M Gass

University Medical Center Utrecht, Utrecht, Utrecht, Netherlands

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Publications (22)40.96 Total impact

  • Klinische Padiatrie - KLIN PADIAT. 01/2010; 222(02).
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    ABSTRACT: Syncope and palpitations occur frequently in young patients. Noninvasive diagnostic testing may be inconclusive. To assess the diagnostic yield of implantable loop recorders in young patients. Thirty-three young patients underwent implantation of a loop recorder for long-term monitoring of cardiac rhythm, to establish symptom-rhythm correlation. They belonged to one of three subgroups: those with structurally normal heart, normal electrocardiogram at rest, and negative family history (n = 16); patients with structural heart disease and previous surgical repair (n = 11), and patients with proven or suspected primary electrical disease (n = 6). A combination of automatic and patient-activated recordings was used to monitor cardiac rhythm during symptomatic episodes. There were no procedural complications. Diagnostic electrograms could be obtained in all patients. A high degree of symptom-rhythm correlation was established. In 8/33 patients, no recurrence of symptoms was observed either until end of battery life of the device (n = 4) or until last follow-up (n = 2). Specific cardiac therapy was required, based on rhythms recorded by the device in 15 patients (until last follow-up). This consisted of catheter ablation of a tachyarrhythmia (n = 7), pacemaker implantation or upgrade (n = 5) or ICD implantation (n = 5). In the remaining patients (n = 10), recurrence of symptoms was associated with a normal electrocardiogram, and in two of these patients a non-cardiac diagnosis was made. In selected patients, the implantable loop recorder provides valuable diagnostic information to guide further therapy.
    Clinical Research in Cardiology 06/2008; 97(5):327-33. · 3.67 Impact Factor
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    ABSTRACT: Patients with Fontan circulation represent a significant cardiorespiratory risk during spinal surgery. We report about two patients with severe scoliosis and Fontan circulation and their successful operative treatment. The case report will be compared with the national and international literature.
    European Spine Journal 02/2008; 17 Suppl 2:S312-7. · 2.47 Impact Factor
  • Zeitschrift Fur Geburtshilfe Und Neonatologie - Z GEBURTSH NEONATOLOGIE. 01/2008; 212.
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    ABSTRACT: Recurrent but infrequent syncopes represent a diagnostic challenge, since they frequently remain unexplained despite extensive investigations. This applies specifically for patients who carry an increased risk of potentially lifethreatening arrhythmias, either due to congenital cardiac disease or primary electrical disorders. Implantable loop recorders permit long-term electrocardiographic monitoring. Experience with these devices is still limited in children. Between January 1999 and August 2005, 12 patients underwent implantation of a loop recorder in our tertiary referral centre. The mean age was 10.9 years, with a range from 2 to 17 years. Of the patients, 6 had structural disease, 3 had primary electrical abnormalities, and 3 had no cardiovascular disease. Resyncope occured in 9 of the 12 patients. Arrhythmic origin of the syncope was diagnosed in 4 of these patients. The events recorded were ventricular fibrillation in 2, intermittent asystole in 1, and pacemaker-syndrome in the other patient. Malignant arrhythmia was ruled out in the remaining 5 patients. There were no complications related to implantation of the loop recorder, and the mean duration until explantation was 8.3 months. Based on our experience, we suggest that implantation of a loop recorder represents an additional tool for a selected group of children. Due to its invasive nature, it should be restricted to patients at high risk, or those in which there is substantial clinical suspicion of the likelihood of serious arrhythmias when conventional testing has been inconclusive. In this cohort, implantation of the loop recorder either helps to establish the correct diagnosis, or to exclude an arrhythmic event, thus avoiding unnecessary escalation of therapy and providing reassurance for the family.
