Transesophageal three-dimensional echocardiographic guidance for pacemaker lead extraction.

BACKGROUND: The ability of transesophageal three-dimensional echocardiography (3DE) to aid in pacemaker lead extraction has not yet been evaluated. 3DE provides real-time evaluation of intracardiac anatomy and the location of pacemaker leads in greater detail than either fluoroscopy or -two-dimensional echocardiography (2DE), aiding in the extraction of such leads, which can be potentially dangerous. We sought to investigate the feasibility and utility of 3DE to visualize intracardiac anatomy and pacemaker leads, and to assist in lead extraction procedures. METHODS: We utilized 3DE in nine encounters for eight different patients, to visualize intracardiac anatomy and leads before, during, and after extraction to evaluate the feasibility and utility to aid in the procedure and evaluate for potential sequelae. RESULTS: 3DE was able to identify pertinent intracardiac anatomy and leads in all cases. 3DE detected procedural complications or altered management in five of nine encounters (five of eight patients); this included detection of an avulsed papillary muscle, tricuspid valve leaflet damage, and cast/thrombus after lead removal, as well as adjustment of excess lead slack to avoid future valve damage, or risk stratification of lead removal. CONCLUSION: 3DE is feasible and adds utility to lead extraction cases by visualizing intracardiac anatomy and leads beyond fluoroscopy or 2DE, providing real-time information during extraction, and identifying potential complications.

Common Left-to-Right Shunts.

Left-to-right shunts represent a significant portion of congenital heart disease. Such lesions are common in isolation, but are frequently seen in conjunction with other, often more complex, congenital heart disease. This review covers basic anatomy, physiology, physical examination findings, diagnosis and management for atrial septal defects, ventricular septal defects, and patent ductus arteriosa.

Relationship Between Left Ventricular Geometry and Invasive Hemodynamics in Pediatric Pulmonary Hypertension.

Background Ventricular septal flattening, frequently present in pulmonary hypertension (PH), can be quantified using eccentricity index (EI). EI has not been evaluated by concurrent echocardiography and cardiac catheterization and traditionally does not account for postsystolic septal flattening, often seen in PH. We evaluated left ventricular shape, including a novel measure of maximal EI to account for postsystolic septal flattening, to establish the relationship with concurrent invasive hemodynamics. Methods Echocardiography was performed at 2 institutions in 78 pediatric PH patients during cardiac catheterization and in 78 matched controls. From midpapillary parasternal short-axis views, EI and right-to-left ventricular diameter ratio were assessed. Results EI and right-to-left ventricular measures were significantly increased in PH compared with controls. Shape measures correlated with invasive hemodynamics and PH outcome measures (PH-related hospitalization, functional class, medical therapy escalation, and BNP [brain natriuretic peptide]). End-systolic EI of 1.16 best identified the presence of PH, whereas a maximal EI of 1.42 and 1.94 best identified half-systemic and systemic PH, respectively. A maximal EI of 1.27 was associated with an odds ratio of 16.16 (95% CI, 6.62-39.46) for PH-related hospitalization or escalation of therapy. Conclusions Using simultaneous echocardiography and catheterization in the largest study population to date, we demonstrate that EI and right-to-left ventricular ratio correlate with invasive hemodynamics and outcomes measures, and EI can accurately define those with clinically important PH. These measures strengthen the ability of echocardiography to identify and follow pediatric PH patients, especially in the absence of methods to quantify right ventricular systolic pressures.

Parameters of Right Ventricular Function Reveal Ventricular-Vascular Mismatch as Determined by Right Ventricular Stroke Work versus Pulmonary Vascular Resistance in Children with Pulmonary Hypertension.

