Added Value of Live 3-Dimensional Transesophageal Echocardiography During Procedures in Fontan Patients.

3D transesophageal echocardiography (3D-TEE) has proven useful and accurate during some operating room (OR), interventional cardiac catheterization (Cath), and electrophysiologic (EP) procedures. The use of 3D-TEE during similar procedures in patients who have undergone Fontan surgery and its additional value have not been previously reported. To determine if live 3D-TEE during procedures post Fontan has added value, 3D-TEEs in 58 post-Fontan patients over a 5-year study period were reviewed. Additional information provided by 3D-TEE (over 2D-TEE) was classified into the following: A: new information which changed/refined the plan and 0: no new important information. Pre- and post-bypass OR 3D-TEEs were counted as one study. A total of 67 3D-TEEs (41 Cath, 13 OR, and 13 EP procedures) were performed. Median age was 14 years (6-39 years). Median weight was 47 kg (21-109 kg). In Cath procedures, only 2/41 (5%) were graded A (R to L atrial level shunt [Fontan leak], n = 1; thrombus in pulmonary artery stump, n = 1). In the OR, 6/13 (46%) were graded A (atrioventricular valvuloplasty, n = 1; neo-aortic valvuloplasty, n = 1; relief of systemic and pulmonary venous outflow obstruction, n = 2 and n = 2; respectively). In EP procedures, 4/13 (31%) were graded A (thrombus, n = 3; mapping for lead placement to assist in multisite pacing for dyssynchrony, n = 1). 3D-TEE of Fontan improved visualization and frequently added value in the OR/EP lab and may be helpful in select catheterization cases. Future studies with a larger sample could build on this data to identify when 3D-TEE will be most useful.

Saline Contrast Transesophageal Echocardiography in Fontan Patients: Assessment of the Presence, Type, and Size of Right to Left Shunts.

Right to left (R-L) shunts resulting in cyanosis or systemic embolization occur after the Fontan procedure. The primary modality of diagnosing these is angiography. Successful delineation of these shunts in Fontan patients using selective saline contrast transesophageal echocardiography (SCTEE) may allow for reduced radiation and contrast exposure. We hypothesized that SCTEE could accurately determine the presence, type, and semiquantitative shunt size of R-L shunts in Fontan patients. SCTEE was performed in Fontan patients undergoing angiography for clinical indications. Injections were performed in six sites: mid-Fontan, right and left pulmonary arteries, superior and inferior vena cavae, and innominate vein. R-L shunt size was subjectively graded as 0 = absent, 1 = small, and 2 = medium or large based on echo contrast density in the left atrium. SCTEE was compared to angiography. 33 patients with Fontan were studied with median age 15 years, median weight 50.1 kg, and median O2 saturation of 90% in the R-L shunt group and 95% in the no R-L shunt group. R-L shunt types included intracardiac shunts (ICS), veno-venous collaterals (VVCs), arteriovenous malformations (AVMs), and their combinations. SCTEE versus angiography results were the same for the presence, type, and size of R-L shunts in 79% (26/33). SCTEE identified shunts in 88% (29/33). Angiography identified shunts in 85% (28/33). Neither method missed any medium or large R-L shunts. SCTEE and angiography had similar accuracy. SCTEE accurately detected the presence, type, and size of R-L shunts in most Fontan patients in this study. This can be used to guide targeted angiography, reducing radiation exposure and contrast load.

Right Ventricular Mechanical Dyssynchrony in Hypoplastic Left Heart Syndrome: Correlation with Systolic Function and QRS Duration.

The single right ventricle (RV) in hypoplastic left heart syndrome (HLHS) often develops systolic dysfunction with time and this affects prognosis. Mechanical dyssynchrony has been reported in HLHS but has not consistently correlated with systolic function or electrical dyssynchrony. The aims of this study were to assess the relationship between RV mechanical dyssynchrony, RV systolic function, and QRS duration on surface electrocardiography. We hypothesized that surface QRS duration would not be an adequate indicator of mechanical dyssynchrony compared with dyssynchrony parameters. Retrospective analysis of echocardiograms of patients with HLHS divided into preserved vs reduced RV function. We measured two RV function parameters: (1) fractional area change (FAC) and (2) global longitudinal strain (RVGLS). We measured two dyssynchrony parameters: (1) the standard deviation of the time to peak strain for 9 segments (tPS-9) and (2) time difference between the earliest and latest time to peak strain (RV dyssynchrony index or RVDI) both corrected for R-R interval. We also measured the QRS duration from surface EKG. Mechanical dyssynchrony parameters were compared to both RV systolic function and to QRS duration. 41 patients with HLHS were identified: 21 had preserved function and 20 had reduced function defined by a FAC < 35%. The reduced function group had a significantly lower mean FAC and RVGLS. RVDI was higher in the dysfunction group and had a modest correlation with FAC (r = 0.48) and RVGLS (r = 0.57). tPS-9 was longer in the dysfunction group and had a modest correlation with FAC (r = 0.45) and RVGLS (r = 0.57). QRS duration was longer in the dysfunction group and had a modest correlation with FAC (r = 0.56) and RVGLS (r = 0.56). The weakest correlations were between QRS duration and tPS-9 (r = 0.32) and QRS duration and RVDI (r = 0.10). RV dysfunction measured by FAC was associated with mechanical dyssynchrony measured by increased RVDI and tPS-9. QRS duration was longer in the group with dysfunction but did not correlate with directly measured mechanical dyssynchrony. This may have potential implications for cardiac resynchronization therapy in univentricular patients as assessed by mechanical dyssynchrony parameters rather than QRS duration alone.

Right Ventricular Systolic Function Parameters in Hypoplastic Left Heart Syndrome.

