Normal cardiac ventricular geometry and function during the last trimester of pregnancy and early neonatal period

Abstract

Fetal and early neonatal left and right ventricular cardiac geometry and left ventricular cardiac function were studied b y M-mode technique in a cross-sectional study between 28 and 40 weeks of gestation (n=227) and a longitudinal study from 24 h before until 48 h after delivery (n-15). Antenatally both ventricles were geometrically uniform; there was a 3.2-3.4-fold increase in left ventricular volume and a nearly 3-fold increase in left ventricular stroke volume and cardic output. During the early neonatal period the right ventricular transverse diameter reduced in size; there was a further 1.1-fold rise in left ventricular volume a n d a further 1.2-1.3-fold rise in left ventricular stroke volume and cardiac output.

Fetal Atrial Measurements before and after Delivery: Correlation with Plasma Atrial Natriuretic Peptide

“…In animal experiment, the percentage of right ventricular output to the combined ventricular out put was 66% [ 17], and the right ventricular function of the fetal heart was dominant over the left [1], Moreover, the direction through the foramen ovale was from right to left in utero [18], After delivery, the circulatory dynamics of the neonate change dramatically mainly due to three fac tors: (a) removal of the placenta, (b) decrease in the pul monary vascular resistance, and (c) closure of the foramen ovale. The elimination of the placental circulation after birth results in a marked increase in overall systemic vas cular resistance, and the onset of the respiration decreases the pulmonary vascular resistance [19].…”

“…The elimination of the placental circulation after birth results in a marked increase in overall systemic vas cular resistance, and the onset of the respiration decreases the pulmonary vascular resistance [19]. Therefore, a shift of work load from the right to the left ventricle is evident [1,2]. The dominant direction through foramen ovale was changed from left to right even in the early postnatal period [20], These dramatic circulatory changes from fetal to neonatal life might cause the significant decrease of the fetal atrial size.…”

“…With respect to échocardiographie studies in humans from fetal to neonatal life, there are only three investiga tions [1][2][3], Wladimiroff et al [1] reported that the right ventricular transverse diameter reduced in size whereas there was a further 1.1-fold rise in left ventricular volume and a further 1.2-to 1.3-fold rise in left ventricular stroke volume and cardiac output. Left preejection period/ventricular ejection time decreased from before delivery to just after delivery whereas right preejection period/ventricular ejection time increased from before to just after delivery [2], Wilson et al [3] demonstrated the physio logic changes in pulmonary vascular resistance and ven tricular compliance evaluated by Doppler echocardiogra phy in fetuses and newborns.…”

Blood flow measurements in the fetal descending aorta: Technique and Clinics

“…An additional inaccuracy is introduced by expressing blood flow figures per kilogram fetal weight, the latter being achieved from intrauterine ultrasound measurement of abdominal circumference (Campbell and Wilkin, 1975) From previous cardiac output data (Wladimiroff et al, 1981b(Wladimiroff et al, , 1982 and blood flow data similar to those in Table I, Tonge et al (1983) estimated that the percentage of total cardiac output directed to the descending aorta varies between 65 and 80%. There seems to be general agreement now on the importance of flow velocity waveform analysis in complicated pregnancies.…”

Difference between the left and right ventricular thickness in fetal heart

“…Recently attempts have been made to characterise cardiac growth in the fetus with real-time ultrasound but have provided conflicting results as to the ventricular size. Also, measurement of cardiac chamber sizes with ultrasound is restricted to the later half of the second trimester due to the limited resolution of currently available echocardiographic instrumentation [4][5][6][7][8] . There was no study done so far on gross anatomy of fetal heart especially on ventricular thickness, most of the study focus only by ultrasonography which has many limitation.…”