Cardiovascular System: Anatomy, Assessment, and Heart Failure

Normal Heart Anatomy, Sounds, and Blood Flow

• The heart has a base at the top and an apex at the bottom.
• Mnemonic for valve order and location: All People Take Money (APTM) represents Aortic, Pulmonic, Tricuspid, and Mitral valves.
  • Aortic valve: Right 2nd intercostal space near the sternum.
  • Pulmonic valve: Left 2nd intercostal space near the sternum.
  • Tricuspid valve: Left 4th intercostal space near the sternum.
  • Mitral valve: Left 5th intercostal space, mid-clavicular line.
• S1 Heart Sound:
  • Closure of atrioventricular (AV) valves (mitral and tricuspid).
  • Best heard at the apex of the heart.
• S2 Heart Sound:
  • Closure of semilunar valves (aortic and pulmonic).
  • Best heard at the base of the heart.
• Blood Flow Through the Heart:
  • Deoxygenated blood enters the right side of the heart via the superior vena cava.
  • Blood is pumped to the lungs, where it picks up oxygen.
  • Oxygenated blood returns to the left side of the heart.
  • Blood is pumped through the aorta to the rest of the body.
• Cardiac Cycle:
  • Diastole: Ventricles relax and fill with blood from the atria.
  • Systole: Ventricles contract, AV valves close, and blood is pushed out of the heart.

Basic Cardiac Assessment Abnormalities

• Extra Heart Sounds:
  • S3 Heart Sound:
    • Indicates volume overload.
    • Common in heart failure and high-output conditions like pregnancy.
    • Best heard at the apex of the heart.
  • S4 Heart Sound:
    • Occurs when the atrium pumps blood into a non-compliant ventricle.
    • Common causes include uncontrolled hypertension and left ventricular hypertrophy.
    • May also be benign with aging due to heart stiffening.
    • Best heard at the apex of the heart.
  • Split S2:
    • Normal only during inspiration.
    • If heard during both inspiration and expiration, refer to cardiology.
• Murmurs:
  • Diastolic Murmurs (MS ART):
    • Mitral Stenosis (MS), Aortic Regurgitation (AR)
    • Aortic Regurgitation: Early diastolic blowing murmur.
    • Mitral Stenosis: Mid-diastolic and low-pitched.
    • Management: Refer to cardiology.
  • Systolic Murmurs (MR PASS MVP):
    • Mitral Regurgitation (MR), Aortic Stenosis (AS), Mitral Valve Prolapse (MVP)
    • Systolic murmurs radiate outside the heart.
    • Aortic Stenosis: Injection murmur radiating to the neck or carotid arteries.
    • Mitral Regurgitation: Holosystolic murmur radiating to the armpit, typically high pitched.
    • Mitral Valve Prolapse: Characterized by a clicking sound; doesn't typically radiate.
    • Murmur Grades:
      • Grade 4 or higher has a palpable thrill.

Heart Failure Overview

• Heart failure is the heart's inability to pump oxygen-rich blood effectively.
• Types of Heart Failure:
  • Left-Sided Heart Failure (most common):
    • Diastolic Heart Failure:
      • Left ventricle is stiff and cannot fill properly.
      • Preserved ejection fraction (HFpEF).
    • Systolic Heart Failure:
      • Left ventricle doesn't pump effectively.
      • Reduced ejection fraction (HFrEF).
  • Right-Sided Heart Failure (often due to left-sided failure):
    • Fluid backs up into the body.
    • Causes jugular venous distension (JVD), peripheral edema, and abdominal swelling.
• Symptoms:
  • Left-Sided: Dyspnea, orthopnea, coughing (fluid in lungs).
  • Right-Sided: Systemic fluid retention (edema, JVD).
• Acute Decompensated Heart Failure:
  • New onset or acute worsening of chronic heart failure symptoms.
  • Often requires hospitalization.
  • Characterized by fluid overload and shortness of breath.
• Diagnostic Labs:
  • CBC, metabolic panel (electrolytes, kidney function, liver enzymes).
  • B-type Natriuretic Peptide (BNP): Increases with heart stretching and stress.
• Imaging Tests:
  • Echocardiogram: Evaluates heart structures and ejection fraction.
    • Ejection fraction < 40% is diagnostic for systolic heart failure.
    • There is a gray area between 40-55%.
  • Chest X-ray.
  • ECG.
• Treatment:
  • Diuretics:
    • Loop diuretics (e.g., furosemide/Lasix) to remove fluid.
    • Monitor potassium levels (often requires supplementation).
  • Potassium-Sparing Diuretics (e.g., spironolactone):
    • Counteract aldosterone.
    • Monitor kidney function and potassium levels (can cause hyperkalemia).
    • Side effect in men: gynecomastia.
  • ACE Inhibitors (historical first-line).
  • ARBs with Neprilysin Inhibitors (newer drug class).
  • Beta Blockers.
  • SGLT2 Inhibitors (originally for diabetes).
• Medications to Avoid:
  • NSAIDs: Worsen fluid retention.
  • Thiazolidinediones (if patient has diabetes): Worsen fluid retention.
  • Non-Dihydropyridine Calcium Channel Blockers (non-DHPs like verapamil, diltiazem): Cause bradycardia and reduce cardiac output.
• Patient Education:
  • Daily weights: Notify provider for weight gain of 2-3 pounds in a day or 5 pounds in a week.
  • Low-sodium diet and potential fluid restriction.