Heart transplantation in adolescent and adult patients with congenital heart disease: a case-control study.

BACKGROUND: The number of adolescent and adult patients with congenital heart disease undergoing heart transplantation is increasing. We aimed to better define the characteristics of these patients and their survival after transplantation. METHODS: We describe a group of patients with end-stage heart failure owing to congenital heart disease undergoing heart transplantation at a single tertiary center and compare their short- and long-term survival with a group of matched controls with dilated cardiomyopathy and the entire cohort of transplanted patients at our center. RESULTS: Between 1985 and 2006, a total of 322 orthotopic heart transplantations were performed at our center. Thirteen patients (mean age, 27.5 years) had a diagnosis of congenital heart disease with a wide spectrum of lesions. The survival of these 13 patients was 85% at 30 days, 1, 5, and 10 years and 77% at 20 years, which did not differ significantly to the short- and long-term survival of the entire cohort of patients with heart transplantation and to the survival of age-matched controls with dilated cardiomyopathy. CONCLUSION: In our single-center experience, short- and long-term survival after heart transplantation in a selected, small group of patients with end-stage heart failure owing to congenital heart disease did not differ significantly compared with a group of age-matched controls and the entire cohort.

Cardiac resynchronisation therapy in paediatric and congenital heart disease: differential effects in various anatomical and functional substrates.

BACKGROUND: Cardiac resynchronisation therapy (CRT) is increasingly used in children in a variety of anatomical and pathophysiological conditions, but published data are scarce. OBJECTIVE: To record current practice and results of CRT in paediatric and congenital heart disease. DESIGN: Retrospective multicentre European survey. SETTING: Paediatric cardiology and cardiac surgery centres. PATIENTS: One hundred and nine patients aged 0.24-73.8 (median 16.9) years with structural congenital heart disease (n = 87), congenital atrioventricular block (n = 12) and dilated cardiomyopathy (n = 10) with systemic left (n = 69), right (n = 36) or single (n = 4) ventricular dysfunction and ventricular dyssynchrony during sinus rhythm (n = 25) or associated with pacing (n = 84). INTERVENTIONS: CRT for a median period of 7.5 months (concurrent cardiac surgery in 16/109). MAIN OUTCOME MEASURES: Functional improvement and echocardiographic change in systemic ventricular function. RESULTS: The z score of the systemic ventricular end-diastolic dimension decreased by median 1.1 (p<0.001). Ejection fraction (EF) or fractional area of change increased by a mean (SD) of 11.5 (14.3)% (p<0.001) and New York Heart Association (NYHA) class improved by median 1.0 grade (p<0.001). Non-response to CRT (18.5%) was multivariably predicted by the presence of primary dilated cardiomyopathy (p = 0.002) and poor NYHA class (p = 0.003). Presence of a systemic left ventricle was the strongest multivariable predictor of improvement in EF/fractional area of change (p<0.001). Results were independent of the number of patients treated in each contributing centre. CONCLUSION: Heart failure associated with ventricular pacing is the largest indication for CRT in paediatric and congenital heart disease. CRT efficacy varies widely with the underlying anatomical and pathophysiological substrate.

Regional cerebral oxygenation by NIRS does not correlate with central or jugular venous oxygen saturation during interventional catheterisation in children.

