Transcript Electrode Placement for Chest Leads, V1 to V6

C H A P T E R
18
Exercise and Heart
Disease
David R. Bassett Jr.
Chapter 18
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
• 1.255 million myocardial infarctions (MIs) in
2010
• 785,000 of these are first-time MIs; rest are repeats
• 80% survival rate
• Many show up in cardiac rehabilitation programs
Hypertension
• Stage I: SBP 140-159 mmHg; DBP 90-99 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 160-179 mmHg; DBP 100-109 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
VO2max (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 VO2max 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 VO2
• 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 O2 demand or
vasodilate coronary arteries
• Radionuclide examples
• Thallium 201: IV injected and taken up by wellperfused 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 VO2 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