Global myocardial function is compromised in infants with pulmonary hypertension

Area of Science:

• Neonatal Cardiology
• Pediatric Critical Care Medicine
• Cardiovascular Physiology

Background:

• Persistent pulmonary hypertension of the newborn (PPHN) is a critical condition associated with high mortality and morbidity.
• Understanding myocardial function, particularly diastolic function, is crucial for managing PPHN in neonates.
• Nitric oxide is a common treatment for PPHN, but its effects on cardiac function require detailed investigation.

Purpose of the Study:

• To investigate the myocardial function profile, with a specific focus on diastolic function, in term infants diagnosed with PPHN.
• To assess cardiac hemodynamics in neonates with PPHN treated with nitric oxide.
• To identify the prevalence of right ventricular diastolic dysfunction in this patient population.

Main Methods:

• Retrospective analysis of a unit electronic database for infants (≥34 weeks gestation) treated with nitric oxide for PPHN over six years.
• Exclusion criteria included lack of echocardiogram on nitric oxide administration day, congenital heart disease, or age ≥2 weeks at treatment initiation.
• Echocardiographic parameters were used to assess biventricular function, tricuspid regurgitation, ductal shunting, and right ventricular diastolic function (systolic to diastolic duration ratio).

Main Results:

• Over two-thirds of the infants exhibited low biventricular outputs.
• Tricuspid regurgitation was present in 80% (20/25) of infants, with bidirectional ductal shunting in the majority.
• Right ventricular diastolic dysfunction was widely prevalent, as indicated by the systolic to diastolic duration ratio.

Conclusions:

• A significant proportion of neonates with PPHN present with severe hemodynamic compromise.
• This study provides the first detailed account of right ventricular diastolic dysfunction in infants with PPHN.
• Comprehensive cardiovascular hemodynamic evaluation is essential for optimizing clinical management, potentially including therapies like milrinone that improve myocardial relaxation.