Leo Lopez

Unnatural history of the right ventricle in patients with congenitally malformed hearts.

The long-term outcome of patients with congenitally malformed hearts involving abnormal right ventricular morphology and haemodynamics is variable. In most instances, the patients are at risk for right ventricular failure, in part due to morphological differences between the right and left ventricles and their response to chronic volume and pressure overload. In patients after repair of tetralogy of Fallot, and after balloon valvotomy for valvar pulmonary stenosis, pulmonary regurgitation is the most significant risk factor for right ventricular dysfunction. In patients with a dominant right ventricle after Fontan palliation, and in those with systemic right ventricles in association with surgically or congenitally corrected transposition, the right ventricle is not morphologically capable of dealing with chronic exposure to the high afterload of the systemic circulation. In patients with Ebsteins malformation of the tricuspid valve, the degree of atrialisation of the right ventricle determines how well the right ventricle will function as the pump for the pulmonary vascular bed.

Myocardial dysfunction in pediatric septic shock.

OBJECTIVEnTo evaluate the prevalence and significance of myocardial dysfunction in children with septic shock.nnnSTUDY DESIGNnThirty patients with septic shock were evaluated by transthoracic echocardiography within 24 hours of admission to a pediatric critical care unit. Transthoracic echocardiography evaluation included left ventricular (LV) size and function, mitral valve inflow velocities in early and late diastole, mitral valve annular velocities in systole and early and late diastole, and LV myocardial performance index. LV systolic dysfunction was defined as an ejection fraction or shortening fraction z-score <-2, and LV diastolic dysfunction was defined as a mitral valve inflow velocity/annular velocity in early diastole ratio z-score >2. Secondary outcomes included troponin I concentration, acute kidney injury, and 28-day mechanical ventilation-free duration.nnnRESULTSnMortality for the 30 patients (mean age, 9.5 ± 7 years) was 7%. The prevalence of LV systolic and/or diastolic dysfunction was 53% (16 of 30). Eleven patients (37%) had systolic dysfunction, 10 (33%) had diastolic dysfunction, and 5 (17%) had both. Systolic and/or diastolic dysfunction was significantly associated with troponin I level (P = .007) and acute kidney injury (P = .02), but not with ventilation-free duration (P = .12). Kaplan-Meier analyses for pediatric critical care unit and hospital length of stay identified no differences between patients with and those without myocardial dysfunction.nnnCONCLUSIONnMyocardial dysfunction occurs frequently in children with septic shock but might not affect hospital length of stay.

A Transbaffle Approach to Ablation in a Child with an Extracardiac Fontan

We present the case of an 11‐year‐old with D‐transposition, double inlet left ventricle, and dextrocardia 8 years following an extracardiac Fontan with supraventricular tachycardia mediated by a concealed accessory pathway. A transbaffle puncture was performed with fluoroscopic and transesophageal echocardiography guidance and the pathway location as well as its proximity to the HIS bundle were identified. The pathway was successfully ablated and the patient is asymptomatic for 12 months postablation. (PACE 2010; 33:368–371)

The Prevalence of Left Ventricular Hypertrophy in Obese Children Varies Depending on the Method Utilized to Determine Left Ventricular Mass

Obesity and left ventricular hypertrophy (LVH) have been identified as independent risk factors for cardiovascular events. The definition of LVH depends on the geometric algorithm used to calculate LV mass (LVM) by echocardiography and the method used to normalize LVM for body size. This study evaluates the effect of these methods on the prevalence of LVH in obese children. LVM for 109 obese and 109 age-matched non-obese children was calculated using M-mode or two-dimensional echocardiography (2DE). LVM was then normalized to height 2.7 as indexed LVM (LVMI), to body surface area (BSA), height, and lean body mass (LBM) as LVM Z-scores. LVH was defined as LVMI >95th ‰ using age-specific normal reference values or LVM Z-scores ≥2. The prevalence of LVH by LVMI and LVM Z-scores was compared. There was a correlation between LVM determined by M-mode and by 2DE (R2xa0=xa00.91), although M-mode LVM was greater than 2DE LVM. However, the difference between these values was greater in obese children than in non-obese children. Based on the method of normalization, the prevalence of LVH among obese children was 64xa0% using LVMI, 15xa0% using LVM Z-scores for height, 8xa0% using LVM Z-scores for BSA and 1xa0% using LVM Z-scores for LBM. Height-based normalization correlates with obesity and hypertension. The methods used to measure and normalize LVM have a profound influence on the diagnosis of LVH in obese children. Further study is needed to determine which method identifies children at risk for cardiovascular morbidity and mortality.