    Cardiology in the Young 01/2007; 16(6):572-8. · 0.95 Impact Factor
  • Clinical Research in Cardiology 12/2006; 95(11):610-3. · 3.67 Impact Factor
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    BMJ (online) 06/2006; 332(7550):1139-41. · 17.22 Impact Factor
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    ABSTRACT: The compelling safety and efficacy data in numerous large, blinded trials on adult patients, and the progress in device- and leadtechnology have led to increasing use of implantable cardioverter defibrillators in pediatric patients. The purpose of our study was to assess the efficacy and safety of ICD in the pediatric age group of a tertiary referral centre. Between March 1998 and October 2003 12 patients underwent ICD-implantation. The mean age at implantation was 14,8 years with a range between 10-17 years. The underlying cardiac disorders included long QT-syndrome in 4 patients, ventricular fibrillation in 3 patients, dilated cardiomyopathy in 4 patients, and congenital heart disease in 1 patient (pulmonary atresia with ventricular septal defect after Rastelli repair). All patients received a transvenous ICD-system (VVI-ICD in 4 patients, DDD-ICD in 8 patients). The mean follow up was 35 months (6-68 months). During this period there were no severe complications nor mortality. We haven't seen infections, thromboembolic complications or lead-perforations. 2 patients (17 %) received appropriate DC-shocks, 1 patient (8 %) received an inappropriate DC-shock. 10 patients (83 %) had no malignant ventricular arrhythmia under medical therapy. 2 patients (17 %) required revision because of lead-dysfunction. In 2 patients with DCM the device was explanted during orthotopic heart transplantation. Our data demonstrate that advances in device- and leadtechnology have resulted in a decrease of severe complications in the pediatric age group. We conclude that ICD-implantation represents a safe and effective therapy for children and adolescents with lifethreatening ventricular dysrhythmias. Since it represents an invasive therapy, indication should be confined to patients with lifethreatening dysrhythmias according to the guidelines of the American Heart Association.
    Klinische Pädiatrie 01/2006; 218(5):270-5. · 1.90 Impact Factor
  • Klinische Padiatrie - KLIN PADIAT. 01/2006; 218(5):270-275.
  • Thomas Borth-Bruhns, Matthias Gass
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    ABSTRACT: We report our single centre experience with a new fractally coated myocardial unipolar lead (ELC35UP; Biotronik) in 96 pediatric patients (59% male, 41% female). Congenital heart disease (CHD) was associated in 89%. The age at implantation ranged between 2 days and 19 years, median for children with CHD 7.8 years, without CHD 4.7 years. Twenty percent of the children were younger than one year at implantation. Mean follow-up was 30 months (1-57 months). We compared our findings with a steroid eluting epicardial lead (CapSure EPI 4968; Medtronic) in 46 children with comparable age and sex-distribution. We found a lead survival of 87% after 57 months in the ELC35UP group (steroid lead: 87% after 129 months). Pacing energy thresholds were equal after 12 months (median 3.0 microjoules), but the sensing characteristics of the fractally coated lead was significantly superior to the steroid eluting lead with median R waves of 7.0 mV (steroid lead: 3.5 mV) after 12 months. Children with myocardial scar tissue requiring pacemaker therapy after surgery of CHD showed no differences in sensing and pacing thresholds in comparison to children with congenital rhythm disorders. The fractally coated screw-in lead offers technical advantages concerning the subxiphoidal implantation procedure. CONCLUSION: Fractally coated ventricular screw-in leads represent a feasible alternative to the common steroid eluting leads- especially in children requiring pacemaker therapy after surgery for CHD.
    Journal of Interventional Cardiac Electrophysiology 11/2005; 14(1):37-43. · 1.39 Impact Factor
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    ABSTRACT: Formation of systemic to pulmonary venous or systemic venous left atrial collaterals frequently occurs in patients after Glenn or Fontan-type operations. Embolization with detachable metal coils is the therapy of choice for the closure of small vessels. These devices however are not appropriate for the occlusion of large collaterals, e. g. recanalized bilateral caval veins. We report two patients who presented late after Fontan-type operations with a gradual decrease in oxygen saturation due to recanalisation of bilateral caval veins. Interventional closure of these large veins was carried out successfully with the use of 8 mm Amplatzer muscular VSD Occluders, resulting in an increase of arterial oxygen saturations. CONCLUSION: The closure of recanalized bilateral superior caval veins after Fontan procedures is possible without technical problems by means of the Amplatzer muscular VSD Occluder. In order to avoid future formation of venous collaterals via the azygos or hemiazgos system, the occluder should be placed in the vena cava below the orifice of the azygos/ hemiazygos vein.
