Heart rate control in patients with atrial fibrillation referred for exercise testing

Isa WYH. 24-Hour Holter Monitoring for Identification of an Ideal Ventricular Rate for a Better Quality of Life in Atrial Fibrillation Patients

Introduction Atrial fibrillation (AF) is the most common persistent cardiac arrhythmia. The impact of AF on quality of life (QoL) is significant, and much has related to the achieved resting ventricular rate (VR). Strategies to control VR can improve QoL in AF patients. However, the ideal VR target remains unclear. Therefore, we aimed to identify the ideal VR target by comparing the QoL of AF patients with different VR cut-off means from the 24-hour Holter (Holter). Methods A cross-sectional study was conducted on AF patients in the international normalized ratio (INR) clinic at Hospital Universiti Sains Malaysia. Patients were fixed with a Holter monitor while QoL was measured using the SF-36v2 Health Survey. Patients were repeatedly divided into mean 24-hour Holter VR above and below 60, 70, 80, 90, and 100 beats per minute (bpm). The differences in the total SF-36v2 score and its components were examined. Results A total of 140 patients completed the study. There was a significant difference in physical role, vitality, mental health, mental component summary, and total SF-36v2 scores for VR above and below 90 bpm. The total SF-36v2 score difference was also significant in the covariate analysis, while other VR cut-offs (60, 70, 80, and 100 bpm) did not show significant changes in total SF-36v2 scores. Conclusion Significant differences were observed in the QoL scores among AF patients, with a cut-off VR of 90 bpm favoring patients with the higher rate. Hence, higher VR is better in terms of QoL among stable AF patients.

Assessment of ECG during hybrid comprehensive telerehabilitation in heart failure patients-Subanalysis of the Telerehabilitation in Heart Failure Patients (TELEREH-HF) randomized clinical trial

BACKGROUND

Exercise training in heart failure (HF) patients should be monitored to ensure patients' safety. Electrocardiographic (ECG) telemonitoring was used to assess the safety of hybrid comprehensive telerehabilitation (HCTR).

OBJECTIVE

Analysis of ECG recorded during HCTR in HF patients.

METHODS

The TELEREH-HF multicenter, randomized, controlled trial enrolled 850 HF patients with New York Heart Association class I-III and left ventricular ejection fraction of ≤40%. This subanalysis focuses on 386 patients (aged 62 ± 11 years, LVEF 31 ± 7%) randomized to HCTR. HCTR was telemonitored with a device allowing to record 16-s fragments of ECG and to transmit the data via mobile phone network to the monitoring center. ResultsIn 386 patients, 16,622 HCTR sessions were recorded and 66,488 ECGs fragments were evaluated. Sinus rhythm was present in 320 (83%) and permanent atrial fibrillation (AF) in 66 (17%) patients, respectively. The most common arrhythmias were ventricular and atrial premature beats, recorded in 76.4% and 27.7% of the patients, respectively. Non-sustained ventricular tachycardia (21 episodes in 8 patients) and paroxysmal AF episodes (6 in 4 patients) were rare. None of the analyzed demographic and clinical characteristics was predictive for onset of the new arrhythmias on exercise.

CONCLUSION

Telerehabilitation in HF patients was safe without the evidence for symptomatic arrhythmias requiring discontinuation of telerehabilitation. Only one mildly symptomatic paroxysmal AF episode led to the short-term suspension of the training program. The most common arrhythmias were atrial and ventricular premature beats. These arrhythmias did not result in any changes in rehabilitation and therapy regimens.

Effect of induced chronic atrial fibrillation on exercise performance in Standardbred trotters

Background

Atrial fibrillation (AF) is the most common arrhythmia affecting performance in horses. However, no previous studies have quantified the performance reduction in horses suffering from AF.

Objectives

To quantify the effect of AF on maximum velocity (V_max), maximum heart rate (HR_max), heart rate recovery (T₁₀₀), hematologic parameters and development of abnormal QRS complexes.

Animals

Nine Standardbred trotters.

