CIRCULATORY SYSTEM
CIRCULATORY SYSTEM DISEASES
HYPERTENSION (HIGH BLOOD PRESSURE)
Definition: A chronic medical condition in which blood pressure is 130/80 mm Hg or higher. The ideal blood pressure for most adults is lower than 120/80 mm Hg.
Implications: Forces the heart to work harder to pump blood, increasing the risk of heart attack, stroke, kidney diseases, and other complications.
Prevalence and Statistics
Approximately 1.4 billion adults worldwide have hypertension.
Less than 1 in 5 cases are controlled.
Hypertension contributes to over half of cardiovascular deaths globally.
Types of Hypertension
Primary (Essential Hypertension)
Develops gradually over many years.
Secondary Hypertension
Caused by an underlying condition or certain medications.
Causes of Hypertension
Non-modifiable Factors:
Family history
Aging
Modifiable Factors:
Obesity
High sodium diet
Excessive alcohol intake
Physical inactivity
Stress
Medical Conditions:
Kidney disease
Thyroid problems
Adrenal gland tumors
Congenital heart defects
Obstructive sleep apnea
Medications / Substances:
Certain drugs (e.g., birth control pills, pain relievers)
Illegal drugs (e.g., cocaine, amphetamines)
Pathophysiology
Mechanism: Hypertension occurs when blood vessels become narrowed or stiff, increasing resistance to blood flow.
Over time, this increased pressure can damage blood vessels, heart, kidneys, or brain.
Normal Circulation: The heart pumps blood through arteries with minimal resistance.
In Hypertension: Arteries become narrower and less flexible, forcing the heart to pump harder to move blood through the body.
Signs and Symptoms
Often referred to as the “silent killer” due to the lack of symptoms in many patients.
Symptoms, when they appear, are usually at severe or life-threatening stages:
Headaches and dizziness
Shortness of breath
Nosebleeds
Blurred vision
Chest pain and fatigue
Importance of Regular Checks: Due to possible lack of symptoms, regular blood pressure checks are critical.
Diagnosis
Clinics Blood Pressure Measurement:
Blood pressure is checked in a healthcare setting using a cuff device. Readings are repeated at different times for accuracy.
Ambulatory Blood Pressure Monitoring (ABPM):
Uses a portable device that records blood pressure over 24 hours during normal activities and sleep, providing a more accurate picture.
Home Blood Pressure Monitoring (HBPM):
Patients track blood pressure at home using validated devices, helping to monitor long-term control and reduce stress-related spikes seen in clinics.
Treatments and Management
Lifestyle Changes:
Reduce salt intake.
Eat more fruits and vegetables.
Maintain a healthy weight.
Exercise regularly.
Quit smoking, limit alcohol intake.
Medications:
ACE inhibitors
Calcium channel blockers
Diuretics
STROKE (CEREBROVASCULAR ACCIDENT)
Definition: A medical emergency that occurs when blood supply to part of the brain is interrupted or reduced, depriving brain tissue of oxygen and nutrients.
Statistics
11.9 million new cases occur each year.
1 in 4 adults will experience a stroke in their lifetime.
Stroke is the second leading cause of death globally and a leading cause of long-term disability.
Types of Stroke
Ischemic Stroke:
Caused by a blood clot blocking a vessel (80% of cases).
Hemorrhagic Stroke:
Caused by the rupture of a blood vessel in the brain.
Transient Ischemic Attack (TIA):
Known as a “mini-stroke,” it involves a temporary blockage and short-lived symptoms.
Causes of Stroke
Common Causes:
Atherosclerosis (hardened arteries)
Atrial fibrillation (irregular heartbeat)
Clotting disorders
Chronic high blood pressure
Brain aneurysm or vascular malformation
Trauma or tumors
Risk Factors for Stroke
Strongest contributing factor: Hypertension
Other risk factors include smoking, diabetes, high cholesterol, obesity, physical inactivity, excessive alcohol intake, and family history.
