Xenograft transplantation in congenital cardiac surgery at Baskent University: midterm results.

OBJECTIVE: Xenograft valved conduits have been used in several cardiac pathologies. In this study we have presented our midterm results of pediatric patients pathologies who were operated with xenograft conduits. PATIENTS AND METHODS: Between January 1999 and January 2005, 134 patients underwent open heart surgery with xenograft conduits. The conduits were used to establish the continuity of the right ventricle to the pulmonary artery or aorta, the left ventricle to the pulmonary artery, or aorta due to various types of complex cardiac anomalies. Patients were evaluated by transthoracic echocardiography (ECHO) at 6-month follow-ups. Cardiac catheterization was performed when ECHO demonstrated significant conduit failure. RESULTS: Hospital mortality was observed in 28 patients (20.1%), and 13 patients died upon follow-up (9.7%). Mean follow-up was 24.6 +/- 4 months (range, 13 to 85 months). Among 93 survivors 20 patients (21.5%) were reoperated due to conduit failure. The main reasons for conduit failure were stenosis (n=13), valvular regurgitation (n=2), or both conditions in 5 cases. Mean pulmonary gradient before conduit re-replacement was 47.7 +/- 30.1 mmHg. The 1-, 3-, and 6-year actuarial survival rates were 95 +/- 2%, 91 +/- 3%, and 86 +/- 5%. The 1-, 3-, and 6-year actuarial freedom rates from reoperation were 95 +/- 1%, 90 +/- 3%, and 86 +/- 4%. An increased gradient between the pulmonary artery and the right ventricle and prolonged cardiopulmonary bypass times were observed to be significant risk factors for reoperation. There was no mortality among reoperated patients. CONCLUSION: Xenograft conduits should be closely followed for calcification and stenosis. Conduit stenosis is the major risk factor for reoperation. In these patients, reoperation for conduit replacement can be performed safely before deterioration of cardiac performance.

Evaluation of the potential role of echocardiography in the detection of allograft rejection in heart transplant recipients.

PURPOSE: Our objective was to determine the most relevant systolic and diastolic echocardiographic parameters to detect left ventricular (LV) dysfunction associated with allograft rejection among heart transplant recipients. PATIENTS AND METHODS: Seven consecutive recipients underwent serial echocardiographic studies with two-dimensional spectral Doppler and tissue Doppler (TD) according to our institutional protocol. Results were compared with clinical status and endomyocardial biopsies (EMB) whenever available. RESULTS: The time since transplantation was 22 to 850 days. Patient no. 2 had a biopsy-proven acute rejection at the 11th week which was associated with decreased TD velocities, ejection fraction (EF), and stroke volume (SV), as well as increased pericardial effusion and posterior wall thickness. Interestingly, changes in TD parameters preceded those in EF and SV. However, similar but less remarkable changes in TD velocities, EF, SV, pericardial effusion, and posterior wall thickness also occurred during other events, such as systemic infection and immediate postoperative hemodynamic compromise despite no rejection. A biopsy performed 7 months later in a patient with a previous rejection episode due to a relatively low EF and SV as well as increasing pericardial effusion with normal TD velocities revealed no rejection. CONCLUSIONS: These data suggest that echocardiographic findings, although not specific for acute rejection, may play a potential role as a screening test to exclude rejection in heart transplant recipients.

Double-chambered right ventricle: experience with 52 cases.

The presence of anomalous muscle bundles may produce a pressure gradient between the inflow and outflow portions of the right ventricle, thus resulting in double-chambered right ventricle bearing troublesome clinically in its diagnosis. The aim of the present study was to review the diagnostic criteria. Fifty-two patients with a double-chambered right ventricle were seen during an 8-year period. They ranged in age at the catheterization from 4 months to 17 years (mean 7.5 +/- 4.4 years). Diagnosis was confirmed in 51 patients at cardiac catheterization and in other one on operation. The majority of the patients had associated cardiac anomalies: there were 33 ventricular septal defect (63%), 21 pulmonary valve stenosis (40%), nine atrial septal defect (17%), and four double-outlet right ventricle. The electrocardiograms revealed upright T waves alone in right precordial leads suggesting right ventricular hypertrophy in 33% of the patients. At cardiac catheterization, there was a pressure gradient of 20-160 mmHg between the right ventricular inflow and outflow portions. Forty patients have had surgery and four have undergone balloon pulmonary valvuloplasty. Surgical treatment was planned for two patients and other six had no indication for treatment.

Activated protein C resistance and false type 2 protein C deficiency detected after multiple shunt failures in a patient with hydrocephalus.

