Floor Line Research Articles

Modified ablation index: a novel determinant of a successful first-pass left atrial posterior wall isolation.

Although a left atrial posterior wall isolation (LAPWI) in addition to a pulmonary vein isolation is a well-accepted option for persistent atrial fibrillation (AF), a complete isolation can be challenging. This study aimed to evaluate the performance of a modified ablation index (AI) (AI/bipolar voltage along the ablation line) for predicting a durable LAPWI. The study included 55 consecutive patients, aged 65 ± 11years, who underwent an electroanatomic mapping-guided LAPWI of AF. The association between the gaps (first-pass LAPWI failure and/or acute LAPW reconnections), voltage amplitude along the roof and floor lines, and thickness of the LAPW was investigated. Gaps occurred in 22 patients (40%) and in 26 (8%) of the 330 line segments. Gaps were associated with a relatively high bipolar voltage (3.38 ± 1.83 vs. 1.70 ± 1.12mV, P < 0.0001) and thick LA wall (2.52 ± 1.15 vs. 1.42 ± 0.44mm, P < 0.0001). A modified AI ≤ 199 AU/mV, bipolar voltage ≥ 2.64mV, wall thickness ≥ 2.04mm, and roof ablation line ≥ 43.4mm well predicted gaps (AUCs: 0.783, 0.787, 0.858, and 0.752, respectively). A high-voltage zone, thick LAPW, and long roof ablation line appeared to be determinants of gaps, and a modified AI ≥ 199 AU/mV along the ablation lines appeared to predict an acute durable LAPWI.

Catheter ablation for persistent atrial fibrillation: A multicenter randomized trial of pulmonary vein isolation (PVI) versus PVI with posterior left atrial wall isolation (PWI) - The CAPLA study

The success of pulmonary vein isolation (PVI) is reduced in persistent AF (PsAF) compared to paroxysmal AF. Adjunctive ablation strategies have failed to show consistent incremental benefit over PVI alone in randomized studies. The left atrial posterior wall is a potential source of non-PV triggers and atrial substrate which may promote the initiation and maintenance of PsAF. Adding posterior wall isolation (PWI) to PVI had shown conflicting outcomes, with earlier studies confounded by methodological limitations. To determine whether combining PWI with PVI significantly improves freedom from AF recurrence, compared to PVI alone, in patients with PsAF. This is a multi-center, prospective, international randomized clinical trial. 338 patients with symptomatic PsAF refractory to anti-arrhythmic therapy (AAD) will be randomized to either PVI alone or PVI with PWI in a 1:1 ratio. PVI involves wide antral circumferential pulmonary vein (PV) isolation, utilizing contact force sensing ablation catheters. PWI involves the creation of a floor line connecting the inferior aspect of the PVs, and a roof line connecting the superior aspect of the PVs. Follow up is for a minimum of 12 months with rhythm monitoring via implantable cardiac device and/or loop monitor, or frequent intermittent monitoring with an ECG device. The primary outcome is freedom from any documented atrial arrhythmia of > 30 seconds off AAD at 12 months, after a single ablation procedure. This randomized study aims to determine the success and safety of adjunctive PWI to PVI in patients with persistent AF.

Ablation Index-guided 50W ablation for left atrial posterior wall isolation compared with lower powers: feasibility and lesion level analysis

