Naomi J Kertesz

Texas Children's Hospital, Houston, TX, USA

Are you Naomi J Kertesz?

Claim your profile

Publications (29)161.83 Total impact

  • Article: Magnetic versus manual catheter navigation for ablation of free wall accessory pathways in children.
    [show abstract] [hide abstract]
    ABSTRACT: Transcatheter ablation of accessory pathway (AP)-mediated tachycardia is routinely performed in children. Little data exist regarding the use of magnetic navigation (MN) and its potential benefits for ablation of AP-mediated tachycardia in this population. We performed a retrospective review of prospectively gathered data in children undergoing radiofrequency ablation at our institution since the installation of MN (Stereotaxis Inc, St. Louis, MO) in March 2009. The efficacy and safety between an MN-guided approach and standard manual techniques for mapping and ablation of AP-mediated tachycardia were compared. During the 26-month study period, 145 patients underwent radiofrequency ablation for AP-mediated tachycardia. Seventy-three patients were ablated with MN and 72 with a standard manual approach. There were no significant differences in demographic factors between the 2 groups with a mean cohort age of 13.1±4.0 years. Acute success rates were equivalent with 68 of 73 (93.2%) patients in the MN group being successfully ablated versus 68 of 72 (94.4%) patients in the manual group (P=0.889). During a median follow-up of 21.4 months, there were no recurrences in the MN group and 2 recurrences in the manual group (P=0.388). There were no differences in time to effect, number of lesions delivered, or average ablation power. There was also no difference in total procedure time, but fluoroscopy time was significantly reduced in the MN group at 14.0 (interquartile range, 3.8-23.9) minutes compared with the manual group at 28.1 (interquartile range, 15.3-47.3) minutes (P<0.001). There were no complications in either group. MN is a safe and effective approach to ablate AP-mediated tachycardia in children.
    Circulation Arrhythmia and Electrophysiology 05/2012; 5(4):804-8. · 6.46 Impact Factor
  • Article: Impact of the American Heart Association scientific statement on screening electrocardiograms and stimulant medications.
    [show abstract] [hide abstract]
    ABSTRACT: To evaluate the impact of the American Heart Association (AHA) scientific statement regarding electrocardiograms (ECGs) and stimulant medications on the practice of community pediatricians. Retrospective evaluation and survey analysis. Academic tertiary care center. Patients with ECGs referred to our institution by pediatricians with an indication of stimulant medication screening in the year after the AHA statement. We compared the ECG ordering practices of community pediatricians and the outcomes of further evaluation and estimated the associated cost before and after the AHA scientific statement. Abnormal ECG findings, further workup, and change in clinical practice. In the year after publication of the 2008 AHA scientific statement, 372 ECGs were ordered with an indication of stimulant medication screening. Before publication of this statement, a mean (SD) of 6.9 (3.2) ECGs per month were referred for this indication. Despite continuing controversy, this number increased 4-fold to 31.2 (9.5) ECGs per month in the subsequent year. Twenty-four ECGs (6.4%) had abnormal findings. Eighteen patients were referred for further evaluation, and, at last follow-up, none had been found to have definitive disease. Six of 24 patients with abnormal ECG findings (25.0%) had a perceived significant delay in therapy because of the process. In responding pediatricians, 34.6% reported that the scientific statement had clearly affected their practice. The clinical practice of community pediatricians in regard to screening ECGs and stimulant medications has been affected by the recent AHA scientific statement. The yield of performing ECGs with an indication of stimulant medication screening is very low.
    Archives of pediatrics & adolescent medicine 02/2011; 165(2):166-70. · 3.73 Impact Factor
  • Source
    Article: Use of a cardioselective beta-blocker for pediatric patients with prolonged QT syndrome.
