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Introduction: The IMPACT study established the role of controlled esophageal cooling in preventing esophageal thermal injury during radiofrequency (RF) ablation for atrial fibrillation (AF). The effect of esophageal cooling on ablation lesion delivery and procedural and patient outcomes had not been previously studied. The objective was to determine the effect of esophageal cooling on the formation of RF lesions, the ability to achieve procedural endpoints, and clinical outcomes. Methods: Participants in the IMPACT trial underwent AF ablation guided by Ablation Index (30 W at 350–400 AI posteriorly, 40 W at ≥450 AI anteriorly). A blinded 1:1 randomization assigned patients to the use of the ensoETM® device to keep esophageal temperature at 4°C during ablation or standard practice using a single‐sensor temperature probe. Ablation parameters and clinical outcomes were analyzed. Results: Procedural data from 188 patients were analyzed. Procedure and fluoroscopy times were similar, and all pulmonary veins were isolated. First‐pass pulmonary vein isolation and reconnection at the end of the waiting period were similar in both randomized groups (51/64 vs. 51/68; p = 0.54 and 5/64 vs. 7/68; p = 0.76, respectively). Posterior wall isolation was also similar: 24/33 versus 27/38; p = 0.88. Ablation effect on tissue, measured in impedance drop, was no different between the two randomized groups: 8.6Ω (IQR: 6–11.8) versus 8.76Ω (IQR: 6–12.2; p = 0.25). Arrhythmia recurrence was similar after 12 months (21.1% vs. 24.1%; 95% CI: 0.38–1.84; HR: 0.83; p = 0.66). Conclusions: Esophageal cooling has been shown to be effective in reducing ablation‐related thermal injury during RF ablation. This protection does not compromise standard procedural endpoints or clinical success at 12 months. [ABSTRACT FROM AUTHOR]

A 39‐years old ventricular lead of a right‐sided single‐chamber pacemaker required extraction for infection. Angulation at the right subclavian‐superior vena cava junction coupled with calcified fibrotic encapsulating tissue prevented advancement of a rotational dissecting sheath. To straighten the lead, it was pulled from the subclavian and out of the right internal jugular vein, whilst the Needle's‐Eye Snare via the femoral access provided counter‐traction. A 13‐french rotational dissecting sheath was successfully advanced over the lead via the jugular access to complete the lead extraction without any complication. [ABSTRACT FROM AUTHOR]

Aims: To investigate the abnormalities of the coronary venous system in candidates for cardiac resynchronization therapy (CRT) and describe methods for circumventing the resulting difficulties. Methods: From four implanting institutes, data of all CRT implants between October 2008 and October 2020 were screened for abnormal cardiac venous anatomy, defined as an anatomical variation not conforming to the accepted 'normal' anatomy. Patient demographics, procedural detail, and subsequent left ventricle (LV) lead pacing indices were collected. Results: From a total of 3548 CRT implants, 15 (0.42%) patients (80% male) of 72.2 ± 10.6 years in age with an LV ejection fraction of 34 ± 10.3% were identified to have had an abnormal cardiac venous anatomy over the study period. There were 13 cases of persistent left side superior vena cava (pLSVC), five of which had coronary sinus ostium atresia (CSOA) including two with an "unroofed" coronary sinus (CS); one patient had a unique anomalous origin of the CS and one patient had an isolated CSOA. In total 14 patients (60% repeat attempt) had successful percutaneous implant under general anesthesia (46.7%) via the cephalic vein (59.1%), using the femoral approach (53.3%) for levophase venography and/or pull‐through, including one case of endocardial LV implant. Pacing follow‐up over 37.64 ± 37.6 months demonstrated LV lead threshold between 0.62 and 2.9 volts (pulsewidth 0.4–1.5 ms) in all cases; five patients died within 2.92 ± 1.6 years of a successful implant. Conclusion: CRT devices can be implanted percutaneously even in the presence of substantial abnormalities of coronary venous anatomy. Alternative routes of venous access may be required. [ABSTRACT FROM AUTHOR]

