Ventricular tachycardia after surgical repair of tetralogy of Fallot: Results of intraoperative mapping studies
| Autor: | Thomas C.K. Chen, Eugene Downar, Lynda L. Mickleborough, Albert Chan, S. Massé, Anthony Glanz, L. Harris, William C. Williams, Elias Sevaptsidis, Shane Kimber, Adriana Genga |
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| Rok vydání: | 1992 |
| Předmět: |
Male
medicine.medical_specialty Heart disease Heart Ventricles medicine.medical_treatment Ventricular tachycardia Cryosurgery Sudden death Electrocardiography Monitoring Intraoperative Tachycardia Internal medicine medicine Humans Ventricular outflow tract cardiovascular diseases Child Electrodes Endocardium Tetralogy of Fallot business.industry Signal Processing Computer-Assisted Cryoablation medicine.disease Surgery Child Preschool cardiovascular system Cardiology Female Pulmonary Valve Insufficiency Cardiology and Cardiovascular Medicine business |
| Zdroj: | Journal of the American College of Cardiology. 20:648-655 |
| ISSN: | 0735-1097 |
| DOI: | 10.1016/0735-1097(92)90020-n |
| Popis: | Objectives. Four patients with previous repair of tetralogy of Fallot and ventricular tachycardia underwent map-guided surgery to ablate the arrhythmias. Background. Although patients with repaired tetralogy of Fallot are at increased risk of sudden death due to ventricular tachycardia, little is known of the origin and mechanism of this arrhythmia. Methods. A customized right ventricular balloon with 112 electrodes was used to record endocardial activation and, where possible, simultaneous epicardial recordings were obtained with a sock electrode array. Three patients had an aneurysm of the right ventricular outflow tract and one had a septal aneurysm. All had moderate to severe pulmonary valve insufficiency. Preoperative electrophysiologic study demonstrated inducible rapid (cycle length 180 to 300 ms) hemodynamically unstable monoform ventricular tachycardias. Results. Intraoperatively, five different tachycardias (two in one patient) were induced and mapped. The sites of earliest activation were located in the subendocardium of the right ventricular outflow tract in all, but they varied widely among the septum, free wall and parietal band and could not be identified by visible scar. All were due to a macroreentrant circuit initiated by a critical delay in activation beyond a functional arc of block. Two patients treated by cryoablation while the heart was beating and perfused at normal temperature had inducible ventricular tachycardia postoperatively. In the two subsequent patients, the application of cryoablation under anoxic cardiac arrest resulted in noninducibility of arrhythmia. Conclusions. Ventricular tachycardia in tetralogy of Fallot in these four patients was caused by macroreentry in the right ventricular outflow tract. Surgical success depends on detailed mapping and cryoablation under anoxic cardiac arrest. In patients at risk of sudden death, map-directed surgery may offer distinct advantages over either implantable devices or drug therapy. |
| Databáze: | OpenAIRE |
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