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Groupe de Rythmologie de la Société Française de Rythmologie Background Posterior Wall Isolation (PWI) is increasingly performed for Atrial Fibrillation (AF). The use of Ablation Index (AI)-guided 50W ablation for PWI has not been described, nor the interplay between ablation parameters at this power when compared to lower powers. Methods 40 consecutive AF patients (26 males, 65.5 ± 10.0 years. 95% non-paroxysmal AF) underwent PWI following pulmonary vein isolation. A roof line and floor line were created with point-by-point ablation, targeting a contact force (CF) of 10-30g, AI 550-600 on the roof and 400-450 on the floor, and inter-tag distance of &amp;lt;6mm. 35-40W powers were used for the first 20 patients, and 50W used for the next 20. Generator impedance was monitored in real time for each lesion. Ablation inside the box was delivered in case of failure of first pass isolation (FPI). All VisiTags (n = 959) were analyzed retrospectively. Results PWI was successful in 19(95%) of the 35-40W group and in all 20 patients in the 50W group, with FPI seen in 8(40%) and 10(50%) respectively, p = 0.53. The mean CF and number of RF applications on the roof. floor and inside the box were similar between the two groups. Ablation time per lesion (10.4 [8.8-12.5]sec) and total ablation time per patient (3.84[3.34-4.66] min) were shorter in the 50W group as compared to 35-40W (13.0 [11.6-16.2] sec and 5.86 [4.23-7.73] min respectively), p &amp;lt; 0.005. The mean AI and Impedance Drop were larger in the 50W group (Table). There was no steam pop observed in any of the 959 radiofrequency applications. Conclusion Ablation Index guided 50W ablation has a very high success rate for posterior wall isolation with shorter ablation times and higher impedance drop compared to conventional powers. Steam pops may be avoidable by targeting CF &amp;lt; 30g, and by monitoring impedance in real-time. 50W Group(N = 458) 35-40W Group(N = 501) p-value Number of lesions (s, IQR)Roof lineFloor lineAdditional ablation inside box 21.5 [19.5-26.3]7.0 [5.8-9.0]13.0 [10.8-14.3]6.0 [6.0-6.8] 24.0 [20.8-29.5]8.0 [6.0-10.0]12.5 [10.8-14.0]5.5 [2.8-9.0] 0.330.180.850.59 Ablation Time per lesion (s, IQR)Roof lineFloor lineAdditional ablation inside box 10.4 [8.8-12.5]13.0 [10.9-16.0]9.9 [8.7-11.4]8.1 [6.9-9.0] 13.0 [11.6-16.2]14.5 [12.4-19.0]12.7 [11.4-15.9]11.8 [10.6-14.0] &amp;lt;0.005&amp;lt;0.005&amp;lt;0.005&amp;lt;0.005 Total RF Time (min, IQR)Roof lineFloor lineAdditional ablation inside box 3.84 [3.34-4.66]1.54 [1.15-1.90]2.06 [1.68-2.54]0.79 [0.65-1.07] 5.86 [4.23-7.73]1.98 [1.62-2.59]2.78 [2.28-3.25]1.07 [0.59-1.42] &amp;lt; 0.0050.0190.0090.50 Impedance Drop (ohms, IQR)Roof lineFloor lineAdditional ablation inside box 7.4 [5.2-10.3]8.7 [6.1-11.3]6.9 [5.0-10.1]7.1 [5.4-9.8] 6.9 [4.8-9.7]7.5 [5.1-10.0]6.0 [4.2-8.3]8.3 [5.8-10.9] 0.0070.04&amp;lt; 0.0050.17 Contact Force (g, IQR)Roof lineFloor lineAdditional ablation inside box 21.1 [14.5-30.3]23.9 [17.8-32.7]19.2 [13.2-25.3]25.5 [18.5-36.9] 21.2 [14.9-28.1]24.3 [17.2-30.3]19.0 [14.1-25.0]23.1 [16.9-31.7] 0.560.450.870.21 Ablation Index (IQR)Roof lineFloor lineAdditional ablation inside box 471 [441-519]560 [509-571]453 [436-475]461 [430-488] 461 [434-493]502 [466-541]446 [426-464]455 [434-478] &amp;lt; 0.005&amp;lt; 0.005&amp;lt; 0.0050.59 Lesion level analysis for Posterior Wall Isolation

Spectrum of arrhythmogenic substrate post minimally invasive maze surgery in patients with recurrent.

