Conduction Gap Research Articles

Characteristics of right pulmonary vein with an epicardial connection needing additional carina ablation for isolation.

This study thought to elucidate the anatomical features that can predict an epicardial connection (EC) between the right pulmonary vein (RPV) and right atrium. We retrospectively analyzed 251 consecutive patients undergoing initial radiofrequency pulmonary vein isolation. We defined EC as present when RPV could not be isolated with circumferential ablation and additional ablation for the conduction gap if needed, and RPV isolation could be achieved by ablation for the earliest activation site >10 mm inside the initial ablation line. Using computed tomography data, we evaluated the RPV bifurcation angle, and the area occupation ratio of the carina region to the RPV antrum (ARC) for predicting EC. In subjects with EC undergoing RPV activation mapping after circumferential ablation, the correlation between conduction delay and bipolar/unipolar potential voltage in the carina region was investigated. There were ECs in 45 out of 251 patients (17.9%). The RPV bifurcation angle (47.7° vs. 38.8°, p < .001) and ARC (37.2% vs. 29.7%, p < .001) were significantly greater in the EC (+) group. Multivariate logistic regression analysis revealed that RPV bifurcation angle (odds ratio [OR]: 1.994, p = .002) and ARC (OR: 3.490, p = .013) were independent predictors of EC. In nine patients with EC undergoing carina region mapping, the unipolar potential voltage was correlated with conduction delay in RPV with EC (R = -0.401, p < .001). Anatomical features suggesting a wider RPV carina region could predict the presence of EC, and potential with high voltage could be helpful for detecting EC connection sites.

High-Power Short-Duration Lesion Index-Guided Posterior Wall Isolation beyond Pulmonary Vein Isolation for Persistent Atrial Fibrillation.

Background: High-power short-duration (HPSD) radiofrequency (RF) ablation has been adopted to improve atrial fibrillation (AF) ablation. Although the role of HPSD is well-established in pulmonary vein isolation (PVI), fewer data have assessed the impact of HPSD when addressing extra-pulmonary veins (PVs) targets. Therefore, this study aims to determine the safety, effectiveness, and acute outcomes of HPSD lesion index (LSI)-guided posterior wall isolation (PWI) in addition to PVI as an initial strategy in persistent atrial fibrillation (Pe-AF). Methods: Consecutive patients who underwent ablation of Pe-AF in our center between August 2021 and January 2022 were retrospectively enrolled. All patients' ablation strategy was PVI plus PWI using HPSD LSI-guided isolation. RF parameters included 50 W targeting LSI values of ≥5 on the anterior part of the PVs and anterior roofline and ≥4 for the posterior PVs aspect, bottom line, and within the posterior wall (PW). We compared the LSI values with and without acute conduction gaps after the initial first-pass PWI. Left atrial mapping was performed with the EnSite X mapping system and a high-density multipolar Grid-shaped mapping catheter. We compared the procedural characteristics using HPSD (n = 35) vs. a control group (n = 46). Results: Thirty-five consecutive patients were included in the study. PWI on top of PVI was achieved in all cases in the HPSD group. First-pass PVI was achieved in 93.3% of PVs (n = 126/135). First-pass roofline block was obtained in most patients (n = 31, 88.5%), while first-pass block of the bottom line was only achieved in 51.4% (n = 18). There were no significant differences compared to the control group; first-pass PVI was achieved in 94.9% of PVs (n = 169/178), first-pass roofline block in 89.1%, and bottom-line in 45.6% of patients. To achieve complete PWI with HPSD, scattered RF applications within the PW were necessary. No electrical reconnection of the PW was found after adenosine administration and the waiting period. The procedure and RF times were significantly shorter in the HPSD group compared to the control group, with values of 116.2 ± 10.9 vs. 144.5 ± 11.3 min, and 19.8 ± 3.6 vs. 26.3 ± 6.4 min, respectively, p < 0.001. Fluoroscopy time was comparable between both groups. No procedural complications were observed. At the 12-month follow-up, 71.4% of patients remained free from AF, with no differences between the groups. Conclusions: HPSD LSI-guided PWI on top of PVI seems effective and safe. Compared to a control group, HPSD is associated with similar rates of first-pass PWI and PVI but with a shorter procedural and RF time.

Effect of Drill Induced Noise on Contralateral Normal Ear Following Cortical Mastoidectomy.

