Efficacy of biphasic waveform compared to monophasic waveform for cardioversion of atrial flutter in pediatric patients.

The efficacy of biphasic waveform cardioversion of atrial flutter in pediatric patients has not previously been demonstrated. Cardioversion outcomes were compared in two sequential groups of patients with atrial flutter undergoing transthoracic cardioversion using monophasic and biphasic waveforms at a single pediatric institution. The mean energy required for procedural success was 1.7 +/- 1.2 J/kg in the monophasic group compared to 0.9 +/- 0.6 J/kg in the biphasic group (p = 0.002). The mean number of attempts before achieving procedural success was 1.9 +/- 1.2 for the monophasic group and 1.3 +/- 1.0 for the biphasic group (p = 0.019). Procedure success rate was 89.5% (33/38) in the monophasic group compared to 100% (27/27) in the biphasic group (p = 0.13). Success rate for biphasic waveform cardioversion was 83% (5/6) when using energy less than 0.5 J/kg. These findings provide the impetus for lower starting energies and more widespread use of devices utilizing biphasic waveforms in pediatric patients.

Late onset of pulmonary hypertension after successful Mustard surgery for d-transposition of the great arteries.

Late-onset pulmonary hypertension is a serious complication of Mustard repair for d-transposition of the great arteries. This debilitating complication occurs in 7% of patients who survive to adulthood, even in the face of normal or near-normal postoperative pulmonary pressure.

Long-term outcome in congenitally corrected transposition of the great arteries: a multi-institutional study.

OBJECTIVES: The purpose of this study was to determine long-term outcome in adults with congenitally corrected transposition of the great arteries (CCTGA), with particular emphasis on systemic ventricular dysfunction and congestive heart failure (CHF). BACKGROUND: Patients with CCTGA have the anatomical right ventricle as their systemic pumping chamber, with ventricular dysfunction and CHF being relatively common in older adults. METHODS: Retrospective analysis of records of 182 patients from 19 institutions were reviewed to determine current status and possible risk factors for systemic ventricular dysfunction and CHF. Factors considered included age, gender, associated cardiac defects, operative history, heart block, arrhythmias and tricuspid (i.e., systemic atrioventricular) regurgitation (TR). RESULTS: Both CHF and systemic ventricular dysfunction were common in groups with or without associated cardiac lesions. By age 45, 67% of patients with associated lesions had CHF, and 25% of patients without associated lesions had this complication. The rates of systemic ventricular dysfunction and CHF were higher with increasing age, the presence of significant associated cardiac lesions, history of arrhythmia, pacemaker implantation, prior surgery of any type, and particularly with tricuspid valvuloplasty or replacement. Aortic regurgitation (a previously unreported problem) was also relatively common in this patient population. CONCLUSIONS: Patients with CCTGA are increasingly subject to CHF with advancing age; this complication is extremely common by the fourth and fifth decades. Tricuspid (systemic atrioventricular) valvular regurgitation is strongly associated with RV (anatomical right ventricle connected to aorta in CCTGA patients; systemic ventricle in CCTGA) dysfunction and CHF; whether it is causative or a secondary complication remains speculative.

Course of right and left ventricular function in patients with pulmonary insufficiency after repair of Tetralogy of Fallot.

Surgical repair of tetralogy of Fallot (TOF) frequently results in pulmonary valve insufficiency. Nevertheless, no serial information is available on the long-term impact of the valvular insufficiency on right and left ventricular function. Right and left ventricular ejection fraction was measured serially by radionuclide angiocardiography in 21 patients with at least moderate pulmonary insufficiency after repair of TOF. A baseline study was obtained an average of 1.2 years after repair, and a follow-up study was performed an average of 10.2 years after surgery. Changes in ventricular function over time and deviations from the normal range were analyzed. At baseline evaluation the mean right ventricular ejection fraction (RVEF; 0.52 +/- 0.10) and left ventricular ejection fraction (LVEF; 0.68 +/- 0.10) were normal. At the time of follow-up the mean RVEF had significantly decreased to 0.45 +/- 0.09 (p < 0.01). The mean LVEF had decreased to 0.60 +/- 0.11 (p < 0.02). This change was independent of the RVEF (r = -0.13). Eleven patients (52%) had an abnormal RVEF or LVEF at follow-up. Nineteen patients (90%) showed a decrease of 0.05 or more in RVEF, LVEF, or both between studies. These data suggest a negative impact of long-standing pulmonary insufficiency on right and left ventricular systolic function after repair of TOF. Therefore, continued surveillance of biventricular function in this patient population appears warranted.

