Bidirectional blood flow velocity in the cardiac chambers and great vessels studied with the Doppler ultrasonic flowmeter

Utilizing the bidirectional Doppler flowmeter catheter system, phasic forward and reverse flow velocity was measured in the cardiac chambers and great vessels of man. Recordings of right atrial, right ventricular and aortic flow velocity are characterized by a small reverse flow velocity component, usually occurring during early diastole, followed by a large forward systolic wave. Blood flow velocity in the left ventricular outflow tract and pulmonary artery is forward with negligible or no reverse flow. Ventricular extrasystoles and ventricular tachycardia result in diminished systolic and enhanced retrograde aortic and right ventricular flow velocity, possibly based on valvular incompetence. Aortic regurgitation and tricuspid insufficiency can be identified by their characteristic diastolic and systolic reverse flow velocity patterns. Patients with an increase in right atrial pressure, regardless of its etiology, manifest significant reverse flow velocity toward the caval system. We conclude that this technic is a valuable method for measuring bidirectional flow velocity under normal and pathologic conditions.     

Transposition of the great vessels

Twenty-nine cases of transposition of the great vessels were studied, 15 confirmed by necropsy and 4 by angiocardiography. They were divided into three groups: (1) isolated transposition; (2) transposition with pulmonary stenosis and other associated malformations; and (3) transposition with biventricular origin of the pulmonary artery and hypoplastic aorta.

The relation between the great vessels, the characteristics of the associated malformations, the clinical picture, the scalar electrocardiogram and the radiologic findings were studied in every case.

The anatomic-embryologic relations and the corresponding electrocardiographic and radiologic correlations were established in the different groups.     

Significance of cardiac defects in the developing fetus: a study of spontaneous abortuses

We investigated the impact of heart defects on the developing human fetus by examining 412 hearts from consecutive spontaneous abortuses. In each case, the cardiac morphology was correlated with the autopsy findings and the karyotype (unavailable in 115 hearts not successfully cultured). Of the 412 hearts, 10 (2.4%) contained structural defects (six ventricular septal defects, one atrial septal defect with ventricular septal defect, and one each coarctation, atrioventricular septal defect, and tetralogy of Fallot). Only one of 10 had major extracardiac malformations. Of the 277 fetuses with normal karyotype, three (1.1%) had heart defects. Of the 20 fetuses with abnormal karyotype, four (20%) had heart defects. In the remaining three fetuses with heart defects, the karyotype was not obtained. Thus (1) 57% of spontaneous abortuses with congenital heart defects contained major chromosomal abnormalities, (2) the spectrum of heart defects among spontaneous abortuses was similar to that among liveborns, and (3) since the prevalence of heart defects among fetuses without other major abnormalities was similar to that among liveborns, heart defects alone may not jeopardize the survival of a developing fetus.     

Anatomical and echocardiographic correlates of normal cardiac morphology in the late first trimester fetus.

OBJECTIVES: To describe the normal cardiac morphology as seen by transvaginal ultrasound imaging in the first trimester fetus and to compare it with the morphology of the heart as seen by microdissection at the same gestational age. DESIGN: In 53 mothers undergoing early sonography, the fetal heart was examined and the images recorded. The gestational age range was 5-12 weeks of gestation, which represents 21 to 70 days after conception. Images were analysed frame by frame and compared with the anatomy of embryos and fetuses at the same gestational ages. RESULTS: After the 9th week of gestation, four cardiac chambers, the aortic origin, and the pulmonary artery could be identified on cross sectional echocardiography in conjunction with colour flow Doppler. At 9 weeks, the apex pointed anteriorly and the right ventricle and pulmonary artery lay to the right of the midline. By the 11th week of gestation, the apex pointed to the left and the pulmonary artery lay to the left of the midline as in the older fetus. Between 9 and 12 weeks' gestation the aorta was larger than the pulmonary artery. These findings were confirmed in the microdissected hearts. CONCLUSIONS: The current quality of ultrasound images obtained using transvaginal transducers in the first trimester fetus allows the study of fetal cardiac anatomy. Some of the later developmental changes can be demonstrated. As technology improves further the details of earlier cardiac morphogenesis may also become visible.     

Limb defects in a fetus with homozygous alpha-thalassemia

A fetus with homozygous alpha-thalassemia (alpha-thal) who displayed limb reduction defects is described. These kinds of congenital anomalies should be surveyed by sonography in at-risk pregnancies and included in genetic counseling prior to in utero fetal therapy.