Pathophysiology of Stroke
Ischemic Stroke: A clot blocks blood flow to brain tissue, causing oxygen deprivation and potential brain cell death within minutes.
Hemorrhagic Stroke: A blood vessel bursts, leading to bleeding in the brain and oxygen deprivation, causing brain cells to die.
Neuro-cognitive deficits (e.g., weakness, speech problems, vision loss) can occur depending on the affected brain area.
Signs and Symptoms of Stroke
Mnemonic: BE FAST:
Balance: Sudden dizziness or loss of coordination.
Eyes: Sudden vision changes.
Face: Drooping on one side.
Arms: Weakness or numbness in one arm.
Speech: Slurred or difficulty speaking.
Time: Act immediately — every second counts.
Other symptoms may include:
Severe headache
Confusion
Paralysis on one side
Difficulty walking
Loss of consciousness.
Diagnosis of Stroke
Neurological Exam:
Assesses movement, reflexes, coordination, speech, vision, and level of consciousness to identify affected brain areas.
CT Scan / MRI:
Distinguish ischemic from hemorrhagic stroke and provides detailed images of brain tissue.
Blood Tests and Electrocardiogram (ECG):
Checks for clotting problems, blood sugar levels, infections.
Records heart activity to identify irregular heart rhythms.
Treatments and Management
Emergency Care:
Immediate medical attention is crucial ("time is brain"), focusing on stabilizing breathing, circulation, and blood pressure.
Medications:
Drugs to dissolve clots or control bleeding (dependent on type).
Medicines to manage risk factors (blood pressure, cholesterol, diabetes).
Rehabilitation:
Physical therapy, speech therapy, and occupational therapy to restore lost functions.
Prevention:
Controlling blood pressure (most important), quitting smoking, limiting alcohol, adopting a healthy diet, maintaining regular exercise, and managing diabetes and cholesterol levels.
CORONARY ARTERY DISEASE (CAD)
Definition: A condition in which the coronary arteries become narrowed or blocked due to plaque buildup (atherosclerosis), reducing oxygen-rich blood supply to the heart.
Impacts: Can lead to angina (chest pain), heart attack, arrhythmias, or heart failure.
Prevalence
Responsible for about 9 million deaths annually.
Affects more than 110 million people globally.
Accounts for nearly 1 in 6 deaths worldwide.
Causes of CAD
Atherosclerosis: Gradual buildup of cholesterol, fats, and calcium in artery walls.
Risk Factors for CAD
High blood pressure
High LDL (“bad”) cholesterol
Low HDL (“good”) cholesterol
Diabetes
Obesity
Smoking and excessive alcohol consumption
Family history of early heart disease
Age
Pathophysiology of CAD
Fatty deposits accumulate in artery walls, leading to narrowing and stiffness of arteries.
Blood flow to the heart muscle decreases.
The heart receives less oxygen and nutrients.
A rupture of plaque may occur, leading to a blood clot that could completely block blood flow and cause a heart attack.
Signs and Symptoms of CAD
Angina: Chest pain or pressure, often triggered by exertion or stress.
Heart Attack Symptoms: Crushing chest pain, pain radiating to arm/neck/back, sweating, nausea, dizziness.
Other symptoms include shortness of breath during activity, fatigue, and reduced exercise tolerance.
Diagnosis of CAD
Electrocardiogram (ECG): Detects abnormal heart rhythms.
Echocardiogram: Ultrasound used to assess heart function.
Stress Test: Evaluates heart performance under exertion.
Coronary Angiography / CT Scan: Visualizes blockages in coronary arteries.
Treatments and Management
Lifestyle Changes:
Quit smoking and limit alcohol.
Adopt a heart-healthy diet.
Engage in regular exercise.
Stress management techniques.
Medications:
Aspirin
Statins
Beta-blockers
ACE inhibitors
Nitroglycerin
Procedures:
Angioplasty with stent placement (opens blocked arteries).
Coronary artery bypass graft (CABG) surgery for severe blockages.