Exercise Training with Atrial Fibrillation

OVERVIEW OF ATRIAL FIBRILLATIONAtrial fibrillation (AF), characterized by the heart’s upper chambers (atria) beating out of coordination (quiver) with the lower chambers (ventricles), is the most common cardiac arrhythmia and contributes to increasing hospitalizations (1). AF is a health concern for a number of reasons (2). First, the lack of effective heart contractions causes blood to pool in the atria, and this can lead to the formation of blood clots that can go anywhere in the body. If a clot goes into the brain, it can cause a stroke. If a clot goes into a lung, it can cause a pulmonary embolism. Second, if the heart rate (ventricular response) is too fast, heart failure can occur over time. Third, untreated AF can lead to other health issues such as exercise intolerance and chronic fatigue. Although advanced age is a significant contributing factor, other risk factors also increase the risk of developing AF (see Sidebar). Some individuals with AF have no symptoms and are unaware of their condition until it is diagnosed during a physical examination. Individuals who do have AF symptoms may experience the following (3): Palpitations, irregular heartbeat (flip-flopping in your chest) General weakness Impaired ability to exercise Lightheadedness Dizziness Shortness of breath Chest pain Sidebar: Risk Factors There are a number of risk factors for AF. Advanced age and abnormalities or damage to the heart’s structure are very common causes. Other risk factors include the following (4): Hypertension Coronary artery disease Myocardial Infarction Thyroid disease Heart defects you are born with (congenital) Abnormal heart valves Exposure to certain medications Caffeine, tobacco, or alcohol use Sick sinus syndrome — improper functioning of the heart’s natural pacemaker Lung diseases Previous heart surgery Viral infections Stress due to surgery, pneumonia, or other illnesses Sleep apnea High-volume endurance athletes AF causes stroke or is associated with other factors that cause stroke, which is a serious vascular event involving a loss of neurological functions related to an acute interruption of blood flow to the brain. Stroke is associated with AF due to blood pooling in the atria and forming clots that block blood flow. The risk of a stroke in AF depends on the age (the risk is higher in older adults) and on the patient’s health status (e.g., high blood pressure, diabetes, history of heart failure, or previous stroke) (5). It is important to note that the letters in “FAST” help to check stroke signs, guiding people to know when to call 911 (i.e., F, face drooping; A, arm weakness; S, speech difficulties; T, time to call 911). EXERCISING WITH AF An exercise program for individuals with AF can provide several health and fitness benefits. Specifically, functionality, physical performance, cardiometabolic health, and quality of life can be improved after engaging in a long-term, customized training program (6–12). Such a training program primarily aims to support clients with AF who are likely to be deconditioned, sedentary, obese, or older adults showing limited physical independence, poor functional capacity, and impaired metabolic as well as musculoskeletal health (13,14). A broad spectrum of physical fitness can be improved after comprehensive exercise training programs adapted for this population, resulting in an increased ability to address activities of daily living (15,16). Initially, clients with AF should check with their doctor before beginning an exercise program to ensure it is safe and effective. Individuals with AF may be on medications such as beta-blockers that may affect exercise training, and exercise professionals should be aware of these medications (see Table 1). Some individuals also may benefit from monitored exercise such as outpatient cardiac rehabilitation (although AF alone may not be covered by some insurance). TABLE 1 - Common Medications for AF Class Name Mechanism of Action Antiplatelets and anticoagulant Warfarin, aspirin, dabigatran These medications thin the blood and decrease the risk of a blood clot. They can increase the risk of bleeding and bruising. The exercise professional should use caution with high-impact exercises. Contact sports also are high risk. Heart rate controlling Atenolol, metoprolol, verapamil, digoxin These medications slow the heart rate. Some also reduce the force of the heart’s contractions. Exercise performance may be reduced as well as tolerance to heat. The client/patient should remain well hydrated and exercise in a cool environment. RPE may be a better indication of measuring exercise effort. Heart rhythm controlling Sodium channel blockers: propafenone and flecainide; potassium channel blockers: dofetilide and amiodarone These medications are broken up into sodium channel blockers and potassium