Chapter Exercise and Heart Disease David R. Bassett Jr. C H A P T E R

Terminology Atherosclerosis Endothelial cells Myocardial ischemia Myocardial infarction Claudication Angina

Cardiovascular Disease Leading cause of death in the United States CHD (51%) Stroke (17%) Hypertensive disease (7%) CHF (7%)

Coronary Heart Disease Death rate from CHD has declined in recent decades More survivors due to advances in medicine million myocardial infarctions (MIs) in ,000 of these are first-time MIs; rest are repeats 80% survival rate Many show up in cardiac rehabilitation programs

Hypertension Stage I: SBP mmHg; DBP mmHg often treated initially with lifestyle modification; meds can follow if modifications are unsuccessful Sodium restriction (SBP and DBP change of 5 and 3 mmHg) Weight loss (loss of 1 kg may decrease SBP and DBP by 1.6 and 1.3 mmHg) Endurance training may reduce SBP and DBP by 7 and 6 mmHg, respectively Stage II: SBP mmHg; DBP mmHg Typically, medication is added for control (continued)

Hypertension (continued) Stage III: Persistent SBP >80 mmHg or DBP >110 mmHg Often results in end organ damage Left ventricular enlargement Kidney damage (renal insufficiency) Damage to eyes

Exercise Guidelines for HTN Follow similar guidelines for improving VO 2 max (chapter 11) Moderate-intensity exercise often acutely reduces BP; this reduction may last a few hours postexercise Frequent bouts are encouraged daily Monitor BP frequently Resting levels, exercise, and postexercise initially Make MD aware of chronic changes as endurance program progresses

Populations in Cardiac Rehab Programs CABG, MI, diagnosed angina, balloon angioplasty, stent placement, heart transplants Focus of treatment Reduce further occurrences of angina or MI (secondary prevention) Research indicates a 20 to 25% reduction in all-cause and CV mortality after an MI

Evidence for Exercise Training Higher VO 2 max values after training Higher work rates achieved without ischemia Increased capacity for prolonged submaximal work Moderate reductions in body fat, blood pressure, total cholesterol, triglycerides, LDL-C; increases in HDL-C

Can Atherosclerosis Be Reversed? Dr. Dean Ornish has demonstrated (via studies) that lifestyle modification may reverse CAD in some patients Strict vegetarian diet, yoga, meditation, smoking cessation, physical activity Many patients showed a reversal of blockages (regression is higher after 5 years than after 1) Program can be difficult to follow and maintain but has had some promising results

Special Diagnostic Testing Generally, GXTs offer more benefits than risks See chapter 7 for absolute and relative contraindications to testing Diagnostic testing looks for evidence of CAD or ischemia Goal is not always achieving a percentage of HRmax or predicting VO 2 Almost always done in a hospital setting with MD supervision

Diagnosed CHD and the Angina Scale During exercise, patients should be queried about their level of angina 1: barely noticeable 2: moderate, bothersome 3: moderately severe, very uncomfortable 4: uncomfortable; most severe or most intense pain ever Exercise should stop for subjective level 2 or higher

Other Tests for Heart Function Radionuclide procedures Exercise Nonexercise (pharmacological): pharmacologic agents used to increase myocardial O 2 demand or vasodilate coronary arteries Radionuclide examples Thallium 201: IV injected and taken up by well- perfused cardiac muscle, visible on a screen Technetium-99m: radioisotope that binds to RBC; useful for blood pool imaging (ESV, EDV measurements)

Definitive Tests for CHD Coronary angiography Contrast dye injected into coronary artery; occlusion shows on a screen (figure 18.4) Positron emission tomography (PET) scans Uses substances that allow the level of myocardial cell metabolism to be viewed on a screen Metabolically active areas = highly perfused areas

Typical Exercise Prescription Process of cardiac rehabilitation (CR) should be understood because many of these patients will work their way into the public realm at some point Phase I CR Acute or inpatient phase: education, bedside or hallway ambulation Home care activity instruction (continued)

Typical Exercise Prescription (continued) Phase II: initial outpatient program (several weeks to 1 year postevent) Aerobic (endurance) conditioning Frequency: 3 or 4 days per week Intensity: 40% to 75% (initially) of VO 2 max or HRR** Duration: 20 to 40 minutes per session (plus 5 to 10 minutes of warm-up and cool-down) Mode: treadmill, cycle, stepping, rowing, stair climbing Resistance training (see ch. 13) ** Beta-blockers render traditional THR calculations useless; use alternative methods

Typical Exercise Prescription (continued) Phase II, continued Careful monitoring of HR, BP, ECG, glucose levels Education: healthy eating, stress management, cardiovascular medications, behavior modification Phase III Hospital-based fitness program Clients have learned to self-monitor but still attend classes and sometimes require spot monitoring or assistance Phase IV: nonhospital setting to continue activities