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Funding Acknowledgements Type of funding sources: None. Introduction Transcatheter atrial fibrillation (AF) ablation is in most centres commonly carried out with continuous invasive radial arterial blood pressure (BP) monitoring. Novel devices enable continuous non-invasive BP monitoring, with acceptable agreement and optimal safety profile when compared to standard of care invasive BP monitoring, leading to improved patient comfort in the electrophysiology lab. Purpose Aim of the study was to assess in terms of procedural efficiency continuous non-invasive BP monitoring during transcatheter atrial fibrillation ablation. Methods We prospectively enrolled 42 consecutive patients (age 61±9 years, 80% male) undergoing transcatheter AF ablation (60% paroxysmal, 40% persistent) at our centre undergoing AF ablation with continuous BP measurement using a non-invasive finger volume clamp device. We then compared them with an historical cohort of 42 consecutive patients undergoing AF ablation (62% paroxysmal, 38% persistent) with standard of care invasive BP monitoring with a radial cannula. We compared the two groups in terms of total procedural duration (in and out from the EP lab). Results Mean total procedural duration was 165,29±54,95 minutes in the non-invasive group and 196,55±46,67 minutes in the invasive group (P=0,006). Conclusion In patients undergoing AF ablation, non-invasive finger volume-clamp continuous BP monitoring allowed for a significant reduction of total procedural duration when compared to standard of care invasive BP monitoring. Larger studies are needed to confirm these results.

Funding Acknowledgements Type of funding sources: None. Background The specific and well-known design features of leadless pacing system (Micra Transcatheter Pacing System, M-TPS) have suggested his use in patients that previously underwent transvenous lead extraction (TLE) for any reason. The study aimed to investigate feasibility and long-term outcomes of M-TPS implant in patients underwent TLE. Methods Patients undergone M-TPS implantation in our Institution from May 2014 to September 2022 were included in the study. All patients fulfilled standard criteria for PM implantation (VVI or VDD mode). Follow-up (FU) was scheduled at discharge, after 1 month and every 6 months thereafter and electrical parameters were checked. Major complications were defined as life-threatening events, requiring surgical intervention or any event causing significant hemodynamic instability or resulting in death. Study population was divided between "naïve pacing" and "post-extraction" patients. Results We enrolled 193 patients (76.7% males), 57 (29.5%) received M-TPS implantation after TLE, needed because of infection in 91.4% of cases. Indications for pacing were permanent AF with bradycardia in 107 (55.5%) patients, complete AVB in 59 (30.5%), symptomatic sinus node dysfunction in 20 (10%), and advanced AVB or bifascicular bock in 7 (4%). There were no statistically significant differences between groups for demographics characteristics and primary PM implant indications, except mean age at implant that was significantly inferior in the post-extraction group [80 (IQR 75-84) vs 78 (IQR 72-83), p=0.04]. Implant procedure was successful in all and no complications were recorded. No differences between groups in procedure duration [40 (IQR 30-50) vs 45 (30-65) min, p=0.34], fluoroscopy time [9 (6-14) vs 9 (6-11) min, p=0.31] and single device delivery (64.9% vs 67.9%, p=0.35) were observed. The mean FU was 12 (1-36) months, maximum 8 years. Pacing variables at implantation [pacing threshold 0.5 (0.38-0.63) vs 0.5 (0.38-0.88) V/0.24 ms, p=0.15; impedance 720 (600-837) vs 675 (615-825) Ohm, p=0.51; R wave amplitude 9 (6.25-12.87) vs 8.2 (5.65-12) mV, p=0.47], discharge [pacing threshold 0.38 (0.38-0.63) vs 0.38 (0.38-0.63) V/0.24 ms, p=0.27; impedance 685 (580-770) vs 610 (560-750) Ohm, p=0.16; R wave amplitude 10.25 (7.2-14.5) vs 9.3 (6.5-16.5) mV, p=0.6], and at 6 months [pacing threshold 0.5 (0.38-0.5) vs 0.5 (0.38-1.25) V/0.24 ms, p=0.64; impedance 580 (520-680) vs 570 (510-640) Ohm, p=0.63; R wave amplitude 11.9 (8.2-16.4) vs 11.7 (9-20) mV, p=0.68; battery voltage 3.09 (3.05-3.11) vs 3.09 (3.04-3.13) V, p=0.71] did not show differences. Conclusion M-TPS is an efficacious and safe alternative to conventional PM, with the main advantage of the absence of transvenous leads and a surgically created subcutaneous pocket, avoiding all the related complications. These devices are a reliable alternative after TLE, with similar electrical performances than those observed in patients who did not previously received pacing.

Funding Acknowledgements Type of funding sources: None. Early detection of atrial fibrillation is a major opportunity for mobile health, as portable devices nowadays available can detect multiple-lead electrocardiogram (ECG). The study aims to validate the in-ear region as a new anatomical site for ECG signal detection in patients (pts) affected by atrial fibrillation (AF). Methods We performed the ECG using KardiaMobile 6L device on 40 patients affected by AF and admitted to our hospital for elective electrical cardioversion. All the digital ECGs were detected in a modified modality or using the left in-ear region instead of the right hand. All the recorded ECGs were analyzed by the device and the results checked by two cardiologists. Results We successfully collected all 40 modified digital ECGs performed on the group of 40 pts: age 69.4 ± 9.4 years; male 28 (70)%; medium HR 95±25.4bpm; 26 (65%) affected by hypertension; 2 (5%) affected by diabetes mellitus; 37 (92,5%) in NOACs. In all cases, the KardiaMobile 6L automatic diagnosis of the ECG detected by this modified modality was correct in 100% of cases. Conclusion The in-ear region could be a reliable novel anatomical site for ECG signal detection in patients affected by atrial fibrillation. These data could support the development of new portable mobile ECG devices using the left in ear region and so leaving at least one hand free.

Funding Acknowledgements Type of funding sources: None. Background Catheter ablation is a recommended therapy for patients with ventricular tachycardia (VT). However, recurrences rate in non-ischemic cardiomyopathy (NICM) patients remains high. Objectives To analyze outcomes of VT substrate ablation facilitated by the integration into the navigator system of the preprocedural image scar characterization in both, patients with ischemic cardiomyopathy (ICM) cand NICM. Methods One hundred and sixty-five consecutive patients with structural heart disease undergoing scar related left-side VT ablation were included in a prospective European multicenter (5 centers) registry. Pixel signal intensity (PSI) maps from the late gadolinium enhancement-CMR (LGE-CMR) and/or the multi-detector cardiac tomography (MDCT) were imported into the navigator system. Ablation approach (e.g. endo vs epicardial; left vs right side) was based in the scar distribution aiming to eliminate the entire arrhythmogenic substrate. Mapping and ablation were focused in the scar areas. In all patients Scar dechanneling was the substrate ablation technique used. Results 165 [153 (93%) men, 66+12 y.o, 117 (71%) with ischemic heart disease] patients were included. Pre-procedure CMR was performed in 65 (39%), MDCT in 12 (7%) and both in 88 (53%) patients. VT induction protocol was negative after substrate ablation in 121 (73%) patients, completing the procedure in stable sinus rhythm. Procedure related complication rate was 5.5%. Arter a mean follow-up of 18+19 months, overall survival was 91% and 44 (27%) patients had VT recurrences. There was no difference in VT-free survival in ischemic vs non-ischemic patients (Log rank:0.9), as Figure 1 shows. Conclusions A strategy of VT substrate ablation facilitated by the integration into the navigator system of the preprocedural image scar characterization with the aim of eliminate the entire arrhythmogenic substrate results in a low recurrence rate. This approach minimizes the gap in VT-free survival after ablation in patients with ICM and NICM.