Background: With an increasing number of cardiac implantable electronic devices (CIEDs), there has been a paralleled increase in demand for transvenous lead extraction (TLE). Cardiac surgeons (CS) and cardiologists perform TLE; however, data comparing the two groups of operators is scarce. Objective: We compared the outcomes of TLE performed by cardiologists and CS from six European lead extraction units. Method: Data was collected retrospectively of 2205 patients who had 3849 leads extracted (PROMET) between 2005 and 2018. Patient demographics and procedural outcomes were compared between the CS and cardiologist groups, using propensity score matching. A multivariate regression analysis was also performed for variables associated with 30‐day mortality. Results: CS performed the majority of extractions (59.8%), of leads with longer dwell times (90 [57–129 interquartile range (IQR)] vs. 62 [31–102 IQR] months, CS vs. cardiologists, p <.001) and with pre‐dominantly non‐infectious indications (57.4% vs. 50.2%, CS vs. cardiologists, p <.001). CS achieved a higher complete success per lead than the cardiologists (98.1% vs. 95.7%, respectively, p <.01), with a higher number of minor complications (5.51% vs. 2.1%, p <.01) and similar number of major complications (0.47% vs. 1.3%, p =.12). Thirty‐day mortality was similarly low in the CS and cardiologist groups (1.76% vs. 0.94%, p =.21). Unmatched data multivariate analysis revealed infection indication (OR 6.12 [1.9–20.3], p <.01), procedure duration (OR 1.01 [1.01–1.02], p <.01) and CS operator (OR 2.67, [1.12–6.37], p =.027) were associated with 30‐day mortality. Conclusion: TLE by CS was performed with similar safety and higher efficacy compared to cardiologists in high and medium‐volume lead extraction centers. [ABSTRACT FROM AUTHOR]

Introduction: Research evidence has shown that catheter ablation is a safe and superior treatment for atrial fibrillation (AF) compared to medical therapy, but real‐world practice has been slow to adopt an early interventional approach. This study aims to determine the cost effectiveness of catheter ablation compared to medical therapy from the perspective of the United Kingdom. Methods: A patient‐level Markov health‐state transition model was used to conduct a cost‐utility analysis. The population included patients previously treated for AF with medical therapy, including those with heart failure (HF), simulated over a lifetime horizon. Data sources included published literature on utilization and cardiovascular event rates in real world patients, a systematic literature review and meta‐analysis of randomized controlled trials for AF recurrence, and publicly available government data/reports on costs. Results: Catheter ablation resulted in a favorable incremental cost‐effectiveness ratio (ICER) of £8614 per additional quality adjusted life years (QALY) gained when compared to medical therapy. More patients in the medical therapy group failed rhythm control at any point compared to catheter ablation (72% vs. 24%) and at a faster rate (median time to treatment failure: 3.8 vs. 10 years). Additionally, catheter ablation was estimated to be more cost‐effective in patients with AF and HF (ICER = £6438) and remained cost‐effective over all tested time horizons (10, 15, and 20 years), with the ICER ranging from £9047–£15 737 per QALY gained. Conclusion: Catheter ablation is a cost‐effective treatment for atrial fibrillation, compared to medical therapy, from the perspective of the UK National Health Service. [ABSTRACT FROM AUTHOR]

Introduction: Before ablation, predicting the site of origin (SOO) of outflow tract ventricular arrhythmia (OTVA), can inform patient consent and facilitate appropriate procedural planning. We set out to determine if OTVA variability can accurately predict SOO. Methods: Consecutive patients with a clear SOO identified at OTVA ablation had their prior 24‐h ambulatory ECGs retrospectively analysed (derivation cohort). Percentage ventricular ectopic (VE) burden, hourly VE values, episodes of trigeminy/bigeminy, and the variability in these parameters were evaluated for their ability to distinguish right from left‐sided SOO. Effective parameters were then prospectively tested on a validation cohort of consecutive patients undergoing their first OTVA ablation. Results: High VE variability (coefficient of variation ≥0.7) and the presence of any hour with <50 VE, were found to accurately predict RVOT SOO in a derivation cohort of 40 patients. In a validation cohort of 29 patients, the correct SOO was prospectively identified in 23/29 patients (79.3%) using CoV, and 26/29 patients (89.7%) using VE < 50. Including current ECG algorithms, VE < 50 had the highest Youden Index (78), the highest positive predictive value (95.0%) and the highest negative predictive value (77.8%). Conclusion: VE variability and the presence of a single hour where VE < 50 can be used to accurately predict SOO in patients with OTVA. Accuracy of these parameters compares favorably to existing ECG algorithms. [ABSTRACT FROM AUTHOR]

