Cardiovascular System: Assessment, Pathophysiology, and Pharmacology

Cardiovascular Assessment

Patient History and Risk Factors

Assessment of cardiovascular health begins with a thorough evaluation of patient history and lifestyle factors that may contribute to disease risk.

• History: Family history, smoking, physical activity, occupation (especially if demanding or sedentary), diet, and medication use.

• Modifiable risk factors: Smoking, sedentary lifestyle, poor diet, and certain medications.

• Non-modifiable risk factors: Genetics (familial hyperlipidemia), age, sex, and ethnicity (higher risk in African American, Hispanic populations).

Arteriosclerosis and Atherosclerosis

Definitions and Pathophysiology

Arteriosclerosis refers to the thickening and hardening of arterial walls, while atherosclerosis is a specific type involving plaque buildup.

• Arteriosclerosis: General term for any condition causing thickening, hardening, and loss of elasticity in arteries.

• Atherosclerosis: Characterized by plaque (lipid and fibrous deposits) development within arterial walls, leading to narrowing and reduced blood flow.

• Consequences: Increased blood pressure, risk of heart attack, stroke, and peripheral vascular disease.

Contributing Factors to Atherosclerosis

• Modifiable: Smoking, sedentary lifestyle, poor diet, elevated cholesterol (low HDL, high LDL, high triglycerides).

• Non-modifiable: Genetics, age, ethnicity.

Lab Assessment

• Total serum cholesterol: <200 mg/dL is considered normal.

• Triglycerides: <150 mg/dL is normal.

• HDL (High-Density Lipoprotein): Higher levels are protective; exercise increases HDL.

• LDL (Low-Density Lipoprotein): Lower levels are desirable.

Cardiovascular System: Age-Related Changes

Physiological Changes

Cardiovascular function changes with age, affecting risk and management of disease.

• Middle Age: Vessel walls harden, plaque formation begins.

• Older Age: Cardiac output diminishes, chronic diseases become more prevalent.

Pharmacological Management of Cardiovascular Disease

Lipid-Lowering Medications

• Bile Acid Sequestrants: Bind bile acids in the gut, interrupting cholesterol reabsorption.

• HMG-CoA Reductase Inhibitors (Statins): Inhibit cholesterol synthesis in the liver. Examples: Atorvastatin, Lovastatin, Pravastatin, Rosuvastatin, Simvastatin.

• Omega-3 Fatty Acids: Decrease triglyceride production and increase clearance.

• Fibrates: Reduce triglycerides, enhance fatty acid oxidation.

• PCSK9 Inhibitors: Lower LDL cholesterol by increasing hepatic clearance.

Side Effects of Lipid-Lowering Agents

• Constipation, bloating, nausea (bile acid sequestrants)

• Muscle pain, rhabdomyolysis (statins)

• Liver function monitoring required for statins

Hypertension

Definition and Diagnosis

Hypertension is defined as persistently elevated blood pressure. Diagnosis requires measurements on three separate occasions, at least three hours apart.

• Goal: Blood pressure below 130/80-89 mmHg

Blood Pressure Categories

Blood pressure is classified into categories based on systolic and diastolic values.

Category	Systolic (mmHg)	Diastolic (mmHg)
Normal	Less than 120	Less than 80
Elevated	120-129	Less than 80
Hypertension Stage 1	130-139	80-89
Hypertension Stage 2	140 or higher	90 or higher
Hypertensive Crisis	Higher than 180	Higher than 120

Pharmacological Treatment of Hypertension

• ACE Inhibitors: Block conversion of angiotensin I to angiotensin II, causing vasodilation and decreased blood pressure. Example: Lisinopril.

• ARBs (Angiotensin Receptor Blockers): Block angiotensin II receptors. Example: Losartan.

• Beta-Blockers: Decrease heart rate and contractility. Examples: Atenolol, Metoprolol, Carvedilol.

• Calcium Channel Blockers: Inhibit calcium influx in vascular smooth muscle, causing vasodilation. Examples: Diltiazem, Verapamil, Amlodipine.

• Diuretics: Increase renal excretion of sodium and water, reducing blood volume. Examples: Furosemide, Hydrochlorothiazide, Spironolactone.

• Vasodilators: Directly relax arteriolar smooth muscle. Example: Hydralazine.

Other Cardiovascular Medications

• Antiplatelet Agents: Prevent platelet aggregation. Examples: Clopidogrel, Aspirin.

• Anticoagulants: Inhibit clotting cascade. Examples: Warfarin, Heparin, Dabigatran.

• Antiarrhythmics: Used to treat abnormal heart rhythms. Example: Digoxin.

Assessment and Nursing Care

Patient Monitoring

• Monitor blood pressure, heart rate, weights, intake/output, medications, and supplements.

• Educate patients on risk factors, medication adherence, and lifestyle modifications.

Risk Factors for Hypertension

• Family history, age, obesity, lack of physical activity, high sodium intake, alcohol use, and certain ethnicities (higher risk in African Americans).

Factors Impacting Blood Pressure

• Blood viscosity, vessel diameter, SNS stimulation, circulating catecholamines, RAAS system, and renal function.

Key Equations

• Blood Pressure Equation: $\text{Blood Pressure} = \text{Cardiac Output} \times \text{Systemic Vascular Resistance}$

• Cardiac Output Equation: $\text{Cardiac Output} = \text{Stroke Volume} \times \text{Heart Rate}$

Summary Table: Common Antihypertensive Medications

Class	Mechanism	Examples
ACE Inhibitors	Block angiotensin II formation	Lisinopril, Enalapril
ARBs	Block angiotensin II receptors	Losartan, Valsartan
Beta-Blockers	Decrease HR and contractility	Atenolol, Metoprolol, Carvedilol
Calcium Channel Blockers	Vasodilation via Ca2+ channel inhibition	Diltiazem, Verapamil, Amlodipine
Diuretics	Increase renal excretion of Na+ and water	Furosemide, Hydrochlorothiazide, Spironolactone
Vasodilators	Direct arteriolar relaxation	Hydralazine, Minoxidil

Additional info:

• Some details on medication side effects and monitoring were expanded for academic completeness.

• Tables were recreated and summarized for clarity and study purposes.