LEC 15: Exercise for Cardiovascular Disease

What did the meta analysis find on benefits of aerobic exercise in individuals with CHD?

• Meta-analysis of 85 trials of aerobic exercise, 23,430 subjects with CHD (Dibben et al, 2023)

  • 26% lower risk of CVD related mortality

  • 23% lower risk of hospitalization

  • 18% lower risk of MI

• ↑ exercise capacity

• Improves QoL

• ↓ angina pectoris

• Facilitates return to work

What is exercise for CVD?

Aerobic & RT – highest level recommendation form AHA and ACC Cardiac Rehabilitation is the primary model of clinic-based, supervised exercise training for people with CHD Many patients with CVD will not be able to exercise at moderate intensity workloads (3-6 METs) due to low exercise capacity – this emphasizes the importance of aerobic exercise to increase CRF Exercise programs should focus on aerobic exercise training utilizing exercise modes that engage large muscle groups

What are symptoms of exercise intolerance?

Excessive fatigue Dizziness Light-headedness Angina

What is the special consideration with medications?

Take their medication at usual time as recommended by healthcare provider Those on β-blockers will have reduced resting and exercise heart rates

What is target HR for CVD?

Estimates (e.g., 220-age) should not be used Meds with lower HR Establish based on a sign and symptom-limited maximal exercise test after their cardiac event and their medications have been optimized Upper limit = 10 bpm below the HR at the ischemic threshold

What are the special considerations for intensity with CVD?

Do not exercise at an intensity that causes S&S of MI (angina, ECG findings) or poor perfusion (light-headedness, dizziness) Any chest discomfort, reduce intensity to avoid it Prolonged warm up may reduce the occurrence of exercise-induced angina Those who repeatedly experience angina may benefit from nitroglycerin pre-exercise

What are the alternatives to a symptom-limited max exercise test?

Although symptom-limited max exercise test to determine THR is recommended, only 17% of patients in Cardiac Rehabilitation have a recent test 20-30 bpm above resting HR – suboptimal training intensity Self-reported perceived exertion – Borg RPE scale Align this with HR, or workload Talk Test

What is resistance training for CVD?

Resistance Training Safe & an important adjunct to aerobic training Consider adding RT after adherence to 2-4 weeks of regular aerobic training Contraindications

What is cardiac rehabilitation?

Used to deliver exercise training & other lifestyle interventions Designed to reduce risk, foster & promote healthy behaviours & reduce disability for individuals with several forms of heart disease Inpatient (Phase 1) Outpatient Early (Phase 2) Maintenance (Phase 3)

What are the aims of inpatient cardiac rehabilitation?

Assessment & clinical stability Prevention of secondary events (e.g., embolisms) Avoiding bedrest Exposure to gravitational stress (e.g., intermittent sitting or standing) within 12-24 hours after an MI may prevent deterioration in exercise tolerance that often follows an acute cardiac event & subsequent bedrest Promoting early mobilization & ambulation Health education Diagnosis Risk factors Resumption of activities Medications Discharge planning Referral to outpatient CR

What is inpatient cardiac rehabilitation?

At discharge, the individual should have specific instructions regarding strenuous activities (e.g., heavy lifting, climbing stairs, yard work, household activities) that are permissible and those they should avoid A safe, progressive plan of exercise should be formulated before leaving the hospital Until evaluated with an exercise test or entry into a clinically supervised outpatient CR program, the upper limit of HR or RPE noted during exercise should not exceed those levels observed during the inpatient program Individuals should be counseled to identify abnormal signs and symptoms suggesting exercise intolerance and the need for medical evaluation All eligible individuals should be strongly encouraged to participate in a clinically supervised outpatient CR program

How is outpatient cardiac rehabilitation effective?

Effective in preventing a secondary cardiac event for: MI Heart failure CABG Heart valve surgery Heart transplant Reduces the rate of mortality & morbidity in individuals with various forms of CVD Continues to be underutilized Despite strong evidence demonstrating desirable outcomes < 29% of eligible patients participated in more than 1 session of outpatient CR

What are the components of CR?

CV risk factor assessment Education & support to make healthy lifestyle changes to reduce the risk of a secondary cardiac event Development & implementation/supervision of a safe & effective personalized exercise plan Monitoring with a goal of improving BP, lipids/cholesterol, & diabetes Psychological/stress assessment & counseling Communication with physician & other health care providers regarding progress & relevant medical management issues Return to appropriate vocational & recreational activities

What assessments are required at program entry and what must be monitored during each session?

• At the time of program entry, the following assessments should be performed:

  • Medical and surgical history including the most recent cardiovascular event, comorbidities, and other pertinent medical history

  • Physical examination with an emphasis on the cardiopulmonary and musculoskeletal systems

  • Review of recent cardiovascular tests and procedures including ECG, coronary angiogram, echocardiogram, stress test (exercise or pharmacological studies), cardiac surgeries or percutaneous interventions, and pacemaker/implantable defibrillator implantation

  • Current medication routine/dose/frequency CVD risk factors

• Routine assessment should be performed before, during, and after each rehabilitation session, as follows:

  • HR, BP, body weight

  • Symptoms or evidence of change in clinical status not necessarily related to activity (e.g., dyspnea at rest, light-headedness or dizziness, palpitations or irregular pulse, chest discomfort)

  • Symptoms of exercise intolerance

  • Change in medications and adherence to the prescribed medication regimen

  • Consider ECG and HR surveillance

How is chronic HF classified, what are its risks, and how does it affect exercise physiology?

• Defined by exertional dyspnea/fatigue with:

  • HFrEF (systolic dysfunction)

  • HFpEF (diastolic dysfunction)

• Acute HF distribution: ~53% HFrEF, 47% HFpEF

• 1-year mortality ≈ 30%

• Exercise limitations vs healthy individuals:

  • ↓ peak HR, stroke volume, cardiac output

  • Impaired vasodilation → ↓ blood flow

• Severe limitation (transplant candidates):

  • <50% predicted capacity or VO₂ <12 mL/kg/min

• Clinical implication: start low intensity, gradual progression

What are the benefits and key principles of exercise prescription in HF?

• Adaptations (especially HFrEF):

  • ↑ exercise capacity (10–30%)

  • ↑ central hemodynamics

  • ↑ autonomic function

  • ↑ peripheral vascular & skeletal muscle function

  • Results: lower HR, less effort, ↓ dyspnea/fatigue at submax workloads

• HFpEF:

  • Also benefits (↑ QoL, muscle function, exercise capacity)

• Prescription principles:

  • THR based on peak HR from symptom-limited test

  • HIIT: similar or greater VO₂peak improvements (stable HFrEF)

  • Progression: increase duration/frequency before intensity

  • Dose-response: inverse relationship with mortality/hospitalization up to 7 MET-h/week

  • Add resistance training after ≥4 weeks aerobic adaptation

How is claudication assessed and what is the recommended exercise approach and outcome?

• Assessment:

  • Functional capacity + limitations (often pain-limited)

• Measure:

  • Time/distance to onset of pain Time/distance to maximal pain Total walking distance (pre/post intervention)

• Guidelines:

  • Supervised exercise recommended before revascularization (AHA/ACC)

    • Exercise prescription:

      • Walking to moderate–max claudication pain → rest → repeat

• Targets:

  • Mild pain within 5 min Moderate pain within 10 min

  • Resume once pain fully subsides

• Outcomes:

  • ↑ distance to pain onset: +179%

  • ↑ distance to maximal pain: +122