Ahmed Abdelaal

Rapid and low-cost method to prove the nature of no documented tachycardia in children and teenagers without pre-excitation syndrome

Aims Symptoms in children are often difficult to interpret. The purpose of this study was to report the results of transoesophageal electrophysiological study (EPS) performed in children complaining of sudden onset tachycardia with normal non-invasive studies. Methods and results Eighty-two children and teenagers (mean age 15 +/- 3 years) presented with suspected but no documented paroxysmal supraventricular tachycardia (SVT). ECG was normal. Non-invasive studies were negative; 23 children had syncope with tachycardias. They underwent transoesophageal EPS in our out-patient clinic. The mean duration of transoesophageal EPS was 11 +/- 5 min. Electrophysiological study was negative in 25 children. AV nodal re-entrant tachycardia could be induced in 37 children, 11 of them associated with syncope. Wolff-Parkinson-White syndrome (WPW) was diagnosed in five children in which atrioventricular re-entrant tachycardia was inducible. Atrioventricular re-entrant tachycardia due to a concealed AP was induced in 14 children. Verapamil-sensitive ventricular tachycardia was induced in one patient. Factors associated with tachycardia inducibility were an older age (15.5 +/- 2 vs. 14 +/- 4 years) (P < 0.05) and the absence of syncope (81 vs. 52%) (P < 0.05). During a mean follow-up of 3 +/- 1 year, no patient with negative EPS developed documented tachycardia. In 17 children with inducible SVT, radiofrequency ablation of the re-entrant circuit was subsequently performed. Conclusion Transoesophageal EPS is a fast method for proving the nature of paroxysmal tachycardia in children and teenagers presenting with normal ECG and for demonstrating WPW syndrome not visible on standard ECG. The negative predictive value of transoesophageal EPS for the diagnosis of SVT was 100%.

Ablation de la fibrillation atrialeþ: enjeux du futur, progrès technologiques

Resume Le nombre de procedures d’ablation endocavitaire concernant la fibrillation atriale (FA) augmente regulierement dans les pays industrialises, alors que ces interventions restent longues et demeurent compliquees en cas de FA chronique. Les enjeux du futur sont doubles : reduire la duree de chaque procedure et ameliorer le taux de succes pour les formes de FA les plus complexes, tout en garantissant le plus faible risque possible de complications operatoires. Certains progres technologiques peuvent contribuer a atteindre ces objectifs. Les systemes de navigation, de cartographie et de robotique intracardiaque existent deja et font regulierement l’objet d’ameliorations. Ils facilitent le deplacement et le repositionnement des catheters ainsi que la comprehension des circuits d’arythmies et le reperage des zones cibles pour l’ablation ; mais ils integrent egalement des logiciels d’analyse des signaux endocavitaires qui favorisent l’identification des sites qui soutiennent les FA chroniques. On peut egalement imaginer que l’identification du substrat arythmogene des FA chroniques passe par l’imagerie cardiaque, notamment l’IRM, et l’integration des images obtenues dans un systeme de cartographie 3D. Enfin, plusieurs societes ont investi en recherche et developpement sur des catheters d’ablation qui permettent a la fois de reduire les temps de procedure et d’ameliorer la qualite des lesions produites, notamment grâce a des catheters « intelligents » qui permettent de mesurer le contact avec la paroi myocardique. Qu’il s’agisse de catheters epousant la forme des ostia veineux ou utilisant d’autres sources d’energie que la radiofrequence, des progres technologiques sont toutefois necessaires avant d’arriver a l’efficacite attendue.

Does syncope require rhythmic and non-rhythmic evaluation in patients with previous MI?

Background Multiple factors, in addition to left ventricular ejection fraction (LVEF) influence the risk of mortality in coronary artery disease. The purpose of this study was to evaluate the main causes of syncope after myocardial infarction (MI) and to propose an algorithm of management. Methods 356 patients consecutively admitted for syncope and history of MI (>1 month), without ventricular tachycardia (VT), underwent echocardiography, Holter monitoring, head-up tilt test, exercise testing, signal-averaged ECG, electrophysiological study (EPS) and evaluation of coronary status. The mean follow-up was 4±2 years. Results Monomorphic VT, ventricular flutter or fibrillation (VF) and supraventricular tachyarrhythmia were respectively induced at EPS in 87, 63 and 39 patients; conduction disturbances were noted in 23 patients, and 57 patients had several abnormalities. Among the 144 patients with negative EPS, coronary ischaemia was identified in 37 patients, and hypervagotonia in 27 patients. All studies remain negative in 84 patients (23.6%), more frequently women (p<0.001). Four patients died suddenly during follow-up. A longer QRS duration, a lower LVEF and grade IVa,b of Lown on Holter ECG were associated with the induction of VT. LVEF<40% and VT/VF induction were predictors of cardiac mortality, VT was a predictor of sudden death, and low LVEF and advanced age were predictors of death by heart failure. Conclusion Myocardial ischaemia, hypervagotonia, conduction abnormalities, ventricular or supraventricular tachyarrhythmias were identified in 76% of patients with syncope after MI. Several factors of syncope were found in 57 patients (16%). Non-invasive rhythmological and systematic coronary status assessment should be recommended in patients with syncope following MI.

221 Complete atrioventricular block during ablation of atrial flutter. Incidence and causes

Radiofrequency (RF) ablation of typical atrial flutter (AFl) is largely used to restore and maintain a sinus rhythm. Little is known on the risk of a third degree atrioventricular block (AVB). The purpose of the study was to evaluate the incidence and the causes of iatrogenic complete AVB during RF ablation of a typical AFl. Population AFl ablation was performed in 763 patients (pts), 606 males, 157 females aged from 18 to 90 years (64±12) with recurrent or bad–tolerated typical AFl; 330 pts had associated significant heart disease (valvular 68, congenital 24, ischemic heart disease 71, dilated cardiomyopathy 43, miscellaneous 78) or chronic pulmonary disease (46). Methods AFl RF catheter ablation was performed by conventional method with setting a HALO catheter in coronary sinus and using an 8-F quadripolar with an 8 mm-tip electrode catheter; a maximum power of 70 w and a maximum target temperature of 70 was used. Obtaining a sinus rhythm and a complete isthmus block was the objective of the procedure. Results Complete AVB (1%) was noted when sinus rhythm was restored, in 8 pts aged from 59 to 89 years (73±9) significantly older than other pts (63.5±12) (p Conclusions Complete AVB was a rare complication of RF ablation of typical atrial flutter (1%) which concern old pts; it is significantly more frequent in pts with ischemic heart disease (3/71, 4%) than in pts without ischemic disease (p