Methods

Two‐arm controlled trial. Six horses had AF induced by means of a pacemaker and 3 served as sham‐operated controls. All horses were subjected to an exercise test to fatigue before (SET1) and after (SET2) 2 months of AF or sham. The V_max and HR_max were assessed using a linear mixed normal model. Abnormal QRS complexes were counted manually on surface ECGs.

Results

Atrial fibrillation resulted in a 1.56 m/sec decrease in V_max (P < .0001). In the AF group, HR_max ± SD increased from 226 ± 11 bpm at SET1 to 311 ± 27 bpm at SET 2. The AF group had higher HR_max at SET2 compared with controls (P < .0001), whereas no difference between the control and AF groups was observed at SET1 (P = .96). Several episodes of wide complex tachycardia were observed during exercise in 3 of the AF horses during SET2.

Conclusions and Clinical Importance

Atrial fibrillation resulted in a significant reduction in performance, an increase in HR and development of abnormal QRS complexes during exercise, which may be a risk factor for collapse or sudden cardiac death.

Exercise heart rate acceleration patterns during atrial fibrillation and sinus rhythm

BACKGROUND

Patients with atrial fibrillation sustain a significant lower exercise tolerance compared to those in sinus rhythm, even while seemingly in adequate rate-control.

METHODS

Exercise testing was performed during atrial fibrillation and after electric cardioversion for 30 patients who were initially treated with AV modifying agents and were considered in adequate rate control. Heart rate parameters were obtained during all exercise stages, and a graphic display of heart rate acceleration was obtained. For those patients who remained in sinus rhythm, an additional exercise test was performed after 1 month.

RESULTS

During atrial fibrillation, heart rate at the completion of Bruce stage 1 and the peak exercise heart rate were significantly higher when compared to sinus rhythm (120 ± 10 bpm vs. 98 ± 11 bpm and 164 ± 16 bpm vs. 129 ± 11 bpm respectively, p < 0.001 for both). The time to peak exercise heart rate was significantly shorter during atrial fibrillation (3.5 ± 1 min vs. 6.5 ± 1.5 min, p < 0.001), and the total exercise duration was subsequently shorter as well (6 ± 2 min vs. 8.5 ± 2 min, p < 0.001). Treatment with beta-blockers prior to exercise did not affect the earlier peaking of the heart rate. After 1 month, similar time to peak heart rate and similar exercise performance were observed among patients, who remained in sinus rhythm, when compared to to the post-cardioversion exercise test.

CONCLUSIONS

In patients with atrial fibrillation, exercise heart rate acceleration displays a specific pattern of early peaking. Earlier heart rate peaking occurs regardless of ample rate control while at rest or mild physical activity and contributes to overall lower exercise performance.

Making prudent recommendations for return-to-play in adult athletes with cardiac conditions

Clinicians who treat millions of adult athletes throughout the world may be faced with participation or return-to-play decisions in individuals with known or suspected cardiac conditions. Here we review existing published participation guidelines and analyze emerging data from ongoing registries and population-based studies pertaining to return-to-play decisions for cardiac conditions specifically affecting adult athletes. Considerations related to return-to-play decisions will vary according to age of the athlete, with inherited disorders being the main consideration in younger adult athletes aged 18 to 40 yr, and coronary artery disease being the main consideration in older adult athletes aged 40 yr and older. Although this arbitrary division is based on the epidemiology of underlying heart disease in these populations, the essential return-to-play decision process for both age groups is quite similar. Among the most widely used guidelines to make return-to-play decisions in this group of athletes are the 36th Bethesda Conference Eligibility Recommendations for Competitive Athletes with Cardiovascular Abnormalities. These have long been considered the "gold standard" for determining return-to-play decisions in young athletes in the United States. Other guidelines are available for unique purposes, including The European Society of Cardiology guidelines, and the American Heart Association published recommendations regarding participation of young patients (younger than 40 yr) with genetic cardiovascular diseases in recreational sports. The latter are consistent with the 36th Bethesda guidelines and cover common genetically based diseases such as inherited cardiomyopathies, channelopathy, and connective tissue disorders like Marfan's syndrome. The consensus on masters athletes (older than 40 yr) provides return-to-play decisions for a wide variety of conditioned states, from elite older athletes to walk-up athletes. For any adult athlete with a cardiac condition, return-to-play decisions following use of medications, ablation procedures, device implantation, corrective surgery, or coronary intervention depend on whether the procedure has sufficiently altered the risk for sudden cardiac events, and whether there is a potential for unfavorable interaction with cardiac performance.