Chronic suppurative otitis media (CSOM) is a long standing infection of the middle ear cleft. Mastoidectomy, with or without tympanoplasty, is the preferred treatment for CSOM. However, the drill used during ear surgery generates noise that may potentially cause hearing damage in both the operated and opposite inner ear, leading to temporary or permanent hearing loss. The study included patients diagnosed with CSOM who underwent surgeries in the Otorhinolaryngology department. Postoperatively, all patients were followed up on the 7th day and 1 month after the surgery. Pure Tone Audiometry (PTA) was performed to evaluate the hearing outcomes. A total of 61 patients were included in the study. The mean preoperative PTA of contralateral ear bone conduction among the study participants was 6.48. At the 7th day post-operation, the mean post-operative PTA of contralateral ear bone conduction for the same participants was 7.77. This difference was statistically significant according to the Paired T-test (P = 0.001).However, when evaluating the mean preoperative PTA of contralateral ear bone conduction (6.48) and the mean post-operative PTA at 1st month (6.02), the difference was not statistically significant (P = 0.208).Additionally, there was no statistical difference in air conduction and air-bone gap before and after surgery. The study suggests that mastoid drilling is associated with a significant temporary hearing loss in the contralateral ear immediately after surgery, which eventually recovers within a month. However, the hearing loss is considered negligible and not statistically significant in the long term. It is worth considering additional audiological investigations, such as otoacoustic emissions, to detect this type of hearing loss more accurately.

Electron and hole injection barriers between silicon substrate and RF magnetron sputtered In2O3 : Er films

In2O3 : Er films have been synthesized on silicon substrates by RF magnetron sputter deposition. The currents through the synthesized metal/oxide/semiconductor (MOS) structures (Si/In2O3 : Er/In-contact) have been measured for n and p type conductivity silicon substrates and described within the model of majority carrier thermoemission through the barrier, with bias voltage correction to the silicon potential drop. The electron and hole injection barriers between the silicon substrate and the film have been found to be 0.14 and 0.3 eV, respectively, by measuring the temperature dependence of the forward current at a low sub-barrier bias. The resulting low hole injection barrier is accounted for by the presence of defect state density spreading from the valence band edge into the In2O3 : Er band gap to form a hole conduction channel. The presence of defect state density in the In2O3 : Er band gap is confirmed by photoluminescence data in the respective energy range 1.55–3.0 eV. The band structure of the Si/In2O3 : Er heterojunction has been analyzed. The energy gap between the In2O3 : Er conduction band electrons and the band gap conduction channel holes has been estimated to be 1.56 eV.

Electron and hole injection barriers between silicon substrate and RF magnetron sputtered In2O3 : Er films

In2O3 : Er films have been synthesized on silicon substrates by RF magnetron sputter deposition. The currents through the synthesized metal/oxide/semiconductor (MOS) structures (Si/In2O3 : Er/In-contact) have been measured for n and p type conductivity silicon substrates and described within the model of majority carrier thermoemission through the barrier, with bias voltage correction to the silicon potential drop. The electron and hole injection barriers between the silicon substrate and the film have been found to be 0.14 and 0.3 eV, respectively, by measuring the temperature dependence of the forward current at a low sub-barrier bias. The resulting low hole injection barrier is accounted for by the presence of defect state density spreading from the valence band edge into the In2O3 : Er band gap to form a hole conduction channel. The presence of defect state density in the In2O3 : Er band gap is confirmed by photoluminescence data in the respective energy range 1.55–3.0 eV. The band structure of the Si/In2O3 : Er heterojunction has been analyzed. The energy gap between the In2O3 : Er conduction band electrons and the band gap conduction channel holes has been estimated to be 1.56 eV.

Delineation of conduction gaps of linear lesions during atrial fibrillation ablation using ultra-high-density mapping.

Linear lesions are routinely created by radiofrequency catheter ablation. Unwanted electrical conduction gaps can be produced and are often difficult to ablate. This study aimed to clarify the characteristics of conduction gaps during atrial fibrillation ablation by analysing bidirectional activation maps using a high-density mapping system (RHYTHMIA). This retrospective study included 31 patients who had conduction gaps along pulmonary vein (PV) isolation or box ablation lesions. Activation maps were sequentially created during pacing from the coronary sinus and PV to reveal the earliest activation site, defined by the entrance and exit. The locations, length between the entrance and exit (gap length), and direction were analysed. Thirty-four bidirectional activation maps were drawn: 21 were box isolation lesions (box group), and 13 were PV isolation lesions (PVI group). Among the box group, nine conduction gaps were present in the roof region and 12 in the bottom region, while nine in right PV and four in left PV among the PVI group. Gap lengths in the roof region were longer than those in the bottom region (26.8 ± 11.8 vs. 14.5 ± 9.8 mm; P = 0.022), while those in right PV tended to longer than those in left PV (28.0 ± 15.3 vs. 16.8 ± 8.0 mm, P = 0.201). The entrances and exits of electrical conduction gaps were separated, especially in the roof region, indicating that epicardial conduction might contribute to gap formation. Identifying the bidirectional conduction gap might indicate the location and direction of epicardial conduction.

