HR decelerations were more evident in BB-naive group whereas tachycardic responses remained blunted in the BB+ group. The incidence of ectopies and conduction abnormalities were comparable across two groups. ConclusionsBeta-blockers do not potentiate apnea-induced HR decelerations, attenuate apnea-induced increases in heart rate and do not influence incidence of ectopies and conduction abnormalities in patients with hypertension and moderate-to-severe, untreated OSA.

Modality of fear cues affects acoustic startle potentiation but not heart-rate response in patients with dental phobia

The acoustic startle response (SR) has consistently been shown to be enhanced by fear-arousing cross-modal background stimuli in phobics. Intra-modal fear-potentiation of acoustic SR was rarely investigated and generated inconsistent results. The present study compared the acoustic SR to phobia-related sounds with that to phobia-related pictures in 104 dental phobic patients and 22 controls. Acoustic background stimuli were dental treatment noises and birdsong and visual stimuli were dental treatment and neutral control pictures. Background stimuli were presented for 4 s, randomly followed by the administration of the startle stimulus. In addition to SR, heart-rate (HR) was recorded throughout the trials. Irrespective of their content, background pictures elicited greater SR than noises in both groups with a trend for phobic participants to show startle potentiation to phobia-related pictures but not noises. Unlike controls, phobics showed HR acceleration to both dental pictures and noises. HR acceleration of the phobia group was significantly positively correlated with SR in the noise condition only. The acoustic SR to phobia-related noises is likely to be inhibited by prolonged sensorimotor gating.

Effect of bucindolol on heart failure outcomes and heart rate response in patients with reduced ejection fraction heart failure and atrial fibrillation

There is little evidence of beta-blocker treatment benefit in patients with heart failure and reduced left ventricular ejection fraction (HFREF) and atrial fibrillation (AF). We investigated the effects of bucindolol in HFREF patients with AF enrolled in the Beta-blocker Evaluation of Survival Trial (BEST). A post-hoc analysis of patients in BEST with and without AF was performed to estimate the effect of bucindolol on mortality and hospitalization. Patients were also evaluated for treatment effects on heart rate and the influence of beta1-adrenergic receptor position 389 (β(1)389) arginine (Arg) vs. glycine (Gly) genotypes. In the 303/2708 patients in AF, patients receiving bucindolol were more likely to achieve a resting heart rate ≤ 80 b.p.m. at 3 months (P < 0.005) in the absence of treatment-limiting bradycardia. In AF patients and sinus rhythm (SR) patients who achieved a resting heart rate ≤ 80 b.p.m., there were beneficial treatment effects on cardiovascular mortality/cardiovascular hospitalization [hazard ratio (HR) 0.61, P = 0.025, and 0.79, P = 0.002]. Without achieving a resting heart rate ≤ 80 b.p.m., there were no treatment effects on events in either group. β(1)389-Arg/Arg AF patients had nominally significant reductions in all-cause mortality/HF hospitalization and cardiovascular mortality/hospitalization with bucindolol (HR 0.23, P = 0.037 and 0.28, P = 0.039), whereas Gly carriers did not. There was no evidence of diminished heart rate response in β(1)389-Arg homozygotes. In HFREF patients with AF, bucindolol was associated with reductions in composite HF endpoints in those who achieved a resting heart rate ≤ 80 b.p.m. and nominally in those with the β(1)389-Arg homozygous genotype.

Oxygen Kinetics and Heart Rate Response during Early Recovery from Exercise in Patients with Heart Failure

Background. The purpose of this study was to assess the post-exercise O2 uptake and heart rate response in patients with heart failure (HF) in comparison to healthy individuals. Methods and Results. Exercise testing of all subjects was conducted according to the RITE-protocol. The study subjects were classified according to their peak oxygen uptake (peak VO2) in four groups: healthy individuals with a peak VO2 >22 mL/kg/min (group 1, n: 50), and patients with HF and a peak VO2 of 18–22 mL/kg/min, (group 2, n: 48), 14–18 mL/kg/min (group 3, n: 57), and <14 mL/kg/min (group 4, n: 31). Both peak VO2 and HR declined more slowly in the patients with HF than in the normal subjects. Recovery of VO2 and HR followed monoexponential kinetics in the early post-recovery phase. This enabled the determination of a time constant for both HR and VO2 (TC VO2 and TC HR). From group 1 to 4 there was a prolongation of the time constant for VO2 and HR: TC VO2 (group 1: 110 ± 34, group 2: 197 ± 43, group 3: 238 ± 80, and group 4: 278 ± 50 sec), and TC HR (group 1: 148 ± 82, group 2: 290 ± 65, group 3: 320 ± 58, and group 4: 376 ± 55 sec). Conclusion. The rate of decline of VO2 and HR in the early post-exercise phase is inversely related to the peak VO2. The time constant for oxygen uptake (TC VO2) and heart rate (TC HR) might prove a useful parameter for more precise monitoring and grading of HF.

Delayed effect of blood pressure fluctuations on heart rate in patients with end-stage kidney disease

The time delay of the baroreflex may be affected by decreased autonomic activity in uremia. To assess the magnitude and the time delay of heart rate response in patients with end-stage renal disease, continuous beat-to-beat intervals (IBI) and systolic blood pressure (SBP) recordings were monitored in hemodialysis (HD) patients (n = 72), in patients after renal transplantation (TX) (n = 41) and in age-matched controls (C) (n = 34). A 2-term prediction model was computed, in which each IBI change was represented as a function of SBP difference values of two immediately preceding beats. Baroreflex slope and the frequency domain variables low frequency (LF) α index, phase shift, and lag time were also calculated. b₁ coefficient, representing the dependence of IBI difference with the first previous SBP difference was lower in HD than in Cs, but increased after TX. b₁ correlated with age, baroreflex slope, and LF α, and b₂ (the 2nd term), with both the phase shift between SBP and IBI and lag time. The latter was lower in Cs than in HD or transplanted patients. These findings show that the time delay of the heart rate response to SBP variations is increased in renal insufficiency. The prolonged delay may contribute to the circulatory instability in uremic patients.