Effect of atrial fibrillation on outcome in patients with known or suspected coronary artery disease referred for exercise stress testing

The association of atrial fibrillation (AF) with coronary artery disease (CAD) remains controversial. In addition, the relation of AF to myocardial ischemia and outcomes in patients with known or suspected CAD referred for exercise stress testing has been poorly explored. In this study, 17,100 patients aged > or = 50 years with known or suspected CAD who underwent exercise electrocardiography (n = 11,911) or exercise echocardiography (n = 5,189) were evaluated. End points were all-cause mortality, nonfatal myocardial infarction, and coronary revascularization. Overall, 619 patients presented with AF at the time of the tests. Patients with AF who had interpretable electrocardiograms had a lower likelihood of exercise-induced ischemic ST-segment abnormalities (adjusted odds ratio 0.51, 95% confidence interval 0.34 to 0.76, p = 0.001), and those with AF who underwent exercise echocardiography had a lower likelihood of new or worsening exercise-induced wall motion abnormalities (adjusted odds ratio 0.62, 95% confidence interval 0.44 to 0.87, p = 0.006). During a mean follow-up period of 6.5 + or - 3.9 years, 2,364 patients died, 1,311 had nonfatal myocardial infarctions, 1,615 underwent percutaneous coronary intervention, and 922 underwent coronary artery bypass surgery. The 10-year mortality rate was 43% in patients with AF compared to 19% in those without AF (p <0.001). In multivariate analysis, AF remained an independent predictor of all-cause mortality (adjusted hazard ratio 1.45, 95% confidence interval 1.20 to 1.76, p <0.001), but not of nonfatal myocardial infarction or coronary revascularization. In conclusion, despite being associated with an apparently lower likelihood of myocardial ischemia, AF was an independent predictor of all-cause mortality in patients with known or suspected CAD referred for exercise stress testing.

Atrial Fibrillation And Coronary Heart Disease:Fatal Attraction

In this manuscript, the profile and clinical management of hypertensive patients with chronic ischemic heart disease and atrial fibrillation (AF) is examined and whether high heart rate is associated with a different profile is determined. CINHTIA was a cross-sectional and multicenter survey aimed to define the clinical profile of hypertensive patients with chronic ischemic heart disease daily attended in Spain. Blood pressure, LDL-cholesterol and diabetes control rates were established according to ESHESC 2003, NCEP-ATP III and ADA 2005 guidelines, respectively. Out of the 2024 patients, 338 (16.7%) exhibited AF. The group of patients with AF was older and with higher prevalence of diabetes, organ damage and cardiovascular disease. Blood pressure (41.8% vs 34.5%, p=0.014) and diabetes (28.5% vs 20.9%,p=0.044) were worse controlled in patients with AF, with a trend to a lower control of LDL-cholesterol (31.2% vs 26.8%, p=0.093). When distributing patients with AF according to heart rate, except for smoking, left ventricular hypertrophy and peripheral arterial disease that were more frequent in those with higher heart rate, no significant differences were found in other risk factors or organ damage between groups. Blood pressure, glycemia and LDL-cholesterol were worse controlled in the subgroup with highest heart rate. In clinical practice, hypertensive patients with chronic ischemic heart disease and AF have a bad prognosis not only due to a worse clinical profile, but also due to lower risk factors control rates. In contrast with patients at sinus rhythm, higher heart rate was less related with a worse clinical profile in subjects with AF.