    [show abstract] [hide abstract]
    ABSTRACT: The data on the efficacy of atenolol for long-QT syndrome (LQTS) are controversial. This study aimed to evaluate the efficacy of atenolol for pediatric patients with LQTS. A retrospective observational study investigating all patients who had LQTS treated with atenolol at two institutions was performed. The study identified 57 patients (23 boys and 34 girls) with a mean QT corrected for heart rate (QTc) of 521 ± 54 ms. The mean age of these patients at diagnosis was 9 ± 6 years. Their clinical manifestations included no symptoms (n = 33, 58%), ventricular tachycardia (n = 10, 18%), syncope (n = 6, 10%), resuscitated sudden cardiac death (n = 4, 7%), atrioventricular block (n = 2, 4%), and bradycardia or presyncope (n = 2, 3%). Of the 57 patients, 13 (22%) had a family history of sudden death. The follow-up period was 5.4 ± 4.5 years. Atenolol at a mean dose of 1.4 ± 0.5 mg/kg/day was administered twice a day for all the patients. The mean maximum heart rate was 132 ± 27 bpm on Holter monitors and 155 ± 16 bpm on exercise treadmill tests, with medication doses titrated up to achieve a maximum heart rate lower than 150 bpm on both tests. During the follow-up period, one patient died (noncompliant with atenolol at the time of death), and the remaining patients had no sudden cardiac death events. Four patients (8%) had recurrent ventricular arrhythmias, three of whom received an implantable cardioverter defibrillator (all symptomatic at the time of diagnosis). For three patients (6%), it was necessary to rotate to a different beta-blocker because of side effects or inadequate heart rate control. Atenolol administered twice daily constitutes a valid and effective alternative for the treatment of pediatric patients with LQTS.
    Pediatric Cardiology 10/2010; 32(1):63-6. · 1.30 Impact Factor
  • Article: Frequency of cardiac death in children with idiopathic dilated cardiomyopathy.
    [show abstract] [hide abstract]
    ABSTRACT: The prognosis in children with idiopathic dilated cardiomyopathy (IDC) is guarded, with the 5-year mortality rate ranging from 14% to 50%, owing to sudden cardiac death (SCD) or pump failure. The risk factors for SCD in adults with IDC include asymptomatic nonsustained ventricular tachycardia and poor left ventricular function. It is unclear whether these findings can be extrapolated to the pediatric population. A retrospective review of all patients with the diagnosis of IDC seen at a single institution from 1990 to 2004 was performed. A total of 85 patients (46 males), with a median age of 3.8 years (0 days to 17.3 years) were studied. The mean left ventricular ejection fraction was 25 +/- 12% (median 23%, range 45% to 45%) at presentation. The following arrhythmias occurred at presentation or during the initial hospitalization: nonsustained ventricular tachycardia in 6, sustained ventricular tachycardia or fibrillation in 1, supraventricular arrhythmias in 6, and both atrial and ventricular arrhythmias in 1. During a subsequent hospitalization or outpatient follow-up, 7 patients had the following arrhythmias: supraventricular arrhythmias in 2, nonsustained ventricular tachycardia in 4, and both atrial and ventricular arrhythmias in 1. The cumulative survival rate was 40% at a mean follow-up of 6.2 years (95% confidence interval 4.4 to 8.1). One single episode of SCD occurred in 1 patient without a history of sustained arrhythmias. In conclusion, in children with IDC, despite the low left ventricular ejection fraction and presence of ventricular arrhythmias, only one episode of SCD occurred in this group of patients. Given the 1% incidence of SCD in this cohort, the use of implantable cardioverter-defibrillators as primary prevention in children with IDC might not be indicated.
    The American journal of cardiology 12/2009; 104(11):1574-7. · 3.58 Impact Factor
  • Article: Pediatric nonpost-operative junctional ectopic tachycardia medical management and interventional therapies.