    Zeitschrift für Kardiologie 08/2005; 94(7):469-73. · 0.97 Impact Factor
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    ABSTRACT: We report the observation and analysis of a new adverse event during the insulin tolerance test (ITT) and propose additional safety procedures. An 8-year-old girl with growth hormone insufficiency had a cardiac arrest due to ventricular flutter when she was tested for growth hormone deficiency by the ITT. Severe hypokalaemia (K+ 2.6 mmol/l) was observed after resuscitation. Ergometry ECG revealed catecholaminergic polymorphic ventricular tachycardia, a hereditary arrhythmogenic disease. Consecutive measurements of serum potassium during ITT in 29 short children (21 boys) with growth failure revealed a mean decrease of serum potassium by 1.1 +/- 0.4 mmol/l with the nadir at 30 min after the insulin bolus. Hypokalaemia (serum potassium < 3.5 mmol/l) occurred in all but one child; severe hypokalaemia (serum potassium < 2.9 mmol/l) was measured in every third child. This observation indicates that acute hypokalaemia which is induced by insulin and catecholamine excess occurs frequently in ITT. The case shows that the combination of acute hypokalaemia and the adrenergic counterregulation in ITT is a strong trigger of cardiac arrhythmias, which can become life-threatening if the child has an arrhythmogenic disease. Therefore, we recommend ECG monitoring during ITT to enhance the detection of cardiac arrhythmias. In addition, in the case of a comatose child during ITT the determination of the glucose and potassium level as well as adequate treatment are necessary.
    Hormone Research 01/2004; 62(2):84-7. · 2.48 Impact Factor
  • Monatsschrift Kinderheilkunde - MONATSSCHR KINDERHEILK. 01/2004; 152(11):1250-1252.
  • Monatsschrift Kinderheilkunde 01/2004; 152(11):1250-1252. · 0.19 Impact Factor
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    ABSTRACT: Bradyarrhythmias developing after Fontan-type operations impair the function of the univentricular heart causing fatigue, headaches, ascites, and protein-losing enteropathy (PLE). Transvenous inaccessibility, requiring epicardial implantation, accounts for the reluctance to implant a pacemaker (PM). Between 1997 and 2000, 24 patients (mean age 9.5 years, range 6 months to 19 years) with Fontan-type operations received DDD pacing systems with atrial steroid-eluting stitch-on electrodes (mean capture threshold 1.9 V/0.5 ms, range 0.4-3.5 V) and ventricular screw-in electrodes (mean capture threshold 1.7 V/0.5 ms, range 0.1-3 V). The systems were implanted at the time of conversion from atrio- to cavopulmonary connections in 5 patients, at the time of a total cavopulmonary Fontan operation in 6, and 1-50 months thereafter (mean = 18) in 13 patients. A right ventricular anatomy was present in 13 (54%) of 24 of PM recipients, versus 35% of the overall population. After a mean follow-up of 3.5 years, the PM were functioning in DDD mode in 23 of the 24 patients. Length of hospital stay in the ten patients who underwent repeat sternotomy was 5 days, without procedure related complications. In three children a repeat sternotomy was avoided by implanting the atrial electrodes during the Fontan operation. All patients improved clinically, including resolution of PLE in four patients. Bradyarrhythmias may lead to significant morbidity after Fontan-type operations. Electrophysiological evaluation is advised at follow-up. The indication for implantation of a DDD pacemaker system should be liberal. Placing atrial electrodes during the Fontan operation, especially in the presence of a right ventricular anatomy, avoids repeat sternotomy.
    Pacing and Clinical Electrophysiology 02/2003; 26(1 Pt 2):492-5. · 1.75 Impact Factor
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    ABSTRACT: We describe the case of a 50-year-old woman with the clinical diagnosis of cardiomyopathy associated with supraventricular tachycardia refractory to pharmacological treatment. The totally irregular tachyarrhythmia was the result of different episodes of atrial tachycardia, atrial flutter and atrial fibrillation that could be identified in the surface ECG. These findings and the patient's symptoms were all caused by a single focal tachycardia originating from the left upper pulmonary vein. Ablation of this focus represented a curative antiarrhythmic therapy also restoring a normalized ventricular function. Thus, an ablation of the AV node with consecutive pacemaker implantation could be prevented.
