Heart failure is a clinical syndrome of impaired forward flow and maladaptive neurohormonal activation.

It is not primarily a pump failure problem — it is a neurohormonal disease.

Core equation:

CO = HR × SV

Stroke Volume depends on:

• Preload • Afterload • Contractility

In heart failure:

• ↓ Contractility (HFrEF) • ↑ Afterload • ↑ Preload • ↑ Neurohormonal activation (RAAS + SNS)

• EF ≤ 40% • Systolic dysfunction • Proven mortality-reducing therapies exist

• EF ≥ 50% • Diastolic dysfunction • Limited mortality-reducing therapies

• EF 41–49% • Treated similar to HFrEF

Compensatory systems become maladaptive:

1. Sympathetic activation

2. RAAS activation

3. Aldosterone excess

4. Ventricular remodeling

Modern therapy blocks these pathways.

All patients with HFrEF should receive:

1. ARNI (preferred) OR ACE Inhibitor OR ARB 2. Evidence-Based Beta-Blocker 3. Mineralocorticoid Receptor Antagonist 4. SGLT2 Inhibitor

These therapies reduce mortality and hospitalization.

Preferred:

• Sacubitril/Valsartan (ARNI)

Alternative:

• ACE Inhibitor • ARB

Effects:

• ↓ Afterload • ↓ Aldosterone • ↓ Remodeling • ↓ Mortality

Only three reduce mortality:

• Carvedilol

• Metoprolol Succinate

• Bisoprolol

Effects:

• ↓ Sympathetic drive • ↓ Remodeling • ↓ Sudden cardiac death

• Spironolactone

• Eplerenone

Effects:

• ↓ Aldosterone-mediated fibrosis • ↓ Remodeling • ↓ Mortality

Monitor potassium closely.

• Dapagliflozin

• Empagliflozin

Effects:

• ↓ HF hospitalization • ↓ Mortality • Benefit independent of diabetes status

Hydralazine + Isosorbide Dinitrate

• Particularly beneficial in Black patients

Ivabradine

• If HR ≥70 on maximally tolerated beta-blocker

Vericiguat

• Soluble guanylate cyclase stimulator

Diuretics DO NOT reduce mortality.

Used for congestion relief:

• Furosemide • Torsemide

Effect:

• ↓ Preload • ↓ Pulmonary edema • Symptom improvement only

No strong mortality-reducing therapies except:

• SGLT2 Inhibitors

Management focuses on:

• • Blood pressure control
• • Diuretics for congestion
• • Treating atrial fibrillation
• • Managing ischemia

• IV Loop Diuretics

• Nitroglycerin

• Oxygen

• Positive pressure ventilation if needed

• Dobutamine

• Dopamine

Short-term hemodynamic support only.

Chronic neurohormonal activation causes:

• LV dilation • Fibrosis • Progressive decline in EF

GDMT prevents remodeling.

✔ Heart failure is a neurohormonal disease ✔ Diuretics improve symptoms, not survival ✔ Four pillars reduce mortality ✔ Only specific beta-blockers reduce mortality ✔ SGLT2 inhibitors benefit even non-diabetics ✔ Start low, titrate slowly

Related:

→ Hypertension Module → Dysrhythmias Module → Return to Cardiovascular Modules