Sandra K. Clapp

Augmented norepinephrine and renin output in response to maximal exercise in hypertensive coarctectomy patients

To evaluate a possible neural or renal contribution to the hypertension that occurs in some patients following coarctation of aorta repair, 35 patients underwent graded bicycle exercise with serial measurements of plasma norepinephrine concentrations and plasma renin activity. Sixteen patients with coarctectomy who had systolic or diastolic hypertension at peak exercise were compared with 19 normotensive patients with coarctectomy. The average time interval between coarctation repair and study was significantly longer (p less than 0.05) in the hypertensive group than in the normotensive patients (12.8 +/- 4.8 versus 8.7 +/- 2.2 years). The heart rate response to exercise was similar for both patient groups. The systolic blood pressure in the hypertensive group was higher than in the normotensive group at rest in the supine and upright positions and at 5 minutes of recovery, in addition to peak exercise, and the diastolic blood pressure was increased at peak exercise. Plasma norepinephrine concentrations were significantly higher at peak exercise and during recovery in the hypertensive group than in the normotensive patients. Plasma renin activity was also significantly higher in the hypertensive group at peak exercise. These data suggest that patients with coarctectomy who have a hypertensive response to exercise have an augmented sympathetic nervous system output and increased plasma renin activity that may lead to peripheral vasoconstriction at peak exercise and that may contribute to the development of their hypertension.

Aortic root dilation after the Ross procedure.

This study evaluated changes in neoaortic root geometry in patients who underwent the Ross procedure. Serial postoperative echocardiographic measurements of the neoaortic root indexed to the square root of body surface area (centimeters divided by meters) were obtained from 30 patients (age range 3.1 to 31.4 years) and compared with paired preoperative and immediate postoperative values. Normal aortic root diameter Z scores were derived from root dimensions obtained from 217 healthy controls. Compared with preoperative values, an immediate stretch of the neoaortic versus pulmonary root (annulus and sinuses of valsalva) was observed at a mean follow-up period of 1 week. Additional aortic annular dilation from baseline prehospital discharge values was observed at 2 to 12 months (baseline vs follow-up annulus Z score: 1.4 vs 2.6, p <0.01, n = 16) and at 16 to 33 months follow-up (0.8 vs 2.0, p <0.05, n = 12). In a similar fashion, there was additional enlargement of the aortic sinus from its stretched state at hospital discharge at 2 to 12 months (baseline vs follow-up sinus Z score: 2.0 vs 3.3, p <0.01, n = 17) and at 16 to 33 months (1.7 vs 3.0, p <0.01, n = 13). There were no differences in root size between 2 to 12 and 16 to 33 months after surgery. There was a decrease in left ventricular size with no alteration in blood pressure or degree of aortic valve regurgitation. Thus, aortic root dilation occurs up to the first year after the Ross procedure but does not appear to progress beyond this time.

Pacing in children and young adults with nonsurgical atrioventricular block: Comparison of single-rate ventricular and dual-chamber modes

A prospective comparison of physiologic response to single-rate ventricular and dual-chamber atrioventricular pacing was conducted in 14 pediatric patients (age 1 to 24 years, median 14) with symptomatic nonsurgical second- or third-degree atrioventricular block. All patients were studied acutely during cardiac catheterization before and after 1 hour of both pacing modes. Following pacemaker implant, eight patients were reevaluated after 1 month of each mode with symptom questionnaire, resting ECG, resting echocardiogram, and Doppler cardiac output measurement at rest and at peak treadmill exercise. Cardiac outputs (mean +/- standard error) increased acutely (n = 14) with both ventricular (32 +/- 12%) and dual-chamber (39 +/- 10%) pacing over intrinsic rhythm values (p less than 0.01 in both). During chronic pacing (n = 8), symptoms were reported only with the ventricular mode. Dual-chamber synchronous pacing was associated with improved mean resting shortening fraction and cardiac output, slower mean resting sinus rate (89 +/- 5 compared to 73 +/- 4 bpm (p less than 0.02), and a 23% increase in mean excerise cardiac output (4.2 +/- 0.4 compared to 3.4 +/- 0.3 L/min/m2) compared to single-rate ventricular pacing. Exercise-induced dysrhythmias occurred only with ventricular pacing. This study demonstrates that pediatric patients with nonsurgical atrioventricular block can compensate for loss of atrioventricular synchrony at rest but exhibit improved cardiac function with chronic dual-chamber atrioventricular compared to single-rate ventricular pacing.

