Update on high‐power short‐duration ablation for pulmonary vein isolation

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. However, this procedure remains complex and time‐consuming, and the recurrence of AF after PVI is still unsatisfactory. Current technologies have improved our knowledge of the association between radiofrequency lesion creation and ablation parameters (power and duration), which triggered the development of high‐power short‐duration (HPSD). During the past decade, several preclinical and clinical studies have been conducted to confirm the feasibility, safety, and outcome of PVI ablation with HPSD or very high‐power short‐duration (vHPSD) settings, which increased electrophysiologists' interests in the utility of HPSD strategies. This paper describes the theoretical basis and recent research findings of HPSD or vHPSD ablation and summarizes the state‐of‐the‐art evidence behind the role of this strategy in PVI.     

LSI指数在房颤高功率短时导管消融中的应用研究

目的 评估LSI指数在房颤高功率短时导管消融中对有效性和安全性的指导意义。 方法 入选2019年7月-2020年12月共46例拟行首次导管消融的阵发性房颤病人,随机分为30W常规消融组（A组,n=22）和45W高功率消融组（B组,n=24）,采用Ensite三维标测系统引导,在LSI指数指导下（前壁LSI=5.5,后壁LSI=4.5）行双侧肺静脉电隔离术。 结果 1、LSI量化消融在肺静脉PVI位点中的分布,A组与B组对比差异无统计学意义（P>0.05）;贴靠压力在肺静脉PVI位点中的分布,A组贴靠压力>B组贴靠压力,以两侧肺静脉后壁明显,但差异无统计学意义（P>0.05）;2、两组病人的92个肺静脉隔离圈的观察中,A组单圈隔离率为84%(n=35);B组单圈隔离率为93.7%(n=45)（P<0.05）;两组整体手术即时成功率均为100%。B组与A组相比,有较短的单点消融时间、总PVI隔离时间、左房操作时间、总手术时间,差异有统计学差异（P<0.05）;消融相关并发症差异无统计学意义（P>0.05）。 结论 LSI指数在房颤高功率短时导管消融中可能是高效安全的。     

Fever of intermediate duration

Fever of intermediate duration (FID) is defined as non-localized fever occurring in the community, lasting from one to four weeks, and having no diagnostic orientation after basic clinical, analytical and radiological evaluations are completed. These may include careful recording of clinical history, physical examination, hemogram, plasma creatinine determination, urinalysis, and chest radiography. The etiology of FID is still not completely defined. In our country, 70% of cases are caused by systemic infectious diseases (rickettsiosis, brucellosis, and mononucleosis syndrome) and 7.7% by localized infections; vasculitis and neoplasms account for less than 2%. In most cases FID can be attended on an outpatient basis, with the guarantee of the easy accessibility. In cases without social support or when there is digestive intolerance or criteria of severe disease, hospital care is required. For the diagnostic approach, it is useful to establish basic rules and to organize the study in several stages, taking into account the most frequent etiologies. The first visit would include elaboration of the clinical history, a hemogram, biochemistry analyses, blood cultures, urine culture, serological studies for the most frequent etiologies, a chest radiograph, and other examinations, as indicated by the clinical history data. The care provided and subsequent diagnostic studies performed will depend on the patient's progression and findings from additional studies. Further works conducted in various geographic settings are necessary to define the complete etiological spectrum of FID.     

