Cardiac health, risk factors and rehab programs

• Cardiovascular health is affected by risk factors that cannot be controlled like age (males >45, females >55), gender, and family history (1st degree relative with a coronary event M<55, F<65).
• Risk factors that can be controlled include high blood pressure, smoking, high cholesterol, diabetes, sedentary lifestyle, stress, and abdominal obesity.

Stress Test

• Assessment of heart performance under physical stress.
• Bruce protocol isn't ideal due to large jumps between stages.
• ECGs are placed on the chest, a doctor monitors ECGs, and a kinesiologist monitors BP, HR, and RPE.
• Measuring BP is difficult during the test.
• Gas analysis may be done at some facilities.
• Stress test should be terminated if the patient feels they can't continue.

Cardiac Rehab Programs Testing

• Optimal duration: 8-12 minutes.
• Aim for a 5-6 minute test.
• Hard protocol is not suitable for deconditioned individuals.
• Bike protocol uses an algorithm based on age and weight to calculate the starting point.
• Bike protocol usually involves 10-watt increments.
• Treadmill protocol usually follows the Bruce protocol.

Acute Blood Pressure Response to Aerobic Exercise

• SBP should increase.
• DBP should either stay the same or decrease slightly.

Impact of Endurance Training on Blood Pressure

• Protocol consists of 30 minutes of treadmill exercise at the lactate threshold, 3-6 days per week, for 9 months
• Intensity is readjusted every 3 months.
• Maximal BP lowering effect is achieved within 3 months.
• Expect approximately a 15 mmHg reduction in systolic and 8-10 mmHg reduction in diastolic pressures.
• Initial BP and magnitude of exercise have BP lowering effects.
• The higher the initial BP, the greater the lowering effect.

Detraining Effects on Blood Pressure

• BP lowering effect of aerobic exercise doesn't last long.
• Detraining for just one month can raise BP back to pre-study levels.
• If you stop exercising for a short time, you lose the effects.

Weight Training and Blood Pressure

Valsalva Maneuver

• During strain causes poor venous return and increased intrathoracic and intra-abdominal pressure prevent blood return to the heart and increased venous pressure, arterial pressure, and HR.
• After straining causes a rapid reduction in BP following the release of breath, followed by an overshoot of arterial pressure.
• Sudden spike in BP increases oxygen demand, straining prevents blood from refilling the heart, reducing SV, and causing HR spikes rapidly to compensate.

Prescription for Elderly/Special Populations

• Use lighter weights.
• Avoid heavy weights, as they can cause older adults to strain.
• Don't allow sets to go to failure.
• Provide cues to prevent breath-holding.

Cardio Exercise and Blood Pressure

• Lifting overhead is acceptable.
• Blood pressure is more elevated during arm exercises compared to leg exercises.
• For a matched VO2 between legs and upper body, HR is higher when using arms.
• Arms have less muscle mass than legs, making it harder to match VO2.
• No recommendations advise against overhead presses.

Rate Pressure Product

• Calculated by multiplying systolic BP by HR, estimates the metabolic demand on the heart.
• There is no unit.
• Angina may occur around 23,000.
• Heavy overhead lifting leads to high systolic BP and a quick burst in HR.
• Recognize when something is wrong

Angina

• It is difficult to distinguish between pain from angina and pain from a heart attack.
• Blockages are likely during angina.
• The person feels more pain with movement during angina.

Early Warning Signs of Myocardial Infarction

• Anatomic locations include arm, chest, jaw, down the arm, between shoulder blades, and upper abdomen.
• Upper abdominal pain is hard to recognize because it often masks something else.
• Other signs include being pale, anxious, sweating, shortness of breath, overall weakness, nausea, and elevated HR.

Heart Attack Signs in Women

• Symptoms are generally milder.
• Suffer uncomfortable pressure, squeezing, fullness, or pain in the center of the chest lasting more than a few minutes that goes away and comes back (most common)
• Other signs include pain or discomfort in one or both arms, back, neck, jaw, or stomach, shortness of breath with or without discomfort, cold sweat, nausea, lightheadedness, or mistaking it for the flu.