Should pediatric echocardiography be performed in adult laboratories?

OBJECTIVES: Current health care management has resulted in a change in referral patterns. The present study was undertaken to define the efficacy and value of pediatric echocardiography performed and interpreted in adult laboratories. METHODS: We reviewed the findings in 100 consecutive pediatric patients 1 month to 18 years of age referred for possible heart disease and evaluated previously by echocardiography performed in an adult laboratory. Technical adequacy and interpretation of the echocardiogram at the outside facility was correlated with our final diagnosis. RESULTS: Of the studies, 32 (32%) were performed in hospital laboratories, and 68 (68%) in physician offices. A total of 52 (52%) of the 100 patients arrived with an outside diagnosis in agreement with our final diagnosis. Technical difficulties were reported in 14 (14%) studies by the original laboratory; we felt that 32 (32%) studies were inadequate. Interpretation or communication between the outside echocardiography laboratory, primary care physicians, and patients' family was erroneous in 32 (32%) cases. Repeat echocardiography was necessary in 38 (38%) patients (6 because of planned surgery). If initial referral had been to our own institution, 25 to 30 patients would not have undergone echocardiography. CONCLUSIONS: Slightly more than half of echocardiography studies performed in pediatric patients in adult laboratories were technically adequate and interpreted correctly with proper physician-family communication. Many patients require repeat studies on further referral. A significant number would be spared echocardiography if they were sent to a pediatric cardiology center initially.

Right ventricular systolic function in adolescents and young adults after Mustard operation for transposition of the great arteries.

This study evaluates long-term ( > 10 years since surgery) right ventricular (RV) systolic function in patients who had previously undergone intraatrial baffle surgery for transposition of the great arteries. Studies suggest these patients are clinically stable and lead satisfactory lifestyles, but long-term ventricular performance is not known. Radionuclide angiocardiography was used to estimate RV ejection fraction in 58 patients a mean of 14 years after the Mustard operation. Repeat studies were performed in 32 patients. The absolute RV ejection fraction of 0.53 +/- 0.10 in our patients did not differ from normal values. Nine patients had a value < 0.42, placing them > 2 SDs below normal. Repeat RV ejection fraction decreased from 0.54 +/- 0.11 to 0.51 +/- 0.11 (p < 0.1) in 32 patients, and > 0.10 in 6. Thus, RV ejection fraction was abnormal in 9 of 58 patients (16%) evaluated > 10 years after a Mustard operation. Repeat studies demonstrate worsening in at least 6 of 32 patients (19%). These postoperative Mustard patients require continued evaluation, even in the absence of overt symptomatology.

Surgical management of complete atrioventricular septal defects. A twenty-year experience.