Is tai chi exercise programme beneficial for patients with coronary artery disease?

Chang RY, Koo M, Kan CB, Yu ZR, Chu IT, Hsu CT, Chen CY. Effect of tai chi rehabilitation on heart rate responses in patients with coronary artery disease. Am J Chin Med 2010; 38: 461–72.

Effects of Tai Chi Rehabilitation on Heart Rate Responses in Patients with Coronary Artery Disease

The objective of the present study was to evaluate the effect of a six-month Tai Chi (TC) exercise cardiac rehabilitation program on two prognostic factors of cardiac events, rate-pressure product and rate-pressure product reserve, in patients with coronary artery disease (CAD). Patients (N = 54) with CAD were recruited from the clinics of cardiology and cardiovascular surgery at a regional hospital in Taiwan. Twenty-two of them enrolled in the TC rehabilitation program which consisted of weekly 90-min sessions of Yang's style TC for six months in addition to receiving usual care. The remaining 32 patients received usual care only. Modified Bruce treadmill exercise test was performed to evaluate their exercise test responses at baseline and at six months. The change over time was significantly different between the TC and control group in peak rate-pressure product (RPP) (interaction between group and time, p = 0.029) and in RPP reserve (interaction between group and time p = 0.009) over the six-month period, there was a decrease in peak RPP of 32.0 mmHg x bpm x 10(-2) and in RPP reserve of 37.4 mmHg x bpm x 10(-2) in the TC group. In conclusion, participating in a six-month TC exercise-based cardiac rehabilitation program was associated with improved peak RPP and RPP reserve during exercise testing in patients with CAD. TC exercise program may lead to a better prognosis for cardiac events in patients with CAD.

Influence of chronic renal failure on the heart rate response to dipyridamole in patients undergoing myocardial perfusion SPECT

Dipyridamole promotes a reduction in blood pressure and an increase in heart rate (HR), considered the normal hemodynamic response to the drug. Data suggest that patients with chronic renal failure (CRF) have an attenuation of this hemodynamic response. This study sought to evaluate the HR response to dipyridamole and its determinants in patients with or without CRF undergoing gated myocardial perfusion single photon emission computed tomography. Consecutive patients (n = 355, 9.6% with CRF) undergoing rest/dipyridamole myocardial perfusion single photon emission computed tomography were evaluated. The HR response to dipyridamole was considered to be reduced if the HR ratio (maximal HR/rest HR) was 1.20 or less. A logistic regression analysis determined independent predictors of a blunted HR response. A reduced HR response was found in 84.4% of patients with CRF and 40.6% of those without CRF (P < .0001). In patients without CRF the independent predictors of abnormal HR response were hypertension, rest and differential perfusion scores, and left ventricular ejection fraction. In contrast, in CRF patients there was no significant association of any of the studied variables with abnormal HR response. An abnormal HR response to dipyridamole is frequently found in patients with CRF. Different mechanisms may account for abnormal HR response in patients with or without CRF.

618 The prognostic value of heart rate response in patients with mild and moderate heart failure

618 The prognostic value of heart rate response in patients with mild and moderate heart failure

Prognostic value of heart rate response in patients with atrial fibrillation undergoing gated SPECT Tc-99m sestamibi exercise stress testing

Prognostic value of heart rate response in patients with atrial fibrillation undergoing gated SPECT Tc-99m sestamibi exercise stress testing

Comparison of aqueous and gellan ophthalmic timolol with placebo on the 24-hour heart rate response in patients on treatment for glaucoma

PURPOSE: Topical beta-blocker treatment is routine therapy in the management of patients with glaucoma. Therapy results in systemic absorption, however, the degree of reduction of resting and peak heart rate has not been quantified. DESIGN: This trial evaluated the effect of placebo, 0.5% aqueous timolol (timolol solution) and a 0.5% timolol suspension that forms a gel on application to the conjunctiva (timolol gellan) on the 24-hour heart rate in patients currently being treated for glaucoma to quantify the reduction in mean heart rate. METHODS: Forty-three Caucasian patients with primary open-angle glaucoma or ocular hypertension with a mean (±SD) age of 63 (±8) years were randomized and crossed over in a double-masked manner to 14 days of treatment with placebo (morning and evening in both eyes), timolol solution (morning and evening in both eyes), or timolol gellan (morning in both eyes with placebo in the evening). On the 13th day of each period, heart rate was recorded continuously during a typical, ambulant 24-hour period. RESULTS: Both timolol solution and timolol gellan reduced the mean 24-hour heart rate compared with placebo ( P ≤ .001), and this reduction was most pronounced during the daytime (−7.5% change in mean heart rate, −5.7 beats/min). Timolol gellan showed a numerically but not significantly smaller reduction in 24-hour heart rate, compared with timolol solution. During the night, the mean 12-hour heart rate on placebo and timolol gellan were both significantly less than on timolol solution; the difference between solution and gellan treatments was statistically significant ( P = .01). CONCLUSIONS: Both timolol solution and timolol gellan decrease the mean 24-hour heart rate compared with placebo. This response was most pronounced during the active daytime period. These data quantify the modest bradycardia associated with ophthalmic β-blocker therapy in a typical patient population on therapy for glaucoma. Although exercise performance was not assessed in this trial, reductions of this magnitude should not have substantial clinical consequences.