Funding Acknowledgements Type of funding sources: None. Introduction A previously validated algorithm allows to accurately identify ventricular tachycardia (VT) exit site in a 17-segments American Heart Association left ventricle model in patients with structural heart disease (SHD). ADAS3D is a novel artificial-intelligence cardiac magnetic resonance (CMR) post-processing software which enables heterogeneous tissue channel (HTC) identification. Purpose The aim of this study is to compare inferred VT exit site between QRS-axis based model and HTC identification from CMR post-processing. Methods All subjects allocated to a CMR-guided or aided approach from a multicenter randomized clinical trial were analyzed. Patients with available 12-lead ECG of clinical VT obtained before ablation were analyzed in terms of concordance between VT site of origin inferred from a QRS-axis and location of HTCs in a 17-segments model. Results 10 out of 15 patients had 12-lead ECG of clinical VT (80% male, 60% with ischemic cardiomyopathy, mean age 63,5±16,95 years, mean tachycardia cycle length 373,7±99,55 ms). 7 out of 10 patients (70,00%) had at least one HTC located at VT exit site as predicted by a QRS axis-based algorithm. In all remaining cases (3 out of 10) HTC location was found in a segment adjacent to ECG-derived exit site. All patients underwent CMR-guided or CMR-aided VT ablation with acute clinical success (noninducibility of the clinical VT). Conclusion VT site of origin prediction via a QRS axis-based algorithm allows for reasonable prediction of HTC presence at inferred site of origin. Larger studies are needed in order to confirm such findings and their potential clinical implications.

Funding Acknowledgements Type of funding sources: None. Background Electrical storm is a specific clinical presentation yielding to high morbidity and mortality. Acute development of electrical storms results from the underlying myocardial substrate, autonomic activation, and trigger factors. Main therapeutic approaches range from pharmacological to interventional treatment. Methods We enrolled in a prospective single center registry all patients admitted from March 2018 to March 2022 at our Centre who satisfied diagnostic criteria for electrical storm. Demographic, instrumental, and interventional data were obtained from local electronic health record. Results A total of 87 patients (79% male sex, mean age 72,21±10,49 years) were enrolled. Mean left ventricular ejection fraction was 37,27±11,62%. Underlying cardiomyopathy was ischemic in 57,47%; dilated cardiomyopathy in 20,69%, arrhythmogenic cardiomyopathy in 8%, other in 13,84%. A definite trigger was identified in 34 cases (39%), most frequent ones were sepsis (11 events, 32,4%), acute heart failure (6 events, 17,6%), myocardial ischemia (5 events, 14,7%), thyrotoxicosis (5 events, 14,7%), ionic disorder (4 events, 11,8%). An ICD was already implanted in 89,66% of patients, all remaining patients were implanted during index hospitalization. An ablation strategy was pursued in 65,52% of cases. Mean days from hospitalization to ablation were 7±5. Median hospital stay was 11 days (IQR 8-18). Conclusion In our single referral centre experience, in patients with electrical storm, ischemic cardiomyopathy was the dominant underlying heart disease. An identifiable trigger was found in a large cohort of patients, with sepsis being the most frequent. An ablation strategy was pursued in most cases.

Funding Acknowledgements Type of funding sources: None. Background the leadless pacing system, like Micra Transcatheter Pacing System (M-TPS) is precisely designed to reduce peri- and post-procedural complications, like pneumothorax, lead dislodgement, infections, and lead fracture.Previous studies have already demonstrated its good safety profile and the excellent electrical performance during the follow up. The study aimed to investigate feasibility and long-term electrical outcomes of M-TPS implant and estimate sex differences in leadless pacing. Methods All patients undergone M-TPS implantation in our Institution from May 2014 to October 2022 were included. All patients fulfilled standard criteria for VVI or VDD pacing according to guidelines. Device FU was scheduled at discharge, after 1 month and then every 6 months. Electrical performance was checked. Major complications were defined as life-threatening events, requiring surgical intervention or significant hemodynamic instability or resulting in death. Study population was divided between genders in order to analyze potential differences during the FU Results One hundred ninety-three consecutive patients [148 males, 76.7%, mean age 79 (IQR 73-84) y] were enrolled in this study. Indications for pacing were permanent AF with bradycardia in 107 (55.5%) patients, complete AV block in 59 (30.5%) patients, symptomatic sinus node dysfunction in 20 (10%) patients, and advanced AV block or bifascicular bock in 7 (4%). One hundred seventy-seven patients received VVI pacing, while 16 VDD. There were no statistically significant differences between groups for demographics characteristics (mean age at implant 79 vs 81, p=0.12), except gender. The mean was FU 12 (IQR 1-36) months, maximum 8 years. The implant procedure was successful in all patients and no complications were recorded. We observed no differences between groups in procedure duration [40 (IQR 30-60) min vs 40 (IQR 29-50), p=0.64], fluoroscopy time [9 (6-14) min vs 9 (7-11), p=0.81] and single device delivery (65.7% vs 65.9%, p=0.34). Electrical performance, except for pacing threshold at implantation [0.5 (IQR 0.38-0.75) V/0.24ms vs 0.38 (IQR 0.25-0.63) V/0.24ms, p=0.02), was similar between groups at discharge [pacing threshold 0.38 (IQR 0.38-0.63) V/0.24 ms vs 0.38 (IQR 0.25-0.55) V/0.24 ms, p=0.30; impedance 650 (IQR 560-760) Ohm vs 675 (IQR 580-780) Ohm, p=0.71; R wave amplitude 10.1 (IQR 7-16.2)mV vs 9.5 (IQR 7-14.45) mV, p=0.71] and during the FU [pacing threshold 0.5 (IQR 0.38-0.63) V/0.24 ms vs 0.5 (IQR 0.38-0.5) V/0.24 ms, p=0.11; impedance 570 (IQR 490-630) Ohm vs 580 (IQR 510-640) Ohm, p=0.46; R wave amplitude 11.5 (IQR 7.8-15.7)mV vs 12.7 (IQR 9-18) mV, p=0.26]. Conclusion Leadless pacing therapy is a feasible and safe alternative to conventional pacemakers with similar electrical performance and outcomes during a long-term FU. No differences were found between genders making it a good option especially in women who are often considered fragile in surgical procedure.

