Hypertension Lecture

Blood Pressure

• Blood pressure is the force of blood exerting against the walls of blood vessels, which can cause damage to vessel walls due to irritation of the inner layer.
• Systolic pressure is the pressure in the artery during ventricular contraction, while diastolic pressure is the pressure in the artery when the ventricles are relaxed.

Factors Affecting Blood Pressure

• Physical exertion and stressful moments can increase blood pressure.
• Age can decrease elasticity, making blood vessels stiffer, which increases blood pressure.
• Smoking can make blood more viscous, leading to scarring and increased blood pressure.
• Alcohol can stimulate the sympathetic nervous system, increasing blood pressure.
• Caffeine can constrict blood vessels, causing the heart to pump harder and increasing blood pressure.

Hypertension Definition

• Hypertension is defined as consistently elevated blood pressure, specifically:
  • Elevated systolic pressure (≥140 mm Hg) and/or
  • Elevated diastolic pressure (≥90 mm Hg)

Hypertension Complications

• Coronary artery disease (CAD)
• Heart failure
• Chronic kidney disease
• Stroke
• Intracerebral hemorrhage
• Transient ischemic attack (TIA)
• Peripheral artery disease (PAD)
• Aortic regurgitation
• Atrial flutter

Types of Hypertension

• Primary (essential) hypertension: high blood pressure not resulting from a medical condition, due to environmental and genetic factors.
• Secondary hypertension: abnormally elevated blood pressure due to a medical condition or use of certain medicines.

Classification and Measurement

• Blood pressure levels should be based on an average of 2-3 readings on repeated measurements.
• Different professional organizations have varying definitions of hypertension.
• Ambulatory blood pressure monitoring (ABPM) and home blood pressure monitoring can be used to confirm diagnosis.
• Masked hypertension: elevated blood pressure at home/ambulatory BP monitoring but normal office blood pressure.
• White coat hypertension: normal blood pressure at home/ambulatory BP monitoring but elevated office blood pressure.

Additional Testing

• Blood tests: sodium, potassium, creatinine, fasting blood glucose, fasting lipid profile.
• High sodium intake (>2 g/day) is associated with higher blood pressure.
• Low dietary potassium intake (<40 mEq/day) is associated with elevated blood pressure and increased risk of stroke.
• Higher creatinine levels are associated with chronic renal disease.
• Higher fasting blood glucose levels are an independent risk marker for new development of hypertension.
• Cardiovascular disease is associated with hypertension and increased blood levels of LDL, total cholesterol, and triglycerides.

Other Tests to Consider

• Dipstick urine test for proteinuria.
• Electrocardiogram (ECG) for detection of atrial fibrillation, left ventricular hypertrophy, and ischemic heart disease.
• Hemoglobin/hematocrit for oxygen carrying capacity.
• Serum uric acid for decreased renal blood flow.
• Echocardiogram for left ventricular hypertrophy and structural heart disease.
• Fundoscopy for retinal changes, hemorrhages, papilledema, tortuosity, and AV-nicking.
• Carotid ultrasound for plaques and stenosis.
• Targeted testing for suspected causes of secondary hypertension.

Blood Pressure Targets and Cardiovascular Risk Factors

• Blood pressure targets vary depending on the organization.
• As age increases, blood pressure targets also increase due to high fall risk.
• >50% of hypertensive patients have additional cardiovascular risk factors, including diabetes, lipid disorders, hypothyroidism, overweight-obesity, hyperuricemia, and metabolic syndrome.

This lecture covers the definition, incidence, prevalence, risk factors, types, symptoms, pathophysiology, complications, and treatment options of hypertension.