    [show abstract] [hide abstract]
    ABSTRACT: To determine the outcomes of medical management, pacing, and catheter ablation for the treatment of nonpost-operative junctional ectopic tachycardia (JET) in a pediatric population. Nonpost-operative JET is a rare tachyarrhythmia that is associated with a high rate of morbidity and mortality. Most reports of clinical outcomes were published before the routine use of amiodarone or ablation therapies. This is an international, multicenter retrospective outcome study of pediatric patients treated for nonpost-operative JET. A total of 94 patients with JET and 5 patients with accelerated junctional rhythm (age 0.8 year, range fetus to 16 years) from 22 institutions were identified. JET patients presenting at age < or =6 months were more likely to have incessant JET and to have faster JET rates. Antiarrhythmic medications were utilized in a majority of JET patients (89%), and of those, amiodarone was the most commonly reported effective agent (60%). Radiofrequency ablation was conducted in 17 patients and cryoablation in 27, with comparable success rates (82% radiofrequency vs. 85% cryoablation, p = 1.0). Atrioventricular junction ablation was required in 3% and pacemaker implantation in 14%. There were 4 (4%) deaths, all in patients presenting at age < or =6 months. Patients with nonpost-operative JET have a wide range of clinical presentations, with younger patients demonstrating higher morbidity and mortality. With current medical, ablative, and device therapies, the majority of patients have a good clinical outcome.
    Journal of the American College of Cardiology 03/2009; 53(8):690-7. · 14.16 Impact Factor
  • Article: Cross-stimulation: a rare complication of chronic epicardial leads.
    [show abstract] [hide abstract]
    ABSTRACT: Cross-stimulation is a rare phenomenon that occurs during dual-chamber pacing when the pacing stimulus to one chamber results in the inadvertent capture of the other. Most cases are attributable to intrinsic design features of particular device models or lead malpositioning, and only occur early postimplantation with subsequent spontaneous resolution. We report a case of cross-stimulation occurring in a patient with chronic epicardial leads without loss of lead integrity.
    Journal of Cardiovascular Electrophysiology 03/2009; 20(9):1065-7. · 3.06 Impact Factor
  • Article: Results of a multicenter retrospective implantable cardioverter-defibrillator registry of pediatric and congenital heart disease patients.
    [show abstract] [hide abstract]
    ABSTRACT: We sought to determine the implications of implantable cardioverter-defibrillator (ICD) placement in children and patients with congenital heart disease (CHD). There is increasing frequency of ICD use in pediatric and CHD patients. Until recently, prospective registry enrollment of ICD patients was not available, and children and CHD patients account for only a small percentage of ICD recipients. Therefore, we retrospectively obtained collaborative data from 4 pediatric centers, aiming to identify implant characteristics, shock frequency, and complications in this unique population. Databases from 4 centers were collated in a blinded fashion. Demographic information, implant electrical parameters, appropriate and inappropriate shock data, and complications were recorded for all implants from 1992 to 2004. A total of 443 patients were included, with a median age of 16 years (range 0 to 54 years) and median weight of 61 kg (range 2 to 130 kg), with 69% having structural heart disease. The most common diagnoses were tetralogy of Fallot (19%) and hypertrophic cardiomyopathy (14%). Implant indication was primary prevention in 52%. Shock data were available on 409 patients, of whom 105 (26%) received appropriate shocks (mean 4 shocks/patient, range 1 to 29 shocks/patient). Inappropriate shocks occurred in 87 of 409 patients (21%), with a mean of 6 per patient (range 1 to 60), mainly attributable to lead failure (14%), sinus or atrial tachycardias (9%), and/or oversensing (4%). Children and CHD ICD recipients have significant appropriate and inappropriate shock frequencies. Optimizing programming, medical management, and compliance may diminish inappropriate shocks. Despite concerns regarding generator recalls, lead failure remains the major cause of inappropriate shocks, complications, and system malfunction in children. Prospective assessment of ICD usage in this population may identify additional important factors in pediatric and CHD patients.
    Journal of the American College of Cardiology 05/2008; 51(17):1685-91. · 14.16 Impact Factor
  • Article: Maintenance of AV synchrony in a small child utilizing two pacemakers and the triggered VVT mode: triggered pacing in small children.
