Search

Surgery for congenital heart disease is now often performed in the first months of life because mortality is higher and myocardial damage more serious in unoperated children or those undergoing delayed surgery. Fetal cardiac intervention may prove a logical extension and has been proposed for fetuses with critical semilunar valve stenosis or atresia. Early ventricular decompression may halt disease progression, alter the natural history and improve postnatal outcomes either by preserving a two-ventricle circulation or by improving the outlook for single-ventricle candidates because of a healthier myocardium and pulmonary bed. Without intervention, fetuses with a closed interatrial septum may develop circulatory failure resulting in hydrops and intrauterine death, whereas in utero balloon atrial septostomy may stabilise the situation and increase duration of pregnancy. [ABSTRACT FROM AUTHOR]

Objective: To compare ventricular long axis function in fetuses of diabetic mothers (FDM) with contemporaneously studied normal controls (N) and to assess the effect of pre-pregnancy diabetic control on these measurements. Design: Long axis function was compared in 41 FDM and 159 N fetuses in a cross sectional observational study. Setting: Fetal medicine unit. Methods and results: Echocardiography confirmed structural normality. Pulsed wave valvar Doppler velocimetry, lengthening and shortening myocardial velocities, and amplitude of ventricular long axis movement were recorded at the base of the left and right ventricular free walls and septum. Periconceptual diabetic control was assessed by haemoglobin A1c (HbA1c) in early pregnancy. Doppler and myocardial velocities were negatively related and myocardial thickness was positively related with HbA1c. In both cohorts all variables except mitral and tricuspid late filling (A wave) velocities were dependent on gestational age. FDM gestational age related values were higher for most variables and robust analysis of covariance showed significantly different maturation patterns in mitral valve E:A ratio (p = 0.036) and pulmonary velocity (p = 0.04), late lengthening myocardial velocities (left p = 0.016 and right p = 0.066), left myocardial shortening velocities (p = 0.008), and left free wall (p = 0.03) and septal (p = 0.04) amplitude of motion. FDM septal thickness was significantly increased throughout gestation (p < 0.0001). Conclusion: Periconceptual diabetic control influences fetal cardiac performance and myocardial hypertrophy but, unlike the pathophysiology of adult ventricular hypertrophy, is accompanied by functional adaptation. It is unlikely to explain the increased rate of late stillbirth observed in diabetic pregnancies. [ABSTRACT FROM AUTHOR]

Considerable advances in ultrasound technology and close collaboration between the specialties of paediatric cardiology and fetal medicine have resulted in the increasing ability to diagnose congenital heart disease before birth over the last two decades. Fetal cardiology differs from paediatric cardiology not only in the spectrum of diseases seen, but also in the assessment of function because of the extended feto-placental circulation. Importantly, outcomes for specific lesions may differ as extracardiac abnormalities and chromosomal defects may alter the prognosis of otherwise straight forward cardiac lesions such as tetralogy. Historically the examination of the fetal heart and circulation developed separately, obstetricians using Doppler to examine the uteroplacental circulation to study the pathophysiology of pregnancy.

OBJECTIVE--The origin of innocent systolic murmurs is uncertain. This study was designed to evaluate the relative contribution in the same subjects of the main factors implicated in the genesis of vibratory innocent systolic murmurs--that is, the presence of left ventricular bands and increased left ventricular flow indices--and to examine evidence for turbulence in relation to these findings. PATIENTS--40 children with innocent systolic murmurs and 40 paired controls without murmurs were matched for age and body surface area. DESIGN--These subjects were examined prospectively by cross sectional echocardiography with pulsed and continuous wave Doppler and colour flow mapping. SETTING--A tertiary referral centre for paediatric cardiology. RESULTS--Left ventricular bands were significantly more prevalent in patients with innocent murmurs (70%) than in controls (48%) but only if apical bands were included (p = 0.039). Cases had significantly higher aortic peak flow velocities (p less than 0.001), flow integrals (p = 0.001), and stroke volumes (p = 0.014), and significantly lower heart rates (p = 0.033) than controls. There were no significant differences between cases and controls in mean aortic diameter, cardiac output, or ejection fraction. There was no evidence of turbulence in the left ventricle or outflow tract in any individual but curvilinear periodic vibrations and audible "whoops" were detected in the left ventricle by pulsed wave Doppler echocardiography. These were significantly more common in cases than controls (p less than 0.01) but were not related to the presence of bands. CONCLUSIONS--Innocent systolic murmurs were unrelated to aortic size but they were strongly associated with higher aortic flow volume and velocity, with relative bradycardia, and with evidence of vibratory phenomena in the left ventricle. The role of left ventricular bands remains uncertain. [ABSTRACT FROM PUBLISHER]

The article reports that the fetal circulation works in parallel with the dominant right ventricle, ejecting approximately 60% of the combined ventricular output. Three important communications exist between the two circulations (oval foramen and the arterial and venous ducts) that influence loading conditions. In particular, the determinants of fetal left ventricular filling differ considerably from those seen in the adult heart. Pulmonary venous return contributes only a small proportion to left ventricular preload because of the relatively low pulmonary blood flow in fetal life (rising from an estimated 11% to 25% of right ventricular output by the third trimester).