PURPOSE: To evaluate whether regional cerebral oxygenation (rSO(2)) by near-infrared spectroscopy correlates with central venous (SvO(2)) or internal jugular (SjO(2)) oxygen saturation, and whether changes over time (Delta) in rSO(2) (DeltarSO(2)) predict changes in SvO(2) (DeltaSvO(2)) and SjO(2) (DeltaSjO(2)). METHODS: The rSO(2) values were measured using the INVOS 5100 cerebral oximeter in children undergoing interventional cardiac catheterization and were compared with the oxygen saturation of analysed central venous and internal jugular blood samples. Changes over time (Delta) were calculated as the difference between the values before and after catheter intervention for rSO(2).(DeltarSO(2)), SvO(2).(DeltaSvO(2)) and SjO(2).(DeltaSjO(2)). Simple regression and Bland-Altman analysis were performed. Data are presented as median (range). RESULTS: Sixty patients aged 4.3 (0.2-16.0) years were investigated. A closer correlation was found between rSO(2) and SvO(2) (r=0.728, P<0.0001) than between rSO(2) and SjO(2) (r=0.665, P<0.0001). The bias between rSO(2) and SvO(2).(SjO(2)) was 0.17% (-0.60%), with limits of agreement from -15.5% to 15. 9% (-18.6-17.4%). The sensitivity/specificity for DeltarSO(2) to indicate a fall in SvO(2) or in SjO(2) was 70.3%/65.2% and 68.6%/60.0%, respectively. CONCLUSION: Neither absolute values nor changes in rSO(2) using the INVOS 5100 allowed reliable estimation of SvO(2) or SjO(2) and their trends.

Comparison of cardiac output measurement using the CardioQP oesophageal Doppler with cardiac output measurement using thermodilution technique in children during heart catheterisation.

The minimally invasive CardioQP oesophageal Doppler probe estimates cardiac output by measuring blood flow velocity in the descending aorta. Individual variables to enter are patient's age, weight and height. We measured cardiac output simultaneously with CardioQP and pulmonary artery catheter thermodilution techniques during heart catheterisation in 40 paediatric patients with congenital heart defects. Median [range] age was 8.2 years [0.5-16.7 years], cardiac output values measured by thermodilution and CardioQP were 3.6 l.min(-1) [1.2-7.1 l.min(-1)] and 3.0 l.min(-1) [0.7-6.7 l.min(-1)], respectively. These values showed only moderate correlation (r = 0.809; p < 0.0001). Bias and precision were 0.66 l.min(-1) and 1.79 l.min(-1) (95% limits of agreement: -1.13 to +2.45 l.min(-1)). Based on our preliminary experience, cardiac output values measured by CardioQP in children do not reliably represent cardiac output values compared with the thermodilution technique. We suggest measurement of individual aortic diameter to improve performance of the CardioQP.

Cardiac output measurement in children: comparison of Aesculon cardiac output monitor and thermodilution.

BACKGROUND: We compared cardiac output (CO) measurements by the non-invasive electrical velocimetry (Aesculon) monitor with the pulmonary artery catheter (PAC) thermodilution method in children. METHODS: CO values using the Aesculon monitor and PAC thermodilution were simultaneously recorded during cardiac catheterization in children. Measurements were performed under general anaesthesia. To compare, three consecutive measurements for each patient within 3 min were obtained. The means of the three values were compared using simple regression and Bland-Altman analysis. Data were presented as mean (sd). A mean percentage of <30% was defined to indicate clinical useful reliability of the Aesculon monitor. RESULTS: A total of 50 patients with a median (range) age of 7.5 (0.5-16.5) yr were enrolled in the study. Mean CO values were 3.7 (1.5) litre min(-1) (PAC thermodilution) and 3.1 (1.7) litre min(-1) (Aesculon) monitor). Analysis for CO measurement showed a good correlation between the two methods (r=0.894; P<0.0001). The bias between the two methods was 0.66 litre min(-1) with a precision of 1.49 litre min(-1). The mean percentage error for CO measurements was 48.9% for the Aesculon monitor when compared with PAC thermodilution. CONCLUSIONS: Electrical velocimetry using the Aesculon monitor did not provide reliable CO values when compared with PAC thermodilution. Whether the Aesculon monitor can be used as a CO trend monitor has to be assessed by further investigations in patients with changing haemodynamics.

The fate of children with microdeletion 22q11.2 syndrome and congenital heart defect: clinical course and cardiac outcome.

