What is the management approach for a patient with aortic stenosis and right ventricular (RV) strain on electrocardiogram (ECG)?

Management of Aortic Stenosis with Right Ventricular Strain on ECG

A patient with aortic stenosis and RV strain on ECG requires immediate comprehensive echocardiographic evaluation to determine AS severity, assess biventricular function, and guide urgent intervention decisions, as RV dysfunction indicates advanced disease with poor prognosis. 1, 2

Initial Diagnostic Workup

Confirm AS severity and assess cardiac function:

• Obtain transthoracic echocardiography immediately to measure aortic valve area (AVA ≤1.0 cm²), mean gradient (≥40 mmHg for high-gradient AS), and peak velocity (≥4 m/s) 1, 3
• Perform 3D echocardiographic assessment of both left and right ventricular ejection fractions, as RV dysfunction (RVEF <45%) is more common in low-gradient AS (63.6% vs 39% in high-gradient) and predicts worse outcomes 2
• Measure indexed stroke volume (<35 mL/m²) to identify low-flow states, which are associated with poor outcomes regardless of gradient 1, 3
• Assess pulmonary artery systolic pressure, though pulmonary hypertension does not independently predict RV dysfunction in AS 2

Additional risk stratification imaging:

• Obtain cardiac CT for aortic valve calcium scoring if low-flow, low-gradient pattern is present (male: >2000 AU; female: >1200 AU confirms true severe AS) 1
• Measure BNP levels, as elevated BNP (ratio >2 times normal for age/sex) indicates higher risk 1
• Assess left atrial volume (indexed area ≥12.2 cm²/m²) and LV global longitudinal strain (<16%) as markers of advanced dysfunction 1

Understanding the Clinical Significance

RV strain on ECG signals advanced disease:

• RV dysfunction in AS is primarily driven by LV dysfunction through ventriculo-ventricular interaction, not pulmonary hypertension alone 2
• The only significant predictor of RV dysfunction is LV dysfunction (correlation r=0.78, p<0.0001), indicating that RV strain reflects severe hemodynamic compromise 2
• Patients with low-flow, low-gradient AS have significantly worse RV function (RVEF 36% vs 46% in high-gradient, p=0.02) 2

Management Algorithm Based on Flow-Gradient Classification

For symptomatic patients with high-gradient severe AS (mean gradient ≥40 mmHg, AVA ≤1.0 cm²):

• Proceed directly to aortic valve replacement (AVR) regardless of surgical risk or RV function 1, 3
• Both TAVR and SAVR are appropriate; choice depends on surgical risk assessment by Heart Team 1
• Medical management alone is rated "Rarely Appropriate" for symptomatic severe AS 3

For patients with low-flow, low-gradient AS and reduced LVEF (<50%):

• Perform dobutamine stress echocardiography to distinguish true severe AS from pseudosevere AS 1, 4
• If flow reserve demonstrated (stroke volume increase ≥20%), AVR is strongly recommended (score 8-9) regardless of surgical risk 3
• If no flow reserve but heavy valve calcification on CT (male >2000 AU, female >1200 AU), AVR remains appropriate (score 7) 1, 3
• This phenotype has the worst prognosis but benefits greatly from valve replacement 4

For patients with low-flow, low-gradient AS and preserved LVEF (paradoxical LF-LG):

• Confirm true severe AS using dobutamine stress echo or CT calcium scoring 1, 4
• These patients have the worst outcome among AS phenotypes and benefit greatly from AVR when severity is proven 4
• AVR is appropriate if flow reserve demonstrated or calcium score confirms severity 3

Heart Team Evaluation

Multidisciplinary assessment must include:

• Cardiac surgery, interventional cardiology, cardiac imaging, anesthesiology, and geriatrics expertise 1, 5
• Calculate STS-PROM score and assess frailty, comorbidities, and procedure-specific impediments 5
• Evaluate for concomitant coronary artery disease (present in 40-75% of AS patients) requiring revascularization 1
• Assess for severe mitral regurgitation or mitral stenosis that may complicate decision-making 1

Critical Pitfalls to Avoid

Do not delay intervention based on "low" gradients:

• Low gradients with low flow represent advanced disease with poor prognosis, not less severe stenosis 3
• The Poiseuille-Hagen relationship explains that reduced flow through a severely stenotic valve produces deceptively low gradients 3

Do not assume RV dysfunction is solely from pulmonary hypertension:

• RV dysfunction in AS is primarily driven by LV dysfunction through ventriculo-ventricular interaction 2
• Pulmonary hypertension does not independently predict RV dysfunction in severe AS 2

Do not pursue medical management alone in symptomatic severe AS:

• Once symptoms develop, prognosis deteriorates dramatically to 25% mortality at 1 year and 50% at 2 years without intervention 5
• Delay in definitive treatment is "Rarely Appropriate" for symptomatic severe AS 3

Special Considerations for Futility

Medical management with palliative care is appropriate when:

• Life expectancy <1 year from non-cardiac causes 1, 5
• Moderate to severe dementia is present 1
• Irreversible severe RV dysfunction exists where expected benefit from AVR is less than risk 1
• Balloon aortic valvuloplasty may be considered as bridge to decision or palliative measure in highly selected cases 1, 3