Wesley Covitz

Late status of Fontan patients with persistent surgical fenestration.

OBJECTIVES This study was undertaken to determine the effects of creating a systemic-to-pulmonary venous atrial-level communication (fenestration) at the time of the Fontan procedure on late outcomes. BACKGROUND Fenestrations are frequently performed during Fontan procedures, but late consequences are not well described. METHODS Patient characteristics were compared between those with and without surgical fenestration among 536 subjects (mean age 11.9 years) enrolled in the Pediatric Heart Network Fontan Cross-Sectional Study. The status of the fenestration and the association of a currently patent fenestration with health status and measures of ventricular performance were investigated. RESULTS Fenestration was performed in 361 patients (67%), and frequency differed by year and center (p < 0.001 for each). After adjustment for center, age at Fontan, year of Fontan, and prior superior cavopulmonary surgery, the fenestrated group had shorter length of Fontan hospital stay. At the time of cross-sectional testing 8 ± 3 years after Fontan, the fenestration remained open in 19% of subjects. Among those with confirmed fenestration closure, 59% were by catheter intervention and 1% by surgical intervention, and 40% had apparent spontaneous closure. Compared with those without evidence of a fenestration, subjects with a current fenestration were taking more medications (p = 0.02) and had lower resting oxygen saturation (median 89% vs. 95%, p < 0.001). Functional health status, exercise performance, echocardiographic variables, prevalence of post-Fontan stroke or thrombosis, and growth did not differ by current fenestration status. CONCLUSIONS Surgical fenestration is associated with well-demonstrated early post-operative benefits. This cross-sectional study found few associations between a persistent fenestration and deleterious later outcomes.

The conduction system in patients with a prolonged QT interval.

The conduction system and the myocardium of five patients with Romano-Ward syndrome and one patient with the Jervell and Lange-Nielsen syndrome were studied to determine the cause of the prolonged QT interval. The patients were 9 and 15 months and 2, 5 and 19 years of age, respectively. All had a prolonged QTc interval. A sixth patient was a 16 year old girl who died suddenly; several members of her family had a prolonged QT interval. The only common finding in the conduction system in all cases was marked fatty infiltration in the approaches to the atrioventricular (AV) node. In four, the AV bundle was lobulated, with loop formation in one. In four, the AV bundle and bundle branches showed fibrosis. The ventricular myocardium in all cases was chronically inflamed. In two cases, the AV node was partially embedded in the central fibrous body. It is not clear how these changes are related to the disturbance in the repolarization process and the prolongation of the QT interval. However, it is interesting that all patients had an abnormality in the conduction system.

Cardiovascular function during rest and exercise in patients with sickle‐cell anemia and coexisting alpha thalassemia‐2

Cardiac function was measured at rest and during exercise in 9 patients with sickle‐cell anemia (SS) and coexisting homozygous alpha thalassemia‐2 (alpha thal‐2). Results were compared with 18 sickle cell patients with normal alpha globin genes, who were matched to the study group by age, gender, and size, and to published normal values. SS alpha thal‐2 patients were less anemic: 9.9 ± 1.0 vs 8.2 ± 1.2 gm/dl for SS alone (P < .05). Left ventricular dimensions were normal in SS alpha thal‐2 (4.9 ± 0.7 cm), but increased in SS (5.4 ± 0.7, cm P = .05) (normal range, 3.7–5.6 cm). Left ventricular wall thickness was, however, dramatically increased in the SS alpha thal‐2 patients (free wall, 1.8 ± 0.6 cm; septum, 1.6 ± 0.4 cm), though SS controls had normal wall thickness (free wall, 1.0 ± 0.2 cm; septum, 1.0 ± 0.2 cm, P < .001) (normal range, 0.6–1.1 cm). At rest, Doppler indices of systolic function were not significantly different between sickle groups and normal values. SS alpha thal‐2 patients did have abnormal diastolic filling at rest, as evidenced by a reduced ratio of early/late diastolic filling, 1.4 ± 0.3 vs. 2.0 ± 0.5 for SS controls (P < .01), and 1.8 ± 0.4 for normals. An analysis of covariance suggested that this abnormality persisted after taking into account the previously demonstrated hypertrophy. During exercise, SS alpha thal‐2 patients had higher heart rates and blood pressures than SS controls in spite of performing the same or less work. This resulted in a higher double product (an estimate of oxygen consumption) in SS alpha thal‐2 patients (37,470 ± 2,310 mm Hg‐BPM) than in SS controls (33,310 ± 1,490 mm Hg‐BPM, P < .01). Work capacity, peak heart rate, and blood pressure were all abnormally decreased in both sickle‐cell groups when compared to normal. Cardiac abnormalities noted at rest and during exercise in SS alpha thal‐2 patients suggest a role of microvascular occlusion and a protective effect of decreased hemoglobin.