Long duration Jakob-Creutzfeldt disease

The first patient was a woman hospitalized at the age of 43 years; she received the diagnosis of presenile dementia because of a progressive deterioration of her intellectual functions over an interval of 3 years. On admission there were no localizing neurological findings. During the ensuing years she became unable to speak and was no longer able to respond to commands. Death occurred at the age of 46 years from bronchopneumonia. The brain showed marked atrophy of the frontal lobes, moderate in the temporal lobes. The anterior horns of the lateral ventricles were greatly dilated. Microscopically cortical atrophy was severe, with marked depletion of neurons in involved regions. Lamination and polarity were not preserved. There was considerable increase of astrocytes and microglia, and focal sponginess was prominent. The hippocampus showed atrophy of Sommer's sector and subiculum. There were no neurofibrillary tangles and no argyrophilic plaques. The occipital sections showed little neuronal loss and no increased astrocytes or sponginess. The insulae showed neuronal loss and gliosis. There was bilateral atrophy of the caudate nuclei and globus pallidus adjacent to the dystrophic anterior limbs of the internal capsule. In the brain stem the frontopontine tracts were partially demyelinated and showed reactive gliosis. Ventral horns were atrophic with moderate glial reaction. In the second patient the microscopic changes were quite similar to those in Case 1, but there was more severe degeneration of the corticospinal tracts and the ventral horns of the spinal cord which showed considerable loss of neurons and degenerative changes in the remaining nerve cells and nerve fibers. There were many instances of axonal degeneration.(ABSTRACT TRUNCATED AT 250 WORDS)     

Menses and duration of cycles

A study of HIV and menstruation presented by S. D. Harlow at CROI confirmed earlier scientific studies showing that HIV has little if any influence on the nature and duration of cycles in women with HIV. Women with CD4 counts below 200 cells/mm3 had slightly longer cycles, but age, ethnicity, and body mass index seem to have stronger influences on menstrual cycles than does HIV.     

Incidence of ablation-induced esophageal lesions and gastroparesis in patients undergoing ablation index guided high power short duration atrial fibrillation ablation

Introduction

Aim of this study was to evaluate the incidence of ablation-induced endoscopically detected esophageal lesions (EDEL) and gastroparesis in patients undergoing high-power short-duration (HPSD) atrial fibrillation (AF) ablation using different target ablation index (AI) values.

Methods and Results

Consecutive patients undergoing AF ablation were included. Radiofrequency (RF) ablation was performed using HPSD ablation (50 W, target AI of 320 and 350 (group 1) and 380 (group 2) at posterior wall). Postablation endoscopy was performed in all patients. In total, 233 patients (66.8 ± 10 years; 52% male) were included consecutively (n = 137 patients in group 1 and n = 96 patients in group 2). Mean AI values und RF time at posterior wall was significantly higher and longer in group 2 compared to group 1 patients (413 ± 9 vs. 392 ± 19 AI, p < 0.01; 9.0 ± 0.8 s vs. 7.8 ± 0.7 s, p < 0.01). Esophageal endoscopy revealed esophageal lesions or gastroparesis in 43 of 233 patients (18.5%) in the total cohort (13.1% in group 1 and 26.0% in group 2; p = 0.02). Incidence of EDEL was 8.0% and 13.5% in group 1 and group 2, respectively. According to logistic analysis incidence of EDEL and/or gastroparesis was significantly lower in patients with a higher body mass index and higher in group 2 patients compared to group 1 patients.

Conclusion

The incidence of EDEL or gastroparesis in patients undergoing HPSD AF ablation was 18.5% in the total cohort. The risk of EDEL and gastroparesis was associated with a higher AI target value of 380 compared to 320 and 350 at posterior wall and was reversely associated with body mass index.     

Rate-dependent changes in atrial action potential duration after short- duration rapid atrial pacing in humans.

The effect of rapid atrial pacing on the rate adaptation of the atrial action potential duration was studied in humans. The right atrial monophasic action potential (RAMAP) of 5 patients was recorded before and after 30 min of rapid atrial pacing. The pacing cycle length (CL) was 146 +/- 9 ms, the shortest duration at which 1:1 capture was possible. The RAMAP duration at 90% repolarization (RMAPD) was measured. CL-dependent changes in RAMAPD (CL 600 ms-CL 300 ms) before and after rapid atrial pacing were 51.8 +/- 10.7 ms and 30.8 +/- 7.6 ms (p < 0.05), respectively.