Echocardiographic evaluation of univentricular physiology and cavopulmonary shunts.

Since the surgical palliation of a univentricular congenital heart defect was first described in the early 1970s, thousands of lives were saved by this groundbreaking operation. Although initially described for the palliation of tricuspid valve atresia, the Fontan operation is now utilized for many other univentricular heart defects involving either hypoplastic right or left ventricles, and the number of babies who survive the surgery and the postsurgical hospitalization continues to grow. Echocardiography constitutes the mainstay follow-up imaging modality for patients with a Fontan system. In order to obtain all the needed information from the echocardiographic studies, close familiarity with the native congenital heart defects, the build of the Fontan systems, and the potential long-term complications is required. Detailed studies provide valuable information on the various components of the Fontan circulation such as the function of the single ventricle and the valves, flow in the Glenn and Fontan pathways, and possible sources of cyanosis and shunts. Three-dimensional and transesophageal echocardiogram studies can assist in delineating the Fontan anatomy and to evaluate smaller intracardiac structures.

Echocardiographic evaluation of univentricular physiology and cavopulmonary shunts.

The term univentricular heart (UH) defines complex congenital heart disease that lacks a pulmonic ventricular chamber either in the original anatomy or the final palliation. The prevalence of patients with this type of physiology continues to increase due to improved surgical palliative procedures. This review will outline the physiology, complications, and echocardiographic approach to image patients with palliated UH.

Comparative roles of the atrial septal aneurysm versus patent foramen ovale in systemic embolization with inferences from neonatal studies.

Patent foramen ovale (PFO) and atrial septal aneurysm (ASA) have a significant statistical relation to ischemic strokes in adults. We reviewed their prevalence in 106 echocardiograms of neonates. Although all normal neonates have PFO, only 4% had ASA. From fetal and neonatal echocardiograms, we conclude that ASAs are more likely to be caused by inadequate size of the PFO, but the ASA can act as a funnel, enhancing the chances of paradoxic embolization in the presence of a PFO. There is no convincing evidence that an ASA alone causes strokes in adults; the confounder is probably atrial fibrillation.

Prospective comparison of valve regurgitation quantitation by cardiac magnetic resonance imaging and transthoracic echocardiography.

BACKGROUND: Both transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) imaging allow quantification of chronic aortic regurgitation (AR) and mitral regurgitation (MR). We hypothesized that CMR measurement of regurgitant volume (RVol) is more reproducible than TTE. METHODS AND RESULTS: TTE and CMR performed on the same day in 57 prospectively enrolled adults (31 with AR, 26 with MR) were measured by 2 independent physicians. TTE RVol(AR) was calculated as Doppler left ventricular outflow minus inflow stroke volume. RVol(MR) was calculated by both the proximal isovelocity surface area method and Doppler volume flow at 2 sites. CMR RVol(AR) was calculated by phase-contrast velocity mapping at the aortic sinuses and RVol(MR) as total left ventricular minus forward stroke volume. Intraobserver and interobserver variabilities were similar. For AR, the Bland-Altman mean interobserver difference in RVol was -0.7 mL (95% confidence interval [CI], -5 to 4) for CMR and -9 mL (95% CI, -53 to -36) for TTE. The Pearson correlation was higher (P=0.001) between CMR (0.99) than TTE readers (0.89). For MR, the Bland-Altman mean difference in RVol between observers was -4 mL (95% CI, -21 to 13) for CMR compared with 0.7 mL (95% CI, -30 to 32) for the proximal isovelocity surface area and -10 mL (95% CI, -76 to 56) for TTE volume flow at 2 sites. Correlation was similar for CMR (0.94) versus TTE readers (0.90 for the proximal isovelocity surface area). CONCLUSIONS: Compared with TTE, CMR has lower intraobserver and interobserver variabilities for RVol(AR), suggesting CMR may be superior for serial measurements. Although RVol(MR) is similar by TTE and CMR, variability in measured RVol by both approaches suggests that caution is needed in clinical practice.