Advancements in minimally invasive surgical ablation (MISA) have focused on improving pulmonary vein isolation. Additional ablation targets have been developed (such as posterior wall isolation). The mid- and long-term effects of current techniques (including electrophysiologic findings and recurrent arrhythmia mechanisms) have not previously been reported. Twenty eight patients with recurrent atrial arrhythmias after bipolar clamp ablation of the pulmonary vein antrum, ganglionated plexi, posterior wall isolation (roof and floor lines to create a posterior box), and ligament of Marshall ligation/cauterization and left atrial appendage clipping underwent follow up electrophysiology study including left atrial mapping an average of 2.3 years postoperatively. Atrial fibrillation was the most common recurrent arrhythmia (n=18) followed by micro-reentrant atrial tachycardia (n=5), macro-reentry left atrial flutter (n=3), and typical cavo-tricuspid isthmus atrial flutter (n=2). Eighty six of 112 (77%) PVs mapped were electrically isolated, 16 (57%) patients had all four pulmonary veins (PVs) isolated. The posterior wall (PW) was completely isolated in only four (14%) patients, seven (25%) patients had normal PW voltage, while 17 (61%) patients had abnormal delayed or fractionated electrograms in the posterior wall (incomplete isolation). Abnormal PW electrograms were more frequently found in patients with complex recurrent left atrial arrhythmia (micro-reentry or left atrial macro-reentry flutter). With current surgical techniques PV isolation has improved, but PW isolation remains challenging. Incomplete PW isolation may produce arrhythmogenic substrate.

Change in nostril ratio after cleft rhinoplasty: correction of nostril stenosis with full-thickness skin graft.

BackgroundPatients with secondary deformities associated with unilateral cleft lip and nose might also suffer from nostril stenosis due to a lack of tissue volume in the nostril on the cleft side. Here, we used full-thickness skin grafts (FTSGs) to reduce nostril stenosis and various methods for skin volume augmentation. We compared the changes in the symmetry of both nostrils before and after surgery.MethodsFrom February 2016 to January 2020, 34 patients underwent secondary cheiloplasty and open rhinoplasty for secondary deformities of the unilateral cleft lip and nose with nostril stenosis. FTSG was used on the nostril floor, nasal columella, and alar inner lining. The measured nasal profile included the nostril surface, nostril circumference, width of the nostril floor, and distance from the alar-facial groove to the nasal tip. The “overlap area,” which was defined as the largest overlapping area when the image of the cleft nostril was flipped to the left and right and overlaid on the image of the normal side nostril, was also calculated. The degree of symmetry was evaluated by dividing the value of the cleft side by that of the normal side of each measured profile and expressed as “ratios.”ResultsThe results of all profile ratios, except for the nostril floor width, became significantly close to 1, which represents full symmetry. The overlap area ratio improved from 62.7% to 77.3%, meaning that the length and width of the nostril as well as the overall shape became similar (p<0.05).ConclusionWhen performing cleft rhinoplasty with nostril stenosis, FTSG is useful to achieve symmetry in the nostril size and shape. Skin grafting is simpler to perform than the other types of local flap, and the results are generally satisfactory.

Procedure characteristics and outcomes of atrial fibrillation ablation procedures using cryoballoon versus radiofrequency ablation: A report from the GWTG-AFIB registry.

Cryoballoon ablation (CBA) is an alternative to radiofrequency ablation (RFA) for ablation of atrial fibrillation (AF) and real-world comparisons of this strategy are lacking. As such, we sought to compare patient and periprocedural characteristics and outcomes of CBA versus RFA in the Get With the Guidelines AFIB Registry. Categorical variables were compared via the χ2 test and continuous variables were compared via the Wilcoxon rank-sum test. Adjusted analyses were performed using overlap weighting of propensity scores. A total of 5247 (1465 CBA, 3782 RFA) ablation procedures were reported from 33 sites. Those undergoing CBA more often had paroxysmal AF (60.0% vs. 48.8%) and no prior AF ablation (87.5% vs. 73.8%). CHA2 DS2 -VASc scores were similar. Among de novo ablations, most ablations involved intracardiac echocardiography and electroanatomic mapping, but both were less common with CBA (87.3% vs. 93.9%, p < .0001, and 87.7% vs. 94.6%, p < .0001, respectively). CBA was associated with shorter procedures (129 vs. 179 min, p < .0001), increased fluoroscopy use (19 vs. 11 min, p < .0001), and similar ablation times (27 vs. 35 min, p = .15). Nonpulmonary vein ablation was common with CBA: roof line 38.6%, floor line 20.4%, cavotricuspid isthmus 27.7%. RFA was associated with more total complications compared to CBA (5.4% vs. 2.3%, p < .0001), due to more volume overload and "other" events, although phrenic nerve injury was more common with CBA (0.9% vs 0.1%, p = .0001). In the adjusted model, any complication was less common among CBA cases (odds ratio, 0.45; confidence interval, 0.25-0.79, p = .0056). CBA was associated with fewer complications, and shorter procedure times, and greater fluoroscopy times, compared to RFA. Nonpulmonary vein ablation and electroanatomic mapping system use was common with CBA.

