Indomethacin is a potent agent in the treatment of premature labor, but its use has been limited because of concern about its constrictive effects on the fetal ductus arteriosus. To study these effects we used serial fetal echocardiography in 13 pregnant women in premature labor who received indomethacin according to three different dose schedules, ranging from 100 to 175 mg per day, for a maximum of 72 hours. The gestational ages of the fetuses ranged from 26.5 to 31.0 weeks. The detection of ductal constriction in 7 of the 14 fetuses by echocardiography led to the discontinuation of indomethacin. Three fetuses also had tricuspid regurgitation. There was no statistically significant difference between the mean (+/- SEM) gestational age of the fetuses with ductal constriction and that of those without constriction (29.3 +/- 0.59 and 28.4 +/- 0.52, respectively). There was no relation between serum indomethacin levels in the mothers and ductal constriction. In all seven fetuses affected, ductal constriction had resolved by the time they were restudied 24 hours after the discontinuation of indomethacin. Persistent fetal circulation was not detected in any of the 11 neonates studied after delivery. Indomethacin used to treat premature labor appears to cause transient constriction of the ductus arteriosus in some fetuses, even after short-term use.

Pulmonary hypertension may occur in the fetus in the presence of constriction of the ductus arteriosus. The feasibility of detection and quantitation of fetal ductal constriction by Doppler echocardiography was assessed in an animal preparation in which ductal constriction was created in the fetal lamb with a variable ligature causing varying degrees of fetal pulmonary hypertension (fetal pulmonary arterial systolic pressure 57 to 97 mm Hg and ductal gradient 9 to 42 mm Hg). Comparison of blinded, continuous-wave peak Doppler velocity (V) measurements of the ductal gradient with the modified Bernoulli assumption (gradient 4V2) compared well with direct catheter measurements of instantaneous peak systolic gradient (r = .99, catheter = 0.95 x Doppler + 0.6), peak-to-peak gradient (r = .97), and mid-diastolic gradient (r = .85). Ductal constriction was characterized by an increase in the peak systolic and diastolic velocities. The normal human fetal ductus arteriosus blood flow velocity pattern was assessed by pulsed Doppler techniques in 25 normal human fetuses after 20 weeks gestation. The peak systolic flow velocity in the ductus arteriosus measured by image-directed pulsed Doppler echocardiography ranged from 50 to 141 cm/sec (mean 80 cm/sec) and increased with gestational age (r = .50). Diastolic velocity in the ductus arteriosus was consistently directed toward the descending aorta and ranged from 6 to 30 cm/sec. The ductal systolic velocities were the highest blood flow velocities in the fetal cardiovascular system. Application of these techniques to fetuses whose mothers were receiving indomethacin for treatment of premature labor at 30 to 31 weeks gestation confirmed this method to be sensitive for detection of fetal ductal constriction, which developed in three fetuses. Doppler echocardiography can be used to assess the flow velocity in the fetal ductus in humans and to detect constriction and a pressure gradient across it. Quantitation of fetal ductal gradient is possible and may be useful for assessment of the severity of fetal ductal constriction in such patients. Circulation 75, No. 2, 406-412, 1987. THERE IS EVIDENCE from animal experiments in the fetal lamb that constriction of the ductus arteriosus by a prostaglandin inhibitor can cause fetal pulmonary hypertension and pulmonary arteriolar changes.I 2 The administration of a prostaglandin inhibitor in late gestation has been associated with persistent neonatal pulFrom the Lillie Frank Abercrombie Section of Cardiology and the Section

Congenital coronary anomalies (CCAs) are uncommon but can cause sudden cardiac death or other symptoms of myocardial ischaemia, especially in young healthy subjects. Conventional coronary angiography (CA) is an invasive and expensive procedure, and cannot provide three-dimensional data on the anomalous vessel. Electrocardiographic gated multidetector CT (MDCT) has been reported to be useful for non-invasive evaluation of CCAs. The purpose of this pictorial review is to discuss and illustrate different CCAs in terms of clinical importance, type and manifestations using MDCT. Knowledge of the CT appearances and an understanding of the clinical significance of these anomalies are essential for making the correct diagnosis and planning patient treatment.

The prevalence of coronary artery ectasia in consecutive participants who underwent coronary computed tomography angiography is 8%. The right coronary artery was most commonly affected and most participants had single-vessel involvement. Coronary artery ectasia usually is associated with atheromatous changes, but not with significant coronary artery disease. Coronary artery ectasia thrombosis was a rare complication. No specific predisposing factors have been identified.

Objective To compare coronary flows between premature infants with and without hemodynamically significant patent ductus arteriosus (hsPDA) and to determine if coronary flow is influenced by medical PDA treatment.Design Prospective, observational pilot study. Forty-three infants <32 weeks gestation underwent echocardiography when routinely indicated. Study group included infants with hsPDA requiring treatment. Comparison groups included infants with nonsignificant PDA and infants without PDA. Results The study group (n = 13), compared with the comparison groups with nonsignificant PDA (n = 12) and without PDA (n = 18) had higher troponin levels (p = 0.003 and 0.004, respectively). In infants with hsPDA compared with infants with no PDA there was a significant increase in myocardial oxygen demand and decrease in left main coronary artery flow, with nonsignificant increase in cardiac output. Conclusions Decrease in coronary artery flows and higher troponin values may suggest a "steal effect," not allowing to meet the elevated myocardial oxygen demand in infants with hsPDA.