BACKGROUND: Right ventricular (RV) failure, a determinant of outcomes in pulmonary hypertension (PH), occurs when the right ventricle cannot compensate for increased afterload. The authors showed that RV stroke work (RVSW) can be estimated in children with PH as the product of stroke volume and RV pressure and is related to adverse outcomes. The aim of this study was to test the hypothesis that ventricular-vascular (VV) mismatch (high afterload and low RVSW) is associated with echocardiographic measures of RV performance and adverse outcomes. METHODS: Invasive hemodynamic data and concurrent echocardiograms were reviewed. Fifty subjects with PH were included. Four groups were created by dividing the patients using median RVSW and median pulmonary vascular resistance. For each group, tricuspid annular plane systolic excursion, fractional area change, myocardial performance index, and anterior RV wall thickness were determined. Both major (i.e., death) and minor (i.e., worsening World Health Organization class) clinical outcomes were tabulated. Groups were compared using the Kruskal-Wallis or Fisher exact test. RESULTS: Patients in the high pulmonary vascular resistance/low RVSW cohort (VV mismatch) had the worst RV dysfunction: median tricuspid annular plane systolic excursion, 0.8 cm (interquartile range, 0.7-0.8 cm; P = .0002); median fractional area change, 0.29% (interquartile range, 0.27%-0.30%; P = .004); median myocardial performance index, 0.622 (interquartile range, 0.548-0.789; P = .0004). This group had the highest incidence of adverse outcomes: major events in 40%, minor events in 80%, and syncope in 60%. CONCLUSION: VV mismatch in pediatric PH can be assessed using RVSW and pulmonary vascular resistance and is associated with RV performance and adverse events. RVSW increases in compensated high-afterload states and falls as the right ventricle fails to meet increased load; thus, VV matching status may be a sensitive predictor of outcomes in pediatric PH.

Retrospective Comparison of the Supported and Unsupported Bovine Jugular Vein Conduit in Children.

BACKGROUND: Bovine jugular vein (BJV) conduits are commonly used for pulmonary valve replacement in pediatric patients. They are available in supported (sBJV) and unsupported (uBJV) versions. The purpose of this study was to compare outcomes of sBJV and uBJV conduits. METHODS: In this single-center retrospective review of patients younger than 18 years undergoing BJV placement (2009 to 2017), blinded cardiologists reviewed postoperative 6-, 12-, 24-, 36-month, and the most recent echocardiogram before any valve-related event or death. Outcomes assessed included conduit stenosis (m/s), regurgitation (none to mild vs moderate to severe) and right ventricular function (normal vs abnormal). Cox proportional models and Kaplan-Meier analyses were performed. RESULTS: BJV conduits (N = 109) were placed (39 supported, 70 unsupported) in 101 patients. Patient characteristics and conduit size were not different between cohorts. sBJV had more stenosis at 6 and 12 months (p = 0.02 and p = 0.03), but Vmax in both groups was mild (≤2 m/s). A greater proportion of uBJV had moderate to severe regurgitation at 12 months compared with sBJV (p = 0.03). Right ventricular function did not differ at any time point. On last follow-up echocardiogram, sBJV conduits had higher gradients (p = 0.01). This was not associated with increased intervention or replacement. Freedom from replacement or intervention did not differ between valve types (median follow-up, 3.6 years). There was a 9% incidence of endocarditis at median follow-up 2.4 years. Seventy percent of cases with endocarditis were managed medically. CONCLUSIONS: There were no clinically significant echocardiographic or outcome differences between sBJV and uBJV conduits. We identified a relatively high incidence of endocarditis, which is consistent with prior reports.

Transesophageal 3-Dimensional Echocardiographic Guidance for Pacemaker Lead Placement.

The feasibility of transesophageal 3-dimensional echocardiography to reduce fluoroscopy in pacemaker lead placement has not yet been evaluated. This clinical vignette demonstrates the ability of 3-dimensional echocardiography to visualize intracardiac anatomy and the pacemaker lead and to guide positioning of the lead into the right atrial appendage, thus reducing fluoroscopy by nearly 50%. (Level of Difficulty: Advanced.).

Three-Dimensional Echocardiographic Guidance of Right Heart Catheterization Decreases Radiation Exposure in Atrial Septal Defect Closures.

BACKGROUND: Radiation reduction is desirable in children undergoing cardiac catheterization. Three-dimensional (3D) transesophageal echocardiographic (3D TEE) imaging obviates the need for mental reconstruction of 3D structures from two-dimensional images. Three-dimensional TEE imaging is used in atrial septal defect (ASD) closures. Three-dimensional TEE guidance of right heart catheterization (RHC) without fluoroscopy for ASD closures has not been demonstrated. The aim of this study was to evaluate the feasibility of 3D TEE guidance of RHC in ASD closures and radiation reduction compared with historical control subjects. METHODS: Twenty-two patients underwent 3D TEE guidance of RHC and ASD closures and were compared with 44 control subjects. RHC time, total fluoroscopy time, radiation dose, and procedural time were compared. Fluoroscopy time during RHC was recorded in patients undergoing 3D TEE guidance. RESULTS: There was a 54% reduction in total fluoroscopy time and a 78% radiation reduction demonstrated with 3D TEE guidance of patients with ASDs compared with control subjects. Although there were no statistically significant differences in the RHC time compared with control subjects, the fluoroscopy time (mean, 0.06 ± 0.23 min) for RHC guidance using 3D TEE imaging was almost zero. There was decreased RHC time as we progressed through the learning curve of performing 3D TEE guidance of RHC (r = -0.63, P < .01). There were no statistically significant differences in total procedural time. CONCLUSIONS: Three-dimensional TEE guidance in RHC is feasible without the use of fluoroscopy and reduces radiation exposure in percutaneous ASD closures. Three-dimensional TEE guidance may be used in other interventional procedures in the future to further reduce radiation exposure and facilitate catheter interventions.