Background: Transvenous lead extraction (TLE) is rising in parallel to cardiac implantable electronic device implantations. Persistent left side superior vena cava (PLSVC) is a relatively common anatomical variant in the healthy population; TLE in patients with a PLSVC is rare. Method: Data were collated from 6 European TLE institutes of 10 patients who had undergone lead extraction with a PLSVC. Patient demographics, procedural challenges and outcomes were reported. Results: Ten patients aged 73.4 ± 7.8 years (60% male) underwent TLE of 20 leads (3 left ventricle, 10 right ventricle, 7 right atrium) with dwell time of 82.95 ± 39.1 months. Of the 10 cases, 4 had an infection indication and 5 were biventricular system extractions; 25% of the extracted leads were defibrillator leads. The majority of the procedures were completed in the cardiac catheterization suite (80%) under general anaesthesia (60%) by cardiologists (80%) using a rotational powered sheath (65%). The Tandem approach was used successfully in 3 cases. Complete procedural success was obtained in 100% of cases in the absence of complications within 127.4 ± 74.7 min. There was no 30‐day mortality. Conclusion: TLE in PLSVC is feasible albeit rare. Standard extraction techniques in experienced hands are associated with favorable outcomes; the Tandem procedure may be an additional technique to improve the safety and efficacy of TLE in PLSVC. [ABSTRACT FROM AUTHOR]

Background: Cardiac implantable electronic device (CIED) therapy contributes to an improvement in morbidity and mortality across all patient demographics. Patient age is a recognized risk factor for unfavorable outcomes in invasive procedures. This is the largest series of non‐laser transvenous lead extraction (TLE) evaluating the association between patient age and procedure outcomes. Methods: Data of 2205 (3849 leads) patients was collected retrospectively from six European TLE centers between January 2005–December 2018 in the PROMET study. Of these, 153 patients with 319 leads were excluded for incomplete data. A comparison of outcomes was performed between the age groups young [< 50 years], young intermediate [50–69 years], older intermediate [70–79 years], and octogenarian [≥80 years]. Results: Infection was most common indication for TLE in the octogenarian cohort, less common in the younger population (60.1% vs. 33.2%, respectively, p <.01). High‐voltage leads were extracted most frequently from young patients, less frequently from octogenarians (31.6% vs. 10%, p <.001), while the opposite was evident for pacemaker leads (p <.001). Rotational sheath use was equally prevalent across all patient groups (p =.79). Minor and major complications across all the age groups were statistically similar, as was procedural success; the 30‐day mortality was most significant in the octogenarian and least in the young patients (4.9% vs. 0.4%, p =.005). Propensity matching multivariate analysis found systemic infection, lead dwell time, and patient age (p =.013, OR 1.064 [1.013–1.116]) increased risk of 30‐day mortality. Conclusion: TLE is safe and effective across all age groups. 30‐day mortality risk is significantly higher in the older patients. [ABSTRACT FROM AUTHOR]

Background: The Sars‐Cov‐2 infection is a multisystem illness that can affect the cardiovascular system. Tachyarrhythmias have been reported but the prevalence of bradyarrhythmia is unclear. Cases have been described of transient high‐degree atrioventricular (AV) block in COVID‐19 that were managed conservatively. Method: A database of all patients requiring temporary or permanent pacing in two linked cardiac centers was used to compare the number of procedures required during the first year of the pandemic compared to the corresponding period a year earlier. The database was cross‐referenced with a database of all patients testing positive for Sars‐Cov‐2 infection in both institutions to identify patients who required temporary or permanent pacing during COVID‐19. Results: The number of novel pacemaker implants was lower during the COVID‐19 pandemic than the same period the previous year (540 vs. 629, respectively), with a similar proportion of high‐degree AV block (38.3% vs. 33.2%, respectively, p =.069). Four patients with the Sars‐Cov‐2 infection had a pacemaker implanted for high‐degree AV block, two for sinus node dysfunction. Of this cohort of six patients, two succumbed to the COVID‐19 illness and one from non‐COVID sepsis. Device interrogation demonstrated a sustained pacing requirement in all cases. Conclusion: High‐degree AV block remained unaltered in prevalence during the COVID‐19 pandemic. There was no evidence of transient high‐degree AV block in patients with the Sars‐Cov‐2 infection. Our experience suggests that all clinically significant bradyarrhythmia should be treated by pacing according to usual protocols regardless of the COVID status. [ABSTRACT FROM AUTHOR]

The World Health Organization recognises that sexual harassment is an occupational hazard in medicine, but the prevalence of sexual harassment by patients is unknown. This global meta‐analysis found that a pooled prevalence of 45.13% of 18 803 physicians from several specialities (e.g. internal medicine and surgery) have ever experienced it. Hospitals should implement protective measures such as panic alarms for night shifts and isolated wards. [ABSTRACT FROM AUTHOR]