Bilateral Complete Cleft Lip Repair: A Step-by-Step Video Series.

Surgeons-in-training learning how to perform cleft surgery should not only acquire a broad repertoire of technical details but also master the proper execution of techniques based on the modern principles of bilateral cleft lip repair with synchronous reconstruction of cleft nose deformity. This article describes a bilateral complete cleft lip repair by adopting these principles, plus a modified composition of mucosal flaps for the nasal floor and intraoral linings, including the prolabial mucosal flap, C-flap mucosal flap, inferior turbinate mucosal flap, and lateral nasal mucosal flap. The accompanying four-part video series presents the step-by-step approach for design and execution of this alternative technique.

Abstract 16499: Hybrid Cryoballoon Pulmonary Vein Isolation and Radiofrequency Posterior Wall Isolation for Persistent Atrial Fibrillation

Introduction: Catheter ablation of persistent atrial fibrillation (AF) is associated with less successful outcomes compared to paroxysmal AF. The optimal ablation strategy for persistent AF is not well established. We report our center’s experience utilizing a hybrid ablation approach of cryoballoon (CB) pulmonary vein isolation (PVI) followed by radiofrequency (RF) left atrial posterior wall isolation (LAPWI). Methods: 134 patients with persistent AF who underwent catheter ablation between 2016 and 2019 at our center were retrospectively reviewed. Patients with congenital heart disease or prior left atrial ablation or surgery were excluded. Hybrid ablation (n=62) consisted of CB PVI followed by RF roof and floor lines resulting in LAPWI. The control group (n=72) had PVI ±LAPWI with either CB (n=38) or RF (n=34). Outcomes were monitored with office visits and 7-day Holter monitors at 3, 6, 12, and 24 months post-ablation. The primary endpoint was freedom from any documented atrial tachyarrhythmia over 30 seconds. Results: Concomitant atrial flutter ablation was performed in 19/62 (31%) and 5/72 (7%) of hybrid and control cases, respectively. There was no significant difference in procedure time, however fluoroscopy time was shorter with hybrid ablation compared to control (p&lt;.01). 18-month freedom from atrial tachyarrhythmias was 70.4% with hybrid ablation and 51.6% with PVI±LAPWI with a single energy source (p=.048). Among those with recurrence, mean AF burden was significantly lower with hybrid ablation (7%) than with a single-energy approach (60%). Conclusion: In this single center experience with multiple operators, hybrid CB-RF PVI and LAPWI reduced AF recurrence (incidence and burden) compared to PVI±LAPWI with a single energy source.

Epicardial course of the septopulmonary bundle: Anatomical considerations and clinical implications for roof line completion

Gaps in the roof line have been ascribed to epicardial conduction using the septopulmonary bundle. We sought to evaluate the frequency of septopulmonary bundle bypass during roof line ablation, to describe anatomical conditions favoring this epicardial gap, and to propose an alternative strategy when present. One hundred consecutive patients underwent atrial fibrillation ablation. A de novo roof line was created between the superior pulmonary veins. In cases of residual gaps, a floor line was created between the inferior pulmonary veins. Microtomography imaging and histological analyses of 5 human donor hearts were performed: a specific focus was made on the dome and the posterior wall. Residual gaps were more frequent in roof lines than floor lines (33% vs 15%; P = .049). Electrogram morphologies, activation sequences, and pacing maneuvers indicated an epicardial bypass of the roof line in all cases. Conduction block was obtained in 67 roof lines and 28 floor lines, resulting in a 95% success rate of linear block, without "box" isolation. Between the superior pulmonary veins, the atrial myocardium was thicker and consistently displayed adipose tissue separating the septopulmonary bundle from the septoatrial bundle. Epicardial conduction across the roof line is common and requires careful electrogram analysis to detect. In such cases, a floor line can be an effective alternative strategy, with clear validation criteria. Myocardial thickness and fat interposition may explain difficulties in achieving lesion transmurality during roof line ablation.

