Right Ventricular Failure

Definition

Right ventricular (RV) failure is a clinical syndrome of inadequate right ventricular output relative to venous return, arising from abnormalities of preload, afterload, contractility, or lusitropy — or any combination thereof. It manifests as systemic venous congestion (elevated JVP, oedema, ascites, hepatic congestion) and/or reduced cardiac output. The right ventricle plays a critical prognostic role in left heart failure, pulmonary arterial hypertension, acute PE, and COVID-19 — a fact historically underestimated.

Key Concepts

Anatomy and Physiology

• RV is a thin-walled crescent-shaped structure derived from the secondary heart field; sits anterior, just beneath the sternum
• Mechanically integrated with the LV via the interventricular septum; the LV contributes ~25–30% of RV contractile function via systolic ventricular interdependence
• Contractile pattern: helical septal myofibrils → longitudinal shortening (dominant); RV free wall circumferential fibres → transverse shortening (minor contribution normally)
• Removal of effective RV function (Fontan procedure) → 40% reduction in exercise capacity, confirming the RV is essential even in disease (sources/rvfailure-nejm-2023, rating: very high)

Pathophysiology — Adaptive to Maladaptive Transition

Adaptive Phase (Homeometric Adaptation)

• Chronic afterload increase → concentric RV hypertrophy with maintained stroke volume
• Neurohormonal activation (adrenergic tone) is initially compensatory
• Maintained coupling: Ees rises proportionally to Ea; see concepts/RV-PA-Coupling

Maladaptive Phase (Heterometric Adaptation)

• Neurohormonal activation becomes harmful: reduced β₁-adrenergic receptor density, depleted adrenergic effectors, failure of adenylate cyclase stimulation in response to β-agonists
• RV dilates to maintain stroke volume → RV ischaemia from O₂ supply-demand mismatch
• Eventually: O₂ demand exceeds supply → further contractility decline → ventriculoarterial uncoupling → RV failure (sources/rvfailure-nejm-2023, rating: very high)

Fibrosis

• Cardiac fibroblast activation by mechanical stress, ischaemia, neurohormonal stimulation
• Early fibrosis protects against RV dilatation; progressive fibrosis impairs diastolic function and excitation–contraction coupling
• Most prominent at septal insertion points (peak mechanical stress) but also affects RV free wall
• Highest collagen content: systemic sclerosis–associated PAH; lowest: CHD-related PH — partly explains better long-term RV adaptation in CHD (sources/rvfailure-nejm-2023, rating: very high)

RV Ischaemia

• Increased wall stress with hypertrophy increases O₂ demand
• Capillary rarefaction and reduced right coronary arterial flow (proportional to RV mass and RVEDP) reduce supply
• Right coronary artery flow impairment reported in PH patients; RV ischaemia = key mechanism of decompensation (sources/rvfailure-nejm-2023, rating: very high)

Metabolic Dysfunction

• Normal RV derives 60–90% of ATP from fatty acid oxidation (FAO)
• Progressive hypertrophy → relative hypoxia → HIF-1 activation → glycolytic enzyme upregulation + FAO suppression
• Glucose uptake (FDG-PET) correlates inversely with RV function; partially reversed by pulmonary vasodilator therapy
• Whether the glycolytic shift is adaptive or maladaptive remains unresolved (sources/rvfailure-nejm-2023, rating: very high)
• Advanced cardiac PET (⁶⁸Ga-Dotatate for inflammation, ¹¹C-CGP-12177 for β-adrenergic density) adds mechanistic information (sources/rv-failure-aha-2026, rating: very high)

Obesity and Diabetes as Modifiable Risk Factors

• Diabetes associated with worse RV systolic and diastolic function via fibrosis, inflammation, microvascular ischaemia, lipotoxicity
• Obesity contributes via: increased preload, afterload (pulmonary pressure), pericardial constraint, impaired sarcomere function, sleep-disordered breathing, circulating proinflammatory adipokines (sources/rvfailure-nejm-2023, rating: very high)

Diagnosis and Evaluation

Clinical Assessment

• Symptoms: dyspnoea, lower-extremity oedema, early satiety, abdominal fullness, fatigue, exertional intolerance, RUQ tenderness
• Signs: elevated JVP, RV heave, loud P₂, TR murmur, pulsatile liver, hepatojugular reflux, ascites, lower-extremity oedema
• Historical clues: CAD, left heart failure, valvular disease, lung disease, VTE, connective tissue disease, HIV, anorexigen use; family history PAH (20% of "idiopathic" PAH carry heritable mutation)
• ECG: right atrial dilatation, right axis deviation, RVH signs; inferior ST changes ± right-sided leads for RV MI
• BNP/NT-proBNP: sensitive but non-specific; most useful in absence of left heart failure (sources/rvfailure-nejm-2023, rating: very high)

