Effect of isolated right ventricular outflow obstruction on left ventricular function in infants

Area of Science:

• Pediatric Cardiology
• Cardiovascular Physiology
• Congenital Heart Disease

Background:

• Right ventricular (RV) outflow obstruction can impact left ventricular (LV) function.
• Understanding the relationship between RV outflow obstruction and LV geometry is crucial for pediatric cardiac care.

Purpose of the Study:

• To evaluate resting left ventricular (LV) function in infants with isolated right ventricular (RV) outflow obstruction.
• To determine the correlation between the degree of RV outflow obstruction and alterations in LV geometry and function.

Main Methods:

• Echocardiographic assessment of LV function and geometry in 29 infants with RV outflow obstruction.
• Correlation analysis between the degree of obstruction and measured LV parameters.
• Evaluation of functional changes before and after surgical intervention in a subset of patients.

Main Results:

• A significant inverse correlation was found between cardiac index and the degree of RV outflow obstruction (r = 0.59, p = 0.0001).
• RV hypertension led to septal displacement, altered LV geometry, and impaired LV diastolic filling.
• LV end-diastolic volume index and diastolic inflow ratios correlated with obstruction severity and septal displacement.
• Surgical relief of obstruction in four infants resulted in a significant increase in cardiac index.

Conclusions:

• Significant RV outflow obstruction in infants is associated with reversible alterations in LV function.
• Abnormal LV geometry and impaired diastolic filling are key mechanisms linking RV obstruction to LV dysfunction.
• These findings underscore the importance of addressing RV outflow obstruction to restore normal LV performance.