    Zeitschrift für Kardiologie 10/2001; 90(9):661-4. · 0.97 Impact Factor
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    ABSTRACT: Wir beschreiben den Fall einer 50-jährigen Patientin mit der klinischen Diagnose einer Kardiomyopathie bei medikamentös therapierefraktärer Tachyarrhythmia absoluta. Deren elektrokardiographisches Korrelat bestand aus Episoden mit atrialer Tachykardie, Vorhofflattern und Vorhofflimmern. Die Symptome und Befunde ließen sich allesamt ursächlich auf eine fokale Tachykardie mit Ursprung in der linken oberen Pulmonalvene zurückführen. Ihre erfolgreiche Ablation stellte eine kurative antiarrhythmische Therapie dar, die auch zur Normalisierung der Ventrikel-Funktion führte. Eine AV-Knoten-Ablation mit Schrittmacher-Implantation konnte so vermieden werden. We describe the case of a 50-year-old woman with the clinical diagnosis of cardiomyopathy associated with supraventricular tachycardia refractory to pharmacological treatment. The totally irregular tachyarrhythmia was the result of different episodes of atrial tachycardia, atrial flutter and atrial fibrillation that could be identified in the surface ECG. These findings and the patient’s symptoms were all caused by a single focal tachycardia originating from the left upper pulmonary vein. Ablation of this focus represented a curative antiarrhythmic therapy also restoring a normalized ventricular function. Thus, an ablation of the AV node with consecutive pacemaker implantation could be prevented. Schlüsselwörter Atriale–Tachykardie–Vorhofflattern–Vorhofflimmern–Pulmonalvenen–fokale Ablation–KardiomyopathieKey words Atrial tachycardia–atrial flutter–atrial fibrillation–pulmonary veins–focal ablation–cardiomyopathy
    Zeitschrift für Kardiologie 01/2001; 90(9):661-664. · 0.97 Impact Factor
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    ABSTRACT: Elektrophysiologische Untersuchungen und Radiofrequenz-Katheterablationen zur Behandlung von Herzrhythmusstörungen sind inzwischen auch im Kindesalter als sichere Standardmethode etabliert. Primär waren überwiegend angeborene Herzrhythmusstörungen wie z. B. akzessorische Leitungsbahnen beim WPW-Syndrom das Ziel der Behandlung. Mit zunehmendem Wissen über die Ursachen der Rhythmusstörungen und besseren technischen Voraussetzungen können inzwischen auch komplexe kongenitale und postoperative Herzrhythmusstörungen zunehmend erfolgreich therapiert werden. Diese Therapieform wird jedoch wegen des immensen personellen, technischen und finanziellen Aufwandes auf nur wenige Zentren mit ausreichender Patientenzahl und Erfahrung beschränkt bleiben. Electrophysiological studies and catheter ablation using radiofrequency is now established as a safe standard method for cardiac arrhythmia in pediatric patients as well as adults. Originally this method was used for congenital cardiac arrhythmias such as accessory conduction pathways in Wolff-Parkinson-White syndrome. With expanding knowledge about cardiac electrophysiology and improved technical conditions it has now also become possible to treat complex congenital and postoperative cardiac arrhythmias more and more successfully. However, this method requires a lot of investment in terms of staff, technical equipment, expertise and funding, so this form of treatment will remain confined to a few specialised centres where it will be accessible to enough patients so that a satisfactory level of collective experience with it can be built up.