Funding Acknowledgements Type of funding sources: None. Background Atrial fibrillation (AF) results in electrical and structural remodeling of the atria, and the extent of remodeling has already been found to be associated with higher AF recurrence rate after catheter ablation (CA). Recently, a novel echocardiographic parameter derived from tissue Doppler imaging (TDI), called PA-TDI, has been introduced to assess the total atrial activation time, as a non-invasive surrogate of fibrosis and atrial cardiomyopathy. The aim of the study was to investigate the role of PA-TDI interval as predictor of AF ablation efficacy. Methods Consecutive patients with persistent or paroxysmal symptomatic AF referred to our Center to perform radiofrequency ablation or cryoablation procedures were prospectively enrolled. In these patients, a complete transthoracic echocardiographic examination was performed before and after the ablation procedure, including assessment of the PA-TDI interval. Results From October 2018 to May 2020, 221 consecutive patients (mean age 61 ± 9 years, 74% male, mean BMI 26.5 ± 3.6, mean Ejection Fraction 61 ± 6%) symptomatic for AF, undergoing the procedure ablation (first procedure or re-do) were enrolled. Out of the blanking period, 25% of patients experienced recurrence of arrhythmia during follow-up (mean 16 months). Compared to patients who did not relapse, patients with AF recurrence have a generally longer post-procedural PA-TDI interval (139.6 ± 22.1 msec vs 153.9 ± 33 msec, respectively). In the multivariable analysis only post-procedure PA-TDI and re-do interventions were found to be independent predictors of AF recurrence. A PA-TDI cut-off>144msec identifies patients at risk of post ablation AF recurrence with sensitivity 58.7% and specificity 73.5% (AUC 0.697). Conclusions The PA-TDI interval is an independent predictor of AF recurrence after catheter ablation. This echocardiographic parameter is easily obtainable, low-cost, reproducible, and accessible even in peripheral centers.

Funding Acknowledgements Type of funding sources: None. Background The need for cardiac pacing progressively increases with age and the elderly constitute a special subset of patients, being often very fragile and at a greater risk for procedural complications. Leadless pacing systems appear to be a safe and effective option, being devoid of most complications associated with traditional transvenous pacing systems. Purpose This study aimed to analyze a single-center experience with M-TPS (Micra Transcatheter Pacing System) implantation in terms of safety and efficacy in a long-term follow-up. Methods Between May 2014 and November 2022, 193 patients underwent M-TPS implantation in our Center, all patients fulfilled standard criteria for pacemaker implantation with indication to receive either VVI or VDD pacing. We divided the study population into two groups according to age (group 1 < 79 y vs group 2 >= 80 y) and analyzed procedural outcomes, electrical performance of the system at follow-up (FU), rate of procedural major complications and of device-related events at FU. Results In 95/193 cases (69 males, 73%) M-TPS was implanted in patients > 80 y. There were no statistically significant differences between groups in baseline characteristics. Implant procedure was successful in all cases and no device-related events were registered during FU. Patients were followed-up for an average of 18 months, up to 7 years. No differences were observed between groups in procedure duration, single device delivery (group 1 vs group 2: 62.1 vs 69.6%, p=0.17), fluoroscopy time [10 (IQR 6-14) vs 8.5 (IQR 6-12.5) minutes, p=0.27], electrical performance at implant: pacing threshold [0.44 (0.38-0.63) vs 0.5 (0.38-0.75) V/0.24 ms, p=0.39]; impedance [710 (610-840) vs 700 (600-810) Ohm, p=0.56]; R wave amplitude [9.3 (6 -13.5) vs 8.2 (6 -11.9) mV, p=0.68] and at 6 months follow-up : pacing threshold [0.5 (0.38-0.5) vs 0.38 (0.38-0.5) V/0.24 ms, p=0.25]; impedance [580 (500-640) vs 570 (530-680) Ohm, p=0.38]; R wave amplitude [13.2 (9.5-17) vs 9.7 (7.8-16.7) mV, p=0.17]. The only statistically significant difference was found in the percentage of ventricular pacing (Vp%), which was higher in group 2 [5.3 (IQR 0.5-35) vs 38% (IQR 14-83), p=0.001] and stayed higher at a 12 months follow-up [11 (1-53) vs 60% (10-94)], p=0.001). High pacing threshold (>= 1mV@0.24ms) at implant was present in thirty-one patients (14 vs 19%, p=0.43). Conclusions As the population ages the incidence of rhythm disturbances raises, increasing the need for cardiac pacing. It is imperative to find a therapeutic solution that suits the elderly offering them high efficacy and a low rate of complications. MTP-S implant is an effective and safe procedure in elderly patients with similar electrical performance and outcomes compared with younger patients at long-term follow-up. While initially thought for patients that could not undergo traditional pacing interventions, MTP-S is now emerging as a valid substitute.

Funding Acknowledgements Type of funding sources: None. Introduction Atrial Fibrillation (AF) ablation is associated with continuous blood pressure (BP) variations related to anesthesiological regimen and energy delivery. Conventional BP monitoring with non-invasive periodic brachial BP controls can miss potential hypotensive events. Continuous non-invasive blood pressure (CNBP) measurement using the volume-clamp method (Clearsight) was demonstrated to be a reliable and effective tool for the assessment of BP during AF ablation. Purpose Aim of the study was to investigate the incidence of hypotensive events during AF ablation. Methods We included consecutive patients scheduled for AF ablation and monitored in parallel with a periodic (10 minutes) brachial BP cuff and in continuous with the CNBP System (Clearsight). All CNBP data were analyzed with the Acumen Analytics software for hypotension evaluation. According to the anesthesiological regimen, patients were divided in 2 Groups, the General Anesthesia (GA) and the Deep Sedation (DS) group. Area under the threshold (AUT, mmHg x min) of 65 mmHg and Time Weighted Average (TWA, mmHg, i.e., the AUT divided by the total duration of procedure in minutes) of area under threshold (MAP Results Forty-eight patients were included, 10 (21%) in the General Anesthesia Group and 38 (79%) in the Sedation Group. Hypotension was detected in 18 patients, 9/10 (90%) were recorded in the GA group and 9/38 (23.7%) in the DS one. A total of 85 hypotensive events were recorded, 68 (80%) in the GA and 17 (20%) in the DS Group. In the overall population, mean duration of hypotensive events was 4.87 minutes (range 0 – 14.73 minutes), mean MAP < 65 mmHg was 54.25 ± 7.2 mmHg, mean AUT (MAP Conclusions CNBP demonstrated a high incidence of hypotension during AF ablation, specially under GA, which are usually missed by the standard intermittent brachial non-invasive BP monitoring. Real time hypotension predictive CNBP indexes could be valuable in this setting.

Background In the early post transcatheter aortic valve replacement (TAVR) discharge era, rate of readmission for permanent pacemaker implantation (PPM-I) due to delayed conduction disturbances (CDs) has significantly increased. This issue has powered post procedural ambulatory electrocardiogram (AECG) monitoring by using implantable cardiac monitors or mobile cardiac telemetry devices, despite several disadvantages as frequent electrode changes and costs. Purpose In this scenario we aimed to evaluate the incidence of post-TAVR new onset arrhythmias and delayed CDs, performing an AECG monitoring through a 30s spot digital ECG (AeECG), by using a mobile electrocardiogram 6 lead (ME6L) device in a 30 days period after a TAVR procedure. Methods Between March 2021 and February 2022 we consecutively enrolled all patients undergoing a TAVR at the University Hospital of Pisa, excepting who already had a PM. At discharge, all patients received ME6L device and were asked to record a spot eECG for 1 month: 1 eECG per day during the first week and then 1 eECG per week. Clinical and follow-up data were collected and analyzed, and eECG scheduling compliance and quality recordings were explored. Results Among 185 consecutive TAVR patients, 12 were excluded due to pre-existing pacing device and 33 due to PPM-I Conclusion Delayed CDs requiring PPM-I are the most important drawback of TAVR procedure. In our study, AeECG was seen to be safe and helpful in the identification and treatment of delayed CDs requiring PPM-I, with a very high eECG schedule level of compliance and quality. Further prospective studies are needed to better identify patient selection for outpatient monitoring, making safer and safer the early post TAVR discharge approach. Funding Acknowledgement Type of funding sources: None.