Echocardiography

• TAPSE (≥17 mm normal), tissue Doppler tricuspid annular velocity, fractional area change: quantitative RV systolic function measures
• TAPSE/PASP ratio: Noninvasive surrogate for RV–PA coupling; moderately correlated with gold-standard Ees/Ea (sources/rvfailure-nejm-2023, rating: very high)
• RV free-wall longitudinal strain: Sensitive RV dysfunction marker; prognostic across cardiovascular disease spectrum (sources/rvfailure-nejm-2023, rating: very high)
• Eccentricity index (AP/SL ratio >1) = RV overload; septal flattening in diastole = volume overload; in systole = pressure overload
• Dilated IVC without inspiratory collapse = elevated RAP
• 4D echo: RVEF and volumetric RV–PA coupling surrogate (SV/ESV ratio)

Cardiac MRI

• Reference standard for RV size, RVEF, and mass
• RVEF, stroke volume index, RVESVI: prognostic markers and risk stratification tools
• SV/ESV ratio: Simplified RV–PA coupling surrogate; larger physiologic range than RVEF; more sensitive to change when RVEF mildly–moderately reduced (sources/rvfailure-nejm-2023, rating: very high)
• LGE and ECV quantification: replacement fibrosis (permanent scar, septal insertion points) vs interstitial fibrosis (dynamic)
• 4D flow CMR: RV/RA morphology, TR impact, predicts PH vs RHC (sources/rv-failure-aha-2026, rating: very high)
• Aids ARVC diagnosis (fibrofatty RV free wall)

Right Heart Catheterisation

• See concepts/Right-Heart-Catheterization
• Measures: mPAP, PAWP, CO, RAP, RVEDP, PVR, PA compliance, PA elastance
• RV function surrogates: stroke volume index, RAP/PAWP ratio, RV stroke work index, PAPi
• PAPi most strongly correlated with maximal RV myocyte force generation (Aslam 2021) (sources/rvfailure-nejm-2023, rating: very high)
• Pressure-only preload estimates have important limitations

Pressure–Volume Loops and RV–PA Coupling

• See concepts/RV-PA-Coupling
• Gold standard: invasive conductance catheters with preload reduction
• Ees/Ea = 1.5–2.0: optimal; <0.6–0.8: uncoupling = worse outcomes
• Single-beat methods and combined RHC + CMR/3D echo approaches being validated

Classification by Mechanism

Disorders of Excessive Preload

• Tricuspid regurgitation: Acute severe TR is initially well-tolerated if afterload is normal; chronic TR causes volume overload, RV dilatation, progressive systolic dysfunction (sources/rvfailure-nejm-2023, rating: very high)
• Intracardiac left-to-right shunts: Detected by bubble contrast echo or oximetric run during RHC; quantified as shunt fraction
• Arteriovenous fistulas (HD access): AV fistula flow correlates with RV dilatation and reduced RV systolic function (sources/rvfailure-nejm-2023, rating: very high)

Disorders of Excessive Afterload

• Acute PE: Prototype of acute, poorly-tolerated afterload surge; McConnell's sign (midwall RV free wall akinesis + apical hypercontractility); CT-PA preferred; see entities/Pulmonary-Embolism
• Acute lung injury + PPV: Positive pressure ventilation magnifies RV afterload in ALI
• Chronic PH Groups 1–5: See concepts/Pulmonary-Hypertension-Classification and entities/Pulmonary-Hypertension

Disorders of Contractility

• RV MI: Proximal RCA occlusion; triad: hypotension, elevated JVP, clear lungs; inferior ST changes + right-sided ECG leads; urgent reperfusion (sources/rvfailure-nejm-2023, rating: very high)
• Myocarditis: Usually bilateral; isolated RV myocarditis rare
• Post-surgical RV dysfunction: Common after cardiac surgery and LVAD implantation (altered septal geometry, loss of LV contribution to RV, free wall anchoring effect)
• Left heart failure: Most common cause of RV failure; LHF → chronic preload increase + same myopathic process affects RV; RV involvement worsens prognosis significantly (sources/rvfailure-nejm-2023, rating: very high)
• ARVC: Fibrofatty dysplasia of RV → impaired contractility and RV failure; 2010 Task Force Criteria concepts/ARVC-Task-Force-Criteria; sarcoidosis can mimic ARVC
• Systemic sclerosis–PAH: Unique depressed sarcomere function → worse outcomes than idiopathic PAH
• Atrial fibrillation: Reduces RA emptying fraction and reservoir function → exacerbates RV failure physiology; commonly co-exists (sources/rvfailure-nejm-2023, rating: very high)

