Effect of High-Intensity Interval Training in Patients With Atrial Fibrillation: A Randomized Clinical Trial.

Importance: Patients with atrial fibrillation (AF) experience poor functional capacity and quality of life (QOL). High-intensity interval training (HIIT) has been shown to elicit greater improvements in functional capacity and QOL compared with moderate to vigorous intensity continuous training (MICT) in other cardiovascular populations, yet HIIT remains understudied in AF. Objective: To compare the effects of 12 weeks of HIIT and MICT-based cardiovascular rehabilitation (CR) on functional capacity and general QOL in patients with persistent and permanent AF. Disease-specific QOL, resting heart rate (HR), time in AF, and physical activity (PA) levels were also assessed. Design, Setting, and Participants: This randomized clinical trial, conducted between November 17, 2015, and February 4, 2020, at a tertiary-care cardiovascular health center in Ottawa, Canada, recruited 94 patients with persistent and permanent AF. Interventions: High-intensity interval training (23 minutes: two 8-minute interval training blocks of 30-second work periods at 80%-100% of peak power output interspersed with 30-second recovery) or CR (60 minutes: continuous aerobic conditioning within 67%-95% of peak HR and 12-16 of 20 ratings of perceived exertion) twice weekly for 12 weeks. Main Outcomes and Measures: The primary outcomes were changes in functional capacity (6-minute walk test [6MWT] distance) and general QOL (Short Form 36) from baseline to 12 weeks' follow-up. Secondary outcomes included changes in disease-specific QOL (Atrial Fibrillation Severity Scale), resting HR, time in AF, and PA levels. An intention-to-treat analysis was used to compare changes between groups. Results: Of the 94 patients who consented, 86 participated (mean [SD] age, 69 [7] years; 57 [66.3%] men). No significant differences in improvements in 6MWT distance (mean [SD], 21.3 [34.1] vs 13.2 [55.2] m; P = .42) and general QOL (Physical Component Summary, 0.5 [6.1] vs 1.1 [4.9] points; P = .87) between HIIT and CR were observed. No significant differences in improvements in disease-specific QOL (AF symptoms: -1.7 [4.3] vs -1.5 [4] points, P = .59), resting HR (-3.6 [10.6] vs -2.9 [12.4] beats per minute, P = .63), and moderate to vigorous PA levels (37.3 [93.4] vs 14.4 [125.7] min/wk; P = .35) between HIIT and CR were detected. Participants attended a mean (SD) of 18.3 (6.1) (75.1%) HIIT sessions and 20.0 (4.5) (83.4%) CR sessions (P = .36). Conclusions and Relevance: In this randomized clinical trial, twice-weekly 23-minute HIIT was as efficacious as twice-weekly 60-minute CR in improving functional capacity, general and disease-specific QOL, resting HR, and PA levels in patients with persistent and permanent AF. Trial Registration: ClinicalTrials.gov Identifier: NCT02602457.

A case series of acute responses to high-intensity interval training in four males with permanent atrial fibrillation.

Background: Atrial fibrillation (AF) is a serious medical condition and a burgeoning patient population. Chronic exercise training, including high-intensity interval training (HIIT), has been shown to improve symptoms and quality of life in patients with AF. Yet, the acute responses to HIIT in this population remain understudied, leaving clinicians and patients hesitant about prescribing and engaging in high-intensity exercise, respectively. Case summary: This case series describes acute exercise responses [i.e. power output, heart rate (HR), blood pressure (BP), ratings of perceived exertion (RPE), symptoms] to 10 weeks (3 days/week) of HIIT. Participants were four white males (58-80 years old) with permanent AF, co-morbidities (diabetes, coronary artery disease, Parkinson's disease), and physical limitations. The increases in HR and BP during HIIT were modest across all participants, regardless of age and medication use. Differences in RPE were observed; the oldest participant perceived the sessions as more challenging despite a lower HR response. All patients complied with the HIIT prescription of 80-100% of peak power output by week 4. No adverse events were reported. Discussion: Patients' concerns regarding high-intensity exercise may discourage them from participating in HIIT, our results demonstrated no abnormal HR or BP (e.g. hypotension) responses during HIIT or cool-down. These findings align with the typical exercise responses noted in other cardiovascular populations. Notwithstanding the high metabolic demands of HIIT, male patients with permanent AF tolerated HIIT without problem. Further investigation of HIIT as an approach to enable those with AF to recover physical capacity and minimize symptomatology is warranted.