Background: Coronavirus disease‐2019 (COVID‐19) causes severe illness and multi‐organ dysfunction. An abnormal electrocardiogram is associated with poor outcome, and QT prolongation during the illness has been linked to pharmacological effects. This study sought to investigate the effects of the COVID‐19 illness on the corrected QT interval (QTc). Method: For 293 consecutive patients admitted to our hospital via the emergency department for COVID‐19 between 01/03/20 ‐18/05/20, demographic data, laboratory findings, admission electrocardiograph and clinical observations were compared in those who survived and those who died within 6 weeks. Hospital records were reviewed for prior electrocardiograms for comparison with those recorded on presentation with COVID‐19. Results: Patients who died were older than survivors (82 vs 69.8 years, p < 0.001), more likely to have cancer (22.3% vs 13.1%, p = 0.034), dementia (25.6% vs 10.7%, p = 0.034) and ischemic heart disease (27.8% vs 10.7%, p < 0.001). Deceased patients exhibited higher levels of C‐reactive protein (244.6 mg/L vs 146.5 mg/L, p < 0.01), troponin (1982.4 ng/L vs 413.4 ng/L, p = 0.017), with a significantly longer QTc interval (461.1 ms vs 449.3 ms, p = 0.007). Pre‐COVID electrocardiograms were located for 172 patients; the QTc recorded on presentation with COVID‐19 was longer than the prior measurement in both groups, but was more prolonged in the deceased group (448.4 ms vs 472.9 ms, pre‐COVID vs COVID, p < 0.01). Multivariate Cox‐regression analysis revealed age, C‐reactive protein and prolonged QTc of >455 ms (males) and >465 ms (females) (p = 0.028, HR 1.49 [1.04‐2.13]), as predictors of mortality. QTc prolongation beyond these dichotomy limits was associated with increased mortality risk (p = 0.0027, HR 1.78 [1.2‐2.6]). Conclusion: QTc prolongation occurs in COVID‐19 illness and is associated with poor outcome. [ABSTRACT FROM AUTHOR]

Background: Cardiac resynchronization therapy‐defibrillator (CRT‐D) implantation via the cephalic vein is feasible and safe. Recent evidence has suggested a higher implantable cardioverter‐defibrillator (ICD) lead failure in multi‐lead defibrillator therapy via the cephalic route. We evaluated the relationship between CRT‐D implantation via the cephalic and ICD lead failure. Methods: Data was collected from three CRT‐D implanting centers between October 2008 and September 2017. In total 633 patients were included. Patient and lead characteristics with ICD lead failure were recorded. Comparison of "cephalic" (ICD lead via cephalic) versus "non‐cephalic" (ICD lead via non‐cephalic route) cohorts was performed. Kaplan–Meier survival and a Cox‐regression analysis were applied to assess variables associated with lead failure. Results: The cephalic and non‐cephalic cohorts were equally male (81.9% vs. 78%; p =.26), similar in age (69.7 ± 11.5 vs. 68.7 ± 11.9; p =.33) and body mass index (BMI) (27.7 ± 5.1 vs. 27.1 ± 5.7; p =.33). Most ICD leads were implanted via the cephalic vein (73.5%) and patients had a mean of 2.9 ± 0.28 leads implanted via this route. The rate of ICD lead failure was low and statistically similar between both groups (0.36%/year vs. 0.13%/year; p =.12). Female gender was more common in the lead failure cohort than non‐failure (55.6% vs. 17.9%, respectively; p =.004) as was hypertension (88.9% vs. 54.2%, respectively, p =.038). On multivariate Cox‐regression, female sex (p =.008; HR, 7.12 [1.7−30.2]), and BMI (p =.047; HR, 1.12 [1.001−1.24]) were significantly associated with ICD lead failure. Conclusion: CRT‐D implantation via the cephalic route is not significantly associated with premature ICD lead failure. Female gender and BMI are predictors of lead failure. [ABSTRACT FROM AUTHOR]