Miscellaneous TopicExercise-induced cardiac dysfunction in sickle cell anemia: A radionuclide study*

Cardiac performance was studied by radionuclide angiography at rest and during exercise in 22 adolescents with sickle cell (SC) anemia and the results were compared with those in 12 control subjects. At rest, cardiac contractility was normal; cardiac output and end-diastolic volume were increased. At maximal exercise, heart rate, cardiac output response, and work capacity were reduced; the reduction was related to the degree of anemia. Left ventricular end-diastolic volume decreased with exercise most markedly in patients with ischemic exercise electrocardiograms. An abnormal ejection fraction response to exercise occurred in 4 patients; electrocardiographic signs of ischemia developed in all 4, and wall motion abnormalities in 2. Those patients who had electrocardiographic signs of ischemia had a significantly lower heart rate, ejection fraction, and cardiac output response to exercise, and a lower hematocrit level than subjects with normal results on exercise electrocardiography. The increase in cardiac output was not sufficient to maintain a normal level of exercise. The decrease in end-diastolic volume suggests that diastolic function was abnormal during exercise. Cardiac dysfunction was manifested by an abnormal ejection fraction response, wall motion abnormalities, and incomplete left ventricular filling during exercise.

Retropharyngeal Edema: An Unusual Manifestation of Kawasaki Disease

BACKGROUND Kawasaki disease (KD) is an acute multisystem vasculitis of unknown etiology that typically affects young children. KD presenting as a retropharyngeal inflammatory process is very rare. OBJECTIVES To report a case of KD initially presenting as a retropharyngeal edema mimicking a deep neck infection, and to review previously published reports in the literature. CASE REPORT We report a case of KD in a previously healthy 3-year-old child who presented with acute onset of fever and cervical adenitis, along with computed tomography scan findings of retropharyngeal edema and inflammation. KD was suspected due to persistent fever and no improvement in the patients condition despite appropriate antibiotic therapy; and other classic findings of KD eventually developed. An echocardiogram obtained on the 10th day of illness revealed pericardial effusion but no coronary ectasia or aneurysm. Treatment with high-dose intravenous immunoglobulin resulted in dramatic clinical improvement. Follow-up echocardiograms obtained 2 and 8 weeks after discharge revealed a small left coronary artery aneurysm (CAA). Nine months later, the CAA had resolved and the patient was well with no sequelae. CONCLUSIONS Although unusual, physicians should be aware of retropharyngeal edema as an atypical presentation of KD.

Growth of the Right Heart After Balloon Valvuloplasty for Critical Pulmonary Stenosis in the Newborn

Eight newborns with critical pulmonary stenosis and intact ventricular septum underwent successful percutaneous balloon dilation. Follow-up using echocardiography showed sustained relief of the obstruction across the pulmonary valve and excellent growth of the right heart structures.