Medications for Cardiovascular Disease

• Common BP medications include Angiotensin converting enzyme (ACE) inhibitors, Angiotensin receptor blockers (ARB’s), Diuretics, Calcium channel blockers (CCB’s), and Beta blockers
• Orthostatic hypotension occurs when systolic BP decreases by 20 mmHg or diastolic BP decreases by 10 mmHg within 3 minutes upon quickly changing body positions
• People on BP medication are likely on hyperlipidemia meds

ACE Inhibitors and ARBs

• Angiotensin 2 is a potent hormone
• ACE inhibitors prevent the conversion of angiotensin 1 to angiotensin 2
• ACE inhibitors do not affect energy metabolism or impair oxygen uptake
• Some ACE inhibitors give orthostatic hypotension because the body must change the amount of pressure it needs to get blood to the brain and BP meds make SV adjustments more difficult
• ACE Inhibitors cause a decrease in HR, increase in SV, and decrease total peripheral resistance TPR
• ARB's prevent angiotensin from binding to its receptor

Diuretics

• Diuretics are often the first medication choice to treat hypertension and make the patient pee more
• They Get rid of plasma, so the less plasma there is then the less pressure on blood vessels while reducing SV and cardiac output
• Plasma helps regulate body temperature during exercise by sweating
• Less fluids increases the likelihood of overheating
• The more calcium in heart muscle cells and blood vessel wall cells, the greater the contractility

Calcium Channel Blockers

• Reduces the amount of calcium in cardiac cells and vascular cells
• Blood vessels have muscles surrounding them
• Reducing the amount of calcium in both heart muscle cells and blood vessel wall cells induces relaxation to elicit a lower work rate for the heart
• Calcium Channel Blockers might provoke hypotensive responses after abrupt cessation from exercise

Beta Blockers

• Competitively block beta-receptors in the heart, preventing changes from heart remodeling after a heart attack by preventing changes.
• A heart remodels following a heart attack (cells start to change significantly)
• Most individuals who have had a heart attack are on beta-blockers

Massive Impact on Exercise

• Impairs a patients HR from going past a certain number.
• Exhaustion occurs because HR is lower, meaning lower oxygen demand
• Cardiac output is poor due to beta-blockers causing a burning sensation when doing cardiac
• Leads to post exercise hypoglycemia and reduced heat tolerance

Programming Recommendations for Individuals Taking Anti-Hypertensive Medications

• Hypoglycemia: Not common, depends on generation of drug prescribed. Older ones have more side effects; be aware of signs and symptoms, instruct individual on prevention strategies.
• Heat tolerance: Proper hydration, wear clothing that promotes evaporation of sweat .
• Post exercise hypotension: Extend cool downs .
• Exercise intensity: Be aware of drugs that impact exercise intensity.

Cholesterol Biosynthesis in the Liver

• All your cells can synthesize cholesterol, but the main organ is the liver
• Statins inhibit HMG-CoA reductase activity which reduce cholesterol production in the liver, e.g. Lipitor.

Medications used to treat Hypercholesterolemia/Hyperlipidemia

Statins

• 80% is reached at a lower dose, when you increase dose, effectiveness doesn't increase by much, but side effects go up
• Bile acid sequestrants increase secretion of bile acids in feces, forcing the liver to take up more cholesterol in order to make more bile Activates a transcription factor which increases expression of proteins involved in fatty acid oxidation, LPL activity, fatty acid transport protein
• Cholesterol uptake inhibitors reduce absorption of cholesterol from ingested food

Lipid Lowering Meds

• Statins can cause muscle soreness, which can lead to rhabdomyolysis
• Fibrates can have a synergistic potential to cause rhabdomyolysis when used together with statins

Nitroglycerine

• Prescribed to cardiac patients
• Used to acutely treat angina
• Works by dilating blood vessels; in low doses, it dilates veins, thus reducing preload and hence O2 demand and dilates arteries as well as reducing afterload in higher doses
• Works in minutes

General Prescription for Patients with CVD

• 40-80% intensity captures most conditions
• Heart rate reserve = (MaxHR - RHR) x training %) + RHR
• Use testing data if available

Cardiac Rehabilitation Considerations

• Allows time for cardiac blood vessels to dilate and allow for increased blood flow to match the increased oxygen requirements by Proper warmup for cardiac patients
• Sudden cessation leads to blood pooling in periphery; leads to reduced venous return = reduced blood to head; increases risk of passing out, especially in people who take BP meds
• Cool down allows for adjustments to gradually constrict, but ability to constrict is blunted for People on BP meds by doing a Proper cool down
• Exercising in hot weather leads to Losing fluid = reduced blood volume and venous return; HR will speed up to maintain the same cardiac output; Heat increases HR because you lose fluid through sweating = CV drift; Sweating = losing plasma volume; Venous return decreases; Decreased by increasing HR = chance of heart attack

Exercising in Cold

• Sympathetic activation increases HR and contractility and can contribute to irregular heart beats
• Sympathetic NS activation occurs along with Vasoconstriction in periphery and skin, increase in resistance and MAP, and Afterload increases
• Heart has to increase amount of work performed
• Breathing cold air can also narrow coronary arteries
• When you increase HR, you increase metabolic demand for heart, which is a problem for older people
• Don't exercise outdoors if temp is below -10 °C or combined temp and wind chill is below this Most heart attacks happen during the first snowfall of the year when shovelling
• Warm weather response is different because warm weather you lose fluids, cold weather = vasoconstriction