Summary
Background
Cardiac resynchronization therapy (CRT) improves clinical outcome in selected patients with advanced congestive heart failure. The Overlay Ref technique may facilitate the procedure for implanting left ventricular (LV) pacing leads to deliver CRT.
Aim
To assess the feasibility of deploying a LV pacing lead into a coronary sinus side branch guided by Overlay Ref.
Methods
Data from 88 consecutive patients who met the CRT implantation criteria in our hospital between 28 November 2007 and 30 December 2009 were randomly assigned to two groups. Forty-four patients underwent CRT device implantation using Overlay Ref to guide target vein selection and advance a specifically designed pacing lead into the target vein (Overlay Ref group); 44 patients were conventionally implanted (control group).
Results
LV lead implantation was successful in all patients. Mean CRT total procedure times (skin-to-skin) were: Overlay Ref group, 80.7 ± 18.0 min; control group, 98.5 ± 32.2 min; p = 0.029. Mean placement of LV pacing lead into target vein times were: Overlay Ref group, 16.2 ± 7.7 min; control group, 36.4 ± 23.4 min; p = 0.004. Mean total fluoroscopy times were: Overlay Ref group, 13.6 ± 4.3 min; control group, 23.8 ± 15.7 min; p = 0.007. Mean LV lead fluoroscopy times were: Overlay Ref group, 5.7 ± 2.9 min; control group, 14.4 ± 4.6 min; p = 0.003. No major complications occurred.
Conclusions
Overlay Ref facilitates location of and entry into the coronary sinus, and shortens the duration of LV pacing lead implantation into the target vein.
Résumé
Objectif
Évaluer la faisabilité d’une sonde ventriculaire gauche implantée dans le sinus coronaire, guidée par une technique appropriée.
Justification
La resynchronisation cardiaque (CRT) est une thérapeutique éprouvée de l’insuffisance cardiaque congestive avérée, à condition de respecter les indications. Cependant, la procédure d’implantation des sondes ventriculaires gauches varie en fonction des opérateurs et de leur technique. Il reste à réduire le temps des procédures. Nous proposons une nouvelle technique pour faciliter cette procédure de mise en place de la sonde en position ventriculaire gauche. Cette étude rapporte notre expérience initiale dans l’implantation du traitement de l’insuffisance cardiaque congestive.
Méthode
Les données de 88 patients consécutifs répondant aux critères d’implantation ont été assignées de façon randomisée dans deux groupes, au cours d’une période s’étendant du 28 novembre 2007 au 30 décembre 2009 : 44 patients ont bénéficié d’une implantation selon la nouvelle technique permettant de guider la veine coronaire cible et de déployer ainsi la sonde ventriculaire gauche dans celle-ci (groupe de référence) ; les témoins étaient constitués de 44 patients, traités et implantés de façon conventionnelle (groupe témoin).
Résultats
La mise en place de la sonde ventriculaire gauche a été obtenue avec succès dans tous les cas. La durée moyenne de la procédure d’implantation (peau à peau) dans le groupe évalué a été de 80,7 ± 18 comparée à 98,5 ± 32,2 minutes dans le groupe témoin ( p = 0,029). Le délai moyen d’obtention de la stimulation ventriculaire gauche a été respectivement de 16,2 ± 7,7 et 36,4 ± 23,4 minutes ( p = 0,004). Le temps moyen d’irradiation per procédure était respectivement de 13,6 ± 4,6 et 23,8 ± 15,7 minutes ( p = 0,007). Le déploiement de la sonde en position ventriculaire gauche a abouti à une irradiation per procédurale de 5,7 ± 2,9 et 14,4 ± 4,6 minutes ( p = 0,003). Il n’y a pas eu de complication majeure recensée.
Conclusion
Cette nouvelle technique d’implantation d’une sonde en position ventriculaire gauche pour resynchronisation cardiaque a permis un repérage plus aisé du sinus coronaire, et une réduction tant du délai de cathétérisme de celle-ci que de la durée d’irradiation en salle de cathétérisme.