A 2-year-old hydrocephalic boy who had suffered multiple shunt failures was evaluated for hypercoagulability after a thrombus was removed from his right atrium. The work-up revealed that the patient had the heterozygous form of activated protein C resistance and false type 2 protein C deficiency by the clotting method. His protein C activity was normal by the chromogenic method. We suggest that patients having hydrocephalus, shunt-associated thrombus formation, or both should be evaluated for thrombophilic disorders, and protein C activity should be measured by chromogenic assay in patients with documented activated protein C resistance.

Occurrence of an aortic arch anomaly in two siblings born to a diabetic mother.

A patient with interruption of aortic arch type A, born to a diabetic mother, is described. The patient, a male infant, was the fourth child of a 29-year-old mother, and had a sibling with coarctation of the aorta. The mother had been treated for insulin-dependent diabetes mellitus for the previous 10 years. The infant died on the 3rd day of life after symptoms of cardiogenic shock. To our knowledge, interruption of aortic arch type A has not been previously described in infants of diabetic mothers. The relevance of the case is discussed and the literature reviewed.

Transtelephonic ECG versus electrophysiologic study in children with recurrent palpitation attacks.

Palpitation may be a terrifying event for children and pose diagnostic problems for pediatric cardiologists. Routine methods often fail to document episodic arrhythmia because the episodes may be brief or infrequent or both. The purpose of this study was to evaluate and compare values of non-invasive and invasive techniques. Twenty-three children (mean age 11.7 +/- 2 years, range 7-16 years) with recurrent palpitation attacks (> 2 times), who had normal physical examinations, ECG, echocardiography, 24 hour ambulatory ECG monitoring and treadmill exercise tests, were included in the study. Redline Model CG 4000 TTE recorders were given to patients for 10 or 20 days. We performed an intracardiac electrophysiologic study (EPS) on 14 patients. The mean number of palpitation attacks was 11.3 +/- 7.4 (median: 5), lasting 9.6 +/- 7 (median 3) minutes. The number of transmitting records was 2 +/- 1.4 (1-20). Of the 23 patients, only 15 (65%) transmitted during the palpitation attacks. Twenty-four-hour ambulatory ECG monitoring findings were normal in all patients. One patient had a wide QRS tachycardia attack in the TTE records. We stimulated ventricular tachycardia in the same patient in the EPS. Among the other patients who transmitted TTE records during palpitation attacks, we diagnosed two cases of concealed accessory pathway and eight cases of dual AV nodal pathway in the EPS. In conclusion, TTE is a sensitive and accurate method for diagnosis and follow-up of patients with cardiac arrhythmia. It can be used before invasive studies in children with recurrent palpitation attacks.

Incidence and severity of arrhythmias and conduction disturbance after repair of tetralogy of Fallot.

Ventricular and supraventricular arrhythmias and conduction disturbances were evaluated by routine electrocardiography and 24-hour ambulatory monitoring in 31 patients who underwent correction of tetralogy of Fallot. The interval from operation to the study was 1 month to 14 years (mean 4.8 +/- 2.8). Complete right bundle branch block occurred in 22 (71%) patients and incomplete right bundle branch block in 9 (29%) patients. Bifascicular block with right bundle branch block and left axis deviation (LAD) occurred in one patient. Two patients had second degree type II atrioventricular block. Twenty-four-hour ambulatory electrocardiographic monitoring was performed in all patients and they were divided in two groups according to the frequency of ventricular arrhythmias (Lown classification). Group 1 included the 23 patients who had no arrhythmia or rare ventricular arrhythmias (Lown grade 0-1). Group 2 was comprised of eight patients (26%) with significant ventricular arrhythmias (Lown grade 2-5). Twelve patients (39%) had supraventricular arrhythmias, three patients rare supraventricular tachycardia attacks, and seven patients occasional supraventricular ectopies. One patient had bradycardia-tachycardia attacks and one patient had junctional tachycardia. There was no correlation between age at the time of surgery and ventricular arrhythmias. Of the patients who had ventricular and supraventricular arrhythmias of various degrees on ambulatory monitoring, two had significant arrhythmias on routine electrocardiogram. Symptoms were rare in these patients. In conclusion, both supraventricular and ventricular arrhythmias were found in considerable frequency in our patients. As ventricular arrhythmias may be the cause of sudden death and supraventricular arrhythmias are a main cause of morbidity, it is important to evaluate ventricular and supraventricular arrhythmias by ambulatory monitoring in patients who have undergone correction of tetralogy of Fallot.

"Acquired" subvalvular aortic stenosis after repair of several congenital cardiac defects.