Combination of cryothermy with radiofrequency energy sources during hybrid atrial fibrillation ablation- impact on lesion quality and outcomes

Abstract Background Whereas pulmonary vein isolation lays the groundwork of endocardial atrial fibrillation (AF) ablation, it leaves patients undertreated. Additional substrate modification of the left atrium is often required, but lesion gaps and non-transmurality limit restoration of sinus rhythm. Moreover, some low voltage areas and conduction abnormalities are located exclusively on the epicardial aspect, and endocardial ablation alone does not address these issues. Our hybrid endo-/epicardial ablation strategy overcomes all these shortcomings. Purpose To test if the combination of epicardial cryo and radiofrequency (RF) ablation (dual) further improves the quality of ablation lines, and if the combined endo-/epicardial ablation can treat intractable cases of AF. Methods Twenty-six patients (13 paroxysmal, 13 long-persistent; 20 patients with 1–5 prior endocardial AF ablations) first underwent epicardial, total thoracoscopic beating heart ablation (TTA). Lesion sets included bilateral PVI, left atrial appendage closure, as well as superior (roof) and inferior (floor) interpulmonary vein lines. Roof and floor lines were alternatingly ablated by dual energy or RF only. Three months post TTA, endocardial mapping with optional gap closure completed this two-stage hybrid concept. Results Intraoperatively, 24 of 40 (60%) previous left or right endocardial PVIs were found incomplete. Apart from two post-TTA pacemaker insertions and one mini-thoracotomy for bleeding, respectively, no major morbidity was observed during follow up. The full protocol of the hybrid concept was applied in 24 patients. Forty-five of 47 (96%) epicardial PVIs were found gap-less during endocardial mapping, and the remaining 2 PVIs were readily re-ablated. In contrast, only 32 of 46 (70%) roof and floor lines were complete, and endocardial touch up was required in one of three patients. Of note, dual energy lines were more likely to be complete than RF only lines (17 of 22, 77%, vs. 15 of 24, 62%; p NS). Among 19 patients with continuous monitoring, only 4 (21%) had any AF burden including two patients within blanking period and before endocardial gap closure. The remaining 7 patients without continuous monitoring never experienced any symptoms related to recurrent AF, and serial Holter EKG were without pathology. Conclusions Hybrid ablation and dual energy provides a strong armamentarium for extra-pulmonary venous triggers of AF. Linear ablation lines were more likely to be gap-less and transmural, if dual energy sources were used. Dual energy TTA is highly efficient to restore sinus rhythm in patients with prior failed endocardial AF ablation. However, one of three patients will require endocardial gap closure to realize the full benefit of our two-stage hybrid concept. Further study will evaluate if dual energy lines outside the box can improve outcome in these challenging cases of intractable AF. Funding Acknowledgement Type of funding source: None

Thermal behaviour of waterproof coated fabrics and identification of chemical groups present in melt-blown polyester non-woven fabrics coated with waterproof acrylic polymer binder

Polyester non-woven fabrics are a good choice for base material in development of engineered waterproof fabrics. They find wide applications in bathroom floor lining, Roof lining, Car floor lining and many such applications. These fabrics not only provide strength and durability to the structure but also enhance the thermal as well as shelf-life of the structure. The presence of Chemical groups like ethylene functional group which is a chemical compound prominently present in polyester and observation of strong peaks of polyester functional groups aids in robust behaviour of the waterproof coated fabrics. These chemical groups present in the waterproof acrylic polymer binder also influences the development of durable fabrics with good hardness values. In this research a waterproof fabric for such applications is developed using a non-woven polyester fabric as the base material and roller coating process. The changes in the surface morphology of the fabrics is recorded and analysed using SEM micrographs. However, the analysis of thermal properties of these coated fabrics using DSC, TG/DTA instruments show melting of the coated material at 375 °C and TGA graphs show degradation of material occurring at 400 °C. The density measurement results show the fabrics ability to achieve lower values when nonwoven fabric layers are doubled which may be due to consumption of less binder and locking of air between layers. The Rockwell hardness results of 31.4 HRB (B scale) for single layer and 68.2 HRB for double layer proves the performance of the coated fabric at par with soft steel. The coated fabrics show zero air porosity when tested under air-permeability tester. The process of roller coating proves to be robust method of application of water proof polymer binder on non-woven fabrics.