Creation of a competent left atrioventricular valve is a cornerstone in surgical repair of complete atrioventricular septal defects. To identify risk factors for mortality and failure of left atrioventricular valve repair and to determine the impact of cleft closure on postoperative atrioventricular valve function, we retrospectively analyzed hospital records of 203 patients between January 1974 and January 1995. Overall early mortality was 7.9%. Operative mortality decreased significantly over the period of the study from 19% (4/21) before 1980 to 3% (2/67) after 1990 (p = 0.03). Ten-year survival including operative mortality was 91.3% +/- 0.004% (95% confidence limit): all survivors are in New York Heart Association class I or II. Preoperative atrioventricular valve regurgitation was assessed in 203 patients by angiography or echocardiography and was trivial or mild in 103 (52%), moderate in 82 (41%), and severe in 18 (8%). Left atrioventricular valve cleft was closed in 93% (189/203) but left alone when valve leaflet tissue was inadequate and closure of the cleft might cause significant stenosis. Reoperation for severe postoperative left atrioventricular valve regurgitation was necessary in eight patients, five of whom initially did not have closure of the cleft and three of whom had cleft closure. Six patients had reoperation with annuloplasty and two patients required left atrioventricular valve replacement. Five patients survived reoperation and are currently in New York Heart Association class I or II. On most recent evaluation assessed by angiography or echocardiography (a mean of 59 months after repair), left atrioventricular valve regurgitation was trivial or mild in 137 of the 146 survivors (94%) examined; none had moderate or severe left atrioventricular valve stenosis. By multiple logistic regression analysis, strong risk factors for early death and need for reoperation included postoperative pulmonary hypertensive crisis, immediate postoperative severe left atrioventricular valve regurgitation, and double-orifice left atrioventricular valve. These results indicate that complete atrioventricular septal defects can be repaired with low mortality and good intermediate to long-term results. Routine approximation of the cleft is safe and has a low incidence of reoperation for left atrioventricular valve regurgitation.

Ventricular function in the single ventricle before and after Fontan surgery.

To better delineate the importance of ventricular function in patients with a single ventricle and assess its relation to outcome after the Fontan procedure, 47 patients with a single ventricle were studied. Ventricular ejection fraction was estimated by radionuclide angiocardiography. Before Fontan surgery, ejection fraction was 0.57 +/- 0.10 (mean +/- standard deviation). This differed significantly from the normal mean left ventricular ejection fraction of 0.68 +/- 0.09 (p less than 0.001) derived in our laboratory by radionuclide angiocardiographic methods. Age, ventricular morphology and the presence of pulmonary artery band or systemic to pulmonary artery shunts had no statistical relation to ventricular ejection fraction in patients with a single ventricle. Serial preoperative evaluation in 15 patients over 3.8 +/- 1.3 years revealed no significant change in ventricular ejection fraction; however, increased atrioventricular valve regurgitation was documented in 4 of these 15. Modified Fontan procedure was performed in 24 of the 47 study patients; 7 have died, 1 has undergone cardiac transplantation and 1 faces possible transplantation. No difference was noted in preoperative ejection fraction between survivors and nonsurvivors. Ventricular morphology, age at Fontan surgery and operative factors such as bypass and cross-clamp time were not related to functional outcome. Preoperative ejection fraction of 0.52 +/- 0.08 decreased to 0.39 +/- 0.11 (p less than 0.001) when evaluated 1.16 +/- 0.44 years after Fontan surgery. In patients with a single ventricle (1) ventricular ejection fraction is less than that of the normal systemic ventricle; (2) during childhood, ejection fraction is not related to age or ventricular morphology; and (3) ventricular ejection fraction frequently decreases after a Fontan repair.(ABSTRACT TRUNCATED AT 250 WORDS)

Preoperative and postoperative "aneurysm" associated with coarctation of the aorta.