    [show abstract] [hide abstract]
    ABSTRACT: Infants and small children with atrioventricular (AV) nodal disease frequently require pacing in order to maintain an adequate heart rate. The maintenance of AV synchrony is physiologically optimal in this setting. Unfortunately, small size and congenital anomalies often preclude the placement of standard transvenous dual chamber pacing systems. We report the case of a small child with a pre-existing dual chamber epicardial pacing system and subsequent ventricular lead dysfunction who underwent implantation of a new single chamber transvenous system which was programmed in VVT (triggered) mode in order to maintain AV synchrony.
    Pacing and Clinical Electrophysiology 12/2007; 30(11):1404-7. · 1.35 Impact Factor
  • Article: Ventricular function and long-term pacing in children with congenital complete atrioventricular block.
    [show abstract] [hide abstract]
    ABSTRACT: To determine the sequela of right ventricular pacing in children with congenital complete atrioventricular block. Pacing is a well-accepted therapy for patients with congenital complete atrioventricular block. The long-term sequela of right ventricular pacing in this population has not been well described. We performed a cohort study on all patients with congenital complete atrioventricular block who underwent pacemaker implantation at our institution from 1972 to 2004. Patients with associated congenital heart disease or ventricular dysfunction prior to pacemaker implantation were excluded. A total of 63 patients were included in the study. The median age at pacemaker implantation was 6.5 years, with an average follow-up of 9.9 years. The cumulative dysfunction free survival at 20 years was 92%. In total, four patients (6%) were noted to develop LV dysfunction an average of 15.1 years after pacemaker implantation. Of 30 patients who were paced for >10 years, only three (10%) developed echocardiographic evidence of LV dysfunction. Right ventricular apex pacing and prolonged QRS duration were found to be predictive of decreased long-term LV systolic function (P < 0.05). Left ventricular dysfunction in patients with congenital complete atrioventricular block is a rare finding, even in those who have been paced for more than 10 years. Right ventricular apex pacing and prolonged QRS duration may be associated with decreased ventricular function over time. At this time, with such a low incidence of cardiac dysfunction, right ventricular pacing should be considered an acceptable first-line therapy in this population.
    Journal of Cardiovascular Electrophysiology 04/2007; 18(4):373-7. · 3.06 Impact Factor
  • Article: Transient complete atrioventricular block after placement of a central venous catheter in a neonate.
    [show abstract] [hide abstract]
    ABSTRACT: We present a case of trauma-induced complete atrioventricular block (transient) after placement of a central venous catheter. Case report. Neonatal intensive care unit in a tertiary care children's hospital. Review of the medical record and clinical course of a single premature infant. Removal of central venous catheter, monitoring of the cardiac output exam, and serial monitoring of the arrhythmia profile. Trauma-induced complete atrioventricular block from placement of the central venous catheter resolved in 9 days, obviating the need for pacemaker placement. Complete atrioventricular block is an infrequent complication of central venous catheter placement and may require several days to resolve.
    Pediatric Critical Care Medicine 02/2007; 8(1):64-6. · 3.13 Impact Factor
  • Article: Therapeutic levels of intravenous procainamide in neonates: a retrospective assessment.