Prevalence, Patterns, and Predictors Of Conduction Gaps And Reconnections After Single Ring Pulmonary Vein Isolation for Atrial Fibrillation

Prevalence, Patterns, and Predictors Of Conduction Gaps And Reconnections After Single Ring Pulmonary Vein Isolation for Atrial Fibrillation

Epicardial ablation of left atrial flutter

Abstract Funding Acknowledgements Type of funding sources: None. Background Left atrial flutter (LAFL) may have epicardial components not accessible to endocardial ablation by radiofrequency (RF) application. Subxiphoid access to the pericardial space has been reported in isolated cases. Purpose to prospectively evaluate the efficacy and safety of subxiphoid access to the pericardial space to map and ablate LAFL refractory to endocardial RF application. Methods Patients with LAFL confirmed by activation and entrainment mapping and refractory to endocardial RF application were consecutively enrolled. An epicardial component of the tachycardia circuit was suspected when parts of the AFL activation, channels of slow conduction or conduction gaps on previous ablation lines intersecting the AFL circuit were not found. Pericardial access was obtained by subxiphoid puncture performed conventionally or facilitated by saline infusion or CO2 insufflation into the pericardial space. Following pericardial access, epicardial mapping and ablation was performed with a conventional RF irrigated tip ablation catheter. All procedures were performed under oral anticoagulation and during following heparin infusion for 350 sec activation clotting time target. Results 15 patients with 18 LAFL were included (61.0 ± 8.8 years, 80% male). 14 patients have had a previous atrial fibrillation (AF) ablation. Epicardial ablation was attempted after a previous LAFL endocardial ablation procedure in 6 patients and during the same endocardial ablation procedure in the last 9 patients. Pericardial access was not achieved in 1 patient due to pericardial adhesions (after prior cardiac surgery). Ablation was successfully performed in 11 patients (73.33%) and failed in 4 patients with perimitral AFL (1 patient also had a peri-left appendage AFL). The successful ablation site was found in the transverse sinus of Theile over the Bachmann bundle in 14 patients with perimitral, septal and anterior-wall LAFL and in the oblique sinus in a posterior-wall LAFL. No patient presented relevant complications except for 2 patients who presented hemopericardium and 1 with delayed cardiac tamponade following accidental RV puncture and who required pericardiocentesis. No patient presented AFL recurrences at 19.8 months (range 6-34 months) follow-up except for 2 patients in whom ablation failed or pericardial access was not achieved. Conclusions Epicardial ablation of LAFL refractory to endocardial ablation is successful in most patients following successful pericardial access. This approach appears associated with low risk of significant complications.

Pulsed-field ablation based pulmonary vein isolation: reconnection pattern and comparison to cryoballoon ablation

Abstract Funding Acknowledgements Type of funding sources: None. Background Pulsed-field ablation (PFA) integrated into a pentaspline catheter is a novel single shot device to perform pulmonary vein isolation (PVI) for treatment of atrial fibrillation (AF). While initial data demonstrated high safety and efficacy, long-term PVI durability and reconnection patterns are unknown. Here, we analyzed findings from repeat ablation procedures after index PFA compared to cryoballoon ablation (CBA) based PVI. Methods We prospectively included consecutive patients with index PVI applying PFA (n=161) or CBA (n=302) who underwent repeat ablation due to symptomatic recurrence of AF or atrial tachycardia (AT) after a blanking period of 3 months. All repeat procedures were performed with a 3D mapping system and RF energy. Results We identified a total of 14 patients after previous PFA and 23 patients after previous CBA. PV reconnection was detected in 9/14 (64%) patients after PFA and in 16/23 (70%) after CBA (p=1.000). A total of 24/55 (44%) vs. 34/92 (37%) initially isolated PVs demonstrated electrical reconduction (p=0.487) after PFA and CB ablation. In both groups the right inferior PV was reconnected most frequently (9/24 (38%) patients after PFA and 10/34 (29%; p=0.578) patients after CBA). Distribution of conduction gaps is shown in figure 1. All PVs were successfully reisolated. Repeat procedures after index PFA and CBA showed similar duration (115±32 min vs. 114±49 min; p=0.785), fluoroscopy time (13±4 min vs. 14±8 min; p=0.558) and number of RF applications (38±23 vs. 36±34, p=0.738). Conclusion During repeat AF/AT ablation after previous PFA- or CBA-based PVI a comparable incidence of PV reconduction gaps was found. Repeat procedure times and fluoroscopy exposure were similar. Randomized controlled trials and longer follow-up are necessary to draw further conclusions.