Treatment

Preload Management

• Acute RV failure with relative volume depletion (RV MI, submassive PE): cautious volume loading may augment stroke volume
• Aggressive volume loading is NOT universally indicated; RV dilation with normal intravascular volume worsens LV filling and cardiac output via pericardial constraint
• Intermediate-risk PE: furosemide single dose superior to placebo for clinical stabilisation (Lim 2022) (sources/rvfailure-nejm-2023, rating: very high)
• Chronic RV failure: Volume removal (IV diuretics, ultrafiltration); reduces TR annular dilatation, wall stress, septal deformation; new splanchnic nerve ablation approaches in development (sources/rvfailure-nejm-2023, rating: very high)

Afterload Reduction

• PAH (Group 1): ERA + PDE5i upfront combination Class I; prostacyclin pathway agents; sotatercept (activin trap) — new pathway, FDA-approved; improving RV–PA coupling in STELLAR trial (sources/rv-failure-aha-2026, rating: very high; sources/rvfailure-nejm-2023, rating: very high)
• PH from lung disease (Group 3): Inhaled treprostinil (RCT demonstrated improved exercise capacity)
• Chronic thromboembolic PH (Group 4): Surgical PEA first-line; BPA for inoperable; anticoagulation + adjunctive pharmacotherapy; see concepts/Balloon-Pulmonary-Angioplasty
• LHD-associated PH (Group 2): Pulmonary vasodilators (PDE5i) are contraindicated — SIOVAC trial: sildenafil worsened outcomes after correction of left-sided valvular disease; reduction of LA pressure via GDMT is the correct strategy (sources/rvfailure-nejm-2023, rating: very high)
• Sleep-disordered breathing: Treat to reduce hypoxaemia, afterload, and RV ischaemia

Contractility Augmentation

• Urgent reperfusion for RV MI
• Immunosuppression for myocarditis/sarcoidosis-related RV failure
• Dobutamine: Increases CO and stroke volume in RV MI and PH patients
• Milrinone: Useful; avoid systemic hypotension (→ RV ischaemia and reduced LV contractility)
• Digoxin: Mixed evidence
• Temporary MCS: Growing proliferation of devices; studied mainly with concomitant left heart failure; isolated RVAD contraindicated in severe PAH (risk of pulmonary haemorrhage); VA-ECMO for severe cases (sources/rvfailure-nejm-2023, rating: very high)
• Palliative care: Early initiation in parallel with pharmacotherapy for intractable RV failure

Contradictions / Open Questions

• Aggressive volume loading in acute RV failure: Widely practised but evidence suggests it can reduce cardiac output in patients without true volume depletion — invasive monitoring should guide decisions (sources/rvfailure-nejm-2023, rating: very high)
• Metabolic substrate shifts (FAO → glycolysis): Whether glycolytic switch is adaptive (O₂-efficient) or maladaptive (reduced ATP) in RV failure remains unresolved in clinical and experimental studies (sources/rvfailure-nejm-2023, rating: very high)
• PDE5i in LHD-associated PH: 77% of centres continue to use PAH-approved therapies in non-Group 1 PH despite evidence of harm (SIOVAC, ENABLE trials) — a major practice gap (sources/rvfailure-nejm-2023, rating: very high)
• Most current therapies are load-based: No approved therapies directly target RV contractility or lusitropy — a major unmet need (sources/rvfailure-nejm-2023, rating: very high)
• Adaptive-to-maladaptive transition is poorly predictable: Individual trajectories vary widely; mechanisms governing who transitions (and when) are not understood; better surrogates for RV contractile reserve needed (sources/rv-failure-aha-2026, rating: very high)

Connections

• Related to concepts/RV-PA-Coupling
• Related to concepts/Pulmonary-Hypertension
• Related to concepts/Pulmonary-Hypertension-Classification
• Related to concepts/PAH-Risk-Stratification
• Related to concepts/Right-Heart-Catheterization
• Related to concepts/Balloon-Pulmonary-Angioplasty
• Related to concepts/ARVC-Task-Force-Criteria
• Related to entities/Pulmonary-Hypertension
• Related to entities/Pulmonary-Embolism
• Related to entities/ARVC
• Related to entities/Heart-Failure
• Related to entities/HFpEF

Sources

• sources/rvfailure-nejm-2023 (very high)
• sources/rv-failure-aha-2026 (very high)