BACKGROUND: This study aimed to evaluate the cardiac outcome for children with microdeletion 22q11.2 and congenital heart defect (CHD). METHODS: A total of 49 consecutive children with 22q11.2 and CHD were retrospectively identified. The CHD consisted of tetralogy of Fallot and variances (n = 22), interrupted aortic arch (n = 10), ventricular septal defect (n = 8), truncus arteriosus (n = 6), and double aortic arch (n = 1). Extracardiac anomalies were present in 46 of 47 children. RESULTS: The median follow-up time was 8.5 years (range, 3 months to 23.5 years). Cardiac surgical repair was performed for 35 children, whereas 5 had palliative surgery, and 9 never underwent cardiac surgery. The median age at repair was 7.5 months (range, 2 days to 5 years). The mean hospital stay was 35 days (range, 7-204 days), and the intensive care unit stay was 15 days (range, 3-194 days). Significant postoperative complications occurred for 26 children (74%), and surgery for extracardiac malformations was required for 21 patients (43%). The overall mortality rate was 22% (11/49), with 1-year survival for 86% and 5-year survival for 80% of the patients. A total of 27 cardiac reinterventions were performed for 16 patients (46%) including 15 reoperations and 12 interventional catheterizations. Residual cardiac findings were present in 25 patients (71%) at the end of the follow-up period. CONCLUSIONS: Children with microdeletion 22q11.2 and CHD are at high risk for mortality and morbidity, as determined by both the severity of the cardiac lesions and the extracardiac anomalies associated with the microdeletion.

Mediastinal widening on chest radiography caused by combined aortic valve disease and primary large B-cell lymphoma.

Poststenotic aortic root dilatation in patients with aortic valvular stenosis may result in mediastinal widening on chest radiograph. Main differential diagnosis of mediastinal widening is a tumour. In fact, besides atypical chest pain or dyspnoea at exertion secondary to compression of intrathoracic structures in the latter, symptoms may be absent. We report a case of combined aortic valve disease and additional primary large B-cell lymphoma.

[Arrhythmias in pediatric patients]. / Arrhythmien im Kindesalter.

Arrhythmias in children occur frequently as isolated phenomena, however, may also represent comorbidities of congenital heart disease. Therefore electrophysiologic assessments must include morphologic and hemodynamic evaluations. Besides the arrhythmias commonly seen in adults children present with arrhythmias unique to pediatric patients. Antiarrhythmic therapy depends on patient age, expected natural history of the arrhythmia and possible congenital heart disease. As in adult patients in addition to antiarrhythmic drug therapy radiofrequency catheter ablation is a preferred definitive treatment especially in patients with supraventricular tachycardias. Bradycardias can be successfully treated with pacing systems which can already be implanted in the newborn period. As antiarrhythmic treatment in pediatric patients may be very complex a referral to a pediatric cardiology center is recommended.

Measurement of activated clotting time in children--comparison of the Celite i-STAT ACT with the Medtronic ACT II.

BACKGROUND: To evaluate a recently introduced blood-saving method for the measurement of activated clotting time (ACT), the Celite i-STAT ACT, by comparing the values obtained with those from the widely used Medtronic ACT II device. METHODS: In a prospective clinical study, we compared ACT values from the i-STAT device with the Medtronic ACT II device in 60 paediatric, interventional, cardiac catheterization procedures necessitating prophylactic heparinization. Blood samples were pair-analyzed using two i-STAT analyzers and one Medtronic ACT II device with double-tube-cartridges before and after heparinization. Data were compared using Bland-Altman bias analysis, Student's t-test and simple regression analysis. RESULTS: Bias and precision between the Medtronic ACT II and the i-STAT ACT values was -5.4 +/- 26.3. The i-STAT and Medtronic ACT II values were similar before heparinization (P = 0.22), but i-STAT ACT values became significantly longer than Medtronic ACT II values after heparinization (P = 0.021). The increase of ACT after heparinization was greater (median 86.3; range 40-187 s) in the i-STAT analyzer than in the Medtronic ACT II analyzer (median 73.0; range 19-235.5 s). Increase in ACT values was inversely affected by intraoperative haemoglobin concentration in the Medtronic ACT II analyzer (P = 0.001) but not in the i-STAT analyzer. CONCLUSION: Activated clotting times obtained from the Celite i-STAT ACT and the Medtronic ACT II demonstrated poor agreement. The technical principles are quite different and the two methods showed diverse susceptibility to intraoperative haemoglobin concentration. Users have to be aware of technique-specific ACT target ranges and their confounders, which need to be provided by the manufacturers.