Background: Cardiac implantable electronic device (CIED)‐related perforation is uncommon but potentially lethal. Management typically includes the use of computed tomography (CT) scanning and often involves cardiac surgery. Methods: Patients presenting to a single referral centre with CIED‐related cardiac perforation between 2013 and 2019 were identified. Demographics, diagnostic modalities, the method of lead revision, and 30‐day complications were examined. Results: A total of 46 cases were identified; median time from implantation to diagnosis was 14 days (interquartile range = 4–50). Most were females (29/46, 63%), 9/46 (20%) had cancer, 18 patients (39%) used oral anticoagulants, and no patients had prior cardiac surgery. Active fixation was involved in 98% of cases; 9% involved an implantable cardioverter defibrillator lead. Thirty‐seven leads perforated the right ventricle (apex: 24) and 9 punctured the right atrium (lateral wall: 5). Abnormal electrical parameters were noted in 95% of interrogated cases. Perforation was visualized in 41% and 6% of cases with chest X‐ray (CXR) and transthoracic echocardiography, respectively. CXR revealed a perforation, gross lead displacement, or left‐sided pleural effusion in 74% of cases. Pericardial effusion occurred in 26 patients (57%) of whom 11 (24%) developed tamponade, successfully drained percutaneously. Pre‐extraction CT scan was performed in 19 patients but was essential in four cases. Transvenous lead revision (TLR) was successfully performed in all cases with original leads repositioned in six patients, without recourse to surgery. Thirty‐day mortality and complications were low (0% and 26%, respectively). Conclusion: CT scanning provides incremental diagnostic value in a minority of CIED‐related perforations. TLR is a safe and effective strategy. [ABSTRACT FROM AUTHOR]

Background: Small series has shown that cardiac resynchronisation therapy (CRT) can be achieved in a majority of patients using exclusively cephalic venous access. We sought to determine whether this method is suitable for widespread use. Methods: A group of 19 operators including 11 trainees in three pacing centres attempted to use cephalic access alone for all CRT device implants over a period of 8 years. The access route for each lead, the procedure outcome, duration, and complications were collected prospectively. Data were also collected for 105 consecutive CRT device implants performed by experienced operators not using the exclusively cephalic method. Results: A new implantation of a CRT device using exclusively cephalic venous access was attempted in 1091 patients (73.6% male, aged 73 ± 12 years). Implantation was achieved using cephalic venous access alone in 801 cases (73.4%) and using a combination of cephalic and other access in a further 180 (16.5%). Cephalic access was used for 2468 of 3132 leads implanted (78.8%). Compared to a non‐cephalic reference group, complications occurred less frequently (69/1091 vs 12/105; P =.0468), and there were no pneumothoraces with cephalic implants. Procedure and fluoroscopy duration were shorter (procedure duration 118 ± 45 vs 144 ± 39 minutes, P <.0001; fluoroscopy duration 15.7 ± 12.9 vs 22.8 ± 12.2 minutes, P <.0001). Conclusions: CRT devices can be implanted using cephalic access alone in a substantial majority of cases. This approach is safe and efficient. [ABSTRACT FROM AUTHOR]

Background: The outcomes of pulmonary vein isolation (PVI) for persistent atrial fibrillation (AF) are suboptimal. The entire pulmonary venous component (PV‐Comp), consisting of the pulmonary veins, their antra, and the area between the antra, provides triggers and substrate for AF. PV‐Comp isolation is an alternative strategy for persistent AF ablation. Methods: Among 328 patients with persistent AF who underwent a first radiofrequency ablation procedure, 200 patients (PVI, n = 100; PV‐Comp isolation, n = 100) were selected by propensity score matching. Both groups were followed up for 1 year. Results: At 6‐ and 12‐month follow‐up, atrial tachyarrhythmia (AF/atrial tachycardia) recurred in 41 and 61 patients in PVI group and 22 (P =.006) and 33 patients (P <.001) in PV‐Comp isolation group, respectively. PV‐Comp isolation was associated with longer mean time to recurrence (PVI: 8 months, PV‐Comp isolation: 10 months, log‐rank P <.001) and a lower probability of recurrence (odds ratio [OR] = 0.32; 95% confidence of interval [CI] = 0.18‐0.56, P <.001), with no increase in procedural complications (PVI: 5 of 100, PV‐Comp isolation: 6 of 100, P =.76). Procedure duration was longer in PV‐Comp isolation group (PVI: 186 ± 42 min, PV‐Comp isolation: 238 ± 44 min, P <.001), as well as fluoroscopy time (PVI: 22 ± 16 min, PV‐Comp isolation: 31 ± 21 min, P =.001). Conclusion: PV‐Comp isolation for persistent AF reduced atrial tachyarrhythmia recurrence up to 1 year compared with PVI alone. While procedure and fluoroscopy time increased, there was no difference in procedural complications. [ABSTRACT FROM AUTHOR]