PO-02-095 UTILITY OF LOCAL IMPEDANCE MONITORING TO GUIDE HIGH-POWER SHORT-DURATION RADIOFREQUENCY ABLATION FOR ATRIAL FIBRILLATION

Local impedance (LI) measurement can predict tissue heating during RF ablation. To evaluate the utility of prespecified target LI to prospectively guide high power, short-duration (HPSD) RF ablation for PV isolation. This is a single-center prospective study of 44 consecutive patients who underwent initial PV isolation for AF. Circumferential ablation around the antrum of each PV was performed using using a 4 mm tip open irrigation RF ablation catheter with an LI sensor. RF energy was applied at each site at power output of 50 W. Adequacy of each RF application was solely guided by LI measured from the ablation catheter. PV electrograms were not monitored during RF ablation. Annotation of RF ablation applications was based on predefined parameters: the: (1) catheter stability <3 mm; (2) LI drops by >5 Ω (regardless of baseline LI) within the first 5 seconds; and (3) RF application duration of >5 seconds. Each tagged RF application was continued for a total duration of 6-10 seconds for the LA posterior wall and 10-15 seconds for other LA regions. If the LI failed to drop quickly (>5-Ω decrease within the first 5 seconds energy delivery), RF application was interrupted and ablation catheter adjusted to achieve better tissue contact, and RF was reapplied. RF application was stopped if esophageal temperature rose to >40°C or LI dropped by >30 Ω. Ultrahigh-density mapping was performed after first pass encircling of all PVs with inter-lesion distance of 4 mm. First-pass PV isolation was achieved in 163 of 175 PVs (93.1%) in 34/44 patients (77.3%). In 5 PVs (in 5 patients), high-density mapping identified 11 LA-PV conduction gaps at sites where RF applications did not meet annotation criteria (due to catheter instability, esophageal heating, or lack of sufficient LI drop). In 7 other PVs (in 7 Patients), 10 conduction gaps were identified at sites where RF applications did satisfy our ablation protocol. Compared to sites with tagged ablation points with conduction gaps, sites without gaps (suggestive of acutely effective ablation lesions) exhibited significantly larger absolute LI drop (16.4 ± 6.7 Ω vs. 12.2 ± 4.6 Ω, p=0.01) and % change in LI (14.8% ± 5.1% vs. 10.9% ± 4%, p=0.013) during RF energy delivery. The anatomical distribution of conduction gaps is shown in Figure. No steam pops or major complications occurred during or after the procedures. Our prespecified LI target drop magnitude may be used prospectively to guide safe and successful HPSD ablation for AF.

AB-452663-2 LEFT ATRIAL BOX ISOLATION GUIDED BY FORCE-POWER-TIME FORMULA (ABLATION INDEX): HIGH PREVALENCE OF EPICARDIAL CONDUCTION VIA SEPTOPULMONARY BUNDLE IN ATRIAL FIBRILLATION PATIENTS