The reported incidence of aortic aneurysm after surgical repair or balloon angioplasty for aortic coarctation varies widely. To determine the incidence of aneurysm formation after surgery, preoperative and postoperative cineangiograms from 65 patients who underwent operation at age 1.5 +/- 3.4 years were examined. Repair included a prosthetic patch in 14 patients, end to end anastomosis in 28 and subclavian flap in 23. Aneurysm was documented by change in contour or irregularities in contour at the repair site or by abnormal dimensions at the repair site, defined by the ratio of the widest measurement at the repair site to the measurement of the aorta at the diaphragm. An aneurysmal bulge above the ductus diverticulum was identified in 14 (23%) of 60 patients preoperatively; the area showed no change 4.72 +/- 4.07 years after surgery. Significant changes at the repair site were seen in only three patients, all of whom had Dacron patch repair. One patient had a change in contour at the repair site, one had an abnormally high repair site to diaphragmatic aorta ratio and one had a progressive increase in this ratio. Thus, during childhood years, 3 (5%) of 65 patients were diagnosed as having aneurysm at the surgical repair site. In conclusion, 1) comparison with preoperative cineangiograms, especially for aneurysmal bulges above the ductus arteriosus, is essential before an aneurysm can be attributed to coarctation repair by any technique, and 2) aneurysm developed only in patients subjected to Dacron patch repair.

Cor triatriatum: clinical presentation and surgical results in 12 patients.

Twelve patients with cor triatriatum have been seen at our institution since 1979. The clinical presentation, diagnostic evaluation, and surgical results are outlined in this retrospective review. Operation is the treatment of choice for this rare congenital cardiac defect. One patient died 1 day before scheduled operation, and 2 patients died postoperatively, yielding a surgical mortality rate of 17% and an overall mortality rate of 25%. Resection of the obstructing atrial membrane was performed using hypothermic cardiopulmonary bypass in all cases. Left atriotomy was performed in 6 patients, and right atriotomy was performed in 7. The two postoperative deaths occurred in patients who had serious associated cardiac defects. Associated anomalies include atrial septal defect, persistent left superior vena cava, and partial anomalous pulmonary venous return. The postoperative course has been excellent in all 9 surviving patients; all remain asymptomatic. Cor triatriatum is amenable to surgical repair with excellent results when diagnosed early and when not complicated by other severe cardiac anomalies.

Assessment of ventricular function in infants and children. Response to dobutamine infusion.

A method to assess ventricular functional reserve in infants and children unable to perform dynamic exercise was evaluated. Left ventricular ejection fraction was measured by radionuclide angiocardiography at rest and during infusion of dobutamine in 5-15 micrograms/kg/min dosages. The only side effects noted were arrhythmias in two patients, who had similar ectopy documented previously. Group left ventricular ejection fraction increased from 0.40 +/- 0.21 to a maximum of 0.49 +/- 0.24 (P less than 0.001). Left ventricular ejection fraction at 5 micrograms/kg/min (0.44 +/- 0.23) was not statistically different from that measured during infusion of dobutamine at 10 micrograms/kg/min (0.48 +/- 0.24). The six patients receiving anthracyclines, who had relatively low function at rest and increased function during dobutamine administration, were continued on their anticancer regimen without deteriorating in condition. Absolute values of left ventricular ejection fraction correlated best with the prognosis in patients with idiopathic dilated cardiomyopathy or structural abnormalities; six out of ten patients whose left ventricular ejection fraction never rose above 0.40 have either died or are in transplant protocols. Thus, study of left ventricular function can be performed easily during dobutamine infusion, generating valuable prognostic information.

Clinical and hemodynamic course of infants and children with anomalous left coronary artery.

The clinical history of all 17 patients with anomalous left coronary artery presenting over the last 20 years was studied, with special emphasis on those who underwent reimplantation of the anomalous coronary artery into the aorta, a procedure that became our "treatment of choice" during this period. These patients were also evaluated for ventricular performance, residual mitral regurgitation, and wall integrity. Early in our experience with reimplantation, two patients died while we waited for them to achieve a more favorable size for surgery. Eight of nine survived reimplantation; three of these were under 1 year of age when operated upon. One of these eight patients has required additional mitral valvuloplasty, but all are doing well clinically up to 12 years after operation. Preoperative left ventricular ejection fraction of 0.37 +/- 0.16 increased to 0.67 +/- 0.07 (p less than 0.001) by 1 year after surgery, despite ventricular wall abnormalities in four patients. Thus reimplantation of the anomalous left coronary artery should be undertaken upon diagnosis, since surgery can be performed successfully in infancy, with resultant improvement in ventricular function and an adequate clinical condition for at least 12 years.

