Histopathological Changes by Low-Power-Long-Duration and High-Power-Short-Duration Subthreshold Laser Treatment in the Rabbit Retina

Simultaneous observations of back-scatter and forward-scatter meteoric echoes have been made by means of a high-power 33 Mc./sec. pulse transmitter at Ottawa, with identical receiving systems at Ottawa and at Scarboro, 337.8 km. distant. Two-way transmissions, employing a low-power transmitter at Scarboro, were also used to measure absolute time delays. The approximate position of each meteor was plotted from the observed time delays, which enabled corrections to be applied to the echo durations for variations in antenna patterns and other factors, and which also determined the forward-scatter angle, [Formula: see text], for each meteor. In the majority of cases an enhancement was observed in the forward-scatter duration relative to the back-scatter duration. The data were divided into a short-duration or underdense group and a long-duration or overdense group. Assuming a theoretical forward-scatter enhancement proportional to [Formula: see text], it was found that the exponent, m, was 1.73 for the underdense group and 1.13 for the overdense group.

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High Power Short Duration and Low Power Long Duration in Atrial Fibrillation Ablation: A Meta-Analysis

10.22541/au.159863012.24417793 ◽

2020 ◽

Author(s):

Jakrin Kewcharoen ◽

Chol Techorueangwiwat ◽

Chanavuth Kanitsoraphan ◽

Thiratest Leesutipornchai ◽

Nazem Akoum ◽

...

Keyword(s):

Atrial Fibrillation ◽

Low Power ◽

Short Duration ◽

High Power ◽

Meta Analysis ◽

Atrial Fibrillation Ablation ◽

Long Duration

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The First-Pass Isolation Effect in High-Power Short-Duration Compared to Low-Power Long-Duration Atrial Fibrillation Ablation: a Predictor of Success

Journal of Cardiac Arrhythmias ◽

10.24207/jca.v33i3.3406 ◽

2020 ◽

Vol 33 (3) ◽

pp. 161-169

Author(s):

Fabricio Vassallo ◽

Lucas Luis Meigre ◽

Eduardo Serpa ◽

Carlos Lovatto ◽

Christiano Cunha ◽

...

Keyword(s):

Atrial Fibrillation ◽

Sinus Rhythm ◽

Low Power ◽

Short Duration ◽

High Power ◽

Arterial Disease ◽

Obstructive Apnea ◽

Long Duration ◽

First Pass

Introduction: Different results are described after atrial fibrillation ablation and multiples predictors of recurrence are well established. Objective: Evaluate and analyze if first-pass isolation effect (FPI) during first atrial fibrillation (AF) ablation with high-power short-duration (HPSD) comparing to low-power long-duration (LPLD) can impact on late outcome. Methods: Observational, retrospective study, 144 patients submitted to HPSD and LPLD ablation. HPSD: 71 patients, 50 (70.42%) males, mean age 59.73 years, 52 (73.24%) hypertension, 44 (61.97%) obstructive apnea, 23 (32.39%) arterial disease, 20 (28.17%) diabetes, and 10(14.08%) stroke. CHADS2VASC2 2.57. CT: 73 patients, 50 (68.49%) males, mean age 60.7 years, 53 (72.60%) hypertension, 41 (56.16%) obstructive apnea, 28 (38.36%) arterial disease, 14 (19.17%) diabetes and 8 (10.96%) stroke. CHAD2SVASC2 2.22. Results: Recurrence occurred in 33 patients (22.92%) at 12 months follow-up, HPSD with 9 patients and LPLD with 24 patients. Higher rate of bilateral FPI were observed in HPSD patients with 62 of 71 patients comparing to 17 of 73 patients in LPLD (P < 0.00001). At the end of study 62 (87.32%) of 71 HPSD patients were in sinus rhythm comparing to 49 (67.12%) of 73 patients in LPLD (P 0.0039). Conclusion: HPSD ablation produced higher rates of FPI comparing to LPLD. HPSD compared to LPLD showed a superiority in maintaining sinus rhythm at 12 months. At patients submitted to HPSD protocol ablation, FPI could predict higher rate of sinus rhythm at 12 months follow-up.

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Relationship between luminal esophageal temperature and volume of esophageal injury during RF ablation: In silico study comparing low power‐moderate duration vs. high power‐short duration

Journal of Cardiovascular Electrophysiology ◽

10.1111/jce.15311 ◽

2021 ◽

Author(s):

Juan J. Pérez ◽

Ana González‐Suárez ◽

Timothy Maher ◽

Hiroshi Nakagawa ◽

Andre d'Avila ◽

...

Keyword(s):

Low Power ◽

Short Duration ◽

High Power ◽

In Silico ◽

Esophageal Injury ◽

Rf Ablation ◽

Esophageal Temperature ◽

In Silico Study

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A Trial of High Power-Short Duration Versus Standard Power-Long Duration Radiofrequency Ablation for Treatment of Atrial Fibrillation

Case Medical Research ◽

10.31525/ct1-nct04148664 ◽

2019 ◽

Author(s):

Keyword(s):

Atrial Fibrillation ◽

Radiofrequency Ablation ◽

Short Duration ◽

High Power ◽

Long Duration

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High-power, short-duration ablation in the coronary sinus: clinical cases and preliminary observations on swine hearts

Journal of Interventional Cardiac Electrophysiology ◽

10.1007/s10840-021-00994-0 ◽

2021 ◽

Author(s):

Chengming Ma ◽

Xiaomeng Yin ◽

Yunlong Xia ◽

Jiao Sun ◽

Shiyu Dai ◽

...

Keyword(s):

Short Duration ◽

Coronary Sinus ◽

High Power ◽

Total Duration ◽

Alternative Strategy ◽

Rf Ablation ◽

Coronary Sinus Ostium ◽

Long Duration ◽

Clinical Cases

Abstract Purpose Coronary sinus-related arrhythmias are common; however, it is difficult to perform radiofrequency (RF) ablation at these sites efficiently and safely. High-power, short-duration ablation (HPSD) is a proven alternative strategy for pulmonary vein isolation (PVI); whether it can be applied to ablation of the coronary sinus is unknown. The purpose of this preliminary study was to evaluate the feasibility and safety of HPSD ablation in the coronary sinus. Methods Firstly, we demonstrated 4 clinical cases of 3 types of arrhythmias who had unsuccessful ablation with standard power initially, but received successful ablations with HPSD. Secondly, RF ablation was performed in the coronary sinus ostium (CSO) and middle cardiac vein (MCV) of 4 in vitro swine hearts. Two protocols were compared: HPSD (45 W/5 S×5 rounds) and a conventional strategy that used low-power, long-duration ablation (LPLD: 25 W/10 S ×5 rounds). The total duration of HPSD protocol was 25 s, and which of LPLD was 50 s. Results A total of 28 lesions were created. HPSD can produce longer, wider, deeper, and larger lesions than LPLD. This difference was more pronounced when the ablation was in the MCV. One instance of steam pop occurred during LPLD in the MCV. Conclusions HPSD is an effective alternative strategy for ablation in coronary sinus according to clinical applications and preliminary animal study. However, the safety needs to be further evaluated based on more animal and clinical studies.

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