Introduction PVI isolation confirmation after RF ablation is often time-consuming, especially in case of a single transeptal catheter approach into the left atrium. A novel Live View (LV) dynamic display mapping software, utilized in combination with the High Density (HD) Grid mapping catheter, allows to display beat-to-beat, dynamic regional mapping data. Purpose We evaluated the feasibility and the procedural impact of a procedural left atrial workflow with a single transeptal-single HD catheter analysis, incorporating the LV Mapping Software for the assessment of PVI after ablation. Methods Paroxysmal and persistent AF patients scheduled for AF ablation were prospectively enrolled. All patients underwent only PVI under LSI guidance (LSI between 5.5 and 6 anteriorly; LSI between 4.5 and 5 posteriorly) with a point by point strategy and an inter-lesion distance Results Forty-six patients with AF (58% paroxysmal) were prospectively enrolled. Twenty-five patients were included in the HD-LV Group and 21 in the HD-SM Group. PVI was successful in all patients. LV dynamic display analysis was feasible in all patients and allowed a simple and fast validation of right and left PVI, without the necessity of introducing a second catheter into the left atrium. The split screen modality, with a dynamic activation map on the left and a dynamic voltage map on the right, allowed to switch from CS pacing to sinus rhythm without the necessity of a remap. The overall mapping time (27±10 vs 37±14 min, p=0.006), total procedure time (138±33 vs 178±50 min, p=0.006) and fluoroscopy time (14±5.3 vs 23±11 min, p=0.006) were significantly lower in the HD-LV Group. No complication was seen in either group. Conclusions A simplified clinical utilization of LiveView dynamic display with a single transeptal-single HD catheter approach is feasible and efficient after PVI, potentially simplifying the procedural workflow. A real-time dynamic mapping in daily practice may further enhance the clinical benefits of HD mapping during radiofrequency (RF) catheter ablation procedures. Funding Acknowledgement Type of funding sources: None.

Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): The registry was sponsored Medtronic, Inc., Minneapolis, MN. Background Atrial fibrillation (AF), the most common cardiac arrhythmia, burdening patients with a myriad of symptoms. Three recent randomized trials demonstrated that cryoballoon ablation (CBA) is superior to antiarrhythmic drugs (AADs) as a first-line treatment for the prevention of arrhythmia reoccurrence in patients with paroxysmal AF. However, the global outcome of CBA performed according to local standard of care as a first-line therapy for AF is not reported. Purpose To compare safety, efficacy, and quality of life outcomes in patients treated with CBA for first-line management of AF against patients treated with CBA following failed AAD therapy. Methods The Cryo AF Global Registry, an ongoing, prospective, multicenter registry, of AF patients undergoing index CBA performed according to local standards at 58 centers in 26 countries worldwide. In this analysis, subjects undergoing first-line cryoablation were compared to patients who were refractory to AAD therapy and/or taking AADs at baseline. Safety was assessed utilizing a composite of serious procedure-related complications. To evaluate efficacy, time-to-first atrial fibrillation, -flutter and/or -tachycardia (AF/AFL/AT) recurrence post a 90-day blanking period was compared between groups using Kaplan-Meier estimates. Quality of life was evaluated using the EQ-5D-3L questionnaire at baseline and at 12 months following CBA. Log-rank, two-sample t-test, and exact binomial tests were utilized to test difference between groups. Results Of 1,394 total patients, 433 (31.1%) were drug naïve prior to CBA. Patients in the AAD therapy cohort failed a mean of 1.2 ± 0.5 AADs before CBA. Freedom from AF/AFL/AT recurrence at 12 months was 87.8% in first-line patients compared to 81.6% in AAD-refractory patients (p Conclusion This real-world global evaluation supports CBA as a safe and efficacious first-line treatment that improves the quality of life for patients with symptomatic AF.

Funding Acknowledgements Type of funding sources: None. Introduction Patients undergoing transvenous lead extraction (TLE) usually receive general anesthesia, although in our experience local anesthesia is a frequent alternative. Purpose We sought to verify safety and effectiveness of local anesthesia in patients undergoing tranvenous lead extraction (TLE). Methods A retrospective analysis of patients who underwent to TLE in our center was performed. 1293 patients were divided in three groups depending on EROS class and comparisons were made in each group depending on type of anesthesia. Lead extraction was performed by manual traction or mechanical dilatation and use of transjugular approach was evaluated on case-by-case. Results In the EROS 1 group (726 pts.) 559 (77%) receive local anesthesia, in the EROS 2 (367 pts.) 252 (69%) and in the EROS 3 (200 pts.) 73 (36%). There was no differences in total complications (EROS 1 3.76% vs 2.99%, p=0.814, EROS 2 4.76% vs 5.21%, p=0.851, EROS 3 5.48% vs 11.81%, p=0.210) and clinical success (EROS 1 98.75% vs 99.40%, p=0.689, EROS 2 98.41% vs 94.78%, p=0.077, EROS 3 80.82% vs 85.04%, p=0.439) between local and general anesthesia throughout the groups; use of internal jugular approach was significantly higher in EROS 2 patients undergoing general anesthesia (4.76% vs 11.30%, p=0.021), while in EROS 1 and 3 patients this difference was not statistically significant (EROS 1 5.01% vs 8.38%, p= 0.101, EROS 3 8,22% vs 18,11%, p=0.056). Conclusion These results suggest that local anesthesia in patients undergoing transvenous lead extraction does not affect procedural outcomes and safety. Complex procedures with the need for internal jugular approach may drive this choice with preference for general anesthesia.

Funding Acknowledgements Type of funding sources: None. Purpose Early detection of cardiac arrhythmias is a major opportunity for mobile health, as portable devices nowadays available can detect multiple-lead electrocardiogram (ECG). The study aims to validate the in-ear region as a new anatomical site for ECG signal detection in patients (pts) affected by atrial tachyarrhythmias. Methods We performed the ECG using KardiaMobile 6L device on 20 patients affected by tachyarrhythmias and admitted to our hospital for electrical cardioversion. All the digital ECGs were detected in a modified modality or using the left in-ear region instead of the right hand. All the recorded ECGs were analyzed by the device and the results checked by two cardiologists. Results We successfully collected all 20 modified digital ECGs performed on the group of 20 pts (age 68.4 ± 9.2 years; male 60%; 14pts in atrial fibrillation (AF); 6pts in atrial flutter (AFl); medium HR 94±28.4bpm; 65% affected by hypertension; 5% affected by diabetes mellitus; 95% in NOACs). In case of AF, the KardiaMobile 6L diagnosis of the ECG detected by this modified modality was correct in 100% of cases. In the 6 pts affected by AFl the KardiaMobile 6L diagnosis was "normal" in 3 cases and "not classified" in the other 3. For that reason, in these 6 pts, we performed a new digital ECG using the KardiaMobile 6L in the standard modality, and the diagnosis for each patients was the same. Conclusion The in-ear region could be a reliable novel anatomical site for ECG signal detection in patients affected by atrial fibrillation. Further studies are needed to overcome the misdiagnosis of digital ECG in case of patients affected by atrial flutter. These data support the development of new portable ECG devices using the left in ear region and so leaving at least one hand free.