Surgical and medical results of complete atrioventricular canal: A ten year review

The files of 121 patients who presented to Childrens Hospital of Michigan over the last 10 years with complete atrioventricular (AV) canal were reviewed to evaluate long-term management and overall outcome. Of 121 patients, 70 underwent corrective surgery, 21 (30%) of whom died perioperatively. The surgical mortality rate was 13% when patients with hypoplastic left or right ventricle (n = 6), double-orifice mitral valve or extreme deficiency of mitral tissue (n = 5), and pulmonary vascular obstructive disease (n = 5) were excluded. Of the 49 patients who survived operation, 36 are in New York Heart Association class I, 1 patient requires a pacemaker and 3 died late. In 34 of the 51 patients (28%) who did not undergo operation, pulmonary vascular obstructive disease developed; it occurred within 12 months in 10 patients (8%). Eight other patients who did not undergo operation died before planned surgery (age 1 to 9 months). Although surgical prognosis in good candidates is acceptable, the overall prognosis for children with complete AV canal is guarded because of the risk of early death or early pulmonary vascular obstructive disease and frequently unfavorable anatomy.

Bidirectional cavopulmonary anastomosis with intracardiac repair.

BACKGROUND Patients with hypoplasia of the right ventricle and tricuspid valve have historically undergone a total cavopulmonary connection or a two-ventricle repair with atrial fenestration. METHODS We reviewed our experience with 9 patients with hypoplasia of the right ventricle and tricuspid valve who underwent a bidirectional cavopulmonary anastomosis with intracardiac repair. Patient diagnoses included pulmonary atresia with intact ventricular septum (n = 3); hypoplastic right ventricle and tricuspid valve with atrial septal defect, ventricular septal defect, and right ventricular outflow tract obstruction (n = 3); unbalanced atrioventricular canal defect (n = 1); inlet ventricular septal defect with coarctation (n = 1); and tricuspid stenosis with atrial septal defect (n = 1). RESULTS The median age at operation was 36 months. There was hypoplasia of the right ventricle and tricuspid valve in all patients. The tricuspid valve measured 56.5% of normal (range, 43.6% to 70.4%) by echocardiography, and the median ratio of the tricuspid valve to the mitral valve was 0.67 (range, 0.54 to 0.82). At operation, the median tricuspid valve annulus diameter was 65.6% of published autopsy normals (range, 57.8% to 78.5%) with a median Z value of -3.8 (range, -6.6 to -2.1). All patients survived operation. At a median follow-up of 16 months, 5 patients are asymptomatic, and 2 have occasional early-morning periorbital edema. Two patients are on a regimen of diuretics, 1 of whom is also taking an unloading agent. The patient with unbalanced atrioventricular canal died suddenly at home 6 months postoperatively. CONCLUSIONS Bidirectional cavopulmonary anastomosis with intracardiac repair may avoid the long-term complications associated with the Fontan modifications and eliminates the need of atrial fenestration in most instances. This operation should be considered for select patients with hypoplasia of the right ventricle and tricuspid valve.

Primary pulmonary artery sarcoma in two children

SummaryThe clinical and pathological features of primary pulmonary artery sarcoma in two children are reported. The first patient presented with right ventricular outflow obstruction and underwent successful surgical resection of his tumor. The second patient developed cardiac arrest following a relatively short period of symptoms of right heart failure and could not be revived. The pathological diagnosis in both patients was hemangiopericytoma. To the best of our knowledge, primary pulmonary artery sarcoma in children has not been previously reported.

Enhanced resting left ventricular filling in patients with successful coarctation repair and exercise-induced hypertension

M-mode and Doppler echocardiographic analyses of left ventricular (LV) shortening and filling were performed in 50 patients who underwent coarctectomy (median follow-up 9.5 years) and in 16 athletes in a control group before an exercise stress test with upright bicycle ergometry was performed. Thirty-two of 50 patients and 18 of 50 patients had a normotensive and hypertensive response to exercise, respectively. Preexercise echocardiographic data were compared among the control, normotensive, and hypertensive patient groups. LV peak filling rates (dD/dt, diastole) were increased in the hypertensive group (18.3 +/- 3.5) compared with those in the normotensive group (14.4 +/- 3.2; p < 0.001) and the control group (13.6 +/- 2.8; p < 0.001). LV shortening was enhanced in the coarctectomy group compared with that in the control group. A higher aortic isthmus Doppler gradient at peak exercise was not found in the hypertensive group compared with that in the normotensive group. Therefore patients with successful coarctectomy in childhood have enhanced LV shortening and relaxation at rest. Demonstration of enhanced LV peak filling rates may help identify patients at risk for exercise-induced hypertension.