Long-term follow up of children with congenital complete atrioventricular block and the impact of pacemaker therapy.

AIMS: This study assessed survival, morbidity and impact of pacemaker (PM) therapy in children with Congenital Complete Atrioventricular Block (CCAVB). METHODS AND RESULTS: Data of 32 children, diagnosed as showing CCAVB at a median age of 0.4 years (range foetal-10 years), were retrospectively analysed. For comparison of clinical data patients were separated into two groups: CCAVB without structural heart disease (group 1; n = 23) and with structural heart disease (group 2; n = 9). Median follow-up time was 10.2 years. Pacemakers (PM) were implanted in 17 group 1 and all group 2 children. Frequency of PM therapy, age and symptoms before PM implantation did not differ significantly between the groups. Indications for PM implantation were bradycardia in 15, decreased exercise tolerance in 6, syncope in 3 and heart failure in 2 children. PM system related complications occurred in 11/26 (42%) children. Although 1 child died due to PM exit block no further CCAVB related symptoms were recorded in children with PM. CONCLUSION: PM therapy reduces mortality and morbidity in children with CCAVB when compared with natural history data. Although children with PM are free from CCAVB related symptoms limited morbidity remains due to PM system related complications.

Transcatheter occlusion of the patent ductus arteriosus with a single device technique: comparison between the Cook detachable coil and the Rashkind umbrella device.

UNLABELLED: Transcatheter coil occlusion of the patent ductus arteriosus (PDA) has become the interventional treatment option of choice. Immediate occlusion of any residual shunting results in excellent closure rates, but frequently requires multiple coil deployment. AIMS: To assess the efficacy and limitations of single Cook detachable coil PDA closure compared to a preceding series of Rashkind umbrella procedures. METHODS AND RESULTS: Between 1990 and 1999, transcatheter occlusion of a small (<2 mm; n=45) or moderate-sized (2-4 mm; n=47) PDA was successfully attempted in 90/92 consecutive patients (mean age 6+/-4.8 years) with a coil (39/41) or Rashkind device (51/51). Immediate angiographic closure rates for both devices were low, although better for small (54-68%) than moderate ducts (7-22%, P<0.01). A 2-year echocardiographic closure rate of small ducts increased to 92% for the coil group versus 95% for the Rashkind group. By that time, moderate-sized ducts were only occluded in 64% with the coil and 54% with the Rashkind device. A visible residual shunt at post-implant angiography in moderate ducts was associated with a high incidence (59%) of long-term echocardiographic shunt patency and a need for repeat interventions for audible residual shunts (32%). CONCLUSIONS: Single coil transcatheter occlusion is the treatment of choice for the small duct as most residual shunts will resolve spontaneously. However, long-term shunt persistence after single coil deployment in moderate sized ducts is as frequent as with the Rashkind device. A primary multiple coil approach is advocated if the postcoil aortogram shows residual ductal shunting and if there is persistence of a ductal murmur on auscultation.

[Diagnosis and treatment of common pediatric supraventricular tachycardias]. / Diagnose und Therapie häufiger supraventrikulärer Tachykardien.

The incidence of paediatric supraventricular tachycardias is approximately 0.1-0.4%. AV node and AV reentrant tachycardias represent the most common supraventricular tachycardias in children. Atrial ectopic tachycardias are the second most common group of pediatric arrhythmias with a predominance in younger children. All these arrhythmias may result in a significant morbidity and necessitate therapy. During the last decade the widespread use of newer antiarrhythmic agents and the invention of radiofrequency catheter ablation have revolutionized the treatment of supraventricular tachycardias in children. A thorough knowledge of these various treatments options is essential to achieve a safe and effective management of supraventricular tachycardias in children. This article focuses on diagnostic and therapeutic aspects of the most frequent supraventricular tachycardias.