    [show abstract] [hide abstract]
    ABSTRACT: To evaluate dosing and pharmacokinetic parameters of intravenous continuous-infusion procainamide in neonates, and to identify dosage regimens and factors leading to therapeutic procainamide levels and minimal adverse events. Retrospective, observational study. Pediatric hospital. . Twenty-one patients (seven preterm, 14 full term) younger than 30 days who received continuous-infusion procainamide therapy for more than 15 hours or had two consecutive therapeutic procainamide levels obtained while receiving therapy between June 1, 2002, and December 31, 2005. Data on demographics, dosing, drug levels, and adverse effects were collected. Doses that achieved therapeutic levels were documented, and procainamide clearance was calculated and evaluated with regard to renal function and gestational age in patients who were at steady state. Mean clearance and mean N-acetylprocainamide (NAPA):procainamide ratios were compared between preterm and term neonates. No patients experienced hemodynamic instability or other adverse effects due to procainamide. Procainamide was given as a mean +/- SD 9.6 +/- 1.5-mg/kg bolus in 20 of 21 patients before continuous infusion. The mean +/- SD dose at which two therapeutic levels were achieved was 37.56 +/- 13.52 microg/kg/minute. Procainamide clearance was 6.36 +/- 8.85 ml/kg/minute and correlated with creatinine clearance (r=0.78, p<0.00001) and age at day of sampling (r=0.49, p<0.00001). The NAPA:procainamide ratio at steady state was 0.84 +/- 0.53; two patients were determined to be fast acetylators (ratio > 1). Preterm infants had lower mean clearance rates (p<0.001) but higher NAPA:procainamide ratios (p<0.01) than those of term infants. Five patients experienced seven supratherapeutic levels while receiving therapy; four of these patients were preterm, and all had creatinine clearances less than 30 ml/minute/1.73 m(2). Three patients had four pairs of levels obtained after discontinuation of procainamide, and elimination rate constant and half-life were calculated. Procainamide can be safely used in neonates, with no short-term adverse effects. The dosage regimen for intravenous procainamide required to achieve therapeutic levels in neonates is similar to that of older infants and children. Doses may need to be reduced in premature infants and in those with renal dysfunction.
    Pharmacotherapy 01/2007; 26(12):1687-93. · 2.90 Impact Factor
  • Article: Atrial flutter in infants.
    [show abstract] [hide abstract]
    ABSTRACT: We sought to characterize the clinical nature of atrial flutter (AFL) in a large cohort of infants. There are no large studies describing the natural history of AFL in infants. Previous studies vary in the therapy used and expected prognosis. We reviewed the records of all children younger than 1 year of age who were diagnosed with AFL at our hospital during the past 25 years, excluding those with previous cardiac surgery. We identified 50 infants with AFL. Most, 36 (72%), presented within the first 48 h of life. Congestive heart failure was evident in 10 infants, with 6 presenting at 1 day of age, and 4 presenting beyond 1 month of age. The remainder were asymptomatic. A large atrial septal defect was the only structural heart disease. Spontaneous conversion to sinus rhythm occurred in 13 (26%) infants. Sinus rhythm was restored in 20 of 23 (87%) attempts at direct current cardioversion and 7 of 22 (32%) attempts at transesophegeal pacing; 7 required antiarrhythmic therapy. An additional arrhythmia, all supraventricular, appeared in 11 (22%) infants. The recurrence of AFL developed in 6 infants; 5 of 6 of these incidents occurred within 24 h of the first episode. All patients with recurrence had an additional arrhythmia. Infants with AFL usually present within the first 2 days of life. No association was found with structural heart disease. Direct current cardioversion appears to be most effective at establishing sinus rhythm. Chronic AFL has the potential to cause cardiovascular compromise. Atrial flutter in the absence of other arrhythmias has a low risk of recurrence. Once in sinus rhythm, infants with AFL have an excellent prognosis and may not require chronic antiarrhythmic therapy.
    Journal of the American College of Cardiology 10/2006; 48(5):1040-6. · 14.16 Impact Factor
  • Article: Outpatient continuous parenteral inotropic therapy as bridge to transplantation in children with advanced heart failure.
    [show abstract] [hide abstract]
    ABSTRACT: Advanced heart failure in children is associated with high morbidity and mortality and is often refractory to standard medical therapy. The purpose of this study was to review our institutional experience with the use of outpatient parenteral inotropic therapy (PIT) for advanced chronic heart failure in children. We reviewed the medical records of all patients treated with PIT as outpatients. Seven patients received outpatient PIT from 2/99 to 1/05 (mean age was 14.6 years +/- 3.7). Median duration of therapy was 10 weeks (range 4-84 weeks). The mean number of emergency department visits per patient was greater before starting PIT than after starting PIT (2.3 +/- 1.8 versus 1.1 +/- 2.2, P < .05). The mean number of hospital admissions from exacerbation of heart failure symptoms decreased after starting PIT (2.1 +/- 1.3 versus 0.6 +/- 0.8, P < .05). Mean EF% in patients with systolic dysfunction improved while on therapy (30 +/- 14% before versus 39 +/- 16% after, P < .05). There was 1 death and 5 complications in 2 patients. Six patients were successfully bridged to transplantation. Outpatient continuous parenteral inotropic therapy may serve as a successful bridge to cardiac transplantation in selected pediatric outpatients.