Development of Superior Vena Cava to Pulmonary Vein Fistulae Following Modified Fontan Operation: Case Report of a Rare Anomaly and Embolization Therapy

Abstract. A patient with double inlet single ventricle, L-transposition of the great arteries, and atrioventricular valve regurgitation developed progressive heart failure necessitating modified Fontan operation at 16 months of age. The procedure included replacement of the atrioventricular valve and pacemaker insertion. Eight years following the operation, the patient developed progressive cyanosis. Catheterization confirmed the presence of fistulae from the superior vena cava and innominate vein to the pulmonary veins as the cause of cyanosis. Coil embolization of several fistulae was performed successfully at catheterization. Contributing factors for fistula formation in Fontan patients are discussed, and therapy is reviewed.

Original ArticlesBidirectional Cavopulmonary Anastomosis With Intracardiac Repair 1

BACKGROUND Patients with hypoplasia of the right ventricle and tricuspid valve have historically undergone a total cavopulmonary connection or a two-ventricle repair with atrial fenestration. METHODS We reviewed our experience with 9 patients with hypoplasia of the right ventricle and tricuspid valve who underwent a bidirectional cavopulmonary anastomosis with intracardiac repair. Patient diagnoses included pulmonary atresia with intact ventricular septum (n = 3); hypoplastic right ventricle and tricuspid valve with atrial septal defect, ventricular septal defect, and right ventricular outflow tract obstruction (n = 3); unbalanced atrioventricular canal defect (n = 1); inlet ventricular septal defect with coarctation (n = 1); and tricuspid stenosis with atrial septal defect (n = 1). RESULTS The median age at operation was 36 months. There was hypoplasia of the right ventricle and tricuspid valve in all patients. The tricuspid valve measured 56.5% of normal (range, 43.6% to 70.4%) by echocardiography, and the median ratio of the tricuspid valve to the mitral valve was 0.67 (range, 0.54 to 0.82). At operation, the median tricuspid valve annulus diameter was 65.6% of published autopsy normals (range, 57.8% to 78.5%) with a median Z value of -3.8 (range, -6.6 to -2.1). All patients survived operation. At a median follow-up of 16 months, 5 patients are asymptomatic, and 2 have occasional early-morning periorbital edema. Two patients are on a regimen of diuretics, 1 of whom is also taking an unloading agent. The patient with unbalanced atrioventricular canal died suddenly at home 6 months postoperatively. CONCLUSIONS Bidirectional cavopulmonary anastomosis with intracardiac repair may avoid the long-term complications associated with the Fontan modifications and eliminates the need of atrial fenestration in most instances. This operation should be considered for select patients with hypoplasia of the right ventricle and tricuspid valve.

Arch growth after staged repair of interrupted aortic arch using carotid artery interposition

BACKGROUND Between 1980 and 1990, our practice was to perform carotid artery interposition as part of a staged repair of interrupted aortic arch with various associated cardiac defects. METHODS This procedure was used in 16 patients with IAA type B. The median age at operation was 4.5 days and the median weight, 3.2 kg. Ten of the patients had an associated ventricular septal defect. Six more had complex anatomy. There were two death at carotid interposition, two interim deaths, and two deaths after intracardiac repair. Preoperative echocardiographic and angiographic studies were compared with postoperative studies in 11 survivors of arch repair to assess sequential growth of the interposed carotid artery. Measurements of the carotid artery were normalized to the descending aorta. RESULTS Preoperatively, the left carotid artery had a median diameter of 3.7 mm and was 42.9% of the descending aortic diameter. Postoperative studies performed at a median age of 5.7 months disclosed that the interposed carotid artery had grown to a median diameter of 7.0 mm and was 69.6% of the diameter of the descending aorta (normal > or = 81%). On follow-up at a median time of 4 years, 6 of 9 patients have no gradient by blood pressure measurements or echocardiographic Doppler studies, and 3 have modest gradients. No patient has required revision of the arch repair. CONCLUSIONS Survival is good after carotid artery interposition for interrupted aortic arch and growth of the carotid artery approaches that of a normal arch. Carotid artery interposition is a viable alternative for repair of this lesion should primary definitive repair not be feasible.