Closure of a superior vena cava baffle leak in a patient with D-transposition after Mustard palliation: importance of both angiography and echocardiography for confirmation of closure.

An 18-year-old boy with dextrotransposition of the great arteries (D-TGA) after Mustard palliation at the age of 6 months had a 2 year history of increasing cyanosis with exertion. Echocardiography identified a large leak in the superior limb of the Mustard repair. He was catheterized in an attempt at transcatheter closure of the leak. Figure 1 shows an angiogram of the superior vena cava (SVC) demonstrating a large baffle leak with significant right-to-left shunting. This defect measured approximately 18 mm on the angiogram and by transesophageal echocardiogram (TEE) measurements performed at the catheterization. The aortic saturation with room air during this procedure was 93%. Using TEE and angiographic guidance, a 34-mm-long Numed (Numed Corp., Hopkinton, NY, USA) polytetrafluoroethylene (PTFE)-covered stent was mounted on a Numed BiB balloon catheter with a diameter of 22 mm and advanced to the level of the defect from the SVC. Angiography demonstrated the stent/balloon apparatus in good position, and the stent was implanted at the level of the defect. Figure 2a shows an SVC angiogram demonstrating the stent to be in good position without any further left-toright shunting. However, Fig. 2b exhibits the simultaneous TEE image that clearly demonstrates a residual defect (asterisks). Color Doppler mapping showed right-to-left shunting now through this small residual defect that was superior to the top edge of the stent. Because of the residual defect, a second stent/balloon of the same caliber and size as the first was positioned more superiorly in the SVC, with roughly one-third of its length overlapping the first stent. The stent was implanted at this position, and Fig. 3 demonstrates the final angiogram, which shows no left-to-right shunting at the level of the defect. Importantly, the simultaneous TEE now showed complete occlusion of the defect, with no further left-to-right or right-to-left shunting. At this writing,

Outflow Tract Anomalies

Anomalies of the aortic and pulmonary outflow tracts are usually associated with obstruction, regurgitation, and/or aneurysmal dilation of the proximal great arteries, and they represent some of the conditions most frequently encountered by congenital heart disease specialists. In most instances, a full preoperative diagnosis is performed by standard transthoracic echocardiography and other imaging modalities such as cardiac catheterization and magnetic resonance imaging. However, transesophageal echocardiography (TEE) serves an important role in the perioperative management of these patients. Preoperative TEE can provide information regarding the morphology of the outflow tracts and the degree of obstruction and regurgitation; postoperative TEE can evaluate the success of a surgical procedure and exclude residual obstruction, regurgitation, or other potential complications. In addition, TEE is sometimes necessary outside of the operating room setting for older patients with poor transthoracic echocardiographic windows, particularly if the patient has undergone prior surgery. This chapter discusses the use of TEE for the evaluation of both right and left sided outflow tract anomalies.

Unplanned Repeat Echocardiography with Sedation in Children: Patient Risk Factors.

