Jérôme Lacotte

Effects of inadvertent atrioventricular block on clinical outcomes during cryoablation of the slow pathway in the treatment of atrioventricular nodal re-entrant tachycardia

AIMS The study aimed at evaluating the long-term effects of transient atrioventricular (AV) block on clinical outcomes during atrioventricular nodal re-entrant tachycardia (AVNRT) cryoablation. METHODS AND RESULTS In 150 consecutive patients (39 +/- 14 years, ineffective anti-arrhythmic drugs 1.9 +/- 1.3), slow-pathway cryoablation for AVNRT was performed. A 7 Fr 6 mm-tip cryocatheter was used. After successful cryomapping (-30 degrees C), defined as jump abolition or AV nodal refractory period prolongation, cryoablation (-80 degrees C for 4 min) was applied if no AV block occurred. Atrioventricular nodal re-entrant tachycardia inducibility was checked after 30 min. Acute success (AVNRT non-inducibility) was achieved in 142 patients (95%). Overall, after a follow-up of 18 +/- 10 months, 118 of 150 patients (79%) were recurrence-free (including 2 patients for whom the procedure was unsuccessful). Among successful procedures, 116 of 142 (82%) patients were recurrence-free. During cryoablation, inadvertent transient AV block of varying degrees occurred in 34 patients (22.7%), namely, increased PR in 17 patients and a 2nd-3rd AV block in the remaining 17. In 24 patients, AV block occurred at the last effective site (increased PR in 13 patients and a 2nd-3rd AV block in 11). In the study population as a whole, univariate predictors of recurrence in the follow-up were AVNRT inducibility (P < 0.001), increased PR at the last effective site (P < 0.001), residual jump (P < 0.02), and small Kochs triangle (X-ray distance < 11 mm between the His and coronary sinus ostium catheters; P < 0.02). Atrioventricular nodal re-entrant tachycardia inducibility (P < 0.03), increased PR (P < 0.01), and small Kochs triangle (P< 0.04) were independently significant. For attempts at the last effective site, 3 groups of patients were compared: 13 patients with increased PR duration (Group A), 11 with a 2nd-3rd AV block (Group B), and 126 without AV block (Group C). Cryo-application time was 277 +/- 203 s in Group A, 75 +/- 87 s in Group B, and 253 +/- 135 s in Group C (A vs. B, P < 0.01; B vs. C, P < 0.001; and C vs. A, P= NS). There was no statistical difference among groups in the atriogram/ventriculogram amplitude ratio at the site of the last attempt, unsuccessful acute procedure, small Kochs triangle, and residual jump. Actuarial incidence of recurrence-free status at 12 months was 38% in A, 82% in B, and 82% in C (A vs. B, P < 0.05; B vs. C, P = NS; and C vs. A, P < 0.001). CONCLUSION All AV blocks occurring during cryoablation were transient, confirming the safety of this method. An increased PR duration at the last effective site is associated with a higher recurrence rate, whereas a 2nd-3rd degree AV block has a recurrence rate similar to that of patients without AV block despite a shorter cryo-application time at the last site.

Indications du défibrillateur automatique implantable en 2007

La mort subite rythmique est l’une des principales causes de deces chez les patients porteurs d’une cardiomyopathie ou d’une insuffisance cardiaque. Le benefice du defibrillateur automatique implantable a largement ete demontre ces dernieres annees grâce a de nombreuses etudes effectuees en prevention primaire et secondaire de la mort subite, la reduction de la mortalite globale etant d’environ 25 a 30 %. Les recommandations francaises publiees en 2006 ont logiquement integre ces nouvelles indications et vont generer a court terme une augmentation spectaculaire du nombre d’implantations.

Catheter Ablation of Ventricular Tachycardia

Antiarrhythmic surgery (ventriculotomy) was used in our institution between 1973 and 1980 to treat 15 patients with Arrhythmogenic Right Ventricular Dysplasia (ARVC/D) who had ventricular tachycardia (VT) resistant to antiarrhythmic drug therapy. When catheter ablative procedures became available, we used fulguration (F) with DC energy shock alone in 27 patients between August 1983 and February 1992. However, this technique was associated with serious complications. The causes of these complications are now understood and the problems associated with F have been corrected. We now use radiofrequency (RF) energy followed by F if RF ablation is not successful. This protocol has been used in 23 patients from 1992 until October, 1999. The results of ablation using these two approaches over 16 years has been reported [1]. We wish to report our most recent experience with 22 additional patients over 6 years using the combined treatment with RF ablation immediately followed by the use of F if necessary.

Cardiomyopathies ventriculaires droites arythmogènes

Les progres recents de la biologie moleculaire, dont ont beneficie l’anatomie pathologique et la clinique, ont permis d’isoler un groupe de maladies affectant le myocarde du ventricule droit denommees cardiomyopathies du ventricule droit. La « dysplasie ventriculaire droite arythmogene », le syndrome de Brugada et les tachycardies infundibulaires representent les formes les plus frequemment observees en clinique. Cependant, il existe de nombreuses variantes plus rares, qui doivent etre connues des cliniciens en raison des incidences therapeutiques allant des medicaments antiarythmiques a l’approche chirurgicale en passant par les methodes ablatives et le defibrillateur implantable.