Heart Failure Lecture Notes

Introduction

Focus: Heart Failure (CHF - Congestive Heart Failure)
Main Sections: Pathophysiology, Types, Causes, Compensatory Mechanisms, Complications, Diagnosis, and Treatment
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Left Heart Failure:
- Systolic Heart Failure (HFrEF)
  - Decreased contractility of the left ventricular myocardium
  - Common Causes: Myocardial Infarction (MI), Dilated Cardiomyopathy, Myocarditis
  - Results: Reduced ejection fraction (<40%), drop in cardiac output
- Diastolic Heart Failure (HFpEF)
  - Problem during filling due to increased afterload
  - Common Causes: Chronic Hypertension, Aortic Stenosis
  - Results: Preserved ejection fraction (≥40%), reduced ventricular filling, low cardiac output
Right Heart Failure:
- Systolic Right Heart Failure
  - Decreased right ventricular contractility (often due to right ventricular MI)
- Diastolic Right Heart Failure
  - Increased afterload (pulmonary hypertension)
  - Results: Right ventricular hypertrophy, decreased filling
High Output Heart Failure
- Occurs with high cardiac output not meeting body's demands
- Causes: Sepsis, Thiamine Deficiency (Beriberi), Thyrotoxicosis, AV Fistulas, Severe Anemia
- Results: Massive vasodilation, low systemic vascular resistance, compensatory increased heart rate and stroke volume, but still insufficient tissue perfusion

Sympathetic Nervous System Activation
- Increases heart rate and systemic vascular resistance
- Can worsen heart failure by increasing afterload and preload
Renin-Angiotensin-Aldosterone System (RAAS)
- Releases hormones that constrict vessels and retain sodium and water
- Worsens heart failure
Atrial Natriuretic Peptide (ANP)
- Released in response to stretch, aims to inhibit RAAS

Left Heart Failure Complications
- Pulmonary Congestion and Edema:
  - Dyspnea, Orthopnea, Proximal Nocturnal Dyspnea (PND)
  - Severe cases lead to V/Q mismatch and hypoxia
- Cardiogenic Shock:
  - Low cardiac output, poor systemic perfusion, organ malperfusion, cold/pale extremities, encephalopathy, myocardial infarction, AKI, lactic acidosis
Right Heart Failure Complications
- Increased Central Venous Pressure -> Jugular Venous Distension (JVD), Peripheral Edema
- Hepatic Congestion -> Liver Failure, Ascites
- Septal Shift (right to left) -> Decreased Left Ventricular Filling -> Cardiogenic Shock

Chest X-Ray: Cardiomegaly, Pulmonary Edema, Curly B Lines
BNP Levels: Used in emergency to exclude CHF exacerbation
Echocardiogram: Gold standard for assessing ejection fraction
Right Heart Catheterization: Definitive, measures Pulmonary Capillary Wedge Pressure
Other Tests: EKG for MI, medication review

Medical Management
- Reduce Sympathetic Activity: Beta blockers (Metoprolol), SGLT2 Inhibitors
- Reduce RAAS Activity: ACE Inhibitors, ARNI (e.g., Sacubitril/Valsartan), ARBs, Aldosterone Antagonists
- Alternative Treatments: Hydralazine and Isosorbide Nitrate (for African-Americans), Diuretics, Digoxin
- Device Therapy:
  - CRT for LBBB and EF <35%
  - AICD for EF <35% with arrhythmias
  - LVAD as a bridge to transplant
Acute Management
- Ionotropes: Dobutamine, Milrinone
- Mechanical Circulatory Support: Intra-aortic Balloon Pump, VA-ECMO
- Non-invasive Ventilation: BiPAP to reduce pulmonary edema

Summary: Understand the mechanisms, types, and treatments for heart failure to manage both chronic and acute presentations effectively.