Effects of respiration on left ventricular diastolic function in healthy children.

Pulsed Doppler echocardiographic indices of mitral valve filling were measured in 20 healthy children, between 3 and 12.5 years old, in order to evaluate the effects of spontaneous respiration on left ventricular diastolic filling patterns. There were significant respiratory variations in four parameters of left ventricular diastolic function: The peak early filling velocity, the ratio of early to late peak filling velocity, and the ratio of early to late diastolic velocity-time integral decreased significantly during inspiration (mean decrease 7%, P < 0.05; 16%, P < 0.01; and 12%, P < 0.05, respectively). On the other hand there was a significant increase in late peak filling velocity with inspiration (10% increase, P < 0.05). Other variables of left ventricular diastolic filling were unchanged with inspiration. These results suggest that assessment of left ventricular diastolic function in children should be standardized with regard to respiratory phases in any clinical application.