Circumferential, continuous, transmural atrial lesions are desired to facilitate pulmonary vein (PV) isolation. However, atrial wall thickness around the PV is variable (5-6 mm in the superior/anterior segments and 2-4 mm in the inferior/posterior segments). Previous experimental studies have shown that radiofrequency (RF) lesion depth and diameter can be predicted by a logarithmic formula using contact force (CF), RF power and application time (Force-Power-Time Formula, Ablation Index, AI). The purpose of this study was to test the ability of AI guided ablation to achieve left atrial (LA) box isolation by a single RF encirclement and examine the location of residual conduction (gap) within the box in patients with atrial fibrillation (AF). In 42 patients with AF, LA box isolation was performed using a 7.5Fr CF catheter (ThermoCool SmartTouch SF, Biosense Webster) and CARTO system. Using RF power (35-40Watts) and CF (5-45g), a target AI value of 380-400 was used for posterior/inferior segments with an inter-lesion distance (ILD) of 4mm and a target AI value of 550-600 for anterior/superior/septal segments with an ILD of 6mm along the box circumference (Figure). RF was delivered until AI reached target values or terminated prematurely when esophageal temperature reached <38.5°C. After the first encirclement along the box line, activation mapping was performed to confirm box isolation and identify gap locations. Total RF time for box isolation was 27.2±4.6 min and box circumference length was 21.2±2.5 cm. Complete box isolation was obtained by the first encirclement in 17/42 (40%) pts. In the remaining 25/42 (60%) pts, activation mapping within the box lesion set identified earliest atrial activation along the ablation line in only 4/42 (10%) pts (indicating endocardial gaps), whereas activation mapping within the box identified earliest atrial activation at a site distant from the ablation line in 21/42 (50%) pts, suggesting epicardial conduction through a septopulmonary bundle (Figure). Focal ablation at endocardial gaps along the ablation line or at the epicardial focal breakouts within the box resulted in compete box isolation in all 25 pts. LA box isolation guided by AI effectively prevented endocardial gaps along the ablation line. However, epicardial conduction via a septopulmonary bundle was often observed (50%).

PO-01-038 THE PREVALENCE AND CHARACTERISTICS OF THE ESOPHAGEAL THERMAL INJURY IN EXTENSIVE PULMONARY VEIN ISOLATION USING HIGH POWER-SHORT DURATION ABLATION STRATEGY

There is little knowledge regarding the impact of radiofrequency (RF) ablation on the esophageal area when using the high power-short duration (HPSD) strategy. The purpose of this study was to evaluate the prevalence and the characteristics of the esophageal thermal injury in extensive pulmonary vein isolation (extensive-PVI) using HPSD strategy. Eighty-five consecutive patients (age:67±9 year, male:63) undergoing index extensive-PVI followed by the esophagogastroscopy performed within 5 days after the procedure were studied. Fluoroscopic image of esophagography was registered on the CARTO3 system (Biosense Webster, Inc., CA, USA) using the CARTOUNIVU (Biosense Webster, Inc.) module to precisely determine the ablation sites, and RF applications were limited to the fixed 50W/5-second setting at the esophageal area without any use of esophageal temperature monitoring. Extensive-PVI including esophageal area was performed by the 50W RF applications, with the targeted interlesion distance of ≤6 mm, ablation index (AI) of 400 for the posterior wall, and contact force (CF) of 5-15g using Thermocool SmartTouch Surround Flow catheter (Biosense Webster, Inc). Esophagogastroscopy was performed 2±1 days after the procedure. In the esophageal area, a median number of RF applications was 8 per patient, application time was 5.1±1.2 seconds, CF was 8.9±2.8g, and AI was 300.9±28.0 per lesion. After the first encircling, additional RF application was required for the conduction gap on the esophageal area in 4.7% (4 of 85) of the patients. Sixteen patients (18.8%) developed esophageal thermal injury (esophageal erosion: 1 patient, gastric hypomotility: 15 patients). All patients with esophageal thermal injury were asymptomatic. Multivariate logistic regression analysis revealed that RF applications to the esophageal area positioned at the posterior wall of right pulmonary veins because of the central or right esophageal location was the independent predictor of the esophageal thermal injury (odds ratio: 7.92, 95% confidence interval: 1.15 to 54.49, p=0.035). Although asymptomatic esophageal thermal injury were not rare, extensive-PVI using HPSD with exclusive 50W/5-second applications on the esophagus could be performed with low risk of the esophageal mucosal injury while maintaining the durability of lesion. More careful RF applications may be required for the esophageal area positioned at the posterior wall of right pulmonary veins.

PE-452787-3 INITIAL EXPERIENCE OF PULSED FIELD ABLATION OF ATRIAL FIBRILLATION AND ATRIAL TACHYCARDIA IN ADULT PATIENTS WITH CONGENITAL HEART DISEASE