Sustained Effects of Different Exercise Modalities on Physical and Mental Health in Patients With Coronary Artery Disease: A Randomized Clinical Trial.

BACKGROUND: Twelve-week high-intensity interval training (HIIT), moderate-to-vigorousintensity continuous training (MICT), and Nordic walking (NW) have been shown to improve functional capacity, quality of life (QoL), and depression symptoms in patients with coronary artery disease. However, their prolonged effects or whether the improvements can be sustained remains unknown. In this study we compared the effects of 12 weeks of HIIT, MICT, and NW on functional capacity, QoL, and depression symptoms at week 26. METHODS: Patients with coronary artery disease were randomized to a 12-week HIIT, MICT, or NW program followed by a 14-week observation phase. At baseline, and at weeks 12 and 26, functional capacity was measured with a 6-minute walk test (6MWT); QoL was assessed using the HeartQoL and Short Form-36; and depression severity using the Beck Depression Inventory-II. Prolonged (between baseline and week 26) and sustained (between weeks 12 and 26) effects were assessed using linear mixed models with repeated measures. RESULTS: Of 130 participants randomized, 86 (HIIT: n = 29; MICT: n = 27; NW: n = 30) completed week 26 assessments. There were significant improvements in 6MWT distance, QoL, and depression symptoms from baseline to week 26 (P < 0.05); NW increased 6MWT distance (+94.2 ± 65.4 m) more than HIIT (+59.9 ± 52.6 m; interaction effect P = 0.025) or MICT (+55.6 ± 48.5 m; interaction effect P = 0.010). Between weeks 12 and 26, 6MWT distance and physical QoL increased significantly (P < 0.05). CONCLUSIONS: Twelve weeks of HIIT, MICT, and NW have positive prolonged effects on functional capacity, QoL, and depression symptoms. However, NW conferred additional benefits in increasing functional capacity. The effects of the 12-week exercise programs were sustained at week 26.

Effects of high intensity interval training on cardiorespiratory fitness and salivary levels of IL-8, IL-1ra, and IP-10 in adults with asthma and non-asthma controls.

OBJECTIVE: The purpose of this study was to determine whether high intensity interval training (HIIT) would lead to improvements in 1) maximal VO2, VE, VE/VCO2, and VE/MVV, and/or 2) resting salivary concentrations of pro-inflammatory markers Interleukin (IL-8), interferon-gamma-inducible-protein (CXCL10/IP-10)) and anti-inflammatory marker IL-1 receptor antagonist (IL-1ra) in adults with well-controlled asthma compared to non-asthma controls. METHODS: Participants completed a maximal exercise test at the beginning (T1) and end (T2) of a 6-week HIIT intervention; saliva samples were obtained at the beginning and 30 min following the first (T1) and last (T2) exercise session. RESULTS: Adults with asthma (n = 20; age: 21.4 ± 2.4 years) and non-asthma controls (n = 12; age: 22.5 ± 3.4 years) completed the intervention. VO2max increased from T1 to T2 in both groups (asthma T1 32.9 ± 8, T2 38.6 ± 8.2 ml/kg/min; controls T1 34.5 ± 11.8, T2 38.9 ± 12.3 ml/kg/min). VEmax also increased in both groups (asthma T1 97.7, T2 110.8 units, p < 0.001, hp2 = <0.04; control T1 106.3, T2 118.1, p < 0.001, hp2 0.02). An increase in VE/VCO2 (F(1, 10)=22.11, p = 0.001) and VE/MVV (F(1, 10) = 111.30, p < 0.001) was observed in the control group; no differences were observed in the asthma group. No differences in IL-8 or IL-1ra were observed between groups. In the asthma group, resting salivary IP-10 concentrations significantly decreased from T1 (0.025 pg/ug protein) to T2 (0.015 pg/ug protein, p = 0.039, hp2 = 0.3 (moderate effect)). CONCLUSION: A 6-week HIIT intervention led to a similar increase in VO2max and VEmax in those with and without asthma, and a decrease in resting salivary IP-10 levels among adults with asthma.