channel blockers. They help restore the heart rate to a normal rhythm. RPE, rating of perceived exertion. Common side effects and complications include fatigue, shortness of breath, and nausea. The exercise professional should adjust the exercise routine according to the person’s energy levels, use a dyspnea scale, and cancel an exercise session if nausea is present. It is notable that there are many other medications not listed. The reader is encouraged to research a more comprehensive list. The American Heart Association recommends at least 150 minutes of moderate-intensity aerobic exercise for adults each week. Resistance training should be performed at least twice a week for all major muscle groups. Flexibility exercises should be performed as well. Examples of physical activity include the following (2): Climbing stairs Walking Jogging Swimming Biking Resistance training Other aerobic exercise (e.g., elliptical training) Individuals with AF should have their pulse assessed before each training session, as they may have reduced exercise tolerance and become more easily fatigued when exercising due to an inappropriate ventricular response (16). Reduced exercise tolerance is very common in those with AF because of a high chance of coexisting heart disease (17). Given that AF is associated with the variable ventricular response that makes heart rate unreliable as a measure of exercise intensity, rating of perceived exertion is highly recommended to exercise professionals supervising clients with AF while monitoring intensity (18). SPECIAL CONSIDERATIONS For individuals who are overweight or obese and in those demonstrating lower-body injuries or musculoskeletal diseases (e.g., arthritis), aerobic training appears to be a great approach for maximizing weight loss and management in those with AF. However, weight-bearing exercise should be implemented gradually (13–15,19). In resistance training, individuals with AF should avoid the Valsalva maneuver given that such an action raises blood pressure levels when exercising. Thus, a pace of 1 to 2 seconds each during the concentric and eccentric phases of each repetition is highly recommended to avoid any health complications in prehypertensive and hypertensive clients with AF (17–19) (Tables 2–4). TABLE 2 - Aerobic Training Recommendations for Individuals with AF Training Parameter Recommendation Frequency 3–5 days per week Intensity 50%–80% HRR (RPE 11–14) Time 30–60 minutes per day Type Walking, jogging, stationary cycling, elliptical stepping, rowing, or swimming Progression Initiate exercise at 30%–59% HRR (RPE 11–14); increase time gradually by 5–10 minutes as tolerated; gradually increase frequency to 4–7 days per week Adapted from Chodzko-Zajko et al. (13), Garber et al. (14), Keteyian et al. (19), and ACSM (20).HRR, heart rate reserve; RPE, rating of perceived exertion. TABLE 3 - Resistance Training Recommendations for Individuals with AF Training Parameter Recommendation Frequency 1–2 days per week (>60 years old); 2–3 days per week (≤60 years old) Intensity 40%–50% 1RM, RPE = 11–12 (>60 years old); 60%–70% 1RM, RPE = 13–14 (≤60 years old) Time Repetitions 10–15 (>60 years old); 8–12 (≤60 years old) Sets 1–2 per muscle group (>60 years old); 2–4 per muscle group (≤60 years old) Rest periods 30–60 seconds between sets Type 8–10 Multijoint exercises using bodyweight movements, free weights, machines, elastic resistance, and medicine balls Progression Increase load intensity when 1–2 reps can be performed properly beyond the prescribed number during two consecutive sessions Adapted from Chodzko-Zajko et al. (13), Garber et al. (14), Williams et al. (16), Keteyian et al. (19), ACSM (20), and Ratamess et al. (21).1RM, one-repetition maximum; RPE, rating of perceived exertion. TABLE 4 - Flexibility Training Recommendations for Individuals with AF Training Parameter Recommendation Frequency 2–3 days per week Intensity Stretch to the point of feeling tightness or slight discomfort. Time 10–30 seconds hold for static stretching; 2–4 repetitions of each exercise Type Static, dynamic, and/or PNF stretching Progression Gradually increase frequency to 4–7 days per week PNF, proprioceptive neuromuscular facilitation. SUMMARY AF is considered one of the most common cardiac arrhythmias globally, particularly in the elderly. Individuals with AF are very likely to take a number of medications while suffering from other chronic diseases such as hypertension. Regular exercise can play a vital role in health promotion and quality of life enhancement in those with AF who have been medically cleared for participation in progressive, supervised exercise protocols, including both aerobic and resistance training. A comprehensive, individualized exercise program can safely improve physical fitness, functional capacity, cardiometabolic, and mental health in clients with AF.