Prevalence of atrial tachycardias (AT) and atrial fibrillation (AF) is increasing in adult patients with congenital heart disease (CHD) significantly contributing to morbidity. Catheter ablation of AT and AF in the adult CHD population is challenging and recurrence is significant. Pulsed field ablation (PFA) is a new, non-thermal energy source for catheter ablation of AF. Due to its inherent properties of creating effective ablation lesions without permanent affection of non-myocardial tissue, it is attractive for the use in the adult CHD population. To date, its use in the adult CHD population has not been reported. This study describes initial experience of PFA of AT and AF in adult CHD patients. Prospective enrollment of adult CHD patients with a history of recurrent AT/AF, who had prior radiofrequency (RFA)/cryoenergy (Cryo) ablation of AT/AF. A high-density map using a 3D mapping system (EnSite™ Precision; Abbott) in conjunction with a high-density catheter (Advisor™ HD Grid; Abbott) was performed prior and after PFA. PFA was performed using the FARAWAVE™ ablation catheter (Boston Scientific) and applying repeated 2 kV pulses (2.5 s each) to the respective substrate. Procedural success was defined as complete substrate ablation (residual atrial electrograms < 0.05 mV on voltage map). Four adult CHD patients with recurrent AT/AF despite repeated previous RFA/cryoablation were enrolled. 2/4 had interrupted inferior V. cava and a transhepatic access was used to get access to the left atrium. PFA of all pulmonary vein ostia and the left atrial posterior wall was performed in 3 subjects. Additional PFA of a septal low voltage area was achieved in one of these patients. In the fourth patient with Ebstein’s anomaly, PFA of the cavotricuspid isthmus (CTI) and of a conduction gap within the crista terminalis was performed. Complete procedural success was achieved in all patients. Transient, fully reversible spasm of the right coronary artery without ECG changes occurred after PFA within the CTI. No recurrence of AT/AF was observed during follow-up of 5 months. Herein, we report for the first time the use of PFA in adult CHD patients with recurrent AT/AF. PFA turned out to be effective and generally safe. When using it in proximity to the coronary arteries, one must be aware of reversible coronary artery spasm. PFA might be a valuable tool to improve mid- and long-term outcome of AT/AF ablation in the adult CHD population.

Clinical Impact of Cardiac Fibrosis on Arrhythmia Recurrence after Ablation in Adults with Congenital Heart Disease

Adults with congenital heart disease (ACHD) are often affected by cardiac arrhythmias requiring catheter ablation. Catheter ablation in this setting represents the treatment of choice but is flawed by frequent recurrencies. Predictors of arrhythmia relapse have been identified, but the role of cardiac fibrosis in this setting has not been investigated. The aim of this study was to determine the role of the extension of cardiac fibrosis, detected by electroanatomical mapping, in predicting arrhythmia recurrencies after ablation in ACHD. Consecutive patients with congenital heart disease and atrial or ventricular arrhythmias undergoing catheter ablation were enrolled. An electroanatomical bipolar voltage map was performed during sinus rhythm in each patient and bipolar scar was assessed according to the current literature data. During follow-up, arrhythmia recurrences were recorded. The relationship between the extent of myocardial fibrosis and arrhythmia recurrence was assessed. Twenty patients underwent successful catheter ablation of atrial (14) or ventricular (6) arrhythmias, with no inducible arrhythmia at the end of the procedure. During a median follow-up period of 207 weeks (IQR 80 weeks), eight patients (40%; five atrial and three ventricular arrhythmias) had arrhythmia recurrence. Of the five patients undergoing a second ablation, four showed a new reentrant circuit, while one patient had a conduction gap across a previous ablation line. The extension of the bipolar scar area (HR 1.049, CI 1.011-1.089, p = 0.011) and the presence of a bipolar scar area >20 cm2 (HR 6.101, CI 1.147-32.442, p = 0.034) were identified as predictors of arrhythmia relapse. The extension of the bipolar scar area and the presence of a bipolar scar area >20 cm2 can predict arrhythmia relapse in ACHD undergoing catheter ablation of atrial and ventricular arrhythmias. Recurrent arrhythmias are often caused by circuits other than those previously ablated.