    Monatsschrift Kinderheilkunde 01/2001; 149(10):1024-1033. · 0.19 Impact Factor
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    ABSTRACT: We investigated pulmonary mechanics in 46 children (27 males, 19 females) with congenital heart defects with left-to-right shunt and pulmonary hypertension. Patients ranged in age from 6 weeks to 4 years. Babybodyplethysmography studies were performed before corrective heart surgery, and again at 2 weeks and 6 months after surgery. Preoperative pulmonary function data were compared to hemodynamic data obtained during cardiac catheterization: pulmonary artery pressure, oxygen saturation, and ratios of pulmonary to systemic blood flow (Qp/Qs) and vascular resistance (Rp/Rs). Airway resistance was elevated before surgery to 148% of predicted and it dropped significantly to normal levels, 104% of predicted, only 6 months after surgery. Functional residual capacity (FRCpleth) was increased to 127% of predicted before surgery and normalized significantly to 101% of predicted within the same time period. On the other hand, breathing frequency and minute volume, indexed to body weight, decreased significantly in the 2 weeks after surgery. Statistical analysis of the hemodynamic data and lung function tests showed only a poor linear correlation between functional residual capacity and oxygen saturation in the pulmonary artery (r=0.26–0.37) and the Rp/Rs ratio (r=0.38). Airway resistance also correlated poorly with the Qp/Qs and Rp/Rs ratios (both r=0.29). In young children with heart defects with increased pulmonary blood flow and pulmonary hypertension, lung mechanics are abnormal leading to bronchial obstruction and hyperinflation. Additional studies of dynamic lung compliance and elastance will be needed to look for interstitial lung alterations in these patients.
    Progress in Pediatric Cardiology 01/1999; 9(2):85-88.
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    ABSTRACT: Background: Catheter ablation is an established method to treat paroxysmal supraventricular tachyarrhythmias. However, the risks of catheter ablation have to bee weight against antiarrhythmic therapy. With catheter ablation AV-block III°, pulmonary embolism, pericardial tamponade (in some cases followed by death), arterial embolism as well as other complications have been described. Especially the long term consequences of prolonged fluoroscopy time are an increased risk for fatal malignancies in young patients. On the other hand the efficacy of antiarrhythmic therapy in patients with paroxysmal supraventricular tachycardia has been shown. The risk of proarrhythmia associated with the treatment with class 1 and class 3 antiarrhythmic drugs that has been documented in patients after mayocardial infarction and in heart failure patients cannot be transferred to patients without structural heart disease. Conclusion: It is concluded that drug therapy is still an important form of treatment in patients with paroxysmal supraventricular tachycardia. Hintergrund: Die Katheterablation ist eine inzwischen etablierte Methode zur Therapie supraventrikulärer Tachykardien. Allerdings sind bei der Wahl des Therapieverfahrens die Risiken dieser Intervention im Vergleich mit der konservativen Therapie zu berücksichtigen. Hier sind AV-Blockierungen, Lungenembolie, Perikardtamponade (in Einzelfällen mit Todesfolge) und arterielle Embolie zu nennen. Darüber hinaus ist die Strahlenbelastung - insbesondere bei Kindern und Jugendlichen - zu berücksichtigen. Es ist bekannt, daß lange Durchleuchtungszeiten in Einzelfällen zu Röntgenschäden führen können. Andererseits ist die Effektivität antiarrhythmisch wirksamer Substanzen sehr gut dokumentiert. Selbstverständlich haben auch antiarrhythmisch wirksame Medikamente Nebenwirkungen, jedoch können die Daten zum Risiko proarrhythmogener Nebenwirkungen einer Therapie mit Antiarrhythmika der Klasse 1 und 3 nicht auf Patienten mit paroxysmalen supraventrikulären Tachykardien übertragen werden. Schlußfolgerungen: Auf Grund der Risiken der Katheterablation hat die medikamentöse Therapie unverändert einen wichtigen Stellenwert bei der Therapie supraventrikulärer Tachykardien.
    Herzschrittmachertherapie & Elektrophysiologie 01/1999; 10(6).

Publication Stats

85 Citations
40.96 Total Impact Points

Institutions

  • 2008
    • University Medical Center Utrecht
      Utrecht, Utrecht, Netherlands
  • 2005–2007
    • University of Tuebingen
      Tübingen, Baden-Württemberg, Germany
    • Universitätsklinikum Tübingen
      Tübingen, Baden-Württemberg, Germany
    • Diabetes Clinic for Children and Adolescents
      Muenster, North Rhine-Westphalia, Germany