Advantages and challenges for noninvasive atrial fibrillation ablation.

Although catheter ablation is an effective therapy for atrial fibrillation (AF), risks remain and improved efficacy is desired. Stereotactic radiotherapy is a well-established therapy used to noninvasively treat malignancies with precision. We sought to evaluate stereotactic arrhythmia radioablation (STAR) as a therapeutic option for treating AF. Three cancer patients with drug refractory AF were enrolled. Planning software using 3-D CT of the left atrium was used to design a desired ablation volume encompassing antral circumferential pulmonary vein isolation, roof and floor lines to create a "box" lesion set. After planning, patients were treated in the radioablation suite. STAR was able to deliver the intended radiation dose to the target in all 3 patients. No complications were observed over a follow-up period of 24 months. One patient with paroxysmal AF died from deterioration of cancer. The autopsy revealed evidence of fibroblasts and fibrogenesis in the region of atrial tissues targeted with radioablation. In one of these patients, left atrial posterior wall electrograms recorded from the esophagus before and 3 months after STAR indicated successful electrical isolation. This is the first report of non-invasive radioablation of the left atrium with demonstration of successful electrical isolation. Although STAR may be safe and effective in delivering ablative energy to the left atrium, further evaluation is warranted regarding effectiveness.

Initial experience with fractionation mapping-guided ablation strategy in patients with long-standing persistent atrial fibrillation.

We aimed to define the role of extended pulmonary vein isolation (PVI), posterior wall isolation, and mitral isthmus lines to eliminate electrograms exhibiting fractionation pattern during stepwise ablation on acute atrial fibrillation (AF) termination rate in patients with long-standing persistent AF (LSPAF). Twelve patients with LSPAF underwent ablation during AF. Using the fractionation mapping tool of the Ensite™ (Abbott Medical, Chicago, USA) system, sites exhibiting discrete atrial complexes and consistent activation sequence were mapped. The areas with a fractionation score above 4 were accepted as potential drivers for AF. During stepwise ablation consisting of circumferential PVI, roof and floor lines for posterior wall isolation, and mitral isthmus lines, ablation lines were extended toward potential AF drivers on the fractionation map as much as possible until sinus was achieved by ablation. Fractionation-guided ablation caused acute AF termination in 8 of 12 patients. In 6 of 12 cases, AF returned to sinus rhythm during the extended ablation. In 2 patients, AF shifted to sinus after cavotricuspid isthmus ablation. Sinus was achieved by cardioversion in 3 of cases. Procedural failure was seen in one case with significant scar tissue. During a mean follow-up of 31.5 ± 11months, overall arrhythmia-free survival was 92% with 2 procedures. This pilot study demonstrates that fractionation mapping-guided ablation may provide an adjunctive benefit in terms of acute AF termination in patients with LSPAF. These results should be confirmed by larger, randomized, comparison studies between linear ablation and extended ablation without elimination of electrograms (EGMs) with fractionation.

A Surgical and Educational Video of the Inferior Turbinate Mucosal Flap for the Nasal Floor and Intraoral Reconstruction in Unilateral Complete Cleft Lip Repair.

Since the original description of Millard rotation advancement principle for cleft lip repair, many important contributions have subsequently been described by other surgeons worldwide. However, the reconstruction of the nasal floor and intraoral lining has received less attention over time. This article demonstrates a modified unilateral complete cleft lip repair using the rotation advancement principle plus multipurpose inferior turbinate mucosal flap. The accompanying videos display the 10 key steps for rationale, design, and proper execution of the inferior turbinate mucosal flap for the nasal floor and intraoral reconstruction.

Characteristics and health effects of volatile organic compound emissions during paper and cardboard recycling

Urbanization generates increased amounts of solid wastes in cities and as a consequence leads to high air pollution levels. As a result of these trends, the subject of air quality management for sustainable concept of cities has received increasing attention. This work characterized volatile organic compound (VOC) emissions and health effects at different processing stages in a recycling facility for waste paper and cardboard. The highest total VOC levels were observed in the conveyor belt line one (5.23 ± 0.33 mg/m3), followed by a baling machine (1.38 ± 0.07 mg/m3), conveyor belt line two (1.34 ± 0.08 mg/m3), tipping floor line one (1.22 ± 0.07 mg/m3), and manual separation line one (1.20 ± 0.06 mg/m3). Hence, exposure to VOCs lead to high health risks in this PCSWRF, especially at the manual separation stage (HQ = 2.7–3 and lifetime cancer risks (LTCRs) = 1.11 × 10−4 - 1.03 × 10−4), and strategies such as adjustment of the factory to enclose the conveyors, designing proper ventilation and air conditioning systems, minimization of VOC-contaminated waste generation (pre-treatment), and using personal protective equipment should be considered to eliminate pollutants and to protect workers from the non-carcinogenic and carcinogenic effects.