Effect of contact vector direction on achieving cavotricuspid isthmus block

Cavotricuspid isthmus (CTI) ablation is an important treatment strategy for CTI-dependent atrial flutter (AFL). The location of the catheter contact area is confirmed by the contact vector direction (CVD) through three-dimensional mapping during the procedure. However, the relationship between CVD during radiofrequency ablation and its efficacy in achieving CTI block has not been clarified. This study aimed to investigate the relationship between CVD and efficacy in achieving CTI block. CVDs during radiofrequency ablation were divided into proximal vectors against the distal tip (P-vector) and other vectors (normal-vector). In 39 patients who underwent CTI linear ablation, the CTIs were divided into two segments: the tricuspid valve area (anterior) and inferior vena cava area (posterior). The frequency of the residual conduction gap was compared between segments in which the P- and normal-vectors were observed. P-vectors were observed in 13 of the 78 segments. The median ablation index was not significantly different between segments in which the P-vector and normal-vector were observed (398.2 [384.2–402.2] vs. 393.3 [378.3–400.1], p = 0.15). However, residual conduction gaps were significantly more frequently observed in the segment in which the P-vector was observed than those in which only the normal-vector was observed (6/13, 46.2% vs. 3/65, 4.6%; p < 0.01). During a 6-month follow-up, two patients required a second session of ablation due to AFL recurrence. A residual conduction gap was observed in one patient at the site where the P-vector was observed in the first session. Avoiding the P-vector might be an important factor in improving CTI block and reducing AFL recurrence.

Long-Term Results of Tragal Cartilage Type 1 Tympanoplasty

Aim: Tympanoplasty is one of the most frequently performed operations by ear, nose, and throat specialists. Surgical treatment of tympanoplasty aims to obtain a healthy ear membrane and minimise hearing loss. The purpose of this study was to evaluate the success of the graft and functional hearing outcomes of patients applied with tragal cartilage type 1 tympanoplasty operation in our clinic. Materials and Methods: This study included 43 patients who underwent tragal cartilage type 1 tympanoplasty operation between January 2016 and November 2020. A retrospective evaluation was made of the preoperative pure tone audiometry (PTA) values and the operative findings. In the follow-up examination, the graft status and PTA results were recorded. The graft success and improvements in hearing were evaluated in all the patients. Results: A total of 43 patients were evaluated, comprising 24 males and 19 females with a mean age of 31.2 years (range, 13-58 years). The operation was performed on the right ear of 22 patients and the left ear of 21. The tympanoplasty operation was performed with an endaural approach in 6 cases and a postauricular approach in 37. The mean follow-up period was 20.8 months (range, 12-39 months). The rate of graft success of all the patients was 88.4%. The mean air conduction threshold, air-bone gap, and bone conduction threshold values at 500, 1000, 2000, and 4000 Hz were determined to have statistically significantly decreased postoperatively in comparison with the preoperative values (p&amp;lt;0.05). Conclusion: In tragal cartilage type 1 tympanoplasty operations, high rates of graft success were obtained and a dramatic gain in hearing postoperatively.

Comparative Study of Temporalis Fascia Graft versus Cartilage Shield Tympanoplasty in Chronic Otitis Media - Mucosal Type

Introduction: Tympanoplasty is the procedure of choice for surgical correction of tympanic membrane perforation triggered by either chronic otitis media or trauma. Various types of autologous grafts have been used to close tympanic membrane perforations among which temporalis fascia and tragal cartilage are preferred, due to their anatomic proximity, ease of harvesting and suppleness.&#x0D; Aims: To compare clinical and audiological outcomes of type 1 tympanoplasty where temporalis fascia and tragal cartilage were used as the graft material.&#x0D; Methods: A prospective study was conducted on 50 patients of ages ranging from 10 to 50 years with Chronic Otitis Media - Mucosal. All the patients underwent type 1 tympanoplasty and were categorized into Group-A (Temporalis fascia graft) and Group-B (Cartilage graft), each group comprising of 25 patients. Graft uptake rate, hearing gain and air bone gap closure were compared between the groups in 4 and 8 weeks after surgery.&#x0D; Results: Out of total 50 patients, 20 were male and 30 were female. The average age of the patients was 28.20 years. The total hearing gain in the whole series was 14.94 dB while the total air bone gap closure was 14.78 dB respectively. The difference between pre and post-operative hearing was statistically significant for both air bone gap and air conduction, (P&lt;0.05) in the whole series. There was 15.56 dB improvement in mean hearing threshold and 15.64 dB mean air bone gap closure in the fascia group, compared to 14.32 dB improvement in mean hearing and 13.92 dB mean air bone gap closure in the cartilage group. Graft uptake rate in the temporalis fascia group was 84% and the cartilage group was 92 % with significant difference in the graft uptake rate between the groups.&#x0D; Conclusion: The graft uptake rate and hearing results of tragal cartilage are comparable to those of temporalis fascia. Cartilage tympanoplasty has a higher graft uptake rate with low failure rate and also shows a high degree of reliability in high risk cases. Both cartilage and fascia tympanoplasty provided similar improvements in the hearing outcome post-operatively. Thus, cartilage tympanoplasty is recommended as an alternative option.

