Hypertension - A Comprehensive Guide PDF

## Internal Medicine ### Hypertension - Persistent elevation in blood pressure is called hypertension. - Hypertension is the most common cardiovascular disease in the world. ### Blood Pressure - **Blood pressure** is the amount of **force** the blood uses to get through the arteries. - **Blood p...

## Internal Medicine ### Hypertension - Persistent elevation in blood pressure is called hypertension. - Hypertension is the most common cardiovascular disease in the world. ### Blood Pressure - **Blood pressure** is the amount of **force** the blood uses to get through the arteries. - **Blood pressure** is the **measure of force** that the heart uses to pump the blood around the body. - **Blood pressure** is the **pressure of circulating blood against walls** of blood vessels. ### Types of Blood Pressure - **Systolic BP:** contraction of the ventricles - **Diastolic BP:** relaxation of the ventricles ### Factors Affecting Blood Pressure - **Cardiac Output:** Stroke Volume x Heart Rate - **Total Peripheral Resistance:** Systemic Vascular Resistance + Blood Vessel Resistance ### Classification of Blood Pressure | Stage | Systolic (mmHg) | Diastolic (mmHg) | |---|---|---| | Normal | Less than 120 | Less than 80 | | Elevated (Prehypertension) | 120 to 129 | Less than 80 | | Stage 1 | 130 to 139 | 80 to 89 | | Stage 2 | 140 to 180 | 90 to 120 | | Hypertensive Crisis | Higher than 180 | Higher than 120 | ### Regulation of Blood Pressure **Sympathetic Nervous System** - **Direct:** Stimulates smooth muscle, vasoconstriction -> Increased BP - **Indirect:** - Stimulates SA node -> Increased heart rate -> Increased BP. - Sends impulses to kidney to release Renin. - Sends impulses to adipose tissue (fat cells) to release angiotensinogen. **Renin-Angiotensin-Aldosterone System** - Renin is released from the kidney. - Renin, angiotensinogen and angiotensin converting enzyme react to create angiotensin II. - Angiotensin II, vasoconstricts arteries, goes to adrenal gland and triggers release of aldosterone. - Aldosterone increases sodium reabsorption and water retention. - This overall results in increased blood pressure. **Other Factors** - **Antidiuretic Hormone (ADH):** released from the Posterior Pituitary. Decreases urine volume and increases blood pressure. - **Nitric Oxide:** Causes vasodilation and decreases blood pressure. - **Smooth muscle activation:** Reduces vessel diameter and increases blood pressure. ### Types of Hypertension - **Primary (Essential) Hypertension:** 90-95% of cases. Cause is unknown. - **Secondary Hypertension:** Due to a previous medical condition. ### Other Types of Hypertension - **Labile Hypertension:** Fluctuation between normal and high. - **White Coat Hypertension:** High blood pressure only at the doctor's office. - **Masked Hypertension:** High blood pressure during everyday life, but normal at the doctor's office. - **Malignant Hypertension:** High blood pressure (160/110) that can lead to stroke. ### Risk Factors of Hypertension - Obesity - Smoking - Excessive sodium or alcohol intake - Glucose intolerance - Lack of exercise - Stress - High intake of potassium, calcium, and magnesium. ### Pathophysiology of Hypertension - **Early stages:** Hypertrophy of the left ventricle. Increased force of contraction. Increased heart rate. - **Later stages:** Increased left ventricular wall thickness. Decrease in stroke volume. Decreased cardiac output. - **Advanced stages:** Atrial contraction. Atrial fibrillation. Pulmonary congestion. Heart failure. ### Complications of Hypertension - Stroke - Coronary artery disease - Cerebrovascular disease - Peripheral artery disease - Renal insufficiency ### Impact of Hypertension on Organs - **Retinopathy**: Affects the eyes. - **Cerebrovascular accident (stroke), hemorrhage**: Affects the brain. - **Hypertensive heart disease**: Affects the heart. - **Atherosclerotic heart disease**: Affects the heart. - **Renal insufficiency**: Affects the kidneys. - **Aortic aneurysms**: Affects the aorta. - **Peripheral vascular disease**: Affects the blood vessels. ### Clinical Manifestations of Hypertensive Heart Disease - Fatigue and exertional dyspnea - Signs and symptoms of heart failure. - Exertional chest discomfort. - Symptoms of tachycardia and loss of active atrial contraction. ### Treatment of Hypertension - Goal is to reduce BP to less than 140/90mmHg, ideally less than 125/130/75-85mmHg. - **Lifestyle modification:** Weight reduction, physical activity, stress management. - **Pharmacological therapy:** - **Diuretics:** Reduce blood volume - **Beta-blockers:** Reduce heart rate. - **Calcium channel blockers**: Dilate blood vessels. - **Alpha blockers:** Dilate blood vessels. - **Angiotensin converting enzyme inhibitors (ACE inhibitors):** Block the production of angiotensin II which leads to vasoconstriction. - **Angiotensin receptor blockers (ARB's):** Block the effect of angiotensin II. ### Physical Therapy Role in Hypertension - Benefits of exercise: - Increase elimination of sodium and reduce fluid volume and decrease BP. - Decreases cardiac output, total peripheral resistance, heart rate, and BP at rest and lower levels of exercise. - Decreases visceral fat and body weight. - Decreases resting BP due to a decrease in total peripheral resistance. ### Exercise Prescription - **Mode:** Aerobic or moderate intensity resisted exercise. - **Duration:** 30-60 minutes. - **Frequency:** 3-5 days per week. - **Intensity:** 40-70% of VO₂ reserve. (VO₂ reserve is the difference between resting oxygen consumption and maximum oxygen consumption) - **Training Heart Rate Ranges:** - 65-80% of maximum heart rate - 50-70% of VO₂ max - 40-70% of VO₂ reserve ### Exercise Precautions and Contraindications - Monitor blood pressure before and after exercise. - If systolic blood pressure is greater than 200mmHg or diastolic blood pressure is greater than 110 mmHg, medical clearance is needed before starting exercise. - If patient has history of retinopathy, renal failure, or left ventricular hypertrophy, blood pressure needs to be controlled (systolic < 125-130, diastolic < 75-85) at rest and during exercise.