Assessment of the systolic function of the right ventricle (RV) in patients with hypoplastic left heart syndrome (HLHS) is important. The asymmetric shape and heavy trabeculations make accurate assessment of RV systolic function challenging. Novel measures of RV function could be helpful in distinguishing reduced versus preserved function in HLHS and may also be worse in HLHS with preserved function compared to normal controls. These novel methods offer promise, but research and clinical applicability is hindered as no cut-off values for normal function have been established. We performed a retrospective comparison of functional assessments from echocardiograms of HLHS patients with preserved and reduced RV function along with a control group of normal patients. Measures of function included fractional area change (FAC), tissue motion annular displacement of the tricuspid (TMAD-TV) and pulmonary valves (TMAD-PV), myocardial performance index (MPI), tricuspid tissue Doppler S' velocity, and RV global longitudinal strain (RVGLS). Comparisons were made between three groups: normal patients, HLHS with preserved function, and HLHS with reduced function defined as FAC < 35%. FAC was chosen as the reference as it is a historical standard. 41 HLHS patients were studied. Of these patients, 20 had HLHS with reduced function, and 21 had preserved function. They were compared with 27 age-matched, normal, controls. Comparison between HLHS and normal controls: in HLHS with preserved RV systolic function, compared to normal controls, tissue Doppler S', MPI, and TMAD-TV were all abnormal (all p < 0.05). RVGLS was not statistically different (20.5 ± 3.6% for normal vs. 17.9 ± 2.6% for HLHS with preserved function). TMAD-PV was similar between groups (16.1 ± 4.6% vs. 16.7 ± 5.1%). All measures were significantly worse (all p < 0.05) in the HLHS with reduced function group compared to normal controls. Comparison between HLHS preserved vs reduced function: in HLHS with reduced function defined by FAC < 35%, all measures were significantly worse compared to HLHS with preserved function (all p < 0.05). The cut-off values that correspond to a FAC of > 35% were 14.5% for TMAD-TV and 16% for RVGLS. All measures except RVGLS and TMAD-PV estimated worse function than controls even for HLHS with preserved function. Each of the functional measures was able to identify preserved vs reduced function in HLHS with FAC as the reference standard. Cut-off values between preserved and reduced function in HLHS were estimated for TMAD-TV and RVGLS based on a relatively small cohort. These cut-off values will aid in the research design of future studies.

Tissue Motion Annular Displacement Predicts Mortality/Transplant After the Bidirectional Glenn.

BACKGROUND: Quantifying right ventricular function in patients with a systemic right ventricle (RV) is difficult but important for prognosis. Tissue motion annular displacement tracks displacement of the tricuspid annulus toward the apex. We evaluated this measure alongside fractional area change (FAC) on patients with single, RV prior to the bidirectional Glenn procedure. We tested both measures for correlation with outcomes. METHODS: Retrospective measurement of tissue motion annular displacement and FAC was performed on echocardiographic clips obtained prior to the bidirectional Glenn. A chart review included postoperative outcomes and midterm mortality/transplant. Bivariate correlations and Cox proportional hazards models were used for analyses. RESULTS: Fifty-one patients with dominant RV underwent the bidirectional Glenn procedure and all had image quality that allowed analysis. The age ranged from 3 to 11 months (median 4 months). Neither tissue motion annular displacement nor FAC correlated with short-term postoperative outcomes. Tissue motion annular displacement was independently predictive of mortality/transplant ( P = .03) in the Cox hazard model. The mean for survivors was 12.4% and for nonsurvivors/transplants was 10.0%. Tissue motion annular displacement intra-observer variability was 2.8% (1.2%-3.5%). Interobserver mean variability was 6.1% (3.3%-8.1%). Fractional area change was not predictive of mortality/transplant. CONCLUSION: Tissue motion annular displacement is an independent predictor of midterm mortality/transplant after the bidirectional Glenn procedure in patients with single, RV, in this study. It may outperform FAC in this regard and has good reproducibility. Tissue motion annular displacement may be a useful measure in identifying high-risk children in this population.

Right Ventricular Longitudinal Shortening Before and After Stage I Surgical Palliation Correlates with Outcomes.

Quantification of right ventricular function is difficult, but important, in patients with single ventricles. Tissue motion annular displacement (TMAD) is an echocardiographic tool that measures displacement of the tricuspid valve relative to the apex. We evaluated TMAD, lateral annular displacement (LAD), and fractional area change (FAC) for correlation with outcomes. We measured TMAD, LAD, FAC, and other variables that may affect prognosis in patients with single right ventricle physiology pre- and post-Stage I palliation and correlated them with outcomes up to the Glenn procedure. Intra- and inter-observer variability for TMAD measurements were 2.7% (1.2-3.5%) and 6.1% (3.3-8.1%), respectively. Sixty-six subjects met the inclusion criteria. Pre-Stage I TMAD was 13.7% (SD 3.9%). TMAD had a linear relationship with FAC (r2 = 0.76). There was a correlation between TMAD and hospital stay (p = 0.044) and ECMO/arrest (p = 0.024). LAD correlated with ECMO/arrest (p = 0.045) and mortality/transplant (p = 0.049). FAC correlated with in-hospital mortality (p = 0.028). Post-Stage I TMAD was 11.8% (SD 3.7%). TMAD, LAD, and FAC all correlated with in-hospital mortality and mortality/transplant. In multivariate models, TMAD was independently predictive of weight for age Z score pre-Glenn. TMAD, FAC, and LAD correlate with clinically significant outcomes after the first-stage palliation. TMAD correlated with more outcomes than FAC and was the only measure that was independently predictive of any outcome. TMAD is a reproducible measure of RV function in this population. TMAD has prognostic value before and after first-stage palliation and may outperform more traditional measures.