Funding Acknowledgements Type of funding sources: None. Background Ablation index (AI) is a radiofrequency energy lesion quality marker integrating power, contact force, and time, which was recently shown to be linked to successful catheter ablation (CA) of atrial fibrillation, atrial flutter, and premature ventricular complexes. The possible role of AI as a predictor of outcomes after CA of focal atrial tachycardia (AT) has not been explored so far. Purpose To evaluate the role of AI as a predictor of arrhythmia-free survival after CA of focal AT. Methods We retrospectively enrolled forty-five consecutive patients undergoing CA for focal AT in four referral Italian electrophysiology laboratories. Clinical and procedural information were collected. For each patient, maximum and mean (by averaging maximum AI values for each radiofrequency ablation lesion) values of AI were measured. Focal AT-free survival was the primary outcome, and was assessed with repeated Holter monitors or cardiac implantable electronic devices, when available. The Shapiro-Wilk’s test was used to check continuous variables for normality; non-normal variables were expressed as median (1st-3rd quartile), whereas categorical variables were reported as counts and percentages. The primary outcome was assessed in a time-to-event fashion, with the Kaplan-Meier method, and the role of AI as a predictor of focal AT recurrence was tested with univariable Cox proportional hazard regression. Furthermore, differences in AI values between patients experiencing a primary outcome event and patients not experiencing a primary outcome event were analyzed with the Student t test. Discrimination ability of AI was measured with area under the receiver operating characteristic curve, and the optimal AI cutoff value was identified with Youden’s index. An alpha level Results CA was acutely effective in every patient; however, 20% (n=9) of the study population had a focal AT recurrence over a median follow-up of 288 (160-560) days. Both maximum and mean AI values were significantly higher among patients without AT recurrences (maximum AI=568±91, mean AI=426±105) than in patients with AT relapses (maximum AI=447±142, mean AI=352±76, p=0.036 and p=0.028, respectively). All other procedural parameters were similar between the two groups. In a time-to-event analysis, only maximum AI was significantly associated with survival free from AT recurrence (p=0.001, Figure), whereas mean AI was not (p=0.08). By receiver operating characteristic (ROC) curve analysis, the optimal maximum AI cutoff for predicting effective CA according to Youden’s index was 461 (sensitivity, 0.89; specificity, 0.56). Conclusion We observed a strong association between maximum AI and outcomes, suggesting that maximum AI may be regarded as a quantitative marker of successful CA of focal AT.

Funding Acknowledgements Type of funding sources: None. Introduction Transcatheter atrial fibrillation (AF) ablation is still carried out with continuous invasive radial arterial blood pressure (BP) monitoring in many centers. Continuous noninvasive blood pressure (CNBP) measurement using the volume-clamp method is a non invasive alternative method used in ICU. No data on CNBP reliability are available in the electrophysiology lab during AF ablation, where rhythm variations are common. Purpose The objective of the present study was to compare continuous noninvasive arterial pressure measured with the ClearSight device with invasive radial artery pressure, used as the reference method during AF ablation. Methods We prospectively enrolled 55 consecutive patients (age 62±11 years, 79% male) undergoing transcatheter AF ablation (62% paroxysmal, 38% persistent) at our center. Standard of care invasive BP monitoring via a radial cannula and a contro-lateral non-invasive finger volume-clamp continuous BP measurement device were positioned simultaneously in all patients for the entire procedure. Bland-Altman analysis was used to analyze agreement between the two techniques. Results A total of 1219 paired measurements for systolic, diastolic, and mean arterial pressure were obtained in 55 subjects, with a mean (SD) of 22 (9) measurements per patient. Mean bias (SD) was -12,97 (13,89) mmHg for systolic pressure (level of agreement -14,24–40,20; correlation coefficient 0,84), -1,85 (8,52) mmHg for diastolic pressure (level of agreement -18,54–14,84; correlation coefficient 0,77) and 2,31 (8,75) mmHg for mean pressure (level of agreement -14,84–19,46; correlation coefficient 0,85). Conclusion In patients undergoing AF ablation, non-invasive finger volume-clamp continuous BP monitoring with the ClearSight device showed acceptable agreement with standard of care invasive BP monitoring. Larger studies are needed to confirm potential clinical implications of a continuous non-invasive BP monitoring during AF ablation.

Funding Acknowledgements Type of funding sources: None. Background Infections and malfunction are major indications to transvenous lead extraction. Managing extracted patients represents a clinical and interventional challenge, since this population may be at higher risk for mechanical, vascular or infective complications. The use of leadless pacing systems has been described as a potentially useful technology that could tackle the obstacles that affect this peculiar population. The study aimed to investigate feasibility and long-term outcomes of M-TPS implant in a specific patient population, like post transvenous lead extraction patients, which represent a challenge for conventional cardiac pacing. Methods Between May 2014 and November 2021, 155 patients (120 males, 77.42%, mean age 78 ± 9 y) underwent M-TPS implantation in our Center, targeting a non-apical site of delivery when feasible. A subgroup of 48 patients (39 males, 81.25%) had undergone transvenous lead extraction. All patients fulfilled standard criteria for pacemaker implantation with specific indication to receive VVI pacing. The outcome evaluation included electrical performance (capture threshold, pacing impedance, R wave amplitude) before hospital discharge and then followed at 1, 6, and 12 months and then annually. Major complications were defined as life-threatening events, required surgical intervention or any event causing significant hemodynamic instability or resulting in death. High pacing threshold (HPT) was defined as 1.0 V/0.24 ms. Results In 48/155 cases (39 males, 81,25%) M-TPS was implanted after successful transvenous lead extraction. There were no statistically significant differences between groups for demographics characteristics, and PM implant indications. The implant procedure was successful in all cases and no device-related events were registered during follow-up. In particular, no device infection and/or malfunction were reported. Patients were followed-up for an average of 24 months (median 18 months). No differences were observed between groups in procedure duration, single device delivery (group 1 vs group 2: 63.21% vs 73.91%, p=0.20), fluoroscopy time (group 1 vs group 2: 11.79 ± 7.53 vs 10.49 ± 6.19 minutes, p=0.64), electrical performance at implant (group 1 vs group 2: pacing threshold 0.54 ± 0.35 V/0.24 ms vs 0.62 ± 0.32 V/0.24 ms, p=0.09; impedance 758.02 ± 227.89 Ohm vs 724.26 ± 178.14 Ohm, p=0.36; R wave amplitude 10.1 ± 4.73 mV vs 9.59 ± 5.30 mV, p=0.50) and at 18 month F-U (group 1 vs group 2: pacing threshold 0.50 ± 0.10 V/0.24 ms vs 0.85 ± 0.9 V/0.24 ms, p=0.45; impedance 559.58 ± 94.43 Ohm vs 543.34 ± 64.39 Ohm, p=0.69; R wave amplitude 12.00 ± 5.06 mV vs 13.42 ± 5.77 mV, p=0.55). Conclusions Leadless pacemaker implant is a feasible, safe and effective option for patients treated with transvenous lead extraction, with electrical performance and outcomes comparable to a cohort of naïve patients at long-term follow up.