Sex and Age Differences in Anxiety and Depression Levels Before and After Aerobic Interval Training in Cardiac Rehabilitation.

PURPOSE: The objective of this study was to investigate sex and age differences in anxiety and depression among patients with cardiovascular disease at baseline and following aerobic interval training (AIT)-based cardiac rehabilitation (CR) and secondarily to compare dropout rates between sexes and age groups. METHODS: Participants were younger (≤44 yr), middle-aged (45-64 yr), and older adults (≥65 yr). The AIT protocol consisted of: 4 × 4-min of high-intensity work periods at 85-95% peak heart rate (HR) interspersed with 3 min of lower-intensity intervals at 60-70% peak HR, twice weekly for 10 wk. Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale at baseline and following CR. RESULTS: At baseline, of 164 participants (32% female), 14 (35% female) were younger, 110 (33% female) were middle-aged, and 40 (30% female) were older. Older adults reported lower anxiety levels versus younger (4.4 ± 2.6 vs 7.8 ± 3.4 points, P = .008) and middle-aged adults (4.4 ± 2.6 vs 6.1 ± 3.6 points, P = .05). Baseline depression levels did not differ between age groups (P = .749). All age groups experienced a reduction in anxiety (younger =-2.67; middle-aged =-1.40; older =-0.85) and depression (younger =-1.50; middle-aged =-0.83; older =-0.70) levels following CR. Differences in dropout rates were observed between age groups (χ2[1] = 13.4, P = .001). Within each age group, 43% (female n = 2, male n = 4) of younger, 10% (female n = 8, male n = 3) of middle-aged, and 2.5% (female n = 0, male n = 1) of older participants dropped out. CONCLUSIONS: Younger and middle-aged adults experience higher levels of anxiety upon entry into CR compared with older adults. Cardiac rehabilitation was associated with significant reductions in anxiety and depression severity, yet dropout rates were highest among younger adults.

Moving Together While Staying Apart: Practical Recommendations for 24-Hour Home-Based Movement Behaviours for Those With Cardiovascular Disease.

The novel coronavirus disease 2019 is a global public health crisis that disproportionately affects those with preexisting conditions. Cardiovascular disease (CVD) is the leading cause of death worldwide and many key CVD risk factors are modifiable (e.g., physical inactivity, sedentary behaviour, obesity). To limit the spread of coronavirus 2019, most governments have implemented restrictions and recommended staying at home, reducing social contact to a select and exclusive few, and limiting large gatherings. Such public health constraints may have unintended, negative health consequences on 24-hour movement behaviours. The primary purpose of this review is to provide practical at-home recommendations for sedentary time, sleep, and physical activity in those living with CVD. Adults with CVD will benefit from practical recommendations to reduce sedentary time, increase purposeful exercise, and maintain optimal sleep patterns while being at home and adhering to public health restrictions. Our recommendations include the following: (i) self-monitoring sitting time; (ii) engaging in 2-3 days per week of purposeful exercise for those with low exercise capacity and > 3 days per week for those with moderate-to-high exercise capacity; (iii) self-monitoring exercise intensity through the use of scales or wearable devices; (iv) maintaining a regular sleep schedule; and (v) moving daily. Clinicians should be aware that clear communication of the importance of limiting prolonged sedentary time, engaging in regular physical activity and exercise, and ensuring optimal sleep in association with the provision of clear, comprehensible, and practical advice is fundamental to ensuring that those living with CVD respond optimally to the challenges posed by the pandemic.