    Journal of cardiac failure 03/2006; 12(2):139-43. · 3.25 Impact Factor
  • Article: Innovative techniques for placement of implantable cardioverter-defibrillator leads in patients with limited venous access to the heart.
    [show abstract] [hide abstract]
    ABSTRACT: Because of venous occlusion, intracardiac shunting, previous surgery, or small size placement of implantable cardioverter-defibrillator (ICD) leads may not be possible using traditional methods. The purpose of this study was to evaluate and describe innovative methods of placing ICD leads. The records of all patients undergoing ICD implantation at our institution were reviewed to identify patients with nontraditional lead placement. Indications for ICD, method of lead and coil placement, defibrillation thresholds, complications, and follow-up results were reviewed retrospectively. Eight patients (aged 11 months to 29 years) were identified. Six patients with limited venous access to the heart (four extracardiac Fontan, one bidirectional Glenn, one 8 kg 11-month-old) underwent surgical placement of an ICD coil directly into the pericardial sac. A second bipolar lead was placed on the ventricle for sensing and pacing. Two patients with difficult venous access had a standard transvenous ICD lead inserted directly into the right atrium (transatrial approach) and then positioned into the ventricle. All patients had a defibrillation threshold of <20 J, although one patient required placement of a second coil due to an elevated threshold. There have been no complications and two successful appropriate ICD discharges at follow-up (median 22 months, range 5-42 months). Many factors may prohibit transvenous ICD lead placement. Nontraditional surgical placement of subcutaneous ICD leads on the pericardium or the use of a transatrial approach can be effective techniques in these patients. These procedures can be performed at low risk to the patient with excellent defibrillation thresholds.
    Pacing and Clinical Electrophysiology 02/2006; 29(2):181-7. · 1.35 Impact Factor
  • Article: Resynchronization therapy in pediatric and congenital heart disease patients: an international multicenter study.
    [show abstract] [hide abstract]
    ABSTRACT: Our objective was to evaluate the short-term safety and efficacy of cardiac resynchronization therapy (CRT) in children. Cardiac resynchronization therapy has been beneficial for adult patients with poor left ventricular function and intraventricular conduction delay. The efficacy of this therapy in the young and in those with congenital heart disease (CHD) has not yet been established. This is a multi-center, retrospective evaluation of CRT in 103 patients from 22 institutions. Median age at time of implantation was 12.8 years (3 months to 55.4 years). Median duration of follow-up was four months (22 days to 1 year). The diagnosis was CHD in 73 patients (71%), cardiomyopathy in 16 (16%), and congenital complete atrioventricular block in 14 (13%). The QRS duration before pacing was 166.1 +/- 33.3 ms, which decreased after CRT by 37.7 +/- 30.7 ms (p < 0.01). Pre-CRT systemic ventricular ejection fraction (EF) was 26.2 +/- 11.6%. The EF increased by 12.8 +/- 12.7 EF units with a mean EF after CRT of 39.9 +/- 14.8% (p < 0.05). Of 18 patients who underwent CRT while listed for heart transplantation, 3 improved sufficiently to allow removal from the transplant waiting list, 5 underwent transplant, 2 died, and 8 others are currently awaiting transplant. Cardiac resynchronization therapy appears to offer benefit in pediatric and CHD patients who differ substantially from the adult populations in whom this therapy has been most thoroughly evaluated to date. Further studies looking at the long-term benefit of this therapy in this population are needed.
    Journal of the American College of Cardiology 12/2005; 46(12):2277-83. · 14.16 Impact Factor
  • Article: Danon disease as an underrecognized cause of hypertrophic cardiomyopathy in children.