P4798Stereotactic radiotherapy for atrial fibrillation in three cancer patients

Abstract Background Although catheter ablation is an effective therapy for atrial fibrillation (AF), risks remain and improved efficacy is desired. Stereotactic radiotherapy is a well-established therapy used to noninvasively treat malignancies with precision. Objective We sought to evaluate stereotactic arrhythmia radioablation (STAR) as a therapeutic option for treating AF. Methods Three cancer patients with drug refractory AF were enrolled. Planning software using 3-D CT of the left atrium was used to design a desired ablation volume encompassing antral circumferential pulmonary vein isolation, a roof line, and a floor line to create a “BOX” lesion set. Target dose to the treatment volume was 25 Gy, with exposure to the esophagus excluded. After planning, patients were treated in the radioablation suite. Results STAR was able to deliver the intended radiation dose to target without complication in 3 patients. No acute complications were seen for up to 6 months. One patient with paroxysmal AF died of deterioration of cancer. The autopsy revealed evidence of fibroblasts and fibrogenesis at the regions of atrial tissues targeted with radioablation. Two patients with longstanding persistent AF remained in AF at 6 months. In one patient, atrial electrograms were recorded at the atrial posterior wall from the esophagus before STAR, and it was absent at 3 months after STAR, indicating electrical isolation. BOX isolation created by STAR Conclusions Although STAR may be safe, further evaluation is warranted regarding effectiveness. For longstanding persistent AF, AF may be difficult to terminate only with a BOX lesion set without electrical cardioversion.

Stand-alone surgical ablation for atrial fibrillation: a novel bilateral double-port approach.

To explore an effective, reproducible and less invasive surgical approach for lone atrial fibrillation (AF). A modified "mini-maze" including pulmonary vein isolation (PVI), box-lesion and left atrial appendage (LAA) resection was applied for AF patients in our center from January 2016 to June 2017. A 2.5 cm thoracotomy extended with tissue retractor was made as working port in the fourth intercostal space on each anterior side of the chest. The thoracoscope was inserted in another port lateral to main port for observing. During PVI, the tip of the clamp could be adjusted to reach as superior as the roof of left atrium for transmural lesions. The floor line was made by linear ablation pen. The LAA was removed by stapler before PVI for better exposure of the roof. This modified "mini-maze" was successfully completed in 53 non-paroxysmal AF patients except 1 was converted to sternotomy due to intraoperative hemorrhage. All patients recovered uneventfully. Seven-day Holter was accessed in 3, 6 and 12 months respectively in all patients. The mean follow-up was 14 (range, 3-30) months. Sinus rhythm was achieved in 48.1%, 64.8% before discharge and 3 months after surgery respectively, Twenty-eight patients in sinus rhythm or not, underwent catheter mapping and ablation three months after the operation to conform the lesion set made by this procedure. Sinus rhythm reached 87.0% after subsequent catheter ablation without any anti-arrhythmia treatment at 12 months. All patients survived without stroke, hemorrhage and pulmonary vein stenosis. Modified "mini-maze" procedure is safe, less invasive and highly reproducible for lone AF. Sequential hybrid procedure will shape the treatment of non-paroxysmal AF.

Comparison of Cryoballoon and Hybrid surgical Posterior Wall Isolation for Persistent Atrial Fibrillation to conventional ablation.

