Cardiac Anatomy & Heart Failure

Cardiac Anatomy & Heart Failure

Cardiac Chambers & Valves

• RA → tricuspid → RV → pulmonary → lungs → PV → LA → mitral → LV → aortic → aorta
• AV valves (tricuspid, mitral): prevent backflow during systole
• Semilunar valves (pulmonary, aortic): prevent backflow during diastole

Coronary Arteries

• LAD: supplies anterior LV wall, anterior septum, apex (most common culprit in MI)
• RCA: SA node (60%), AV node (80%), inferior LV wall, posterior descending artery
• LCx: lateral and posterior LV wall

Heart Failure Classification

| Type | EF | Mechanism |

|------|----|-----------|

| HFrEF (systolic) | <40% | Impaired contractility |

| HFpEF (diastolic) | 50% | Impaired relaxation/filling |

NYHA Classification

• I: No symptoms on ordinary activity
• II: Symptoms on moderate exertion
• III: Symptoms on minimal exertion
• IV: Symptoms at rest

Pathophysiology of HFrEF

1. Reduced CO → baroreceptor activation
2. SNS activation: tachycardia, vasoconstriction
3. RAAS: Na+ and water retention → volume overload
4. Maladaptive LV remodelling → progressive dilatation

Key Drugs in HFrEF

• ACE inhibitor/ARB: reduce afterload, block RAAS
• Beta-blocker: reduce HR, prevent remodelling
• MRA (spironolactone): block aldosterone, reduce fibrosis
• SGLT2i (dapagliflozin): reduce hospitalisations and mortality
• Loop diuretic (furosemide): symptom relief (not mortality benefit)