Eduardo Arciniegas

Ultrasonic Pattern of Ventricular Rhabdomyoma in Two Infants

Abstract Two infants with ventricular septal rhabdomyoma were studied with ultrasound. An abnormal cluster of echoes in the vicinity of the ventricular septum corresponded to the angiographic location of the tumor in each case. Disappearance of these echoes after successful surgical resection lends further support to the conclusion that the abnormal cluster of echoes was indeed related to the intracavitary portion of the tumor in both cases.

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.

Improved chronic epicardial pacing in children: steroid contribution to porous platinized electrodes.

Although new “low threshold” epicardial electrodes combine steroid with a porous, platinized‐platinum surface, the actual contribution of steroid elution has not been established. We evaluated this new electrode surface design with and without steroid in 13 children, ages 1–22 years. Both electrodes are unipolar and of similar surface area. The Medtronic Model 4951‐P is a barb design for epimyocardial insertion without steroid while the Model 10295A is a steroid elufing, epicardial disk‐shaped design. Both electrodes were implanted for atriai and ventricular pacing. At implant, sensed P and R waves, and pacing impedances were comparable between both electrodes. There were no significant differences between initial measured pulse width or calculated energy thresholds for the first 2 months following implant. Strength‐duration curves for both electrodes at 1 month were comparable to implant values. After 2 months, the threshold of the nonsleroid electrode peaked and stabilized at a significantly higher fP < 0.05) level than the more constant steroid eluting electrode. This difference continued for the first year following implant. We conclude that the new porous, platinized‐platinum electrode design intrinsically limits initial electrode‐tissue interface reactivity in children and improves epicardial pacing with low chronic threshold values. Steroid elution augments these intrinsic qualities by maintaining fibrous capsule stability with more constant low thresholds over time.

Tetralogy of Fallot

Tetralogy of Fallot is the most common malformation of children born with cyanotic heart disease, with an incidence of approximately 10 per cent of congenital heart disease. There can be a wide spectrum as to the severity of the anatomic defects, which include ventricular septal defect, aortic override, right ventricular outflow tract obstruction, and right ventricular hypertrophy. Cyanosis may vary from mild to severe, and patients may present as newborns or, more commonly, young infants. Infants with classic tetralogy of Fallot and stable anatomy should undergo primary complete intracardiac repair. The overall hospital mortality is approximately 3 to 5 per cent, with most patients who survive having an excellent clinical and hemodynamic result.

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.

Exercise performance after repair of anomalous origin of the left coronary artery from the pulmonary artery.

Eleven patients underwent exercise testing after operative repair of anomalous origin of the left coronary artery from the pulmonary artery. Five patients repaired after 2 years of age comprised a childhood surgery group, and six patients repaired before 2 years of age comprised an infant surgery group. All patients were exercised using either a treadmill or electronically braked bicycle with simultaneous thallium 201 scintigraphy. Oxygen consumption, carbon dioxide production, pulmonary functions, and electrocardiogram were all monitored continuously. Pulmonary reserve was normal in all patients. Based on heart rate reserve, respiratory exchange ratio, and oxygen-consumption response to work load, two patients in the infant surgery group stopped exercise before achieving maximum aerobic capacity. All remaining patients achieved their maximum aerobic capacity. There was no difference in work rate or oxygen consumption during exercise between the infant and childhood surgical group. Four patients (two in each surgical group) had an impaired chronotropic response to exercise. Three of these four patients demonstrated perfusion defects by thallium scintigraphy. Thallium scintigraphy was normal in all remaining patients. Electrocardiographic abnormalities were noted in seven of 11 patients having ventricular arrhythmias or ST segment depression. It is concluded from this study that exercise performance after repair of anomalous origin of the left coronary artery from the pulmonary artery is not affected by the age at which surgery is performed. Exercise is frequently associated with electrocardiographic evidence of abnormal myocardial perfusion despite frequently negative simultaneous 201Tl scintigraphy.

Use of ranitidine in children undergoing cardiopulmonary bypass

Sixty children aged 6 wk to 10 yr were studied. The children were undergoing cardiopulmonary bypass (CPB) for correction of congenital heart defects. The aim of the study was to provide prophylaxis for stress-induced gastric ulceration by elevating the gastric pH to at least 3.5. Two infusion regimes of ranitidine were compared: 0.1 and 0.2 mg/kg.h. The period of study was from induction of anesthesia until the end of the first 24 h after surgery. Both regimes were effective. The 0.2-mg/kg.h infusion produced a significantly higher plasma concentration of ranitidine throughout the study period without any additional clinical benefit. Both regimes produced, within 3 h of cessation of CPB, a significant elevation in mean gastric pH to at least 5.3. This paper concludes that 0.1-mg/kg.h infusion of ranitidine is a safe and efficacious regime for the critically ill pediatric patient.

Pulmonary hypertension postventricular septal defect repair treated by extracorporeal membrane oxygenation.

Severe pulmonary hypertension complicating the correction of congenital cardiac defects is an unusual cause of early postoperative mortality. We present a case of a nine-month-old infant who developed paroxysmal pulmonary hypertension associated with severe hypoxemia after the successful repair of a large perimembranous ventricular septal defect (VSD). The pulmonary hypertension was refractory to all medical and pharmacologic therapy but was successfully treated with extracorporeal membrane oxygenation (ECMO). On ECMO, pharmacologic support was removed, pulmonary artery pressure reduced, and ECMO support withdrawn. To date, ECMO has been applied to pulmonary hypertension of the newborn, neonatal respiratory insufficiency, and for primary cardiac pump failure. Our experience with this case leads us to believe it is an effective therapy for acute pulmonary hypertension occurring after the repair of congenital cardiac anomalies.

156 EFFECTS OF COLD CARDIOPLEGIA IN TETRALOGY OF FALLOT REPAIR

The value of cold cardioplegia was studied in 196 successive patients receiving three different methods of myocardial preservation during intracardiac repair of Tetralogy of Fallot. Group A (n=100)were repaired normothermic using intermittent aortic arch clamping (IAAC). Group B (n=43) received moderate hypothermia (28°C)and IAAC. Group C (n=53) were given moderate hypothermia and cold cardioplegia fluid. There was no significant difference in sex, type of right ventricular outflow tract obstruction or pre-op hemoglobin between groups. More Group A patients had a previous shunt (p<01) and had higher pre-op systemic saturations (p<.01). Group B patients tended to be older and larger at repair though these patients had significantly higher incidence of early death (within 30 days post-op) ,(p<.01). Aortic cross clamp time was significantly longer in C patients than other groups (p<.01). Post-op pressures in the right ventricle (p<.01) and pulmonary artery (p<.01) were lower in C patients. The major difference between groups occurred in comparing duration of inotropic support. Group A patients required 33 ± 2.9 hours,Group B 39 ± 4.3 hours. Significantly, Group C patients required only 12.5 ± 2.9 hours (p<.001) of dopamine or isoproterenol to maintain clinically normal cardiac output in the post-operative period. In conclusion, cold cardioplegia offers markedly better myocardial preservation than previous methods, allowing longer operative time with less compromise of cardiac output in the post-operative period.