Funding Acknowledgements Type of funding sources: None. Introduction The ELECTRa Registry Outcome Score (EROS) was developed to identify patients at increased transvenous lead extraction (TLE) risk Purpose Aim of the study is to explore the efficiency of EROS for stratifying patients undergoing TLE. Methods We performed a retrospective analysis of 1293 patients who underwent to TLE in our center. We performed extraction procedures with manual traction or mechanical dilatation. We calculated EROS, and we divided patients into 3 groups depending on the EROS class. For this purpose, we made statistical analysis and comparison between EROS 1+2 vs. EROS 3 groups. We used an X2 for among-group comparisons or Fisher’s exact test if the expected cell count was less than five. Results Our analysis included 1293 patients. EROS-1 counted 726 patients (56,1%), EROS-2 367 (28,4%) patients and EROS-3 200 (15,5%) patients. There was no statistical difference in peri-procedural death between EROS-1+2 and EROS-3 (0.18% vs 1.50%, p=0.134). Major complications (0.82% vs. 3.00%, p=0.014), minor complications (3.11% vs. 6.50%, p=0.019) and use of internal jugular approach (6.13% vs. 14.50%, p Conclusion EROS effectively separates patients at higher risk of complications. Use of internal jugular approach was significantly higher in EROS 3 patients.

Funding Acknowledgements Type of funding sources: None. Introduction Data on left atrial/left atrial appendage (LA/LAA) thrombus resolution after non–vitamin K antagonist (VKA) oral anticoagulant treatment (OAT) are scarce. Purpose The aim of this study was to explore retrospectively the resolution of LA/LAA spontaneous echo-contrast or thrombus in patients with nonvalvular atrial fibrillation (AF) or atrial flutter (AFL) after OAT in a real-world single center practice. Methods A single center retrospective analysis of patients with AF/AFL who underwent a transesophageal echocardiography (TEE) for an electrical cardioversion and/or atrial fibrillation ablation was performed. Patients showing LA/LAA echo-contrast or thrombus and with at least one TEE follow up to detect the resolution of LA/LAA echo-contrast/thrombus were included and analyzed. Results Among 277 TEE performed, 73 cases (26%) of LA/LAA echo-contrast or thrombus were detected in our hospital. Among them, a total of 53 patients showed LAA/LA echo-contrast (19%) and 20 (7%) patients showed a thrombus. Patients with echo-contrast or thrombus were usually male (78% vs 72%, p=0.05) with more comorbidities, as hypertension (90% vs 72%, p=0.03) and congestive heart failure (36% vs 17%, p=0.007) and with an overall higher CHA2DS2-Vasc score (3.5±1.5 vs 3±1, p=0.0001). All they were under chronic anticoagulation with a VKA (65%) or with a NOAC (35%), without differences between groups. (p=NS). At the TTE/TEE analysis, they showed a comparable ejection fraction (55±11 vs 55±22%, p=NS), a trend for an increased LA dilatation (27±8 vs 26±6 cm2, p=0.07) and a low LAA peak velocity (94% vs 19%, p=0.0001). The Echo-contrast Group maintained the same OAT strategy in 49 patients (93%), switching from VKA to NOAC in 3 cases (6%) and from NOAC to NOAC in 1 (1%). The Thrombus Group kept the same OAT strategy with a NOAC in 6 cases (30%) and changed the strategy in 14 patients (70%). Particularly, they titrated NOAC dose in 1 (5%) and the VKA dose in 4 (20%), switched from NOAC to VKA in 5 (25%), from VKA to NOAC in 3(15%) and from NOAC to NOAC in 1 (5%). Smoke resolution was observed in LA/LAA smoke group in 1/10 cases (10%) after a median time of 52 days (20-135) and LA/LAA thrombus resolution 8/15 (53%) after a median time of 45 days (25-180). Patients with the thrombus resolution had a lower CHA2DS2-Vasc score (3.5±2 vs 4±1, p=0.05), and showed a trend for a more frequent use of a NOAC (37.5 vs 28%, p=0.07) and a longer overall anticoagulation time (7.5 vs 4 months, p=0.08). At one-year follow-up, 1 ischemic stroke (1.9%) and 2 deaths (3.8%) were observed only in the Echo-contrast group. Conclusion(s) In OAT patients with an LA/LAA thrombus changing the OAT strategy is associated with thrombus resolution in more than 50% of cases, after an appropriate anticoagulation period and in lower CHAD2S2Vasc patients. Chronic OAT strategy confirmation, also with NOAC, is rarely effective, also in case of echo-contrast resolution.

Background Atrial fibrillation (AF) results in electrical and structural remodeling of the atria, and the extent of remodeling has already been found to be associated with higher AF recurrence rate after catheter ablation (CA). Recently, a novel echocardiographic parameter derived from tissue Doppler imaging (TDI), called PA–TDI, has been introduced to assess the total atrial activation time, as a non–invasive surrogate of fibrosis and atrial cardiomyopathy. The aim of the study was to investigate the role of PA–TDI interval as predictor of AF ablation efficacy. Methods Consecutive patients with persistent or paroxysmal symptomatic AF referred to our Center to perform radiofrequency ablation or cryoablation procedures were prospectively enrolled. In these patients, a complete transthoracic echocardiographic examination was performed before and after the ablation procedure, including assessment of the PA–TDI interval. Results From October 2018 to May 2020, 221 consecutive patients (mean age 61 ± 9 years, 74% male, mean BMI 26.5 ± 3.6, mean Ejection Fraction 61 ± 6%) symptomatic for AF, undergoing the procedure ablation (first procedure or re–do) were enrolled. Out of the blanking period, 25% of patients experienced recurrence of arrhythmia during follow–up (mean 16 months). Compared to patients who did not relapse, patients with AF recurrence have a generally longer post–procedural PA–TDI interval (139.6 ± 22.1 msec vs 153.9 ± 33 msec, respectively). In the multivariable analysis only post–procedure PA–TDI and re–do interventions were found to be independent predictors of AF recurrence. A PA–TDI cut–off> 144msec identifies patients at risk of post ablation AF recurrence with sensitivity 58.7% and specificity 73.5% (AUC 0.697). Conclusions The PA–TDI interval is an independent predictor of AF recurrence after catheter ablation. This echocardiographic parameter is easily obtainable, low–cost, reproducible, and accessible even in peripheral centers.

Background The use of a leadless pacing system, like Micra Transcatheter Pacing System (M–TPS), is nowadays a convincing alternative to transvenous pacemaker. PURPOSE: The study aimed to investigate feasibility and long–term electrical outcomes of M–TPS implant in a real–world population and to estimate sex differences in leadless pacing. Methods All patients undergone M–TPS implantation in our Institution from May 2014 to October 2022. Device follow–up was scheduled at discharge, after 1 month from procedure and then every 6 months. Electrical performance was checked. Major complications were defined as life– threatening events, requiring surgical intervention or any event causing significant hemodynamic instability or resulting in death. Study population was divided between genders to analyze potential differences and those observed during the follow–up (FU). Results One hundred ninety–three consecutive patients [148 males, 76.7%, mean age 79 (IQR 73–84) years] were enrolled in the study. There were no statistically significant differences between groups for demographics characteristics (mean age at implant 79 vs 81, p=0.12), except gender. The mean FU was 12 (IQR 1–36) months, maximum 8 years. The implant procedure was effectuve in all patients and no complications were recorded. We observed no differences between groups in procedure duration [40 (IQR 30–60) min vs 40 (IQR 29–50), p=0.64], fluoroscopy time [9 (6–14) min vs 9 (7–11), p=0.81] and single device delivery (65.7% vs 65.9%, p=0.34). Electrical performance, except for pacing threshold at implantation [0.5 (IQR 0.38–0.75) V/0.24ms vs 0.38 (IQR 0.25–0.63) V/0.24ms, p=0.02), was similar between groups at discharge [pacing threshold 0.38 (IQR 0.38–0.63) V/0.24 ms vs 0.38 (IQR 0.25–0.55) V/0.24 ms, p=0.30; impedance 650 (IQR 560–760) Ohm vs 675 (IQR 580–780) Ohm, p=0.71; R wave amplitude 10.1 (IQR 7–16.2)mV vs 9.5 (IQR 7–14.45) mV, p=0.71] and during the FU [pacing threshold 0.5 (IQR 0.38–0.63) V/0.24 ms vs 0.5 (IQR 0.38–0.5) V/0.24 ms, p=0.11; impedance 570 (IQR 490–630) Ohm vs 580 (IQR 510–640) Ohm, p=0.46; R wave amplitude 11.5 (IQR 7.8–15.7)mV vs 12.7 (IQR 9–18) mV, p=0.26]. Conclusion Leadless pacing therapy is a feasible and safe alternative to conventional pacemakers with comparable electrical performance and outcomes even during a long–term FU. No differences were found between genders making it a good option especially in women who are often considered fragile in surgical procedures.

