Elevated ejection-phase myocardial wall stress in children with chronic kidney disease

Area of Science:

• Cardiovascular Physiology
• Pediatric Nephrology
• Biomechanical Engineering

Background:

• Myocardial wall stress (MWS) is a primary mechanical stimulus driving left ventricular (LV) hypertrophy.
• Children with chronic kidney disease (CKD) face heightened risks of adverse cardiovascular events, particularly LV hypertrophy.
• Understanding MWS in pediatric CKD is crucial for predicting and mitigating cardiovascular complications.

Purpose of the Study:

• To investigate whether MWS is elevated in children diagnosed with chronic kidney disease (CKD).
• To assess the relationship between CKD severity and MWS levels.
• To explore the underlying mechanisms of MWS changes in pediatric CKD.

Main Methods:

• Carotid tonometry was used to estimate ventricular pressure.
• 2D transthoracic echocardiography with wall-tracking determined LV cavity and wall volumes.
• MWS was calculated using these pressure and volume measurements in 92 children (controls and CKD stages).

Main Results:

• No significant differences in age, height, weight, blood pressure, or LV mass were observed across groups.
• Peak, mean, and end-systolic MWS were significantly higher in children with CKD compared to controls.
• MWS increased progressively with advancing stages of CKD (P=0.01 for peak MWS).

Conclusions:

• Children with CKD exhibit elevated systolic MWS, independent of blood pressure.
• This increase is linked to LV dysfunction, characterized by altered systolic wall/cavity volume dynamics.
• Elevated MWS in pediatric CKD may predispose to LV hypertrophy and future cardiovascular events.