What is the management approach for a patient with a dilated right ventricle (RV) and pulmonary hypertension (PH)?

Management of Dilated RV with Pulmonary Hypertension

The cornerstone of managing a dilated right ventricle with pulmonary hypertension is reducing RV afterload through pulmonary vasodilators while maintaining euvolemia (CVP 8-12 mmHg) and systemic perfusion pressure above pulmonary artery pressure to preserve RV coronary perfusion. 1, 2

Initial Assessment and Hemodynamic Monitoring

• Obtain invasive hemodynamic assessment with pulmonary artery catheterization to accurately measure pulmonary vascular resistance, cardiac output, and right atrial pressure 1
• Perform echocardiography to assess RV size, function, ventricular interdependence (septal shift), and tricuspid regurgitation severity 1, 3
• Measure BNP levels as elevated values predict poor prognosis 1
• Assess functional capacity with 6-minute walk test or cardiopulmonary exercise testing 1

Volume Management: Avoid the "Preload Dependent" Trap

The traditional teaching that the RV is preload-dependent is dangerously misleading and leads to harmful volume overloading. 1

• Target euvolemia with CVP 8-12 mmHg, not aggressive volume loading 1
• RV distention causes leftward septal shift, compromising LV filling and reducing cardiac output 1, 4
• Use diuretics to reduce ventricular dilation and improve biventricular coupling when volume overloaded 1
• Excessive RV dilation worsens tricuspid regurgitation and further impairs function 1

Afterload Reduction: Primary Treatment Strategy

Pulmonary Vasodilators (First-Line)

Inhaled selective pulmonary vasodilators are preferred over systemic agents to avoid hypotension: 1, 2

• Inhaled nitric oxide (5-10 ppm) reduces pulmonary vascular resistance without systemic hypotension 1
• Inhaled prostacyclin (20-30 ng/kg/min) has comparable efficacy to nitric oxide 1
• Both agents improve ventilation/perfusion matching and RV function 1
• Caution: Rebound pulmonary hypertension can occur when weaning inhaled nitric oxide—start oral PDE-5 inhibitor as replacement therapy 1

Oral Pulmonary Vasodilators

• Sildenafil (PDE-5 inhibitor) improves exercise capacity and hemodynamics in PAH 1, 5
• Endothelin receptor antagonists improve exercise capacity but require monthly liver function monitoring 1
• Patients already on chronic pulmonary vasodilators may rapidly develop RV failure and death if these medications are interrupted 6

Inotropic and Vasopressor Support

Maintain Systemic Pressure > Pulmonary Pressure

The critical principle is maintaining systemic vascular resistance greater than pulmonary vascular resistance (SVR > PVR) to preserve RV coronary perfusion. 1, 4

• RV coronary perfusion occurs during both systole and diastole, but if systolic PAP exceeds systolic systemic pressure, RV ischemia results 1
• Target systolic systemic arterial pressure higher than systolic pulmonary arterial pressure 1

Inotrope Selection

Phosphodiesterase type III inhibitors (milrinone) reduce PVR and improve RV function, though hypotension is frequent: 2

• Dobutamine is preferred over milrinone due to shorter half-life when hypotension risk exists 1, 2
• Avoid calcitropic agents as they are associated with progressive decline in RV function, likely due to systemic vasodilation decreasing RV perfusion 1
• Levosimendan may restore RV-pulmonary circulation coupling through combined inotropic and vasodilatory effects, but more data needed 1

Vasopressor Selection

• Low-dose norepinephrine is effective and has neutral or beneficial effects on PVR 1, 2
• Replacement-dose vasopressin offsets vasodilation from inotropes without increasing PVR 1
• Use vasopressin or norepinephrine to maintain systemic afterload during milrinone therapy 1

Ventilatory Management (If Mechanically Ventilated)

Optimize PEEP to avoid both lung derecruitment and overdistension, as both worsen RV afterload: 1

• Lung derecruitment increases RV afterload through hypoxic vasoconstriction 1
• PEEP above 15 cmH₂O promotes overdistension and worsens RV systolic dysfunction 1
• Avoid driving pressure ≥18 cmH₂O and PaCO₂ ≥48 mmHg as these are risk factors for RV failure 1
• Correct hypoxemia (maintain PaO₂/FiO₂ >150 mmHg) and acidosis to reduce pulmonary vasoconstriction 1
• Avoid vigorous spontaneous breathing as forceful inspiratory efforts increase transvascular pressure and worsen pulmonary edema 1
• Consider prone positioning as it may restore RV function by improving ventilation uniformity and reducing VILI 1

Advanced Therapies for Refractory Cases

Mechanical Circulatory Support

For persistent isolated RV failure refractory to medical therapy, RV mechanical support may be indicated: 1

• Impella RP or Protek Duo platforms bypass the failing RV 1
• Protek Duo allows splicing of oxygenator for concomitant respiratory insufficiency 1
• Caution: RV failure from progressive pulmonary hypertension is poorly treated with RV-only support devices—forced perfusion may precipitate pulmonary hemorrhage 1
• Venoarterial ECMO is preferred when the primary lesion is pulmonary vasculature 1

Atrial Septostomy

• May reduce preload and RV wall stress in select cases 7

Specific Considerations for Congenital Heart Disease

In patients with congenital heart disease (repaired pulmonary stenosis, tetralogy of Fallot), pulmonary valve replacement is indicated when: 1

• Symptomatic patients with moderate or greater pulmonary regurgitation AND RV dilation or dysfunction (Class I recommendation) 1
• Asymptomatic patients with progressive RV dilation and/or dysfunction (Class IIb recommendation) 1

Common Pitfalls to Avoid

• Do not aggressively volume load based on outdated "preload-dependent RV" teaching 1
• Do not use systemic vasodilators as they worsen hypotension without selectively reducing PVR 1
• Do not allow systolic PAP to exceed systolic systemic pressure as this causes RV ischemia 1
• Do not abruptly discontinue chronic pulmonary vasodilators in known PAH patients 6
• Do not use high PEEP (>15 cmH₂O) or high driving pressures as these worsen RV function 1

Consultation and Transfer

Early consultation with pulmonary hypertension specialist and transfer to tertiary center with invasive monitoring and mechanical support capabilities is advised for critically ill patients, as they may require pulmonary artery catheter, inhaled vasodilators, or RV assist device/ECMO not readily available in all settings 6