Surgical spectrum of aortic stenosis in children: a thirty-year experience with 257 children.

Aortic stenosis accounts for 5 to 6% of infants and children seen for surgical repair of congenital heart disease. The clinical presentation and reported results of operation for aortic stenosis are highly variable. This retrospective review was undertaken to assess our operative mortality and the degree of gradient reduction afforded by each of several surgical techniques used to treat aortic stenosis in children over a 30-year period. Two hundred fifty-seven patients ranging in age from 1 day to 19 years were operated on between 1957 and 1986. The indication for operation included asymptomatic patients with gradients greater than 50 mm Hg to patients in profound cardiogenic shock. The operative mortality for children older than 6 months was 4%, whereas neonates seen with critical aortic stenosis had a 60% mortality. The late mortality was 2%. Eighty percent of surviving patients to date have undergone cardiac catheterization after repair. This shows an overall reduction of 57 mm Hg in the left ventricular-aortic gradient. Patients with supravalvular aortic stenosis and discrete subvalvular aortic stenosis as well as patients undergoing aortic valve replacement showed a reduction in or elimination of associated aortic insufficiency, whereas patients undergoing aortic valvotomy or neonates having valvotomy had a significant increase in demonstrable aortic insufficiency. The incidence of third-degree heart block or cerebral emboli following operation for aortic stenosis was less than 1%. However, the incidence of late bacterial endocarditis following repair was nearly 5%; six of eleven cases occurred in the group with discrete subvalvular aortic stenosis. Twenty-nine (13%) of the 223 long-term survivors have undergone a subsequent procedure for relief of residual or recurrent obstruction; 12 have had insertion of an aortic valve prosthesis, 12 have had insertion of an apicoaortic conduit, and 6 have required repeat aortic valvotomy. These data demonstrate the low operative mortality and excellent hemodynamic benefit of surgical relief of single-level aortic stenosis in children older than neonates. Conduits placed for complex obstructions or operative procedures in neonates have acceptable hemodynamic benefits, but operative mortality remains high.

Preoperative two-dimensional echocardiographic prediction of prosthetic aortic and mitral valve size in children.

Preoperative two-dimensional echocardiograms (2D-ECHOs) were done on 18 patients to determine the accuracy of assessing the mitral and aortic anulus diameter in children undergoing valve replacement. Fourteen patients underwent primary valve replacement and four underwent repeat valve replacement. The mean age was 11.5 years (range 2 to 17 years). The 2D-ECHO measured mitral or aortic valve anulus was compared with the external diameter of the largest prosthetic valve that could be inserted. There was a strong correlation (r = 0.99, p less than 0.001, SEE = 1.0 mm) between the 2D-ECHO measurements and the prosthetic valve size in patients undergoing primary valve replacement, but the correlation (r = 0.16, p = NS) was poor for those undergoing repeat valve replacement. In conclusion, 2D-ECHO prediction of prosthetic mitral and aortic valve size is accurate in children undergoing primary valve replacement but is poor in those undergoing repeat valve replacement.

Role of radionuclide shunt studies in management of infants and children.

The utility of radionuclide-shunt quantitation in children was assessed by examination of the outcome of 128 patients who underwent shunt study over a two-year period. The possibility of cardiac catheterization was eliminated in 87. Fifty of these had undergone previous cardiac catheterizations, which suggested the necessity for further invasive study or surgery; after radionuclide evaluation, 28 were shown to have had enough spontaneous closure of the defect to cancel planned surgery, 12 were scheduled for surgery without repeat catheterization, and ten had nuclear rather than catheterization estimates of residual shunting following surgical repair of septal defects. Thus, radionuclide shunt study provides a relatively noninvasive technique to quantitate left-to-right shunts, supplementing or supplanting cardiac catheterization in the management of infants and children with such lesions.