Avoiding inappropriate ventricular tachycardia detection due to T-wave oversensing in an implantable cardioverter defibrillator: a novel application of the electrogram width criterion.

Appropriate sensing is an essential function of an implantable cardioverter defibrillator (ICD). T-wave oversensing by an ICD can be a serious problem in some patients, causing overestimation of the heart rate, inappropriate tachyarrhythmia detection and therapy delivery. Decreasing the sensitivity or programming longer refractory periods can sometimes overcome T-wave oversensing, but these measures may interfere with the ability of the ICD to correctly detect tachyarrhythmias. This report proposes a novel application of the electrogram (EGM) width criterion using a recently introduced detection enhancement algorithm intended to improve the specificity of ventricular tachycardia detection, to avoid T-wave oversensing. Based on the course of a case with persistent T-wave oversensing and review of previously published reports, oversensing problems in ICDs and management strategies are discussed.

Treatment of supraventricular tachycardias in the new millennium--drugs or radiofrequency catheter ablation?

UNLABELLED: Supraventricular tachycardias are a cause of significant morbidity in children. Newer anti-arrhythmic drugs and the invention of radiofrequency catheter ablation have revolutionised anti-arrhythmic therapy in children. CONCLUSION: With the availability of these very effective therapeutic options, an improved knowledge of these methods and their indications is required.

Alternative to the transvenous approach in pediatric pacing - long-term experiences with bipolar epicardial pacing leads.

BACKGROUND: Cardiovascular anatomy and limited venous access may preclude the implantation of endocardial pacing systems in children as well as adults with congenital heart disease. Thus, the implantation of myo/epicardial pacing leads is required in these patients. The less favorable long-term results experienced in the past with myocardial screw-in leads are often used to justify the transvenous approach whenever possible, even in infants. However, encouraging preliminary results were reported from modern bipolar steroid eluting epicardial pacing leads. Further follow-up data are now warranted to obtain arguments for the dispute regarding the preferable or optimal pacing approach in infants and small children. Methods From January 1994 to November 2000 a total of 64 bipolar steroid-eluting epicardial pacing leads (Medtronic CapSure Epi 10366 and 4968, Medtronic, Inc, Minneapolis, MN, USA) were implanted in 52 children at our institutions (52 electrodes in ventricular and 12 in atrial position). The median age of the children was 25.5 months (range 0.03 to 193 months). As part of a prospective multicenter study these leads were continuously followed in combination with AutoCapture devices since December 1996. Results Telemetry data demonstrated at discharge low pacing thresholds both for the ventricular (0.8±0.37Volt @ 0.5ms) and the atrial leads (0.8±0.4Volt @ 0.5ms) as well as excellent sensing signals (P wave 2.9±1.4mV and R wave 10.6±5.5mV) without significant changes during follow-up up to 24 months. AutoCapture controlled pacing could be applied in 46/52 (88%) children rendering a calculated battery service life of 14.8±2.9 years with a VVIR device (Regency SR 5130, St. Jude Medical, Sylmar, CA, USA) and 10.8±1.1 years with a dual chamber device (Affinity DR 5330, St. Jude Medical, Sylmar, CA, USA). Apart from the necessity to reposition three leads in the immediate postoperative period no late lead related complications have been experienced during follow-up. Conclusions The new steroid-eluting bipolar epicardial pacing lead demonstrates a high reliability and consistent extraordinary pacing as well as sensing thresholds. AutoCapture controlled pacing is feasible in most patients and may result in marked battery service life extension. Hence epicardial pacing can now be highly recommended as the first choice for permanent pacing in infants and children.

Morphology discriminator feature for enhanced ventricular tachycardia discrimination in implantable cardioverter defibrillators.