    [show abstract] [hide abstract]
    ABSTRACT: Some patients with hypertrophic cardiomyopathy (HCM) or left ventricular hypertrophy also present with skeletal myopathy and Wolff-Parkinson-White (WPW) syndrome; mutations in the gene encoding the lysosome-associated protein-2 (LAMP-2) have been identified in these patients, suggesting that some of these patients have Danon disease. In this study we investigated the frequency of LAMP2 mutations in an unselected pediatric HCM population. LAMP2 was amplified from genomic DNA isolated from peripheral lymphocytes of 50 patients diagnosed with HCM and analyzed by direct DNA sequencing. In 2 of the 50 probands (4%), nonsense mutations were identified. In 1 family the proband initially presented with HCM as a teenager, which progressed to dilated cardiomyopathy (DCM) and heart failure. Skeletal myopathy and WPW were also noted. The teenage sister of the proband is a carrier of the same LAMP2 mutation and has HCM without skeletal myopathy or WPW. The other proband presented with HCM, WPW, and skeletal myopathy as a teenager, whereas his carrier mother developed DCM during her 40s. Skeletal and cardiac muscle sections revealed the absence of LAMP-2 on immunohistochemical staining. LAMP2 mutations may account for a significant proportion of cases of HCM in children, especially when skeletal myopathy and/or WPW is present, suggesting that Danon disease is an underrecognized entity in the pediatric cardiology community.
    Circulation 10/2005; 112(11):1612-7. · 14.74 Impact Factor
  • Article: Radio-frequency catheter ablation of accessory pathway mediated tachycardia in a child after orthotopic heart transplantation.
    [show abstract] [hide abstract]
    ABSTRACT: Successful radio-frequency catheter ablation of accessory pathway mediated supraventricular tachycardia in the transplanted heart has been reported sporadically in adults, but has not been reported in children. This is the first report of a child having received a donor heart with manifest pre-excitation and who subsequently underwent successful radio-frequency ablation of the accessory pathway.
    The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 10/2005; 24(9):1444. · 3.54 Impact Factor
  • Article: Atrioventricular junction ablation and pacemaker therapy in patients with drug-resistant atrial tachyarrhythmias after the Fontan operation.
    [show abstract] [hide abstract]
    ABSTRACT: Drug-resistant intraatrial reentrant tachycardia (IART) occurs frequently after the Fontan operation and is a major cause of morbidity and rarely mortality. We describe our experience with AV junction ablation after pacemaker implantation in postoperative Fontan patients with drug-resistant IART. We performed retrospective analysis of Fontan patients with IART and attempted radiofrequency ablation (RFA) of the AV junction. Seven patients (6 male) were identified, with a mean age at Fontan of 9.3 years (range 5.8-13.3) and a median age at RFA of 18 years (range 14.5-23.3). Mean follow-up prior to RFA was 764 +/- 235 days and after RFA 1,541 +/- 1,235 days. IART was refractory to antiarrhythmic drugs in all patients, and all had undergone pacemaker placement. Mean onset of IART was 44.1 months (range 0-142) after Fontan. Mean duration of atrial arrhythmia prior to RFA was 72 +/- 48 m (range 16-148). Ablation of the AV junction was successful or partially successful in all patients. Complete AV block occurred in 6 patients. Normal AV conduction was not seen during a mean follow-up of 1,541 days. The mean number of antiarrhythmic medications decreased from 2.8 +/- 1.5 to 0.7 +/- 0.8 (P <0.05). In Fontan patients with drug-resistant IART, RFA of the AV junction with prior pacemaker implant is an effective therapeutic option. Despite the introduction of pacemaker dependence, this option should be considered in patients who did not respond to RFA of IART or who are at high operative risk for Fontan conversion.
    Journal of Cardiovascular Electrophysiology 02/2005; 16(1):24-9. · 3.06 Impact Factor
  • Article: Clinical course of atrial ectopic tachycardia is age-dependent: results and treatment in children < 3 or > or =3 years of age.