Right Ventricular Tissue Doppler Myocardial Performance Index in Children with Pulmonary Hypertension: Relation to Invasive Hemodynamics.

Right ventricular (RV) failure is a significant cause of morbidity and mortality in patients with pulmonary hypertension (PH). Myocardial performance index measured by tissue Doppler imaging (TDI-MPI) has been useful in assessing RV dysfunction in adults with PH. However, TDI-MPI as a marker for RV dysfunction or disease severity has not been evaluated in pediatric PH. The aim of this study was to investigate TDI-MPI and correlate with invasive hemodynamics in pediatric PH patients. Eighty pediatric PH patients undergoing cardiac catheterization and simultaneous transthoracic echocardiography were analyzed. RV TDI-MPI was averaged over three cardiac cycles and measured under each condition of vasodilatory testing during the catheterization. TDI-MPI was compared between PH patients and age-matched controls and correlated to invasive hemodynamics. RV TDI-MPI was increased in PH patients compared to controls (0.49 vs. 0.35, p < 0.0001). Significant associations (beta ± SE) are seen between RV TDI-MPI and baseline mean pulmonary arterial pressures (0.0002 ± 0.001, p < 0.05), indexed pulmonary vascular resistance (0.007 ± 0.002, p < 0.002), and pulmonary-to-systemic arterial pressure ratio (0.146 ± 0.063, p < 0.05). No statistically significant associations were seen with vasodilatory testing. RV TDI-MPI is elevated in children with PH, suggestive of RV dysfunction. RV TDI-MPI shows correlation with severity of PH at baseline but lacks sensitivity to evaluate the RV response to acute changes in afterload in children with PH. Therefore, while RV TDI-MPI can help identify RV dysfunction in children with PH, its utility as a non-invasive surrogate marker for acute changes in hemodynamics is limited.

Impact of Pulmonary Hemodynamics and Ventricular Interdependence on Left Ventricular Diastolic Function in Children With Pulmonary Hypertension.

BACKGROUND: Through ventricular interdependence, pulmonary hypertension (PH) induces left ventricular (LV) dysfunction. We hypothesized that pediatric PH patients have LV diastolic dysfunction, related to adverse pulmonary hemodynamics, leftward septal shift, and prolonged right ventricular systole. METHODS AND RESULTS: Echocardiography was prospectively performed at 2 institutions in 54 pediatric PH patients during cardiac catheterization and in 54 matched controls. Diastolic LV measures including myocardial deformation were assessed by echocardiography. PH patients had evidence of LV diastolic dysfunction, most consistent with impaired LV relaxation, though some features of reduced ventricular compliance were present. PH patients demonstrated the following: reduced mitral E velocity and inflow duration, mitral E' and E'/A', septal E' and A', pulmonary vein S and D wave velocities, and LV basal global early diastolic circumferential strain rate and increased mitral E deceleration time, LV isovolumic relaxation time, mitral E/E', and pulmonary vein A wave duration. PH patients demonstrated leftward septal shift and prolonged right ventricular systole, both known to affect LV diastole. These changes were exacerbated in severe PH. There were no statistically significant differences in diastolic measures between patients with and without a shunt and minimal differences between patients with and without congenital heart disease. Multiple echocardiographic LV diastolic parameters demonstrated weak-to-moderate correlations with invasively determined PH severity, leftward septal shift, and prolonged right ventricular systole. CONCLUSIONS: Pediatric PH patients exhibit LV diastolic dysfunction most consistent with impaired relaxation and reduced myocardial deformation, related to invasive hemodynamics, leftward septal shift, and prolonged right ventricular systole.