La nouvelle maladie à coronavirus 2019 représente une crise de santé publique mondiale qui touche de manière disproportionnée les personnes présentant des pathologies préexistantes. Les maladies cardiovasculaires (MCV) constituent la principale cause de décès dans le monde et de nombreux facteurs de risque majeurs de MCV sont modifiables (par exemple, le manque d'activité physique, un comportement sédentaire, l'obésité). Pour limiter la propagation du coronavirus 2019, la plupart des gouvernements ont mis en place des restrictions et recommandé de rester à la maison, de réduire les contacts sociaux à un nombre de personnes restreint et exclusif, et de limiter les grands rassemblements. Ces contraintes de santé publique peuvent involontairement entraîner des conséquences sanitaires négatives sur les habitudes de déplacement sur 24 heures. L'objectif principal de cette étude est de fournir des recommandations pratiques, réalisables à domicile, en rapport avec le temps de sédentarité, le sommeil et l'activité physique chez les personnes atteintes de MCV. Les adultes atteints de MCV tireront avantage de recommandations pratiques dans le but de réduire le temps de sédentarité, augmenter l'activité physique volontaire et maintenir des habitudes de sommeil optimales, tout en restant à la maison et en respectant les restrictions sanitaires. Nos recommandations sont les suivantes: (i) autosurveillance du temps passé assis; (ii) pratique d'une activité physique volontaire 2 à 3 jours par semaine pour les personnes ayant une faible capacité d'exercice et > 3 jours par semaine pour les personnes ayant une capacité d'exercice modérée à élevée; (iii) autosurveillance de l'intensité de l'activité par l'utilisation de barème ou de dispositifs portatifs; (iv) maintien d'horaires de sommeil réguliers; et (v) action de bouger quotidiennement. Les cliniciens doivent être conscients qu'une communication claire quant à l'importance de limiter le temps de sédentarité prolongée, de pratiquer régulièrement de l'exercice ou une activité physique, et d'assurer un sommeil optimal, associée à la préconisation de conseils clairs, compréhensibles et pratiques, est fondamentale pour garantir une réponse optimale de la part des personnes vivant avec des MCV quant aux défis posés par la pandémie.

Aerobic fitness is inversely associated with neurohemodynamic transduction and blood pressure variability in older adults.

Higher aerobic fitness is independently associated with better cardiovascular health in older adults. The transduction of muscle sympathetic nerve activity (MSNA) into mean arterial pressure (MAP) responses provides important insight regarding beat-by-beat neural circulatory control. Aerobic fitness is negatively associated with peak MAP responses to spontaneous MSNA in young males. Whether this relationship exists in older adults is known. We tested the hypothesis that aerobic fitness was inversely related to sympathetic neurohemodynamic transduction and blood pressure variability (BPV) in older adults. Relative peak oxygen consumption (V̇O2peak, indirect calorimetry) was assessed in 22 older adults (13 males, 65 ± 5 years, 36.3 ± 11.5 ml/kg/min). Peroneal MSNA (microneurography) and arterial pressure (finger photoplethysmography) were recorded during ≥ 10-min of rest. BPV was assessed using the average real variability index. MAP was tracked for 12 cardiac cycles following heartbeats associated with MSNA bursts (i.e., peak ΔMAP). Peak ΔMAP responses (0.9 ± 0.6 mmHg) were negatively associated (all, P < 0.04) with resting burst frequency (30 ± 11 bursts/min; R = -0.47) and burst incidence (54 ± 22 bursts/100 heartbeats; R = -0.51), but positively associated with BPV (ρ = 0.47). V̇O2peak was inversely related to the pressor responses to spontaneous bursts (R = -0.47, P = 0.03) and BPV (ρ = -0.54, P = 0.01), positively related to burst incidence (R = 0.42, P = 0.05), but unrelated to MSNA burst frequency (P = 0.20). The V̇O2peak-BPV relationship remained after controlling for burst frequency, peak ΔMAP, age, and sex. Lower V̇O2peak was associated with augmented neurohemodynamic transduction and BPV in older adults. These negative hemodynamic outcomes highlight the importance of higher aerobic fitness with ageing for optimal cardiovascular health.