A 66 year old woman with dilated cardiomyopathy, carrier of CRT–D device in secondary prevention since 2013 and a mitralic mechanical prosthesis, suffered of CIED infection, confirmed by PET imaging exam. She was scheduled in our Hospital Unit for transvenous lead extraction. The procedure was performed by the subclavian approach, and the transvenous lead extraction was staged using mechanical telescopic sheats. After the extraction of the atrial and ventricular leads, the advance of the sheats was hampered by tenacious adherences along the site of vascular subclavian access of the coronary sinus lead. Firstly the portion of the lead running inside the coronary sinus was retracted with a pigtail by femoral vein approach. The inability to pass over the tenacious adherences at the point of the subclavian vein access were overcome expanding the surgical field with the help of the Vascular Surgeon, finding out that the adherence was determined by the presence of an osteophyte embracing the lead to the clavicle. The osteophyte was then surgically removed and the lead was finally extracted by jugular vein access. In this case the CIED leads were implanted using a intrathoracic subclavian venous access, where the vein lies behind the medial region of the clavicle. This approach could rarely lead to a periosteal penetration during needle advance that can generate osteophytes between the lead and the bone. In those circumstances the transvenous lead extraction could become extremely complicated, whatever technique is used.

Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This research project is funded by Tuscany Region Background/Introduction Electrocardiograms (ECGs) are rapidly moving from analog to digital versions. Consequently, a series of automatic analyses of standard 12-lead ECGs are attracting interest for their ability to support clinicians in the automatic recognition of specific features associated with different cardiac diseases [2]. Artificial Intelligence applications and Machine Learning (ML) algorithms have gained much attention in the last years for their ability to figure out patterns from data independently, without being explicitly taught rules. Peculiar features define the ECGs of patients with Brugada Syndrome (BrS); however, ambiguities still exist for the correct diagnosis of BrS and discrimination with respect to other pathologies. Purpose The BrAID (Brugada syndrome and Artificial Intelligence applications to Diagnosis) project aims to develop an innovative system for diagnosing Type 1 BrS based on ECG pattern recognition through the application of ML algorithms. In this work, an application of Echo State Networks (ESN), a type of Recurrent Neural Network (RNN), for the diagnosis of BrS from ECG is presented. Methods After approval from the Local Ethical Committees, 12-lead ECGs were obtained in patients enrolled in 5 Centers diagnosed with typical spontaneous Type 1 pattern (coved) (group A, 81 patients). Baseline ECG was also collected in patients undergoing the ajmaline test, classified as positive (group B, 37 patients) or negative (group C, 14 patients) according to test results. 174 patients with no clinical and familial history of arrhythmias were considered controls (group D). Data were collected from 4 beats extracted from the ECGs as input to the ESN. The datasets obtained in the different groups were used for the ESN model’s training and assessment (testing) through a double cross-validation approach. Results As shown in Table 1, the performances using three leads (V1, V2, V3) or V2 only were compared. The algorithm performance was assessed in all the datasets (group A+B+C+D) and in spontaneous BrS (group A) and controls (group D). A good accuracy (79.21%) was seen when the three leads were considered for groups A and D only; the best test set accuracy (80.20%) was obtained in the case in which V2 only was used as input in all the datasets. Conclusion(s) In this work, a novel system for diagnosing Type 1 BrS using an ESN approach was developed. Our preliminary results show that this ML model is able to detect ECG patterns associated with Type 1 BrS with good and comparable accuracy both when three leads (79.21% ) or V2 only (80.20%) were analyzed. The future availability of larger datasets could improve the model performance, increasing the ESN potentialities as a clinical support system tool to be used in everyday clinical practice. Table 1. The accuracy, specificity, and sensitivity reported for each dataset group are obtained through double cross-validation.

BackgroundType 1 Brugada syndrome (BrS) is a hereditary arrhythmogenic disease showing peculiar electrocardiographic (ECG) patterns, characterized by ST-segment elevation in the right precordial leads, and risk of Sudden Cardiac Death (SCD). Furthermore, although various ECG patterns are described in the literature, different individual ECG may show high-grade variability, making the diagnosis problematic. The study aims to develop an innovative system for an accurate diagnosis of Type 1 BrS based on ECG pattern recognition by Machine Learning (ML) models and blood markers analysis trough transcriptomic techniques.MethodsThe study is structured in 3 parts: (a) a retrospective study, with the first cohort of 300 anonymized ECG obtained in already diagnosed Type 1 BrS (75 spontaneous, 150 suspected) and 75 from control patients, which will be processed by ML analysis for pattern recognition; (b) a prospective study, with a cohort of 11 patients with spontaneous Type 1 BrS, 11 with drug-induced Type 1 BrS, 11 suspected BrS but negative to Na + channel blockers administration, and 11 controls, enrolled for ECG ML analysis and blood collection for transcriptomics and microvesicles analysis; (c) a validation study, with the third cohort of 100 patients (35 spontaneous and 35 drug-induced BrS, 30 controls) for ML algorithm and biomarkers testing.DiscussionThe BrAID system will help clinicians improve the diagnosis of Type 1 BrS by using multiple information, reducing the time between ECG recording and final diagnosis, integrating clinical, biochemical and ECG information thus favoring a more effective use of available resources.Trial registrationClinical Trial.gov, NCT04641585. Registered 17 November 2020,https://clinicaltrials.gov/ct2/show/NCT04641585