Discrete subvalvular aortic stenosis is a progressive lesion. In this report we presented nine patients who had no significant left ventricular-aortic obstruction at initial cardiac catheterization or echocardiographic examination, but later developed significant subvalvular aortic stenosis. Associated lesions included ventricular septal defect in three, patent ductus arteriosus in two, aorticopulmonary window in one, tetralogy of Fallot in one, supramitral membrane in one, and ventricular septal defect and patent ductus arteriosus in one case. Nine patients were diagnosed with subvalvular aortic stenosis 18 months to eight years after surgical correction. Eight of the patients required surgery for subvalvular obstruction. In conclusion, discrete subaortic stenosis is a rare, late complication of the surgical repair of several congenital heart defects. It is a progressive lesion after surgery; therefore these patients require careful follow-up.

The role of pulmonary artery anatomy in repair of tetralogy of Fallot.

Pulmonary artery anatomy is the key factor that determines the type of surgical treatment required in tetralogy of Fallot. Despite the fact that routine primary repair is now done on infants, inadequate pulmonary artery size can dictate the need for staged surgical repair in even the oldest age groups. From October 1986 to October 1998, 361 patients at our clinic underwent surgery to correct tetralogy of Fallot. A total of 292 cases were treated with primary repair, 69 surgeries were palliative, and 30 of these 69 underwent corrective surgery. The Nakata index was used as a pulmonary artery index (PAI), and PAI< 200 was the criterion for requirement of two-stage repair. Of the 30 patients that underwent staged repair, the Blalock-Taussig shunt (BTS) procedure was used in 24; the remaining six patients had right ventricular outflow tract reconstruction (RVOTR). The mean age of all the palliative surgery patients was 3.4 years (range 6 months to 11 years), and of those who received corrective surgery was 5.5 years (range 2-12 years). These patients' PAI values were 181 +/- 37.5 mm2/m2 and 359 +/- 130.7 mm2/m2, respectively. The period between the two operations ranged from two months to four years. Mortality rates were 2.8 percent for palliative surgery as a whole, 4.1 percent for primary repair, and 16.6 percent for staged repair. Our policy with regard to corrective surgery for tetralogy of Fallot is to do primary repair regardless of a patient's age and weight, except in cases where the pulmonary artery anatomy is appropriate for the patient's body size.

Gaucher disease with communicating hydrocephalus and cardiac involvement.

A 14-year-old female with Gaucher disease presented with hydrocephalus, corneal opacities, cirrhosis, and cardiac valvular involvement. A homozygous D409H mutation was identified. She underwent surgery for aortic and mitral valve replacement. Because of severe calcification of the aortic root, no successful valve replacement was performed. She died on the third day after the explorative cardiac surgery. Cardiac abnormalities represent a life-threatening presentation of the homozygous D409H mutation. Identification of this type is essential prior to initiating appropriate therapy with enzyme replacement and cardiac corrective surgery.

Unusual and early hyperglycemia following amiodarone infusion in two infants.

Amiodarone is an effective antiarrhythmic agent that is widely used for tachyarrhythmias, especially ventricular tachycardia and supraventricular tachycardia. It has some mild short-term (e.g., skin rashes, gastrointestinal symptoms, and corneal microdeposits) and long-term side effects (thyroid dysfunction, visual disturbances, pulmonary infiltrates, ataxia, and hepatitis). We present two infants who had hyperglycemia following amiodarone infusion during the early postoperative period.

Malnutrition and growth failure in cyanotic and acyanotic congenital heart disease with and without pulmonary hypertension.

AIM: To investigate the effect of several types of congenital heart disease (CHD) on nutrition and growth. PATIENTS AND METHODS: The prevalence of malnutrition and growth failure was investigated in 89 patients with CHD aged 1-45 months. They were grouped according to cardiac diagnosis: group aP (n = 26), acyanotic patients with pulmonary hypertension; group ap (n = 5), acyanotic patients without pulmonary hypertension; group cp (n = 42), cyanotic patients without pulmonary hypertension; and group cP (n = 16), cyanotic patients with pulmonary hypertension. Information on socioeconomic level, parental education status, birth weight and nutrition history, number of siblings, and the timing, quality, and quantity of nutrients ingested during weaning period and at the time of the examination were obtained through interviews with parents. RESULTS: There was no significant difference between groups in terms of parental education status, socioeconomic level, duration of breast feeding, and number of siblings (p > 0.05). Group cP patients ingested fewer nutrients for their age compared to other groups. 37 of the 89 patients were below the 5th centile for both weight and length, and 58 of 89 patients were below the 5th centile for weight. Mild or borderline malnutrition was more common in group aP patients. Most group cp patients were in normal nutritional state, and stunting was more common than wasting. Both moderate to severe malnutrition and failure to thrive were more common in group cP patients. CONCLUSION: Patients with CHD are prone to malnutrition and growth failure. Pulmonary hypertension appears to be the most important factor, and cyanotic patients with pulmonary hypertension are the ones most severely affected. This study shows the additive effects of hypoxia and pulmonary hypertension on nutrition and growth of children with CHD.

Dual sensor pacemakers in children: what is the choice of sensor blending?

