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Cardiovascular System Notes

Antihypertensives

Hypertension

  • Most common cardiovascular disease.

  • Risks: death, stroke, renal failure, vision loss.

  • Often goes unnoticed due to lack of symptoms; this can lead to noncompliance with medication.

Types of Hypertension:

  • Essential Hypertension: No known cause.

  • Secondary Hypertension: Known cause (e.g., adrenal tumor).

Controlling Hypertension

Stepped Care Approach:Step 1: Lifestyle modifications\

  • Weight reduction, smoking cessation, nutritional changes, reduce salt and alcohol intake.Step 2: MedicationsStep 3: Change medication dosage or add a new medicationStep 4: Add additional medications until appropriate blood pressure (BP) is reached.

Medication Classes for Hypertension

  1. Diuretics

    • Function: Increase sodium and water excretion from kidneys, reducing blood volume.

    • Types:

      • Thiazide: HydroDiuril (HCTZ)

      • Loop: Lasix (furosemide)

      • Potassium-sparing: Aldosterone receptor blocker

    • Adverse Reactions: Hypotension, orthostatic hypotension, electrolyte imbalances.

  2. Beta Blockers

    • Function: Block vasoconstriction, decrease heart rate and BP, increase blood flow to kidneys.

    • Common Medications:

      • Tenormin (atenolol)

      • Lopressor (metoprolol)

      • Coreg (carvedilol)

    • Side Effects: Many; not suitable for everyone; often used in step 2 treatment.

  3. Adrenergic Blockers

    • Alpha 1 Blockers: Cause vasodilation, can lead to reflex tachycardia.

      • Example: Flomax (tamsulosin)

      • Adverse Reaction: Hypotension.

  4. ACE Inhibitors

    • Function: Prevent conversion of angiotensin I to II (a vasoconstrictor), causing vasodilation.

    • Common Medications:

      • Vasotec (enalapril)

      • Zestril, Prinivil (lisinopril)

    • Adverse Reactions: Hypotension, cough; contraindicated in pregnancy.

  5. Calcium Channel Blockers (CCBs)

    • Function: Prevent calcium movement into cardiac/smooth muscles, leading to vasodilation.

    • Common Medications:

      • Norvasc (amlodipine)

      • Cardizem (diltiazem)

      • Procardia (nifedipine)

      • Calan (verapamil)

    • Adverse Reaction: Hypotension.

  6. Vasodilators

    • Function: Produce smooth muscle relaxation in blood vessels, often used in emergencies.

    • Common Medications:

      • Apresoline (hydralazine)

      • Imdur (isosorbide mononitrate)

    • Adverse Reaction: Hypotension.

General Information on Antihypertensives

  • Metabolized by liver and excreted by kidneys.

  • Adverse Reactions: Orthostatic hypotension (especially with diuretics), hypotension, lightheadedness, dizziness.

  • Contraindications: Renal or hepatic impairment, breastfeeding.

Antihyperlipidemics

Fat in the Body:

  • Essential for metabolism, hormones, and cell membranes; if limited, body produces cholesterol.

First Line Treatment for Hyperlipidemia:

  • Lifestyle modifications (nutrition, exercise).

Total Cholesterol Formula:

  • Total Cholesterol = HDL + LDL + 20% Triglycerides.

HMG-CoA Reductase Inhibitors

  • Function: Decrease LDL levels by inhibiting HMG-CoA reductase.

  • -statin Suffix Medications:

    • Lipitor (atorvastatin)

    • Zocor (simvastatin)

    • Mevacor (lovastatin)

    • Crestor (rosuvastatin)

  • Adverse Reactions: GI disturbance; contraindications in alcoholism, hepatic impairment.

Fibric Acid Derivatives

  • Common Medication: Tricor (fenofibrate).

    • Adverse Reactions: GI disturbance, gallstones; contraindicated in renal or hepatic impairment, precautions with PUD or diabetes.

Niacin (OTC)

  • Adverse Reactions: GI disturbances, flushing, severe itching.

    • Use aspirin to help with flushing; precautions needed for renal impairment and high alcohol consumption.

Lipid Lowering Herbal Medicines:

  • Garlic: Lowers cholesterol/triglyceride levels, improves HDL/LDL ratio, lowers BP.

  • Fish Oil: Lowers triglycerides and total cholesterol, increases HDLs.

  • Phytosterols: Block absorption of cholesterol, lower LDL without lowering HDL; found in various vegetables and fruits.

Antianginal Medications

Nitrates

  • Relax smooth muscle in blood vessels, increase blood oxygen to tissues.

  • Common Drugs: Nitro-Bid (nitroglycerin) in several forms, Isosorbide mononitrate (Imdur).

  • Adverse Reactions: Hypotension, dizziness, headaches.

Anticoagulants and Thrombolytics

Antiplatelet Drugs:

  • Function: Decrease platelet aggregation; common meds include Aspirin and Plavix.

  • Adverse Reactions: Increased bleeding risk; contraindications in pregnancy/lactation, precautions needed for bleeding disorders.

Coumadin (Warfarin)

  • Function: Depletes prothrombin in the clotting cascade.

  • Adverse Reactions: Risk of bleeding; education includes limiting vitamin K intake.

Heparin and Low Molecular Weight Heparins (LMWH):

  • Function: Inhibits conversion of fibrinogen to fibrin.

  • Adverse Reactions: Thrombocytopenia and bleeding.

Thrombolytics:

  • Convert plasminogen to fibrinolysin to break down clots.

  • Common Drugs: Activase (alteplase).

  • Adverse Reaction: Bleeding; contraindications include active bleeding and recent surgery.

Antianemia Medications

Iron Deficiency Anemia:

  • Treated with Ferrous sulfate or gluconate; vitamin C enhances absorption.

  • Adverse Reactions: GI upset, dark stools.

Pernicious Anemia:

  • Treated with Vitamin B12, especially in at-risk populations.

Diagnostic Testing

  • Lipid Panel: Assess cholesterol levels, fasting required.

  • Electrocardiogram (EKG): Assesses heart’s electrical activity; pretest considerations include resting before the test.

  • Echocardiogram: Uses ultrasound; can detect heart structure issues.

  • Angiogram: Visualizes coronary vessels using contrast dye; requires pretest preparation and monitoring post-procedure.