Extensive atrial ablation in the setting of atrial fibrillation (AF) and atrial tachycardia (AT) can affect interatrial connections. A 76‐year‐old man with a history of tachycardia‐induced cardiomyopathy and nine ablation procedures for AF/AT over 15 years presented with highly symptomatic recurrent AT. Previous ablation lesions included pulmonary vein isolation, left atrial posterior wall isolation, mitral isthmus line, cavotricuspid isthmus line, and the ablation of areas of fractionated electrograms. Electroanatomical mapping found the pulmonary veins and the left atrial posterior wall to be silent, as was the posterior interatrial septum and the mitral isthmus area. Activation mapping showed progression of electrograms in the left atrial appendage (LAA) from the septal aspect posteriorly, and in the coronary sinus from proximal to distal; implying the existence of a septal circuit, where extensive fractionation was noted. This was targeted, while monitoring conduction into the LAA using a multielectrode catheter. Ablation led to prompt termination of tachycardia and simultaneous LAA isolation. Immediate cessation of ablation led to recovery of conduction into LAA. Additional lesions in the interatrial septum were required to render the tachycardia noninducible, accompanied by temporary isolation of LAA. The ablation lesion sets employed while ablating AF and left AT can block many interatrial pathways, rendering conduction dependent on muscle bundles in the interatrial septum and, therefore, vulnerable to block by lesions in this area. LAA isolation has been associated with high incidence of LAA thrombus formation and stroke despite oral anticoagulation. Continuous observation of LAA electrograms during ablation can help to avoid this complication. [ABSTRACT FROM AUTHOR]

Background: Atrial fibrillation (AF) ablation outcome is still operator dependent. Ablation Index (AI) is a new lesion quality marker that has been demonstrated to allow acute durable pulmonary vein (PV) isolation followed by a high single‐procedure arrhythmia‐free survival. This prospective, multicenter study was designed to evaluate the reproducibility of acute PV isolation guided by the AI. Methods: A total of 490 consecutive patients with paroxysmal (80.4%) and persistent AF underwent first time PV encircling and were divided in four study groups according to operator preference in choosing the ablation catheter (a contact force [ST] or contact force surround flow [STSF] catheter) and the AI setting (330 at posterior and 450 at anterior wall or 380 at posterior and 500 at anterior wall). Radiofrequency was delivered targeting interlesion distance ≤6 mm. Results: The rate of first‐pass PV isolation (ST330 90 ± 16%, ST380 87 ± 19%, STSF330 90 ± 17%, STSF380 91 ± 15%, P = .585) was similar among the four study groups, whereas procedure (ST330 129 ± 44 minutes, ST380 144 ± 44 minutes, STSF330 120 ± 72 minutes, STSF380 125 ± 73 minutes, P <.001) and fluoroscopy time (ST330 542 ± 285 seconds, ST380 540 ± 416 seconds, STSF330 257 ± 356 seconds, STSF380 379 ± 454 seconds, P < 0.001) significantly differed. The difference in the rate of first‐pass isolation was not statistical different (P = .06) among the 12 operators that performed at least 15 procedures. Conclusions: An ablation protocol respecting strict criteria for contiguity and quality lesion results in high and comparable rate of acute PV isolation among operator performing ablation with different catheters, AI settings, procedure, and fluoroscopy times. [ABSTRACT FROM AUTHOR]

Background: Pulmonary vein isolation (PVI) using high power delivered by SmartTouch Surround Flow (STSF) catheters guided by ablation index (AI) was evaluated in a multicenter registry. Methods: Patients with paroxysmal AF underwent PVI with STSF catheters using 30 W on the posterior wall and 40 W elsewhere. AI targets were 350 posterior walls and 450 elsewhere. Procedures were compared with controls using conventionally irrigated contact force‐sensing catheters using conventional powers (25 W posterior wall and 30 W elsewhere) guided by force‐time integral (no agreed targets). The waiting period of 30 minutes was observed before adenosine administration to assess acute pulmonary vein (PV) reconnection. Results: One hundred patients from four centers were included: 50 patients in the high power ablation index (HPAI) group and 50 controls. Procedure time was 22% shorter in the HPAI group (156 [133.8‐179] vs 199 [178.5‐227] minutes; P < 0.001). Duration of the radiofrequency application was 37% shorter in the HPAI group (27.2 [21.5‐35.8] vs 43.2 [35.1‐52.1] minutes; P < 0.001). Acute PV reconnection was reduced (28 of 200 [14%] vs 48 of 200 [24%] veins; P = 0.015). Reconnection was predicted by a largest interlesion distance greater than 6 mm, a lesion with impedance drop less than 2.5 Ω, contact force less than 6 g, or less than 68% of the regional AI target (all P < 0.001). Freedom from atrial arrhythmia at 1 year off antiarrhythmic drugs after a single procedure was 78% in the HPAI group vs 64% in the control group (P = 0.186). Conclusion: High‐powered ablation guided by AI was safe and led to shorter procedure times with reduced acute PV reconnection compared with conventional ablation. [ABSTRACT FROM AUTHOR]