The morphology discriminator (MD) feature is an electrogram template matching algorithm that intends to improve tachycardia discrimination in implantable cardioverter defibrillators (ICDs). The aim of this study was to evaluate the performance of this feature during spontaneously occurring ventricular and supraventricular tachyarrhythmias and exercise induced sinus tachycardia. Twenty-three patients (20 men, 3 women; mean age 54.3 +/- 13.8 years) with pectorally implanted Ventritex Contour MD, Angstrom MD, and Profile MD ICDs were studied. The stability of the acquired morphology template and performance of the algorithm during spontaneous tachyarrhythmias were evaluated at follow-up. A treadmill exercise test was performed in 16 patients along with continuous telemetric monitoring of matching scores. A satisfactory template could be acquired at baseline in 22 (96%) patients. Variations in electrogram morphology necessitated new template acquisition in seven (30%) patients at first follow-up (6-8 weeks postimplant). During a mean follow-up of 9.1 +/- 3.7 months, 56 ventricular tachycardia (VT) and 15 supraventricular tachycardia episodes (sinus tachycardia in two-thirds) in 11 patients were all appropriately discriminated by the MD feature. Exercise testing showed appropriate discrimination of sinus tachycardia in 15 (94%) of 16 patients. A common observation was postshock changes in electrogram morphology that resulted in transient mismatch with the template. In conclusion, the recently introduced MD feature in ICDs has a high sensitivity for detection of VT and high specificity for rejection of sinus tachycardia. Postshock changes in electrogram morphology have been observed that may cause inappropriate redetection. Marked variations of electrogram morphology over time may be a concern in some patients, especially during lead maturation.

Threshold tracking pacing based on beat by beat evoked response detection: clinical benefits and potential problems.

Continuous monitoring of pacemaker stimulation thresholds and automatic adjustment of pacemaker outputs were among the longstanding goals of the pacing community. The first clinically successful implementation of threshold tracking pacing was the Autocapture feature which has accomplished automatic ventricular capture verification for every single stimulus by monitoring the Evoked Response (ER) signal resulting from myocardial depolarization. The Autocapture feature not only decreases energy consumption by keeping the stimulation output slightly above the actual threshold, but also increases patient safety by access to high-output back-up pulses if there is loss of capture. Furthermore, it provides valuable documentation of stimulation thresholds over time and serves as a valuable research tool. Current limitations for its widespread use include the requirements for implantation of bipolar low polarization leads and unipolar pacing in the ventricle. Fusion/pseudofusion beats with resultant insufficient or even non-existent ER signal amplitudes followed by unnecessary delivery of back-up pulses and a possible increase in pacemaker output is not an uncommon observation unique to the Autocapture feature. The recent incorporation of the Autocapture algorithm in dual chamber pacemakers has been challenging because of more frequent occurrence of fusion/pseudofusion beats in the presence of normal AV conduction. Along with a review of the previously published studies and our clinical experience, this article discusses the clinical advantages and potential problems of Autocapture.

DDD pacing mode survival in children with a dual-chamber pacemaker.

BACKGROUND: The persistence of DDD pacing is well documented in adults, however, in children survival of the DDD pacing mode is less clear. METHODS: We studied the survival of dual-chamber (DDD) pacing in 36 children aged 1 week to 16 years who underwent implantation of a dual-chamber pacing system between January 1986 and October 1998. The children were divided in the following two groups: 26 had epicardial pacing systems and 10 had endocardial pacing systems. RESULTS: During long-term follow-up 11 patients lost the DDD pacing mode. The DDD pacing survival rate at 3 months and 1, 2, and 5 years was 80%, 77%, 73%, and 69%, respectively. Age, weight, congenital heart disease, and epicardial pacing leads were not found to be risk factors for loss of DDD pacing mode. However, P-wave values of less than 2.5 mV at implantation of epicardial leads were associated with loss of the DDD pacing mode. CONCLUSIONS: The majority of children remain in the DDD pacing mode during long-term follow-up. A P-wave value of less than 2.5 mV at implantation of epicardial leads is a risk factor for loss of the DDD pacing mode.