Comparative Study Of Placement Of Graft Medial Or Lateral To Handle Of Malleus In Inlay Technique Of Myringoplasty: A Retrospective And Prospective Study

Thisrandomized triple blindedretrospective and prospective study,was studied in terms of graft take-up rate, hearing improvement and complications and get more fruitful way for myringoplasty surgery. This studyof 180 patients were divided in two groups. Group A (51 patients) in whom graft was placed medial and in group B (129 patients) graft was placed lateral to the handle of malleus in modified inlay technique of myringoplasty.The results were compared at 3 weeks, 3- and 6-month follow-up. Pre- and post-operative air conduction (AC), bone conduction (BC) and air-bone gap (ABG) were compared. KEYWORDS Chronic otitis media, Myringoplasty, Inlay technique, Air Bone Gap, Conductive hearing Loss

High-density mapping improves detection of conduction gaps after pulmonary vein isolation ablation with a circular mapping catheter.

High-density (HD) mapping of the pulmonary vein (PVs) has been hypothesized to improve the detection of conduction gaps in the radiofrequency ablation lesions set after pulmonary vein isolation (PVI) for the treatment of atrial fibrillation (AF). We aimed to compare the incidence of gaps after PVI with a standard 20-pole circumferential mapping catheter (CMC-20) and an HD mapping catheter (HD Grid). This prospective study included patients scheduled for high-power short-duration PVI. Acute PVI was defined as an entrance and exit block using the CMC-20 after ≥ 20min waiting period. The left atrium was then remapped using the HD Grid high-density mapping catheter to identify residual conduction gaps in the PVI lines by voltage and activation criteria. The primary endpoint was the number of gaps identified per patient by the HD Grid catheter. A total of 20 patients were included (mean age 59.9 ± 10.8years, 15% female, 70% paroxysmal AF). The new map with the HD Grid identified 6 gaps in 4 patients (20%) or 0.3 ± 0.7 gaps per patient (p = 0.055 when compared to CMC-20). Five gaps (83%) were located at the right PVs. There was no difference in mapping time (CMC-20 12.2 ± 2.6min vs HD Grid 11.7 ± 3.4min, p = 0.452); however, the number of points was significantly higher in the HD Grid map (1662.7 ± 366.1 vs 1171.6 ± 313.6, p < 0.001). HD mapping during AF ablation identified PVI gaps in 1 out of 5 patients. Therefore, HD mapping may have the potential to improve AF ablation success rates in the long term. ClinicalTrials.gov NCT04850508 on April 20, 2021.

Optimal local impedance parameters for successful pulmonary vein isolation in patients with atrial fibrillation.

Local impedance (LI) parameters of IntellaNav STABLEPOINT for successful pulmonary vein isolation (PVI) of atrial fibrillation (AF) remain unclear. The purpose of this study was to seek LI data achieving successful PVI. Consecutive AF patients who underwent catheter ablation with STABLEPOINT were prospectively enrolled in two centers. PVI was performed under a constant 35-or 40-watt power, 20-sduration, and >5-gcontact force. The operators were blinded to the LI data. The characteristics of all ablation points with/without conduction gaps (Unsuccess or Success tags) after the first-attempt PVI were evaluated for the right/left PVs and anterior/posterior wall (RPV/LPV and AW/PW, respectively), and cutoff values of LI data were calculated for successful lesion formation. A total of 5257 ablation points in 102 patients (65 [58-72] years old, 65.7% male) were evaluated. The LI drop values were higher in the Success tags than Unsuccess tags on the LPV-AW and RPV-AW/PW (p < .001), except for the LPV-PW (p = .105). The %LI drop values (LI drop/initial LI) were higher for the Success tags in all areas (15.8 [12.2%-19.6%] vs. 11.6 [9.7%-15.6%] in LPV-AW: p < .001, 15.0 [11.5%-19.3%] vs. 11.4 [8.7%-17.3%] in LPV-PW: p = .035, 15.3 [11.5%-19.4%] vs. 9.9 [8.1%-13.7%]in RPV-AW: p < .001, and 13.3 [10.1%-17.4%] vs. 8.1 [6.3%-9.5%]in RPV-PW, p < .001). The LI drop and %LI drop cutoff values were 20.0 ohms and 11.6%, respectively. An insufficient LI drop with STABLEPOINT was associated with a gap formation during PVI, and the best cutoff values for the LI drop and %LI drop were 20.0 ohms and 11.6%, respectively.