Optimal ablation index parameters for radiofrequency ablation therapy of atrial fibrillation

Objective: To explore the optimal ablation index (AI) parameters for radiofrequency catheter ablation (RA) for treating atrial fibrillation (AF). Method: Patients with AF (186) who underwent bilateral PVAI in the Department of Cardiology, Zhuhai People’s Hospital, Guangdong Province, from March 2018 to October 2019 and received catheter ablation as first-round treatment, were grouped according to the received AI. Control group included patients (95) who received the recommended AI ablation (350–400 for posterior wall, 400–450 for non-posterior wall). Patients in optimal AI group were ablated with optimal AI (300–330 for posterior wall, 350–380 for non-posterior wall). Results: Of 186 patients, 66 patients had paroxysmal atrial fibrillation and a mean CHA2DS2-VASc score of 2.83±1.64. Isolation rates of bilateral PVI in both groups were 91.4% and 93.6%, for patients with paroxysmal atrial fibrillation, and 81.7% and 80% for patients with persistent atrial fibrillation (P > 0.05). Left atrial function index (LAFI) decreased under the condition of sinus rhythm at the 3rd and 6th months (P < 0.05). LAFI improvement was significantly better in the optimal AI group than in the control group (P < 0.05). Rates of pain and cough during the ablation, and postoperative gastrointestinal discomfort and use of PPIs were higher in the control group (P < 0.05). Conclusion: Radiofrequency ablation of AF, guided by optimal AI combined with impedance, can minimize atrial injury, prevent atrial failure, promote the recovery of atrial function, reduces intraoperative cough, pain, and postoperative gastrointestinal discomfort and use of PPIs. doi: https://doi.org/10.12669/pjms.38.3.4971 How to cite this:Qin X, Jiang X, Yuan Q, Xu G, He X. Optimal ablation index parameters for radiofrequency ablation therapy of atrial fibrillation. Pak J Med Sci. 2022;38(3):---------. doi: https://doi.org/10.12669/pjms.38.3.4971 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Comprehensive assessment of Mahaim accessory pathways’ anatomic distribution

Objective To present the authors’ experience of Mahaim-type accessory pathways (MAPs), focusing on anatomic localizations. Methods Data from consecutive patients who underwent electrophysiological study (EPS) for MAP ablation in two tertiary centres, between January 1998 and June 2020, were retrospectively analysed. Results Of the 55 included patients, 27 (49.1%) were male, and the overall mean age was 29.5 ± 11.6 years (range, 12–66 years). MAPs were ablated at the tricuspid annulus in 43 patients (78.2%), mitral annulus in four patients (7.3%), paraseptal region in three patients (5.5%), and right ventricle mid-apical region in five patients (9.1%). Among 49 patients who planned for ablation therapy, the success rate was 91.8% (45 patients). Conclusion MAPs were most often ablated at the lateral aspect of the tricuspid annuli, sometimes at other sides of the tricuspid and mitral annuli, and infrequently in the right ventricle. The M potential mapping technique is likely to be a useful target for ablation of MAPs.

Multimodality durable salvage of recurrent brain metastases refractory to LITT, SRS and immunotherapy with resection and cesium-131 brachytherapy: case report and literature review

Brain metastases (BrM) are treated with multimodality therapy, however the optimal combination and timing of modalities in the setting of recurrent tumours that have failed prior treatments remain poorly defined. We present a case of a patient with biopsy-confirmed renal cell carcinoma BrM with good performance status initially treated with laser interstitial thermal ablation therapy (LITT) followed by stereotactic radiosurgery and dual checkpoint inhibitor immunotherapy. He subsequently developed rapid in-field recurrence which was treated with salvage surgical resection and implantation of intracavitary cesium-131 brachytherapy. The patient’s disease remained stable through 18 months postoperatively. This case illustrates the range of options available and provides a combination salvage therapy strategy in a select group of locally recurrent patients who have exhausted conventional treatment options.

Analysis of a two-year independent screening effort for retinopathy of prematurity in rural Egypt

Background The third epidemic of retinopathy of prematurity (ROP) has majorly involved middle income countries in which tailored screening and local guidelines require development. The data regarding ROP prevalence and cutoff numbers for screening in Egypt are lacking. Methods Retrospective analysis of an independent screening effort spanning 2 years (February 2019 to February 2021) and involving 32 neonatal care units within Sharkia governorate, Egypt. Infants of gestational age (GA) ≤ 34 weeks and/or birth weight (BW) ≤ 2000 g were included, as well as those with unstable clinical course. Two eyecare centers located in Sharkia and Cairo governorates served as referral centers for any required interventions. Results Of the 276 screened infants, 133 (48.2%) had some form of ROP that was bilateral in 127 (95.5%) of them. Aggressive posterior ROP (AP-ROP) was detected in both eyes of 24 infants (8.7%). The median (IQR) GA of infants with ROP was 32 (30–34) weeks, and the median (IQR) BW was 1600 (1350–2000) g. Sixty-three infants (47.4%) required treatment. Of the total 84 eyes that primarily were treated, 73 (86.9%) received intravitreal ranibizumab, 8 (9.5%) underwent laser ablation therapy, and 3 eyes (3.6%) underwent surgery. Recurrence rate was 16.7% (14 eyes). Final outcome was favorable in 83 eyes (98.8%). Applying the American Academy criteria would have led to the missing of 36.8% of infants with ROP and 28.6% of those requiring treatment in our sample. Conclusion The incidence of both ROP and AP-ROP in the Egyptian rural setting appears to be in the high end of global reported rates. Prevention measures should urgently be planned and implemented.

Profibrillatory Structural and Functional Properties of the Atrial-Pulmonary Junction in the Absence of Remodeling

Background: Sole pulmonary vein (PV) isolation by ablation therapy prevents atrial fibrillation (AF) in patients with short episodes of AF and without comorbidities. Since incomplete PV isolation can be curative, we tested the hypothesis that the PV in the absence of remodeling and comorbidities contains structural and functional properties that are proarrhythmic for AF initiation by reentry.Methods: We performed percutaneous transvenous in vivo endocardial electrophysiological studies and quantitative histological analysis of PV from healthy sheep.Results: The proximal PV contained more myocytes than the distal PV and a higher percentage of collagen and fat tissue relative to myocytes than the left atrium. Local fractionated electrograms occurred in both the distal and proximal PVs, but a large local activation (&gt;0.75 mV) was more often present in the proximal PV than in the distal PV (86 vs. 50% of electrograms, respectively, p = 0.017). Atrial arrhythmias (run of premature atrial complexes) occurred more often following the premature stimulation in the proximal PV than in the distal PV (p = 0.004). The diastolic stimulation threshold was higher in the proximal PV than in the distal PV (0.7 [0.3] vs. 0.4 [0.2] mA, (median [interquartile range]), p = 0.004). The refractory period was shorter in the proximal PV than in the distal PV (170 [50] vs. 248 [52] ms, p &lt; 0.001). A linear relation existed between the gradient in refractoriness (distal-proximal) and atrial arrhythmia inducibility in the proximal PV.Conclusion: The structural and functional properties of the native atrial-PV junction differ from those of the distal PV. Atrial arrhythmias in the absence of arrhythmia-induced remodeling are caused by reentry in the atrial-PV junction. Ablative treatment of early paroxysmal AF, rather than complete isolation of focal arrhythmia, may be limited to inhibition of reentry.