Efficiency of left ventricular diastolic function increases in healthy full-term infants during the first months of life - A prospective follow-up study

Postnatal changes in left ventricular diastolic filling and systolic cardia c performance were studied monthly by serial echocardiographic measurements from days 3-5 up to six months in 20 healthy full-term infants. The fracti onal shortening area (FSA = (left ventricular end-diastolic area - end-syst olic area)/end-diastolic area) was assessed for systolic performance, and t ransmitral pulsed-wave Doppler how velocity patterns were analysed for dias tolic function. FSA remained stationary during the observation. After birth , left ventricular peak early (E) and atrial (A) Velocities and the respect ive integrals were lower than at one month of age (47 +/- 5 vs. 63 +/- 6 cm /s and 44 +/- 6 vs. 57 +/- 5 cm/s and 3.33 +/- 0.40 vs. 4.05 +/- 0.53 cm an d 2.74 +/- 0.40 vs. 3.18 +/- 0.53 cm; P < 0.05). During the next five month s, the early parameters (E velocity and E integral) increased but the atria l indices (A velocity and A integral) did not change. During the whole obse rvation the E/A velocity ratio, the E/A integral ratio and the early fillin g fraction (EFF) increased. The early filling deceleration time was longer during the first month than later (87 +/- 10 vs. 72 +/- 13 ms; P < 0.05). I n conclusion, age-related changes were observed in the diastolic but not in the systolic performance in healthy full-term infants during the first six months. The most intensive changes took place in the early and atrial tran smitral parameters during the first month of life, suggesting an improvemen t in both left ventricular relaxation and compliance. During the following five months, the early mitral parameters increased but the atrial diastolic values remained stable. These changes may mainly be determined by the impr ovement in left ventricular relaxation. (C) 2000 Elsevier Science Ireland L td. All rights reserved.