Background-Exercise performed at higher relative intensities has been found to elicit a greater increase in aerobic capacity and greater cardioprotective effects than exercise at moderate intensities. An inverse association has also been detected between the relative intensity of physical activity and the risk of developing coronary heart disease, independent of the total volume of physical activity. Despite that higher levels of physical activity are effective in reducing cardiovascular events, it is also advocated that vigorous exercise could acutely and transiently increase the risk of sudden cardiac death and myocardial infarction in susceptible persons. This issue may affect cardiac rehabilitation. Methods and Results-We examined the risk of cardiovascular events during organized high-intensity interval exercise training and moderate-intensity training among 4846 patients with coronary heart disease in 3 Norwegian cardiac rehabilitation centers. In a total of 175 820 exercise training hours during which all patients performed both types of training, we found 1 fatal cardiac arrest during moderate-intensity exercise (129 456 exercise hours) and 2 nonfatal cardiac arrests during high-intensity interval exercise (46 364 exercise hours). There were no myocardial infarctions in the data material. Because the number of high-intensity training hours was 36% of the number of moderate-intensity hours, the rates of complications to the number of patient-exercise hours were 1 per 129 456 hours of moderate-intensity exercise and 1 per 23 182 hours of high-intensity exercise. Conclusions-The results of the current study indicate that the risk of a cardiovascular event is low after both high-intensity exercise and moderate-intensity exercise in a cardiovascular rehabilitation setting. Considering the significant cardiovascular adaptations associated with high-intensity exercise, such exercise should be considered among patients with coronary heart disease. (Circulation. 2012;126:1436-1440.)Key Words: coronary disease Ⅲ death Ⅲ sudden Ⅲ exercise Ⅲ heart arrest H igh levels of physical activity and aerobic capacity are associated with low risk of cardiovascular disease and mortality. 1-3 Aerobic exercise is therefore strongly recommended both for healthy individuals and for patients with cardiovascular disease to improve cardiovascular health and reduce risk of premature mortality. 4,5 If the total energy expenditure of exercise is held constant, exercise performed at higher relative intensities has been found to elicit a greater increase in aerobic capacity 6 and greater cardioprotective effects than exercise at moderate intensities. 7,8 An inverse association has also been detected between the relative intensity of physical activity and the risk of developing coronary heart disease, independent of the total volume of physical activity. 9,10 Indeed, when exercise is performed at high intensity, as little as a single weekly bout of exercise seems to be sufficient for reducing the risk of cardiovascular death in a large uns...

Background Mobile health interventions, especially smartphone applications (apps), have been proposed as promising interventions for supporting adherence to healthy behaviour in patients post cardiac rehabilitation (CR). The overall aim of the study was to examine the effect of individualized follow-up with an app for one year on peak oxygen uptake (VO2peak) in patients completing CR. Design The study was designed as a single-blinded multicentre randomized controlled trial. Methods The intervention group (IG) received individualized follow-up enabled with an app for one year, while the control group (CG) received usual care. The primary outcome was difference in VO2peak. Secondary outcomes included exercise performance (time to exhaustion, peak incline (%) and peak velocity (km/h)), bodyweight, resting blood pressure, lipid profile, triglycerides, exercise habits, health-related quality of life, health status and self-perceived goal achievement. Results In total, 113 patients completing CR (73.4% with coronary artery disease, 16.8% after valve surgery and 9.8% with other heart diseases) were randomly allocated to the IG or CG. Intention to treat analyses showed a statistically significant difference in VO2peak between the groups at follow-up of 2.2 ml/kg/min, 95% confidence interval 0.9–3.5 ( p < 0.001). Statistically significant differences were also observed in exercise performance, exercise habits and in self-perceived goal achievement. Conclusions Individualized follow-up for one year with an app significantly improved VO2peak, exercise performance and exercise habits, as well as self-perceived goal achievement, compared with a CG in patients post-CR. There were no statistically significant differences between the groups at follow-up in the other outcome measures evaluated.

Long PQ time, bradycardia and left atrial enlargement seem to be important risk factors for LAF among long-term endurance cross-country skiers.

Aerobic capacity, measured as the peak oxygen uptake, is a strong predictor of survival in cardiac patients. Aerobic interval training (AIT), walking/running four times four minutes at 85–95% of peak heart rate, has proven to be effective in increasing peak oxygen uptake in coronary heart disease patients. As some patients do not attend organized rehabilitation programs, home-based exercise should be an alternative. We investigated whether AIT could be performed effectively at home, and compared the effects on peak oxygen uptake with that observed after a standard care, four-week residential rehabilitation. Thirty patients undergoing coronary artery bypass surgery were randomized to residential rehabilitation or home-based AIT. At six months follow-up, peak oxygen uptake increased 4.6 (±2.7) and 3.9 (±3.6) mL·kg−1 min−1 (both p<0.005, non-significant between-group difference) after residential rehabilitation and AIT, respectively. Quality of life increased significantly in both groups, with no statistical significant difference between groups. We found no evidence for a different treatment effect between patients randomized to home-based AIT compared to patients attending organized rehabilitation (95% confidence interval −1.8, 3.5). AIT patients reported good adherence to exercise training. Even though these first data indicate positive effects of home-based AIT in patients undergoing coronary artery bypass surgery, more studies are needed to provide supporting evidence for the application of this rehabilitation strategy.Trial RegistrationClinicalTrials.gov NCT00363922

Background The extent of cardiac dysfunction post‐COVID‐19 varies, and there is a lack of data on arrhythmic burden. Methods and Results This was a combined multicenter prospective cohort study and cross‐sectional case‐control study. Cardiac function assessed by echocardiography in patients with COVID‐19 3 to 4 months after hospital discharge was compared with matched controls. The 24‐hour ECGs were recorded in patients with COVID‐19. A total of 204 patients with COVID‐19 consented to participate (mean age, 58.5 years; 44% women), and 204 controls were included (mean age, 58.4 years; 44% women). Patients with COVID‐19 had worse right ventricle free wall longitudinal strain (adjusted estimated mean difference, 1.5 percentage points; 95% CI, −2.6 to −0.5; P =0.005) and lower tricuspid annular plane systolic excursion (−0.10 cm; 95% CI, −0.14 to −0.05; P <0.001) and cardiac index (−0.26 L/min per m 2 ; 95% CI, −0.40 to −0.12; P <0.001), but slightly better left ventricle global strain (−0.8 percentage points; 95% CI, 0.2–1.3; P =0.008) compared with controls. Reduced diastolic function was twice as common compared with controls (60 [30%] versus 29 [15%], respectively; odds ratio, 2.4; P =0.001). Having dyspnea or fatigue were not associated with cardiac function. Right ventricle free wall longitudinal strain was worse after intensive care treatment. Arrhythmias were found in 27% of the patients, mainly premature ventricular contractions and nonsustained ventricular tachycardia (18% and 5%, respectively). Conclusions At 3 months after hospital discharge with COVID‐19, right ventricular function was mildly impaired, and diastolic dysfunction was twice as common compared with controls. There was little evidence for an association between cardiac function and intensive care treatment, dyspnea, or fatigue. Ventricular arrhythmias were common, but the clinical importance is unknown. Registration URL: http://clinicaltrials.gov . Unique Identifier: NCT04535154.