Superior cavopulmonary anastomosis timing and outcomes in infants with single ventricle

OBJECTIVES We sought to identify factors associated with the timing and surgical outcomes of the superior cavopulmonary anastomosis. METHODS The Pediatric Heart Networks Infant Single Ventricle trial database identified participants who underwent superior cavopulmonary anastomosis. Factors potentially associated with age at superior cavopulmonary anastomosis, length of stay and death by 14 months of age were evaluated. Factors included subject demographics, cardiac anatomy, measures from neonatal hospitalization and pre-superior cavopulmonary anastomosis visit, adverse events, echocardiographic variables, intraoperative variables, superior cavopulmonary anastomosis type, and number of concurrent cardiac surgical procedures. Age at superior cavopulmonary anastomosis was analyzed using Cox proportional hazards regression. Natural log length of stay was analyzed by multiple linear regression. RESULTS Superior cavopulmonary anastomosis was performed in 193 subjects at 5.2 months of age (interquartile range, 4.2, 6.2) and weight of 5.9 kg (interquartile range, 5.3, 6.6). The median length of stay was 7 days (interquartile range, 6, 10). There were 3 deaths and 1 transplant during the superior cavopulmonary anastomosis hospitalization, and 3 deaths and 3 transplants between discharge and 14 months of age. Age at superior cavopulmonary anastomosis was associated with center and interstage adverse events. A longer length of stay was associated with younger age and greater case complexity. Superior cavopulmonary anastomosis type, valve regurgitation, ventricular ejection fraction, and ventricular end-diastolic pressure were not independently associated with age at superior cavopulmonary anastomosis or the length of stay. CONCLUSIONS Greater case complexity and more frequent interstage adverse events are associated with an earlier age at superior cavopulmonary anastomosis. Significant variation in age at superior cavopulmonary anastomosis among centers, independent of subject factors, highlights a lack of consensus regarding the optimal timing. Factors associated with length of stay could offer insights for improving presuperior cavopulmonary anastomosis care and surgical outcome.

Fetal cardiovascular hemodynamics in the presence of complete atrioventricular block.

OBJECTIVE Our purpose was to follow serially the hemodynamic adaptation to a congenital complete heart block in a human fetus. STUDY DESIGN Longitudinal and serial M-mode and Doppler echocardiography over a 10-week span were performed on a fetus affected by complete heart block. Ventricular fractional shortening, size, and flow across the atrioventricualr valves and outflow tracts were determined starting at 20 weeks up to the time of delivery. Neonatal Doppler follow-up was performed at 2 days of life after implantation of a temporary pacemaker. RESULTS The right and left ventricles were able to adapt to sustained bradycardia by increasing their size. This ventricular dilatation was also associated with an increase in fractional shortening, which was associated with ventricualr free wall hypertrophy. When ventricualr heart rate decreased to 38 beats/min, fractional shortening decreased, this was associated with the rapid onset of ascites and pericardial effusion. CONCLUSION In the presence of sustained bradycardia ventricular output can increase, because this fetus was able to increase ventricular size and fractional shortening and wall thickness.

Architecture for a high-performance tele-ultrasound system

Clinical prototypes of digital tele-ultrasound systems at the Bowman Gray School of Medicine have provided insight into various design architectures. Until network equipment costs decrease, hybrid systems often provide good cost/feature mixes by using high-cost networking equipment only when digital networking is required. Within the hospital using remote ultrasound system, a video and audio router interconnects the video output of ultrasound modalities and technologist communications subsystems. This is done either manually or by remote signaling, depending on the size of the ultrasound infrastructure and the cost of a remote signaling subsystem. For extramural sites and in hospital areas too distant for cost- effective analog switching techniques, an appropriate coder/decoder (CODEC), with echo cancellation, is used to transfer the audio and visual information to a CODEC in the viewing station location. The CODECs can be T1 (1.544 Mbps) CODECs for areas that cannot be reached economically at asynchronous transfer mode (ATM) data rates. This is contingent upon the diagnostic quality of the output of the T1 CODECs. Otherwise, high-speed CODECs are used with 45 Mbps DS-3 or ATM transmission facilities. This system allows full use of existing hospital infrastructures while adapting to emerging data communications infrastructures being implemented.

Echocardiographic Demonstration of a Ventriculocoronary Artery Communication in a Neonate With Hypoplastic Left Heart Syndrome

A neonate diagnosed with aortic atresia and mitral hypoplasia had a ventriculocoronary artery communication demonstrated by use of echocardiography. These communications have been noted by angiography and on pathologic specimens in the past, but their clinical importance in the surgical management of these patients remains unclear. The ability to noninvasively identify these communications and study their flow characteristics would help to define their impact on surgical outcome.