Optimalablation strategy for persistent atrial fibrillation (AF) is unclear;PWI of the left atrium may improve outcome.Our aim was to compare outcomes of posterior wall isolation (PWI) ablation for persistent AF achieved by cryoballoon ablation (CRYO) or hybrid surgical ablation (HABL) to matched patients undergoing conventional radiofrequency ablation (CRA). In our single center retrospective study,patients underwent HABL and CRYO withcircumferential pulmonary vein ablation (CPVA),roof and floor lines to complete PW box lesion. CRA consisted of CPVA, roof line and lateral mitral isthmus line (MVI). Of 61 patients (mean duration of AF 1.3 ± 0.4 yrs)who underwent ablation, after follow-up of 366 ± 62 days, AF recurrence was 10.5% and 48% (p=0.001) and the need for repeat ablation 5% vs 30% (p=0.007) in PWI and CRA groups respectively, without a significant difference in incidence of AT/FL 18 vs 26 % or cardioversion 5.2 vs 7.1 %. Total procedure time and fluoroscopic time were 242 ±70 min vs 279 ±53 min (p=0.08) and 20±9 min vs 12 ± 4 min (p=0.003) for PWI and CRA respectively. CRYO had less AF recurrence and complications than HABL. Mean length of stayfor CRYO patients was 41 hrs compared to 145 hrs in HABL group, who underwent two procedures. PWI in persistent AF patients decreases recurrence of AF and need for repeat procedure compared to CRA; PWI by CRYO is superior to HABL due to less LOS and complications.

Foot Alignment in Symptomatic National Basketball Association Players Using Weightbearing Cone Beam Computed Tomography.

Background:Weightbearing cone beam computed tomography (WB CBCT) allows detailed 3-dimensional imaging of the foot and ankle in a weightbearing state and provides improved accuracy and reliability of foot alignment measures, especially when compared with conventional radiographic views.Purpose:To describe the foot alignment in National Basketball Association (NBA) players with different symptomatic foot and ankle injuries using WB CBCT and to determine if any predominant morphotype would be identified.Study Design:Cross-sectional study; Level of evidence, 3.Methods:A total of 45 active NBA players (mean age, 24.4 years [range, 20-34 years]; N = 54 feet [29 right, 25 left]) were assessed using WB CBCT. Measurements included the following: (1) foot and ankle offset (FAO), (2) calcaneal offset (CO), (3) hindfoot alignment angle (HAA), (4) angle between the inferior and superior facets of the talus (Inftal-Suptal), (5) angle between the inferior facet of the talus and the horizontal floor line (Inftal-Hor), (6) forefoot arch angle (FAA), (7) navicular-to-floor distance, and (8) medial cuneiform–to-floor distance. Measurements were then compared with values available in the literature for a “normal” foot morphotype.Results:Among the 54 feet, the mean FAO was 0.48% (95% CI, –0.25% to 1.21%), the mean CO was 1.18 mm (95% CI, –0.50 to 2.87 mm), and the mean HAA was 1.42° (95% CI, –0.80° to 3.65°). The mean Inftal-Suptal angle was 5.31° (95% CI, 3.50°-7.12°), while the mean Inftal-Hor angle was 4.04° (95% CI, 2.56°-5.51°). The mean FAA was 15.84° (95% CI, 14.73°-16.92°), the mean navicular-to-floor distance was 38.30 mm (95% CI, 36.19-40.42 mm), and the mean medial cuneiform–to-floor distance was 26.79 mm (95% CI, 25.30-28.28 mm). None of these values were found to be significantly different when comparing forwards, guards, and centers.Conclusion:NBA players presenting with symptomatic foot and ankle injuries had a fairly “normal” foot morphology, with a tendency toward a varus hindfoot and a high-arched morphotype. No significant differences were found between players based on their position on the court. WB CBCT may help to shed light on anatomic risk factors for common injuries in professional players and may aid in the planning of specific prevention programs.

The smoke emission properties of selected elements of passenger car interior design

The paper presents the results of tests for smoke optical density conducted on five various elements of car interior design. The tested samples were taken from the dashboard, ceiling lining, floor lining, seats and side door upholstery. A smoke density chamber was used to measure the propensity of the materials to generate smoke after being exposed to a heat source. The specific optical density, as a function of time, was determined for each material. There were two burning conditions simulated: radiant heating in the absence of ignition, and flaming combustion in the presence of supporting radiation. The highest values for specific optical density were measured for the side door upholstery and driver’s dashboard. The tests results were compared with international optical smoke density requirements for the interior design of ships and trains.