Hypertension and Cardiovascular Risks

Co-morbidities of Untreated Hypertension

• Cardiomyopathy, heart failure, renal disease, myocardial infarction, stroke, and aneurysm are co-morbidities associated with untreated hypertension.
• Hypertension can lead to endothelial dysfunction, hypercoagulability, and autonomic nervous system imbalances, further increasing the risk of cardiovascular events.

Exercise Physiology and Hypertension

• Hypertension is a modifiable risk factor for cardiovascular disease (CVD) with a high lifetime prevalence.
• Understanding the implications of hypertension on cardiovascular health and exercise physiology is crucial for developing effective treatment and prevention strategies.
• Proper diagnostic techniques, treatment procedures, and exercise tests are essential for individuals with hypertension.

Graded Exercise Testing

• Non-invasive graded exercise testing (GXT) is used for differential diagnosis of adults with suspected ischemic heart disease (IHD) under 50 years old.
• GXT with 12-lead electrocardiogram (ECG) is the test of choice to evaluate myocardial ischemia in those with normal resting ECG and the ability to exert themselves.

Cardiac Risk Factors and Pathophysiology

• Endothelial dysfunction contributes to the formation, progression, and complications of atherosclerotic plaque, resulting in cardiovascular disorders, including hypertension and heart failure.
• Chronic inflammation and shear stress are underlying mechanisms of endothelial dysfunction.
• Local endothelial shear stress (ESS) distribution by pulsatile blood flow modulates the atherogenic process.

Cardiopulmonary Conditions

• Co-morbidities include asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis, depression, anxiety, diabetes, arthritis, and more.
• Cardiac risk factors include non-modifiable (family history, gender, age, race) and modifiable (smoking, hypertension, dyslipidemia, physical inactivity, obesity, type 2 diabetes) factors.

Meeting the Client (A)

• The interview process involves collecting subjective information, assessment, and evaluation of objective measures, ensuring a quiet and secure setting, and building empathy and trust with the client.
• The steps include a general interview, assessment and evaluation, environment, reason for referral, demographics, history of present illness, medications and allergies, medical history, family and social history, and goals (SMARTER).

Pathophysiology of Cardiac Risk Factors

• Cardiac risk factors include cardiopulmonary conditions, co-morbidities, and cardiac risk factors.
• Unstable angina is characterized by transient vessel occlusion, necrosis of cardiac myocytes, and timely reperfusion to prevent irreversible damage.

Peripheral Artery Disease

• Risk factors for peripheral artery disease include smoking, diabetes, hypertension, and age above 50.
• Pathophysiology involves endothelial damage in peripheral arteries, resulting in abnormal blood flow and leg pain symptoms, such as cramping, aching, tightening, and fatigue.

Critical Limb Ischemia

• Critical limb ischemia is characterized by ischemic rest pain, foot ulcers, and gangrene attributable to arterial occlusive disease.
• Mortality rates are high, with 25% in the first year, and 25% requiring amputation.

Valvular Disorders

• Valvular disorders involve damage or defects in the aortic, mitral, tricuspid, or pulmonary valves, which can be congenital or acquired.
• Risk factors include smoking, gender, age, hypercholesterolemia, hypertension, and type 2 diabetes.

Myocardial Infarction

• Myocardial infarction is characterized by necrosis of cardiac myocytes caused by prolonged ischemia due to complete blockage of a vessel.
• Diagnosis involves symptoms of ischemia, ECG evidence of myocardial ischemia, new pathological Q waves on the ECG, imaging evidence of infarction, and elevated cardiac necrosis biomarkers (cardiac troponin).

Exercise and Cardiovascular Health

• Regular exercise reduces the death rate by 20-25% in heart attack patients.
• Risk of a cardiac event is significantly lower among regular exercisers.
• A sedentary person's risk is nearly 50 times higher than someone who exercises 5 times a week.

Endothelial Dysfunction and CVD

• Endothelial cells regulate blood flow, vascular tone, and maintain low levels of oxidative stress.
• Imbalance between vasodilators and vasoconstrictors leads to oxidative stress, reactive oxygen species, and endothelial dysfunction.
• Endothelial dysfunction contributes to the formation, progression, and complications of atherosclerotic plaque.
• Damaged endothelial cells decrease nitric oxide production, leading to oxidative stress and inflammatory response.

Chronic Inflammation

• Chronic inflammation is an underlying mechanism for endothelial dysfunction.
• Endothelium controls vascular inflammation by releasing nitric oxide.
• C-reactive protein (CRP) is a protein present in the acute inflammatory response.

Shear Stress

• Local endothelial shear stress (ESS) is a modulator of the atherogenic process.
• Shear stress is distributed throughout the vascular tree, with lesions usually generating at specific arterial regions, such as bifurcations and branching points.

Pathophysiology of Cardiac Risk Factors

• Cardiopulmonary conditions include hypertension, atherosclerosis, myocardial infarction, ischaemic heart disease, peripheral arterial disease, valve diseases, angina, and chronic heart failure.
• Co-morbidities include depression, anxiety, diabetes, arthritis, asthma, COPD, and cystic fibrosis.
• Cardiac risk factors include non-modifiable (family, gender, age, race) and modifiable (smoking, hypertension, dyslipidaemia, physical inactivity, obesity, type 2 diabetes, diet) factors.

Hypertension

• Hypertension is a significant risk factor for cardiovascular disease, with a 90% lifetime risk of developing the condition.
• The pathophysiology of hypertension involves multiple systems, including renal, endocrine, vascular, and central adrenergic systems.
• Primary hypertension is typically due to increased peripheral resistance, while secondary hypertension can be caused by renal issues or endocrine abnormalities.

Gas Exchange

• Cardiorespiratory fitness is inversely related to mortality, with a 13% reduction in risk for all-cause mortality associated with each 1-MET increase in cardiorespiratory fitness.
• CPET (cardiopulmonary exercise testing) measures physiological responses during exercise, including oxygen uptake, ventilation, and heart rate.
• Gas exchange is useful in defining prognosis and guiding the timing for cardiac transplantation in patients with heart failure.

Factors Influencing Prognosis of CVD

• Angina, ST-segment depression, and functional capacity (FC) influence prognosis of CVD.
• The magnitude of ST depression, the number of ECG leads showing significant ST-segment depression, and the time of onset and resolution of ST-segment depression during exercise also affect prognosis.

GXT Protocols

• The Bruce protocol is suitable for people who are not frail and do not have extremely low functional capacity.
• The Naughton protocol is suitable for elderly individuals and involves shorter stages (1-2 minutes) compared to the Bruce protocol.
• The post-monitor period involves a 6-minute recovery period after testing.

ST-Segment Depression

• ST-segment depression > 1mm during exercise is suggestive of sub-endocardial ischemia.
• The likelihood of CAD is high when ST-segment depression occurs with angina, early onset, and longer duration for ST depression to resolve in recovery.

S-T Segment Elevation

• ST-segment or J-point elevation on a resting ECG is often due to early repolarization and is not necessarily abnormal in healthy individuals.
• New ST-segment elevation with exertion (with a normal resting ECG) may suggest transmural ischemia or coronary artery spasm.