What are the causes and management of right ventricular failure?

Causes of Right Ventricular Failure

Right ventricular failure (RHF) can result from diverse causes including primary cardiomyopathies, RV ischemia, volume/pressure overload, and pulmonary hypertension from various etiologies. 1

Primary Causes of RHF

Increased RV Afterload

• Pulmonary Hypertension
  • Pulmonary arterial hypertension (PAH)
  • Left heart disease (most common cause of pulmonary hypertension)
  • Lung diseases and/or hypoxia
  • Chronic thromboembolic pulmonary hypertension
  • Pulmonary vascular disorders with unclear mechanisms 1
• Pulmonary Embolism
  • Acute massive pulmonary embolism (leading cause of acute RHF) 1
• Pulmonary Stenosis
  • Congenital or acquired valvular obstruction

Decreased RV Contractility

• RV Ischemia/Infarction
  • Right coronary artery occlusion
  • Inferior wall myocardial infarction with RV involvement 1
• Cardiomyopathies
  • Arrhythmogenic right ventricular cardiomyopathy
  • Dilated cardiomyopathy with biventricular involvement
  • Hypertrophic cardiomyopathy
• Myocarditis
  • Viral, bacterial, or autoimmune inflammation 1
• Post-cardiotomy Shock
  • Following cardiac surgery 1

Volume Overload

• Tricuspid Regurgitation
  • Primary (endocarditis, rheumatic)
  • Secondary (RV dilation, pulmonary hypertension)
• Left-to-Right Shunts
  • Atrial septal defect
  • Ventricular septal defect
  • Patent ductus arteriosus
• Pulmonary Regurgitation
  • Following repair of tetralogy of Fallot
  • Other congenital heart diseases 1

Congenital Heart Disease

• Fontan Circulation
• Tetralogy of Fallot (repaired)
• Ebstein's Anomaly
• Systemic Right Ventricle
  • Transposition of great arteries after atrial switch 1

Pathophysiology of RHF

Acute RHF

• Occurs due to abruptly increased RV afterload (pulmonary embolism, hypoxia) or decreased contractility (RV ischemia, myocarditis)
• RV is poorly adapted to pressure changes compared to volume changes
• Acute increase in afterload causes steep decline in stroke volume
• Results in RV dilation, tricuspid regurgitation, and ventricular interdependence affecting LV filling 1

Chronic RHF

• Progressive RV hypertrophy initially compensates for increased afterload
• Decompensation phase shows rising pulmonary vascular resistance and right atrial pressure
• Eventually leads to declining cardiac output and pulmonary artery pressure
• RV dilation compresses LV cavity through ventricular interdependence, impairing LV filling 1

Clinical Manifestations

• Decreased exercise tolerance and poor functional capacity
• Reduced cardiac output leading to systemic hypoperfusion
• Progressive end-organ damage from venous congestion and underperfusion
• Peripheral edema, hepatomegaly, and ascites
• Elevated jugular venous pressure
• Cachexia from malabsorption and proinflammatory state 1, 2

Management Approaches

Acute RHF Management

1. Optimize Preload

   • Cautious fluid challenge (≤500 mL) if central venous pressure is low
   • Avoid aggressive volume loading that can worsen RV function 3

2. Support RV Contractility

   • Inotropes: Dobutamine (2.5-5.0 μg/kg/min) or milrinone (0.25-0.75 μg/kg/min) 3
   • Vasopressors: Norepinephrine (0.05-3.3 μg/kg/min) to maintain systemic pressure 3

3. Reduce RV Afterload

   • Inhaled nitric oxide (5-40 ppm)
   • Inhaled prostacyclin (10-50 ng/kg/min)
   • Sildenafil (20 mg three times daily) for pulmonary hypertension 3

4. Ventilation Strategy (if intubated)

   • Low tidal volumes (~6 mL/kg)
   • Minimize PEEP (≤10 cmH2O)
   • Avoid hypercapnia and maintain SaO₂ >90% 3

5. Mechanical Support (for refractory cases)

   • ECMO (veno-venous for isolated RV failure from respiratory failure; veno-arterial for primary RV injury) 4

Chronic RHF Management

1. Treat Underlying Cause

   • Pulmonary hypertension: Specific therapies (endothelin antagonists, PDE-5 inhibitors, prostacyclin analogues) 1
   • Coronary revascularization for ischemic etiology 1
   • Valve repair/replacement for valvular causes

2. Volume Management

   • Diuretics for congestion (used cautiously in isolated RV failure) 1
   • Monitor renal function, electrolytes during diuretic therapy

3. Advanced Therapies

   • Consider heart transplantation for refractory RHF 3

Special Considerations

RHF with Cardiorenal Syndrome

• Acute worsening of renal function may occur in up to one-third of patients
• May limit use of renin-angiotensin-aldosterone system blockers
• Progressive uremia may require renal replacement therapy
• Consider nephrology consultation 1

Isolated Right Ventricular Failure

• Use diuretics and vasodilators cautiously to avoid reducing RV filling
• For pulmonary hypertension-related RV failure, consider phosphodiesterase inhibitors, endothelin antagonists, and prostacyclin analogues 1

RHF with Acute Coronary Syndrome

• Urgent coronary angiography and revascularization
• Consider intra-aortic balloon pump for hemodynamic instability
• Evaluate for mechanical complications (e.g., papillary muscle rupture) 1

Monitoring and Follow-up

• Daily monitoring of blood urea nitrogen, creatinine, potassium, and sodium during IV therapy
• Echocardiography for assessment of RV function
• Cardiac MRI is the gold standard for anatomical and functional assessment of RV 5
• Regular assessment of volume status and optimization of medical therapy