Strategy to achieve mitral isthmus flutter ablation by radiofrequency: the SHERIFF plan

BACKGROUND

Achieving mitral isthmus (MI) block can be challenging. This prospective study evaluated the feasibility and efficacy of a systematic strategy comprising three consecutive steps to achieve MI block.

METHODS

Twenty consecutive patients (mean (± SD) age 71.4 ± 6.98 years) undergoing ablation of perimitral atrial tachycardia (PMAT) between December 2019 and November 2021 were included. MI was ablated using a systematic strategy comprising up to three consecutive steps: (1) endocardial ablation from the superolateral mitral annulus to the left pulmonary veins; (2) additional epicardial ablation in the coronary sinus (CS) on the opposite side of the endocardial line; and (3) ablation of early activation sites between endocardial and epicardial breakthroughs.

RESULTS

MI block was successfully achieved in 19/20 patients (95%). MI block after endocardial radiofrequency ablation alone (step 1) was observed in 7/20 patients (35%). Epicardial ablation within the CS on the other side of the endocardial line (step 2) resulted in bidirectional MI block in three more patients. Endocardial ablation of epicardial conduction was successful for nine additional patients (95% success). At the 12-month follow-up, five patients (25%) displayed recurrence of arrhythmia after a single procedure. One patient had electrical cardioversion for persistent atrial fibrillation. Four patients had a redo procedure for left atrial flutter and only two patients (10%) had conduction across the MI and showed recurrence of PMAT. No complications occurred.

CONCLUSIONS

The three-step ablation strategy resulted in a high rate of acute and durable MI block. PMAT recurrence after a single procedure was 10% at 1-year follow-up.

Micra AV leadless pacemaker implantation after transcatheter aortic valve implantation

BACKGROUND

Transvenous pacemaker (PM) implantation is a complication in patients undergoing transcatheter aortic valve implantation (TAVI). Recently, a second generation of leadless PMs able of atrioventricular (AV) synchronous pacing has been introduced and could be an alternative when ventricular pacing is required after TAVI. Real-world data on Micra AV after TAVI are still lacking. Our aim was to determine the per- and post-procedural outcomes in patients with Micra AV leadless PM implantation after TAVI.

METHODS

A total of 20 consecutive patients underwent Micra AV leadless PM implantation after TAVI between November 2020 and June 2021.

RESULTS

The main indication for ventricular pacing was high-degree AV block (55% of patients) and left bundle branch block (LBBB) associated with prolonged HV interval (45% of patients). At discharge, mean (SD) ventricular pacing threshold was 0.397 ± 0.11 V at 0.24 ms and ventricular impedance was 709.4 ± 139.1 Ω. At 1-month follow-up, 95% of patients were programmed in VDD pacing mode. Mean (SD) ventricular pacing threshold was 0.448 ± 0.094 V at 0.24 ms. In patients with ventricular> pacing > 90% (n = 5), mean AM-VP was 72.5% ± 8.3%. Pacing threshold at 1 month was not significantly different compared to discharge (p = .1088). Mean (SD) impedance was 631.0 ± 111.9 Ω, which remained stable at discharge (p = .0813). No procedural complications occurred during implantation. At 1-month follow-up, two patients displayed atrial under-sensing.

CONCLUSIONS

Micra AV leadless PM implantation after TAVI is associated with a low complication rate and good device performance at 1-month post-implantation.

Early pacemaker insertion after aortic valve replacement with an Edwards Intuity sutureless valve

BACKGROUND

Postoperative conduction disorders are serious adverse events in patients undergoing aortic valve replacement, and may prolong the duration of hospitalization and require pacemaker insertion.

AIM

Our aim was to evaluate the rate of pacemaker insertion after implantation of an Edwards Intuity sutureless aortic valve (Edwards Lifesciences, Irvine, CA, USA) compared with a standard surgical bioprosthesis.

METHODS

This retrospective single-centre study included patients who underwent aortic valve replacement with an Intuity sutureless aortic valve or a standard bioprosthetic valve between 4 June 2014 and 27 June 2016. The main outcome criterion was the rate of postoperative pacemaker insertion. Secondary outcome criteria included the rate of new conduction disorders, the rate of atrial arrhythmia or paroxysmal conduction disorders, mortality and duration of hospital stay.

RESULTS

Ninety-three patients received an Intuity sutureless aortic valve (median age 76 years, interquartile range 71-80 years), and 176 were implanted with a standard biological aortic valve (median age 73 years, interquartile range 68-79 years; P=0.007). The rate of postoperative pacemaker insertion, after adjustment, was 22.44% in the Intuity group and 5.66% in the standard aortic valve group (P=0.030). The main indications for postoperative pacemaker insertion were complete atrioventricular block and left bundle branch block with prolongation of the H-V interval. The rate of new postoperative left bundle branch block conduction disorders was significantly higher in patients implanted with an Intuity valve (odds ratio 5.28, 95% confidence interval 1.59 to 23.05; P=0.012).

CONCLUSION

Higher rates of pacemaker insertion and new conduction disorders were observed in patients implanted with an Intuity sutureless bioprosthesis compared with those who received a standard surgical aortic valve.

[Excimer laser assisted angioplasty. Immediate results in the treatment of complex coronary lesions]

Transluminal coronary angioplasty (TCA) with pulsed excimer laser (CVX 300 Spectranetics) was performed in 89 patients (age 63.7 years); CCS I: 6; CCS II: 12; CCS III: 40; CCS IV: 31; instable: 58%. There was a previous history of myocardial infarction (MI) in 27 cases, TCA (9 restenoses) in 24 cases, 19 bypass graft procedures, 13 failures of TCA. The lesions (n = 90) affected the left main coronary artery: 1 case; the left anterior descending artery: 37 cases; the left circumflex: 8 cases; the right coronary: 28 cases and there were saphenous vein grafts in 16 cases. The lesions were classified B2 (ACC/AHA) in 56 cases and type C in 34 cases. There were 24 lesions > 10 mm, 15 > 20 mm; calcification in 49 cases; excentric in 65 cases; ostial in 9 cases; affecting bifurcations in 13 cases; affecting collateral vessels in 16 cases; chronic occlusions in 12 cases and restenoses of stents in 4 cases. Multifiber catheters: 1.4 mm (50), 1.7 mm (41) and 2 mm (3), were used to deliver energies of 43.3 mj/m2 (+/- 8.1 mj) with an average of 5.2 +/- 1.2 applications persite, and 2.7 +/- 1.1 passages. A balloon dilatation was performed after laser angioplasty in 96% of cases. The following results were observed: success of laser angioplasty (20% reduction of stenosis) in 95.5%, a successful procedure (residual stenosis less than 50% without major complications) in 95.5%, and a clinical success (no pathological Q wave or non-Q wave infarction, bypass graft, or repeat TCA): 92.1%. The following complications were observed: death = 0, non-Q wave infarction 2.2%, emergency bypass surgery in 1 case with Q wave infarction: 1.1%. The use of laser angioplasty may be proposed in the following indications: long, moderately calcified lesion, ostial lesions, complete occlusions, bypass graft disease, failure of angioplasty. In addition to these indications, we propose the treatment of restenosis on stents. The main disadvantage of the Excimer Laser is the poor cost/benefit ratio, given the relatively small number of indications.