Acute ischaemic heart block in hypoplastic left heart syndrome.

In hypoplastic left heart syndrome, thrombosis of the native ascending aorta is rare and often fatal; there are no previously reported cases presenting with acute heart block. We review a case of native ascending aorta thrombosis in a 2-year-old boy with hypoplastic left heart syndrome, presenting with acute heart block. This case highlights the benefit of multi-modality imaging in complex cases.

Echocardiographic estimation of right ventricular stroke work in children with pulmonary arterial hypertension: comparison with invasive measurements.

BACKGROUND: Right ventricular (RV) failure is a key determinant of mortality in children with pulmonary arterial hypertension (PAH). RV stroke work (RVSW) can be estimated as the product of RV systolic pressure and stroke volume. The authors have shown that RVSW predicts adverse outcomes in this population when derived from hemodynamic data; noninvasive assessment of RVSW may be advantageous but has not been assessed. There are few data validating noninvasive versus invasive measurements in children with PAH. The aim of this study was to compare echocardiographically derived RVSW with RVSW determined from hemodynamic data. METHODS: This was a retrospective study, including subjects with idiopathic PAH and minor or repaired congenital heart disease. Forty-nine subjects were included, in whom cardiac catheterization and echocardiography were performed within 1 month. Fourteen additional patients were included in a separate cohort, in whom catheterization and echocardiography were performed simultaneously. Catheterization-derived RVSW was calculated as RV systolic pressure × (cardiac output/heart rate). Echocardiographically derived RVSW was calculated as 4 × (peak tricuspid regurgitant jet velocity)(2) × (pulmonary valve area × velocity-time integral). Statistics included the intraclass correlation coefficient and Bland-Altman analysis. RESULTS: Echocardiographically derived RVSW was linearly correlated with invasively derived RVSW (r = 0.74, P < .0001, intraclass correlation coefficient = 0.76). Bland-Altman analysis showed adequate agreement. Echocardiographically derived RV work was related to indexed pulmonary vascular resistance (r = 0.43, P = .002), tricuspid annular plane systolic excursion (r = 0.41, P = .004), and RV wall thickness (r = 0.62, P < .0001). CONCLUSIONS: The authors demonstrate that RV work, a potential novel index of RV function, can be estimated noninvasively and is related to pulmonary hemodynamics and other indices of RV performance.

Left Ventricular Myocardial Function in Children With Pulmonary Hypertension: Relation to Right Ventricular Performance and Hemodynamics.

BACKGROUND: Through ventricular interdependence, pulmonary hypertension (PH) induces left ventricular (LV) dysfunction. We hypothesized that LV strain/strain rate, surrogate measures of myocardial contractility, are reduced in pediatric PH and relate to invasive hemodynamics, right ventricular strain, and functional measures of PH. METHODS AND RESULTS: At 2 institutions, echocardiography was prospectively performed in 54 pediatric PH patients during cardiac catheterization, and in 54 matched controls. Patients with PH had reduced LV global longitudinal strain (LS; -18.8 [-17.3 to -20.4]% versus -20.2 [-19.0 to -20.9]%; P=0.0046) predominantly because of reduced basal (-12.9 [-10.8 to -16.3]% versus -17.9 [-14.5 to -20.7]%; P<0.0001) and mid (-17.5 [-15.5 to -19.0]% versus -21.1 [-19.1 to -23.0]%; P<0.0001) septal strain. Basal global circumferential strain was reduced (-18.7 [-15.7 to -22.1]% versus -20.6 [-19.0 to -22.5]%; P=0.0098), as were septal and free-wall segments. Mid circumferential strain was reduced within the free-wall. Strain rates were reduced in similar patterns. Basal septum LS, the combined average LS of basal and mid interventricular septal segments, correlated strongly with degree of PH (r=0.66; P<0.0001), pulmonary vascular resistance (r=0.60; P<0.0001), and right ventricular free-wall LS (r=0.64; P<0.0001). Brain natriuretic peptide levels correlated moderately with septal LS (r=0.48; P=0.0038). PH functional class correlated moderately with LV free-wall LS (r=-0.48; P=0.0051). The septum, shared between ventricles and affected by septal shift, was the most affected LV region in PH. CONCLUSIONS: Pediatric PH patients demonstrate reduced LV strain/strain rate, predominantly within the septum, with relationships to invasive hemodynamics, right ventricular strain, and functional PH measures.