Reduced systolic myocardial function in children with chronic renal insufficiency

Area of Science:

• Pediatric Cardiology
• Nephrology
• Cardiovascular Physiology

Background:

• Children with chronic renal insufficiency (CRI) often exhibit increased left ventricular (LV) mass, potentially as an adaptation to increased cardiac workload.
• However, the impact of CRI on intrinsic LV systolic function remains incompletely understood.

Purpose of the Study:

• To investigate whether children with CRI have impaired LV systolic function, specifically intrinsic contractility, despite increased LV mass.
• To assess the prevalence of subclinical systolic dysfunction in this population.

Main Methods:

• Standard echocardiograms were performed on 130 predialysis children (stages II-IV CRI) and 130 healthy controls.
• Systolic function was evaluated using endocardial (eS) and midwall (mS) fractional shortening, with end-systolic stress (myocardial afterload) calculated.
• Subclinical systolic dysfunction was defined by impaired mS after accounting for afterload.

Main Results:

• Children with CRI showed significantly lower eS and mS compared to controls, despite higher blood pressure and increased LV mass.
• Reduced eS was attributed to increased afterload, but mS remained significantly impaired even after correction for afterload.
• The prevalence of subclinical systolic dysfunction (impaired mS) was over five times higher in children with CRI (24.6%) than in controls (4.5%).
• This dysfunction was most prevalent in patients with concentric hypertrophy and associated with lower hemoglobin levels.

Conclusions:

• Chronic renal insufficiency in children is associated with impaired intrinsic left ventricular contractility, independent of increased afterload.
• Increased LV mass in pediatric CRI may not fully compensate for systolic dysfunction, indicating a need for closer cardiac monitoring.