Patient selection criteria for echocardiography with sedation in children are not well defined. We attempted to identify predictors of unplanned repeat echocardiography with sedation. This was a single-center, case–control study of echocardiograms performed in children aged 1–36xa0months. Cases underwent unplanned repeat examinations with sedation, while controls did not. Patient variables and study indications were compared. Logistic regression identified the most significant predictors. Cases (nxa0=xa0104, median time to repeat echocardiogram 17xa0days, median age 12.9xa0months) were older than controls (nxa0=xa0212, median age 5.0xa0months, Pxa0<xa00.001). Significantly more cases than controls had structural cardiac disease (64 vs. 23xa0%) and anatomic complexity ≥moderate (38 vs. 5xa0%, Pxa0<xa00.001 for both). Cases more often had Kawasaki disease (11 vs. 2xa0%), and controls more often had murmur (56 vs. 11xa0%, Pxa0<xa00.001 for both). Logistic regression identified age 6xa0months to <2xa0years (OR 3.26, 95xa0% CI 1.70–6.28, Pxa0<xa00.001), Kawasaki disease (OR 5.20, 95xa0% CI 1.46–18.50, Pxa0=xa00.01), and known pre-echocardiogram anatomic complexity ≥moderate (OR 3.99, 95xa0% CI 1.64–9.66, Pxa0=xa00.002) as significant risk factors. An indication for murmur was protective (OR 0.32, 95xa0% CI 0.13–0.76, Pxa0=xa00.01). We identified several risk factors for unplanned repeat echocardiography with sedation in children, including age 6xa0months to <2xa0years, higher anatomic complexity, and Kawasaki disease. Murmur was a protective factor. These results may help pediatric echocardiography laboratories establish criteria for sedation.

Quality Improvement in Noninvasive Imaging: Present and Future Initiatives

Indicators of quality services in pediatric and congenital echocardiography include structural, process, and outcome factors. Structural indicators involve the available resources related to the facility, the equipment, and the staff. Process indicators relate primarily to the activities and tasks associated with echocardiography, and these include patient selection as well as study performance, interpretation, and reporting. Outcome indicators involve the results of quality services and are intimately related to quality improvement activities as well as quality metrics. Current quality improvement activities in the field of pediatric and congenital echocardiography include development of the accreditation process for sonographers, physicians, and echocardiography laboratories; evaluation of productivity standards within echocardiography laboratories; identification of appropriate use criteria specific to pediatric and congenital echocardiography; and establishment of a robust database of normal reference values for cardiovascular measurements in children. Candidate quality metrics currently in development involve reporting of critical results, adverse events with sedated studies, variability of echocardiographic measurements, diagnostic errors, study completeness, and image quality.

A new “tool” for transcatheter atrial defect closure: The St. Jude SL2™ sheath

Orienting the left atrial disc of an atrial septal defect (ASD) closure device parallel to the septum is important, particularly in cases of ASD with deficient retroaortic rim. Standard vascular sheaths can make this challenging. We report the use of an electrophysiologic sheath, the SL2™ St. Jude Vascular sheath (St. Jude Medical, St. Paul, MN) for closure of ASD.

Reverse ventricular remodeling and improved ventricular compliance after heart transplantation in infants and young children

After heart transplantation (HT) in infants and young children, environmental and intrinsic factors may lead to changes in the geometry and compliance of the donor heart. Serial demographic, clinical, hemodynamic, and echocardiographic data were obtained from HT recipients younger than 4xa0years of age. Echocardiographic chamber measurement z-scores were compared using recipient body surface area from the time of HT to 1xa0week, 3xa0months, and last follow-up visit. Left ventricular end-diastolic volume (LVEDV) z-scores were correlated with pulmonary capillary wedge pressure (PCWP) at each time point. Heart transplantation was performed for 13 children between March 2009 and December 2012, 9 of whom (69xa0%) were boys. The median age at HT was 8xa0months (range, 4–43xa0months), and the mean follow-up period was 13xa0±xa07xa0months. Left ventricular end-diastolic dimension z-scores decreased significantly (pxa0=xa00.03) between HT and 1xa0week, then increased from 1xa0week to 3 and 12xa0months. (−1.32xa0±xa01.7, −0.71xa0±xa01.8, 0.41xa0±xa02.1, 0.79xa0±xa02.3, respectively). A positive relationship (R2xa0=xa00.48) between the LVEDV z-score and PCPW was present at the last follow-up visit. For infants and young children, the allograft demonstrates appropriate growth by 1xa0year after HT. Left ventricular compliance improves over time.