Cryotherapy for Simultaneous CTI Ablation and PVI Introduction Pulmonary vein isolation (PVI) and cavotricuspid isthmus (CTI) ablation are often performed as part of the same procedure. In many cases, PVI is performed by cryotherapy and then CTI ablation by radiofrequency (RF) energy. We sought to determine whether it is more efficient to perform CTI ablation simultaneously with PVI using separate cryogenerators. Methods and Results We performed cryoablation of the CTI during PVI with the Arctic Front cryoballoon in 25 consecutive patients with clinical indications for both (PVI/CTI-cryo group). Procedural data were compared to those of 25 matched patients who underwent PVI only by the same operator (PVI-only group), and 25 patients who underwent PVI by cryotherapy and CTI ablation using RF energy sequentially during the same procedure (PVI/CTI-mixed group). No complication occurred. All veins were isolated; bidirectional CTI block was demonstrated in all cases where it was attempted, except for 1 patient in the PVI/CTI-mixed group. Procedure and fluoroscopy duration were significantly shorter in the PVI/CTI-cryo group (162 ± 34 and 24 ± 5 minutes) than in the PVI/CTI-mixed group (209 ± 46 minutes, P < 0.001 and 59 ± 28 minutes, P < 0.001). Procedure and fluoroscopy duration in the PVI-only group (155 ± 32 and 22 ± 8 minutes) were similar to those in the PVI/CTI-cryo group (P = NS) but significantly shorter than in the PVI/CTI-mixed group (P < 0.001 for both). Clinical outcomes were similar in all groups. Conclusion When CTI ablation is performed with RF energy after PVI by cryoballoon, it adds significantly to the procedure and fluoroscopy durations; when performed contemporaneously using cryotherapy at both sites, the procedure and fluoroscopy durations are not prolonged. [ABSTRACT FROM AUTHOR]

Cardiac resynchronization therapy (CRT) devices are usually implanted using subclavian vein access, which is associated with the risk of pneumothorax. We examined whether cephalic venous access is an effective alternative to subclavian access by the Seldinger technique for CRT delivery. We retrospectively analyzed all CRT procedures performed over a 1-year period at our center with respect to the access methods, primary success rate, safety, and efficiency. We retrospectively analyzed 103 consecutive primary implantation procedures. The procedure was accomplished using cephalic access alone for 54 of 61 (89%) CRT implants attempted by this route. The overall success rate was 100% (61/61) with additional use of subclavian access. CRT implantation via subclavian vein access was successful in 37 of 42 (88%) (P < 0.05 vs cephalic group). The procedure duration was shorter for the cephalic group (118 ± 39 vs 147 ± 36 minutes, P < 0.0005) as were the screening times and radiation exposure (15 ± 9 vs 27 ± 18 minutes and 4.7 ± 5.8 vs 9.3 ± 9.1 Gcm, both P < 0.01). In the cephalic group, procedure duration and radiation exposure diminished significantly with increasing experience of the technique. Complications occurred in two of 61 (3.3%) cases in the cephalic group and three of 42 (7.1%) in the subclavian group (P = NS). CRT devices can be implanted using cephalic access alone in a large majority of cases. This approach is safe and efficient. (PACE 2011; 34:365-369) [ABSTRACT FROM AUTHOR]

Background: Electrical cardioversion (ECV) of atrial fibrillation (AF) is limited by a 5–10% failure rate and by the expense arising from a perceived need for general anesthesia. A transesophageal approach using light sedation has been proposed as a means of augmenting the success rate and avoiding the need for general anesthesia. We hypothesized that the high rate of success and the lower energy requirement associated with biphasic cardioversion might eliminate any advantage of the transesophageal approach. Methods: We randomly assigned 60 patients attending for ECV of persistent AF to a transesophageal or a transthoracic approach. Sedation of moderate depth was achieved with intravenous midazolam. The dose of midazolam was titrated in the same manner in both groups. Results: Sinus rhythm was restored in 29/30 patients (97%) in each group using a similar number of shocks for both groups (1.3 ± 0.6 transesophageal vs 1.4 ± 0.7 transthoracic, P = NS) with a similar procedure duration (14.1 ± 8.2 minutes vs 13.8 ± 7.5 minutes, P = NS). Both groups received similar doses of midazolam (4.2 ± 2.7 mg vs 4.4 ± 2.8 mg, P = NS) and both reported a similar discomfort score in (0.9 ± 1.3 vs 1.1 ± 1.8, P = NS). No complication occurred in either group. Conclusion: AF may be cardioverted safely and effectively by either a transthoracic or a transesophageal approach. The use of sedation of moderate depth renders cardioversion by either approach acceptable. As transesophageal ECV shows no clear advantage, transthoracic cardioversion should remain the approach of first choice. [ABSTRACT FROM AUTHOR]