BACKGROUND: Dental implants are used to replace missing teeth for rehabilitating edentulous patients. In many patients it is not possible to place “standard length” dental implants because of the crestal bone vertical resorption. Clinicians, therefore, are faced with the dilemma of whether to attempt an augmentation procedure or to place shorter implants. Short implants could be a simpler alternative if they could provide similar clinical outcomes to longer implants placed in augmented bone. AIM/HYPOTHESIS: The aim of this RCT was to compare the outcome of 4 mm-long implants with implants at least 10 mm-long placed in posterior jaws augmented either with a mandibular interpositional equine block or with a porcine-derived granular bone placed through a lateral window below the lifted maxillary sinus. MATERIAL AND METHODS: Forty patients with atrophic posterior mandibles having 5–6 mm bone height above the mandibular canal and 40 pa- tients with atrophic maxillae having 4–5 mm below the maxillary sinus, were randomised according to a parallel group design to receive one to three 4.0 mm-long implants or one to three implants, which were at least 10 mm-long, in augmented bone. All implants had a diameter of 4.0 or 4.5 mm. Mandibles were vertically augmented with interpositional equine bone blocks and resorbable barriers. Implants were placed 4 months after interpositional grafting. Maxillary sinuses were augmented with particulated porcine bone via a lateral window and implants were placed simultaneously. Four months later, screw-retained reinforced acrylic restorations were delivered, and then replaced after 4 months by definitive screw-retained metal-composite prostheses. Outcome measures included prosthesis and implant failures, any complication and peri-implant mar- ginal bone level changes. RESULTS: One mandible fractured and the patient did not want to go ahead with the treatment. Six implant from the augmented group failed versus five 4.0 mm implants from the short implant group. There were no statistically significant differences in implant failures (P (chi-square test) = 1.000) or prostheses failures (P (chi-square test) = 0.399). At mandibular sites, nine augmented patients were affected by complications versus one patient treated with short implants (P (chi-square test) = 0.003), with the difference being statistically significant. No significant dif- ferences were found for the maxillae: eight sinus lift patients versus three patients rehabilitated with maxillary short implants were affected by complications (P (chi-square test) = 0.077). The difference in peri-implant marginal bone loss was statistically significant in the mandibles (mean difference: −0.12 mm, P (ANCOVA) = 0.006), but not in the maxillae (mean difference: −0.02 mm, P (ANCOVA) = 0.711). CONCLUSIONS AND CLINICAL IMPLICATIONS: Four months after loading 4.0 mm-long implants achieved similar results, if not better, than longer implants in augmented jaws, but were affected by fewer complications. Short implants might be a preferable choice to bone augmentation, especially in mandi- bles, since the treatment is less invasive, faster, cheaper, and associated with less morbidity, however, 5- to 10-year post-loading data is necessary before making reliable recommendations.

BACKGROUND: Osseointegrated dental implants are traditionally placed in healed ridges. Immediate post-extractive implants and immediate- delayed are those implants placed immediately after tooth extraction and after 2–6 weeks, respectively. The main advantage is to shorten treatment and to presumably decrease the naturally occurring bone resorption after tooth extraction. To the best knowledge of the authors there are no RCTs comparing all the three procedures. AIM/HYPOTHESIS: The aim of this RCT was to compare the clinical outcome of single implants placed immediately after tooth extraction with im- plants placed 6 weeks after tooth extraction (immediate-delayed placement), and with implants placed after 4 months of socket healing (delayed placement). MATERIAL AND METHODS: Two hundred and ten patients requiring a single implant-supported crown to replace a tooth to be extracted were randomised to receive immediate post-extractive implants (70 patients), immediate-delayed implants at 6 weeks (70 patients), and delayed implants after 4-month healing (70 patients) according to a parallel group design. When needed, patients had the socket grafted with a bone substitute and covered with a resorbable membrane. Implants inserted with at least 25 Ncm torque were left to heal unloaded for 4 months, whereas those inserted with less than 25 Ncm were left to heal unloaded for 6 months. Temporary crowns were delivered and were to be replaced by definitive ones after 4 months. Outcome measures were crown and implant failures, complications, peri-implant marginal bone level changes, aesthetic assessed using the Pink Esthetic Score (PES), and patient satisfaction recorded by blinded assessors. Patients were followed up to 1 year post-loading. RESULTS: Four implants (6%) failed in the immediate, four (6.2%) in the immediate-delayed, and one (1.6%) in the delayed group (P (chi-square test) = 0.369). Six immediate, six immediate-delayed and four delayed implants were affected by one complication each (P (chi-square test) = 0.792). Mean peri-implant marginal bone loss after 1 year was −0.25 ± 0.17 mm (CI95% −0.29, −0.20) at immediate, −0.29 ± 0.14 mm (CI95% −0.32, −0.25) at immediate-delayed, and −0.31 ± 0.16 mm (CI95% −0.35, −0.27) at delayed-placed implants (P (Kruskal Wallis test) = 0.015). One year after loading, the mean total aesthetic score was 12.52, 12.49 and 11.78 at the immediate, immediate-delayed and delayed groups, respectively (P (Kruskal Wallis test) < 0.001). All patients were fully satisfied both for function and aesthetics, and would undergo the same procedure again, with four exceptions (partially satisfied with aesthetics) (P = 0.785). CONCLUSIONS AND CLINICAL IMPLICATIONS: No statistically significant differences for failures, complications and patient satisfaction were observed when placing single implants immediately, 6 weeks or four months after tooth extraction, nevertheless failures were more frequent at immediate and immediate-delayed placed implants. Bone level changes were similar between the different procedures, but aesthetics showed better results at immediate and immediate-delayed implants.

This article reports a measurement of the production cross section of prompt isolated photon pairs in proton-antiproton collisions at √s=1.96TeV using the CDF II detector at the Fermilab Tevatron collider. The data correspond to an integrated luminosity of 5.36fb -1. The cross section is presented as a function of kinematic variables sensitive to the reaction mechanisms. The results are compared with three perturbative QCD calculations: (1) a leading-order parton shower Monte Carlo, (2) a fixed next-to-leading-order calculation and (3) a next-to-leading-order/next-to-next-to-leading-log resummed calculation. The comparisons show that, within their known limitations, all calculations predict the main features of the data, but no calculation adequately describes all aspects of the data. © 2011 American Physical Society.

The concept that the Carnot efficiency places an upper limit of 0.60-0.75 on the thermodynamic efficiency of photosynthetic primary photochemistry is examined using the PSI-LHCI preparation. The maximal quantum efficiency was determined approximately 0.99 which yielded a thermodynamic efficiency of 0.96, a value far above that predicted on the basis of the Carnot efficiency. The commonly presented reasoning leading to the Carnot efficiency idea was therefore critically examined. It is concluded that the crucial assumption that the pigment system, under illumination, is in equilibrium with the incident light field, at a black body temperature of Tr, is erroneous, as the temperature of the excited state pigments was experimentally shown to be that of the sample solvent (thermal bath), 280 K in this case. It is concluded that the classical reasoning used to describe the thermodynamics of heat systems is not applicable to "photonic" systems such as plant photosystems.

Recently, E. Montaldi and H. M. Srivastava [1] gave a rather simple proof of the classic hypergeometric identities of Cayley and Orr, which completely avoided the use both of differential equations and of relations between generalized hypergeometric series. The main object of this sequel to the earlier work [1] is to present a similar analysis of the various other hypergeometric identities of Cayley and Orr types. The alternative derivations given here provide a novel insight into the structure of these hypergeometric identities.

In this letter, a simple and efficient approach for the modeling of low-frequency dispersive phenomena in FETs is proposed. The method is based on the definition of a virtual, nondispersive associated device controlled by equivalent port voltages and it is justified on the basis of a physically-consistent, charge-controlled description of the device. Dispersive effects in FETs are accounted for by means of an intuitive circuit solution in the framework of any existing nonlinear dynamic model. The new equivalent-voltage model is identified on the basis of conventional measurements carried out under static and small-signal dynamic operating conditions. Nonlinear experimental tests confirm the validity of the proposed approach.