What is the interpretation of a stress test showing normal left and right ventricular systolic function, no evidence of ischemia, and a dilated inferior vena cava with elevated right atrial pressure?

Interpretation of Stress Test Results

This stress test shows a normal cardiac function with no evidence of ischemia, indicating low cardiovascular risk, despite the finding of a dilated inferior vena cava with elevated right atrial pressure.

Key Findings Explained

Normal Cardiac Function

• Left ventricular systolic function is normal with ejection fraction of 63% 1
• Normal augmentation of all wall segments during stress (no wall motion abnormalities)
• Right ventricular systolic function is normal (S' 14.60 cm/s, TAPSE 2.0 cm)
• Normal exercise treadmill test with no ECG evidence of ischemia
• Good exercise tolerance (8 min 51 sec on treadmill)
• No chest pain during testing
• Duke treadmill score of 8 (low risk)

Abnormal Finding

• Dilated inferior vena cava with >50% collapse upon inspiration, consistent with elevated right atrial pressure (estimated at 8 mmHg)

Clinical Significance

Cardiovascular Risk Assessment

The stress test results indicate low cardiovascular risk based on:

• Normal wall motion with stress indicates absence of inducible myocardial ischemia 1
• Normal exercise ECG without ischemic changes 1
• Duke treadmill score of 8 places the patient in a low-risk category (annual mortality <1%) 1
• Normal left and right ventricular function 1

According to ACC/AHA guidelines, patients with a normal stress test have an annual risk for cardiac death and acute MI that is less than 1%, approximating the risk in the general population 1. The absence of chest pain during the test further supports a low-risk assessment.

Significance of Dilated IVC

The dilated inferior vena cava with >50% collapse on inspiration suggests:

• Mildly elevated right atrial pressure (estimated at 8 mmHg)
• This is an isolated finding in the context of otherwise normal cardiac function
• This finding may represent:
  • A normal variant in some athletic individuals
  • Mild volume overload
  • Early/subclinical right heart pressure abnormality

Clinical Implications

1. No evidence of coronary artery disease requiring intervention

   • The normal wall motion response to stress and absence of ECG changes effectively rule out significant obstructive coronary artery disease 1

2. Low risk for cardiac events

   • Based on the Duke treadmill score of 8, the patient has a low risk for adverse cardiac events (annual risk <1%) 1

3. Follow-up for dilated IVC

   • While not immediately concerning in the context of normal RV function, this finding warrants clinical correlation
   • Consider evaluation for potential causes of elevated right atrial pressure:
     • Volume status assessment
     • Evaluation for pulmonary hypertension
     • Assessment for valvular disease (though the report states no hemodynamically significant valvular abnormalities)

Management Recommendations

1. No immediate cardiac intervention needed

   • The stress test shows no evidence of ischemia requiring intervention

2. Regular follow-up

   • Standard cardiovascular risk factor management
   • Consider repeat echocardiography in 6-12 months to reassess the dilated IVC if clinically indicated

3. Clinical correlation of IVC finding

   • Assess for symptoms of right heart dysfunction (peripheral edema, fatigue, dyspnea)
   • Consider additional testing only if clinically indicated:
     • Complete pulmonary function testing if respiratory symptoms present
     • Sleep study if sleep apnea suspected
     • Right heart catheterization only if clinical suspicion for pulmonary hypertension and symptoms warrant

Conclusion

This stress test demonstrates normal cardiac function with excellent exercise capacity and no evidence of ischemia, indicating low cardiovascular risk. The isolated finding of a dilated IVC with elevated right atrial pressure should be clinically correlated but does not change the overall low-risk assessment based on the stress test results.