What type of exercise is suitable for a 72-year-old with a Supraventricular Index (SVI) of 24, considering recent episodes of skipped beats during exertion?

Exercise Recommendations for a 72-Year-Old with Stroke Volume Index of 24 and Exercise-Induced Arrhythmia

Your current regimen of 30-45 minutes of brisk walking daily is appropriate and beneficial, but you should immediately stop any activity that triggers skipped beats (such as snow shoveling) and obtain cardiac evaluation before resuming vigorous exertion. 1

Understanding Your Current Activity Level

Your brisk walking without ill effects demonstrates you are tolerating moderate-intensity exercise well, which is the foundation of cardiac health in older adults. The American Heart Association recommends at least 150 minutes per week of moderate-intensity aerobic activity for adults aged 65 and older, which you are currently meeting. 1, 2, 3

• Moderate-intensity activity is defined as exercise that noticeably accelerates heart rate (equivalent to brisk walking) and can be accumulated in bouts of 10 minutes or more throughout the day 2, 3
• Your 30-45 minute daily walks fall squarely within recommended parameters for cardiovascular health maintenance 1, 3

The Critical Warning Sign: Exercise-Induced Arrhythmia

The skipped beats you experienced during snow shoveling represent a significant red flag that requires immediate attention. Exercise-induced ventricular ectopy, particularly during recovery or with sudden exertion, can be an independent predictive marker for death. 1

Key distinctions about your symptoms:

• Supraventricular arrhythmias (atrial premature beats) during exercise are common in older adults and generally benign in the absence of structural heart disease 1, 4
• However, any new arrhythmia triggered by exertion—especially one that stops with rest—warrants evaluation to rule out myocardial ischemia, structural heart disease, or dangerous ventricular arrhythmias 1, 5
• The fact that your symptoms resolved with rest and slowing down is reassuring but does not eliminate the need for cardiac assessment 1

Immediate Action Steps

Before resuming any vigorous activity beyond your current walking routine:

1. Obtain a symptom-limited exercise stress test to evaluate for exercise-induced ischemia and characterize the arrhythmia pattern 1
2. Rule out structural heart disease through echocardiography to assess your stroke volume index in context and identify any valvular disease, cardiomyopathy, or wall motion abnormalities 1
3. Verify thyroid function as thyroid dysfunction commonly triggers supraventricular arrhythmias in older adults 4

Exercise Prescription Based on Your Age and Cardiac Status

For your current walking program (which you should continue):

• Maintain your 30-45 minute daily brisk walks at an intensity where you can talk but not sing (moderate intensity) 2, 3
• Use the Borg Rating of Perceived Exertion scale, targeting 11-12 on the 6-20 scale ("fairly light" to "somewhat hard") 1
• Monitor your heart rate to stay below any ischemic threshold if identified on stress testing 1

Additional recommended components for optimal health at age 72:

• Resistance training 2-3 days per week using 1-3 sets of 8-15 repetitions for major muscle groups to maintain independence in activities of daily living 1
• Balance training at least 3 times weekly to prevent falls, which becomes increasingly important after age 65 1, 3, 6
• Flexibility exercises 5-7 days per week to maintain range of motion 1

Activities to Avoid Until Cardiac Clearance

Do not perform the following until you have cardiac evaluation:

• Snow shoveling or other sudden vigorous exertion that previously triggered arrhythmia 1
• High-intensity interval training or vigorous activity exceeding 60% of heart rate reserve 1
• Isometric exercises with heavy loads (such as lifting objects >20 pounds repeatedly) until structural heart disease is ruled out 1

The concern is not that exercise will harm your heart—quite the opposite. Regular moderate exercise reduces cardiovascular mortality and improves functional capacity. 1, 2 However, the specific pattern of exertion-triggered arrhythmia you experienced requires evaluation to ensure you don't have underlying ischemia or structural disease that could make certain activities dangerous. 1

Addressing Your Specific Concerns

"Am I helping my heart or harming it with walking?"

You are definitively helping your heart. Physical inactivity and deconditioning carry greater lifetime cardiovascular risk than prudent exercise, even in patients with cardiac conditions. 1 Your walking program:

• Improves cardiorespiratory fitness and reduces fall risk 1
• Decreases risk of recurrent cardiovascular events 1
• Enhances functional independence and quality of life 1

"Should I limit myself to mild walking until root causes are identified?"

Your current brisk walking is appropriate to continue, but you are correct to avoid activities that trigger symptoms until evaluation is complete. The key is distinguishing between:

• Safe moderate activity (your current walking) that you tolerate without symptoms 2, 3
• Vigorous exertion (snow shoveling) that triggered arrhythmia and requires medical clearance before resumption 1

Common Pitfalls to Avoid

• Do not stop your beneficial walking program based on fear alone—sedentary behavior poses greater risk than continued moderate activity you tolerate well 1
• Do not ignore exercise-induced arrhythmias even if they resolve quickly, as they may indicate underlying ischemia or structural disease requiring treatment 1
• Do not resume vigorous activities that previously caused symptoms without cardiac clearance, as the relative risk of myocardial infarction during exercise is 107 times baseline in sedentary individuals 1