    [show abstract] [hide abstract]
    ABSTRACT: We assessed the clinical presentation, natural history, and treatment response of atrial ectopic tachycardia (AET) in children <3 years of age (group 1) compared with those > or =3 years of age (group 2). Atrial ectopic tachycardia is a common cause of chronic supraventricular tachycardia in children and can be resistant to pharmacologic therapy. Radiofrequency ablation (RFA) can eliminate AET arising from a single focus. A retrospective review identified all children at Texas Children's Hospital diagnosed with AET from March 1991 to November 2000. Data obtained included clinical presentation, echocardiographic evaluation, response to antiarrhythmic therapy, spontaneous resolution, and outcomes of radiofrequency and surgical ablation. Sixty-eight children were identified (22 children <3 years and 46 children > or =3 years of age). Control of AET with antiarrhythmic therapy was achieved in 91% of the younger children but only 37% of the older children (p < 0.001). There was a higher rate of spontaneous resolution in the younger group (78%) compared with the older group (16%) (p < 0.001). Radiofrequency ablation was performed in 35 of the older children, with ultimate success in 74%. Surgical intervention was required for six children. Younger children respond to antiarrhythmic therapy and have a high incidence of AET resolution, thus warranting a trial of antiarrhythmic therapy. In children > or =3 years, AET is unlikely to resolve spontaneously, and antiarrhythmic medications are frequently ineffective. Thus, RFA should be considered early in the course of treatment for these children; however, surgical intervention may be necessary.
    Journal of the American College of Cardiology 02/2004; 43(3):438-44. · 14.16 Impact Factor
  • Article: Late pacemaker requirement after pediatric orthotopic heart transplantation may predict the presence of transplant coronary artery disease.
    [show abstract] [hide abstract]
    ABSTRACT: Few data are available regarding pacemaker implantation after pediatric orthotopic heart transplantation. The purpose of this study was to assess the incidence, indications and associations with regard to pacemaker placement in children who have undergone orthotopic heart transplantation. We performed a retrospective study of all patients undergoing orthotopic heart transplantation at our institution from October 1984 to March 2001. Data obtained included demographics, indications for pacemaker, presence of transplant coronary artery disease and long-term follow-up. Patients were divided into: Group 1, patients requiring a pacemaker within 3 months of transplantation; and Group 2, patients requiring a pacemaker beyond 3 months. Pacemakers were required in 7 of 106 (6.6%) transplant recipients. Pacing indications for patients in Group 1 (n = 2) were persistent bradycardia with pause-related ventricular arrhythmia and atrial flutter with resultant sinus pauses of up to 4 seconds. In Group 2 patients (n = 5), indications for pacing were high-grade atrioventricular (AV) block in 1 patient and episodic sinus pauses up to 3.3 seconds associated with syncope/dizziness in the remaining 4 patients. All patients in Group 2 had transplant coronary disease diagnosed within 1 year of pacemaker implantation. All had resolution of symptoms and no complications after implantation. Pacemakers are infrequently required after cardiac transplantation in children. Despite not meeting classic symptomatic sinus bradycardia criteria, pacemaker placement should be considered post-transplantation in patients with episodic sinus pauses and dizziness or syncope. Patients who present with the aforementioned symptoms or high-grade AV block should be evaluated closely for the presence or development of transplant coronary artery disease, as it may be their first symptom.
    The Journal of Heart and Lung Transplantation 02/2004; 23(1):67-71. · 4.33 Impact Factor

Institutions

  • 2003–2012
    • Texas Children's Hospital
      Houston, TX, USA
    • Yale-New Haven Hospital
      New Haven, CT, USA
    • Stanford University
      • Division of Pediatric Cardiology
      Stanford, CA, USA
  • 2010
    • IntraMed
      Buenos Aires, Buenos Aires F.D., Argentina
  • 2009
    • University of Texas Southwestern Medical Center
      • Department of Pediatrics
      Dallas, TX, USA
  • 2001–2006
    • Baylor College of Medicine
      • Department of Pediatrics
      Houston, TX, USA