Should I refer a patient to cardiology if their echocardiogram (echo) shows a normal ejection fraction (EF) but reduced tissue Doppler velocity?

Should You Refer to Cardiology for Normal EF with Reduced Tissue Doppler Velocity?

Yes, refer patients with normal ejection fraction but reduced tissue Doppler velocity to cardiology, as this finding indicates underlying diastolic dysfunction or early systolic impairment that requires specialized evaluation and may predict adverse outcomes despite preserved EF. 1, 2

Why This Finding Matters

Reduced tissue Doppler velocities in the setting of normal EF represent a critical diagnostic clue that conventional echocardiography misses:

• Tissue Doppler imaging detects subclinical systolic dysfunction even when ejection fraction appears normal, revealing impaired longitudinal myocardial function that precedes EF reduction 2, 3
• Reduced systolic velocity (S wave) at the mitral annulus below 5.8 cm/s has 97% sensitivity for identifying heart failure in patients with preserved EF 2
• Reduced early diastolic velocity (E') indicates diastolic dysfunction, which is the hallmark of heart failure with preserved ejection fraction (HFpEF) and requires specialized management 1, 3

Key Tissue Doppler Parameters to Evaluate

The following abnormalities warrant cardiology referral 1, 2, 3:

• Reduced septal E' velocity (typically <8 cm/s indicates diastolic dysfunction) 1
• Reduced lateral E' velocity (typically <10 cm/s is abnormal) 1
• Elevated E/E' ratio >15 suggests high LV filling pressures and is the best noninvasive predictor of diastolic dysfunction 1, 3
• Reduced systolic velocity (S wave) <5.8 cm/s at the mitral annulus indicates impaired longitudinal systolic function 2
• Prolonged isovolumic relaxation time (IVRT) >115 ms with sensitivity of 94% for diastolic heart failure 2

Clinical Implications

Why Normal EF Doesn't Rule Out Significant Disease

• EF measures radial function only, missing the longitudinal dysfunction that tissue Doppler reveals 2, 3
• Patients with HFpEF have normal EF by definition (≥50%) but suffer significant morbidity and mortality from diastolic dysfunction 1, 4
• Reduced tissue Doppler velocities correlate with decreased functional capacity measured by cardiopulmonary exercise testing, even when EF is normal 5
• These patients have impaired exercise tolerance with lower peak VO2, anaerobic threshold, and METs despite preserved EF 5

What Cardiology Will Evaluate

The specialist will assess for conditions that present with this pattern 1, 6:

• Heart failure with preserved ejection fraction (HFpEF) - requires specific diagnostic criteria including elevated natriuretic peptides and evidence of elevated filling pressures 1
• Hypertrophic cardiomyopathy - may show normal EF with reduced longitudinal strain and tissue Doppler velocities, particularly in basal segments 1, 6
• Infiltrative cardiomyopathies (amyloidosis, sarcoidosis) - characteristically show preserved EF with severely reduced tissue Doppler velocities 1
• Restrictive cardiomyopathy - presents with normal EF but markedly abnormal diastolic function 1
• Early systolic dysfunction - tissue Doppler detects this before EF declines 2

Specific Red Flags Requiring Urgent Referral

Refer more urgently if any of these are present 1, 6:

• Symptoms of heart failure (dyspnea, orthopnea, edema) despite normal EF 1
• Left atrial enlargement (LA volume index ≥34 mL/m²) - highly sensitive marker of chronic diastolic dysfunction 1, 7
• Elevated E/E' ratio >15 - indicates high filling pressures requiring treatment 1, 3
• Left ventricular hypertrophy without clear hypertensive etiology - suggests cardiomyopathy 1, 6
• Restrictive mitral inflow pattern (E/A >2, deceleration time <150 ms) - indicates advanced diastolic dysfunction 1

Common Pitfalls to Avoid

• Do not dismiss reduced tissue Doppler velocities as "normal aging" - while velocities decline with age, symptomatic patients or those with other abnormalities require evaluation 1, 2
• Do not rely solely on EF to assess cardiac function - EF can remain normal until late in disease progression for many cardiomyopathies 1, 2
• Do not overlook the E/E' ratio - this is the single best noninvasive predictor of elevated filling pressures in HFpEF 3
• Do not ignore symptoms in patients with "normal" echocardiograms - tissue Doppler abnormalities explain symptoms that conventional echo misses 5, 2
• Do not delay referral waiting for EF to decline - early intervention may prevent irreversible myocardial damage 1, 2

What Additional Testing Cardiology May Order

The specialist will likely pursue 1, 6:

• Natriuretic peptides (BNP/NT-proBNP) - elevated levels support HFpEF diagnosis 1
• Global longitudinal strain (GLS) - values <-16% indicate early systolic dysfunction even with normal EF 1
• Cardiac MRI - provides tissue characterization to detect fibrosis, infiltration, or hypertrophy 6
• Stress echocardiography - may unmask diastolic dysfunction or dynamic obstruction not apparent at rest 1
• Invasive hemodynamic assessment - gold standard for confirming elevated filling pressures if diagnosis remains uncertain 3