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Jungen c, akbulak r, kahle ak, eickholt c, schaeffer b, scherschel k, dinshaw l, muenkler p, schleberger r, nies m, gunawardene ma, klatt n, hartmann j, merbold l, jularic m, willems s, meyer c.Outcome after tailored catheter ablation of atrial tachycardia using ultra-high-density mapping.J cardiovasc electrophysiol.2020;1-8.In this single-center study all consecutive patients, who were referred to our tertiary center for catheter ablation of ats following prior catheter ablation or cardiac surgery between november 2015 and september 2019, were retrospectively analyzed.The study was conducted in accordance with the provisions of the declaration of helsinki.Data collection and analysis were done under a protocol approved by the institutional review committee.All patients gave written informed consent.Mapping and catheter ablation was performed as described previously using conscious sedation.In brief, a steerable 6-f decapolar diagnostic catheter (non-boston scientific catheter or dynamic deca, bard electrophysiology; boston scientific, marlborough, ma, usa) was placed in the coronary sinus as a reference.The catheters consisted of an expandable, open irrigated 64-pole multielectrode mini-basket catheter (orion; boston scientific) for the rhythmia system (boston scientific) and an open-irrigated 3.5mm tip mapping and ablation catheter (non-boston scientific catheter or intellanav, with three mini-electrodes incorporated within the distal tip electrode; rhythmia; boston scientific).The left atrium was accessed and mapped whenever a left atrial origin of the at was suspected.All catheters were introduced into the left atrium by double transseptal access after a single transseptal puncture using a fixed curve long sheath for the ablation catheter and a long steerable sheath (zurpaz, medium curl, 8.5 f; boston scientific) for the mini-basket catheter.The periprocedural activated clotting time was aimed to be greater than 300 s.If the at was not present at the beginning of the procedure, programmed stimulation or burst pacing was performed.The clinical at was assumed when cycle length and p wave morphology matched the preprocedural 12 lead electrocardiogram (ecg) documentation.The entire chamber of interest was mapped during the at using the basket catheter.Electrogram annotation was performed (semi) automatically by the mapping system as described previously.Maps were considered complete when the entire chamber anatomy was reconstructed with best achievable electrode-tissue contact.If less than 90% of the tachycardia cycle length was displayed in the primarily mapped atrium, additional mapping of the remaining atrium and the coronary sinus was performed.After completion of the electroanatomical map the wavefront propagation, activation patterns, areas of slow conduction, anatomical and functional barriers, and lines of the block were analyzed.Additional entrainment mapping was performed at the operator's discretion.For macro reentry ats a continuous atrial activation sequence was demonstrated with earliest activation neighboring latest activation and the at's reentry loop circuiting around a central obstacle covering the entire at cycle length.Localized reentry was defined as continuous activation or reentry mechanism originating within an area less than 2 cm or when dominant small stable rotational activation patterns were identified.Centrifugal activation from a distinct focal source was considered as true focal at.Voltage maps acquired during the ats were taken into account for the ablation strategy.A voltage of less than 0.1 mv was considered scar and between more than 0.1 and less than 0.3mv as a border zone.Electrograms from areas along the reentry course and at sites that appeared to be critical for tachycardia maintenance in respect to signal duration (ms), signal amplitude (mv), and fractionation (number of deflections) were analyzed during the procedure manually and using an automated software tool (lumipoint) since october 2018.The critical tachycardia site (critical isthmus or earliest activation), at which specific at termination into sinus rhythm could be achieved, was targeted.Radiofrequency current was applied using a maximum power of 25wat the posterior atrial wall and of 30wat the anterioratrium wall.For typical atrial flutter, a radiofrequency current of 38w was used at the cavotricuspid isthmus.For macroreentrant tachycardia, the critical isthmus, which was defined as the narrowest pathway between scars and/or anatomical obstacles, was targeted.After the restoration of sinus rhythm, the planned ablation lines were completed and their connection to nonconducting structures (areas of dense scar, mitral annulus, pulmonary vein isolation line) was performed if appropriate.In case of mechanical termination prior or subsequent to mapping, reinduction was performed.Validation of ablation lines was performed by differential pacing or repeat mapping.Localized reentries were targeted by the ablation of the earliest activation.Endpoints of previously performed ablations such as pulmonary vein isolation or integrity of lines were verified and completed if necessary.After ablation, extensive atrial burst pacing without and with orciprenaline was performed to confirm acute ablation success.The endpoint was the noninducibility of the at.Acute procedure related complications were defined as post procedure hemorrhage requiring blood transfusion, atrioesophageal fistula, aspiration, cardiac surgery, stroke, pericardial effusion requiring/ not requiring pericardiocentesis, postprocedural atrioventricular (av) block with/without indication for pacemaker implantation, groin complications requiring/not requiring surgical intervention.Two hundred and fifty patients (66.5 +/- 0.7 years, 58% male) with a mean arrhythmia history of 7.4 +/- 0.4 years underwent at ablation.A prior ablation was performed in 98% of patients (mean number of previous procedures: 2.2 +/- 0.1), 13% had prior cardiac valve surgery, and 6% a surgically palliated congenital heart disease.A mean left ventricular ejection fraction of 55 +/- 0.5% and a mean body mass index of 26.5 +/- 0.3 were reported.A total of 354 ats with a mean cycle length of 304 +/- 4.3ms were mapped during the index procedure.Patients presented to the procedure with an initial rhythm of at (58%), sinus rhythm (34%), af (6%), or pacemaker stimulation (2%).The mean mapping time was 16.4 +/- 0.6 min in the left and 4.6 +/- 0.4 min in the right atrium.The described mechanisms were macroreentry (64%), localized reentry (27%) or focal (9%).The ats were mainly targeted in the left atrium (70%), but also in the right atrium (22%) or biatrially (7%).Ablation was performed at the mitral-isthmus (mig) area in 33 ats (9%).In 94.8% of cases, the at could be acutely terminated into sinus rhythm.Among all 342 procedures in 250 patients the following complications occurred: pneumonia following intraprocedural aspiration (n = 1, 0.3%), cerebral embolic events with (n = 2, 0.6%) or without (n = 1, 0.3%) complete clinical recovery, pericardial effusion requiring (n = 2, 0.6%) or not requiring pericardiocentesis (n = 1, 0.3%), postprocedural persistent av block i (n = 1, 0.3%) and groin complications not requiring vascular intervention (hematoma n = 10, 2.9%), femoral arteriovenous fistula n = 5 (1.5%).No atrioesophageal fistula was reported after ablation.
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