Diastolic function in newborn infants: understanding pathophysiology, diagnosis and clinical relevance.

Diastolic function, the combined effect of myocardial relaxation, recoil forces, stiffness and atrial function, describes the ability of the ventricle to fill up with blood and prepare a stroke volume for ejection. Diastolic dysfunction (DD), also described as 'an increased resistance to filling' for example due to impaired relaxation, chamber stiffness, volume load or pericardial restraint, is a situation whereby normal filling is only achieved with elevated filling pressure and higher atrial pressure. Diastolic dysfunction can progress to diastolic heart failure, a clinical syndrome with respiratory deterioration and/or edema and is associated with morbidity and mortality. Diastolic dysfunction can be diagnosed with a multi-modal multi-parameter echocardiography approach, but further development of newborn specific diagnostic algorithms is required. Diastolic dysfunction often precedes systolic dysfunction and thus provides an opportunity for management directives in newborns at high risk of heart failure: with a patent ductus arteriosus, septic shock, pulmonary hypertension, congenital diaphragmatic hernia, small for gestational age infants and infants with bronchopulmonary dysplasia. This review describes the current understanding of the physiology and pathophysiology of diastolic function in newborn infants. IMPACT: Diastolic dysfunction is common in the neonatal intensive care and can lead to diastolic heart failure. Understanding pathophysiology and clinical relevance allows for targeted treatments and supportive care. Improved cardiovascular care during a crucial part of development can improve short- and long-term outcomes and limit early heart failure.