Background
Multiple randomized clinical studies have suggested that patients in heart failure with left bundle branch block may benefit from cardiac resynchronization therapy (CRT) . One of the greatest challenges to this therapy is the technical difficulty encountered with implantation of the left ventricular (LV) lead. Implantation of LV pacing leads to deliver CRT typically involves locating and entering the coronary sinus (CS), performing coronary venous angiography, selecting a target vein and advancing a specifically designed pacing lead into the target vein. To overcome this problem, a new technique named Overlay Ref has been introduced into clinical electrophysiology; this technique can overlap the reference images on the real-time fluorescence monitor, to facilitate implantation of LV pacing leads. This article reports our initial experiences with implantation of LV pacing leads guided by Overlay Ref.
Methods
Patient selection
Between 28 November 2007 and 30 December 2009, biventricular pacemaker implantation was performed in 88 consecutive candidates for CRT, who were randomized in a 1:1 ratio based on a permuted blocked randomization list, to provide an approximate balance between treatment groups. The randomization list was stratified by site. Randomization was done by opening sealed allocation envelopes (indicating ‘Overlay Ref’ or ‘conventional’ treatment).
Forty-four randomized patients underwent LV lead placement using the Overlay Ref technique to control the tip of a 0.014-inch guidewire (Medtronic Inc., Minneapolis, MN, USA). The control group was made up of 44 randomized patients scheduled for CRT during the same time period. The Overlay Ref technique was not used in the control group. Standard 0.014-inch guidewires were used in the control group, as well as CS venography. The right ventricular and right atrial leads were initially placed in a standard fashion. The CS leads were commercially available over-the wire leads (Medtronic Inc.).
The institutional review board of our institution approved the study protocol. Each patient signed a written consent form before treatment.
Inclusion criteria were as follows: symptomatic heart failure with idiopathic dilated or ischaemic cardiomyopathy; New York Heart Association functional class III or IV; LV end-diastolic diameter greater or equal to 60 mm; QRS width greater or equal to 120 ms (measured on surface electrocardiogram leads); and obvious mitral regurgitation by echocardiography.
Device
Impulse generators: Insync 8040, Insync III 8042 (Medtronic Inc.). LV leads: 2188, 2187, 4189, 4191, 4193 (Medtronic Inc.); Attain ® OTW 6215 (Medtronic Inc.).
Implantation procedure: Overlay Ref group
After informed consent was obtained, implantation was performed for the patient under local anaesthesia and conscious sedation. After puncturing the left subclavian vein, two steerable hydrophilic guides were inserted. The short guide was used to introduce the atrial and right ventricular leads, and the long guide to introduce the LV lead delivery system.
Location of the coronary sinus ostium
One of the key steps in the implantation procedure for CRT is access to the CS. We used an electrophysiological guided approach to locate the CS ostium. The standard diagnostic CS electrophysiology catheter was used to cannulate the CS. When the catheter was put into the CS, the delivery sheath was then slipped over the catheter inside the CS as deeply as possible and the catheter was exchanged for a balloon catheter to perform an occlusive CS venogram; it then remained in the ostium to secure access ( Fig. 1 ) .
Left ventricular lead implantation
The LV lead was selected on the basis of the anatomy of the CS branches. For large veins with few tortuosities, a large bore lead (2187) was used. For medium-sized or small veins with significant tortuosities, over-the-wire leads (mostly 4193) were selected. The lead was placed preferentially into the lateral or posterolateral vein using percutaneous transluminal coronary angioplasty ( Fig. 2 ) . Sensing and pacing thresholds were determined, along with the pacing threshold for phrenic nerve stimulation. After lead measurement, the sheath was removed and the right ventricular and right atrial leads were implanted. The right ventricular lead was generally placed at a site anatomically remote from the LV lead, with good electrical separation and, preferably, early in the QRS complex.