UNLABELLED: Dual sensor pacemakers were developed to obtain more appropriate responses to activity. We evaluated ten children with dual sensor pacemakers in different sensor blending circumstances using exercise testing to assess which ratio was optimal. Ten patients with several bradydysrhythmias (ages 6-16 years; mean 10.1 years) were included in the study. Eight patients had VVIR pacemakers (Vitatron Topaz), models and two patients had VDD pacemakers implanted via the transvenous route. All patients were in a paced rhythm (98.5% pacing). Accurate T wave sensing ranged from 81%-100%; mean 92%, median 95%. Voluntary exercise testing with a CAEP protocol was performed using a treadmill with the pacemaker in VVIR mode. Medium activity threshold with three sensor blending ratios (QT = ACT, QT > ACT, and QT < ACT) were done in all patients. The mean duration of exercise was not statistically different among the three sensor blending ratios. After 90 seconds of exercise, the mean pacing rate had increased by 12%, 3%, and 5%, respectively, in the three groups. At maximal exercise, the increases were 45%, 42%, and 54%. Mean HRs during exercise in each of the three ratios were not significantly different, although we found a statistically significant increase in HR during the first two stages of rest period in the QT = ACT sensor blending ratio compared to the QT > ACT ratio. No difference was observed after the second stage. IN CONCLUSION: (1) there is no difference between the QT = ACT, QT < ACT, and QT > ACT sensor blending ratios; and (2) each child has to be evaluated by exercise testing to program a correct sensor blending ratio.

One center's experience with remifentanil infusions for pediatric cardiac catheterization.

OBJECTIVE: To investigate the efficacy of a remifentanil infusion for pediatric cardiac catheterization. DESIGN: Prospective. SETTING: University hospital. PARTICIPANTS: Children undergoing cardiac catheterization (n = 55). INTERVENTIONS: All patients (age range, 2 months to 12 years) were premedicated with an oral mixture of hydroxyzine and midazolam 60 minutes before the procedure. A remifentanil infusion was initiated at 0.1 microg/kg/min before the start of cardiac catheterization. Noninvasive systolic blood pressure, heart rate, oxygen saturation (SpO(2)), respiratory rate, and sedation score were recorded before the remifentanil infusion and every 15 minutes thereafter throughout the procedure. Episodes of apnea, vomiting, pruritus, and muscle rigidity and recovery time were noted. MEASUREMENTS AND MAIN RESULTS: There were no significant changes in systolic blood pressure, heart rate, SpO(2), or respiratory rate during the procedure. The sedation scale scores at 30, 45, 60, 75, and 90 minutes of remifentanil infusion were significantly lower than the scores recorded at baseline and 15 minutes. In 23 patients, the remifentanil infusion maintained a satisfactory level of sedation, but 32 patients required additional drugs (18 received midazolam, and 14 received midazolam plus ketamine). Recovery was rapid after the remifentanil infusion was discontinued, with a mean time of 2.04 +/- 2.32 minutes to reach a recovery score of > or =5. Three patients experienced apnea after bolus doses of remifentanil, 1 patient vomited, and 1 patient complained of pruritus. CONCLUSION: In pediatric cases in which other intravenous analgesics and sedatives are contraindicated, remifentanil infusion appears to be a suitable alternative based on its associated rapid recovery and stable hemodynamics.

Adenosine induced torsades de pointes in a child with congenital long QT syndrome.

Torsades de pointes is a rare arrhythmia characterized by its bradycardia dependence and increased adrenergic discharge, whether it occurs as a congenital anomaly or as an acquired problem resulting from drug intoxication or other conditions. There are no reliable tests to assess the propensity toward torsades de pointes or evaluate the efficacy of treatment in these patients. Adenosine can result in marked slowing of sinus and ventricular rate and leads to increased sympathetic discharge when given intravenously. We induced torsades de pointes in a child with congenital long QT syndrome (Jervell-Lange-Nielsen syndrome) using 200 micrograms/kg IV adenosine bolus. Higher dosage of adenosine (600 micrograms/kg) did not lead to torsades de pointes after beta blockade. Adenosine may induce torsades de pointes in patients with the long QT syndrome and may be used as a test to reproduce the clinical arrhythmia. Whether adenosine proves to be useful for assessing the efficacy of treatment will require extensive investigation in larger series of patients.

Anatomic correction in transposition of the great arteries with unusual coronary pattern and side-by-side location.

Switch operation is the treatment of choice in infants with transposition of the great arteries. The anatomic correction restores the left ventricle to its normal systemic function. In complete transposition, however, the diverse spectrum of coronary pattern influences the surgical outcome. We describe a successful arterial switch operation without LeCompte manoeuvre in a neonate with unusual coronary artery anatomy and side-by-side great arteries.