Heart rote variability (HRV) analysis from 24-hour ambulatory ECG has been widely used in risk stratification of patients after myocordial infarction (MI). The accuracy of HRV assessment is known to potentially vary when different commercial systems are used. However, the consistency of HRV measurements has never been fully investigated. Twenty-six post-MI patients (mean age 59 ± 8 years, 22 men) were studied, of whom 13 succumbed to sudden cardiac death (SCD) within 1 year and 13 remained alive for at least 3 years (MI survivors). Each patient had a 24-hour Holter ECG recorded before hospital discharge. HRV analysis was performed four times from the same recordings using three different Holter tape analysis systems (Marquette, Reynolds, and CardioData) by four independent operators (CardloData system was used twice, once in the United Kingdom and once in the United States). Mean normal-to-normal RR intervals (mNN) and 3 HRV parameters (SDNN, RMSSD, and HRV triangular index (HRVi]) were derived from each recording. The consistency of mNN and HRV measurements was evaluated by coefficient of variance (CV) and by the Bland-Altman method. The results demonstrated that (1) all indices measured by different systems were statistically similar (P = NS) except the measurement of RMSSD (P = 0.01), (2) the measurements of mNN were highly reproducible with a maximum mean difference of 1.8 ± 13.8 ms and maximum limits of agreement from - 14.6 to + 15.6 ms. The maximum mean differences were - 1.8 ±1.4 unit an 4.4 ± 9.6 ms for HRVi and SDNN, respectively, and RMSSD was less reproducible with a maximum mean difference of - 11.1 ± 11.5 ms, and limits of agreement from - 16.2 to + 9.6 ms: and (3) the consistency of mNN (CV 0.9% ± 0.9%) was significantly higher than that of HRVi. SDNN. and RMSSD (P < 0.0001). The consistency of HRVi was similar to that of SDNN (4.8% ± 2.1% vs 5.7% ± 4.8%, P = 0.4), and the consistency of RMSSD (26.6% ± 13.3%) was significantly lower than that of the other measurements (P < 0.00001). In conclusion, the measurements of mNN by different analytical systems are the most consistent among the parameters studied. The global 24-hour measurements of HRV (SDNN and HRVi) are highly reproducible, whereas the measurement of short-term HRV components (RMSSD) is significantly less reproducible. [ABSTRACT FROM AUTHOR]

Background:Abnormalities in the adaptation of the QT interval to changes in the RR interval may facilitate the development of ventricular arrhythmias. Methods:This study sought to evaluate the dynamic relation between the QT and RR intervals in patients after acute myocardial infarction. The study population consisted of 14 patients after myocardial infarction (age 60 ± 7 years, 12 men) who died suddenly (SCD victims) within 1 year after the myocardial infarction and 14 pair-matched age, sex, left ventricular ejection fraction, infarct site, thrombolytic therapy) patients who remained event-free after myocardial infarction (Ml survivors) for at least 3 years. Fourteen normal subjects were studied as controls (age 55 ± 9 years, 11 men). QT and RR intervals were measured on a beat-to-beat basis automatically with a visual control from 24-hour ambulatory ECGs using Reynolds Pathfinder 700. Mean hourly values of the QT/RR slope (QT =α+βRR) and corrected QT interval at 1000 ms of RR interval (QT1s) were derived for each subject using an inhouse program (QT1s=α+1000β). The dynamics of the QT/RR slope and QT1s were assessed on the basis of hourly mean values. The circadian rhythm of ventricular repolarization (QT1s and QT/RR slope) was examined by harmonic regression analysis. Results:There was a trend towards a significant difference in 24-hour mean value of QT1s between study groups (408 ± 26 ms vs 381 ± 43 ms and 386 ± 22 ms, P = 0.06), and a significant difference was found between SCD victims and normal subjects (408 ± 26 vs 386 ± 22 ms, P = 0.02). The QT1s differed significantly between study groups (P = 0.038) only during the day time (09:00-19:00 hour), when QT1s was significantly longer in SCD victims than in normal subjects (409 ± 33 vs 380 ± 27 ms, P = 0.02) and tended to be longer than in Ml survivors (409 ± 33 vs 379 ± 42 ms, P = 0.08). The 24-hour mean value of QT/RR slope was significantly different between study groups (P = 0.04), with a significantly steeper slope in SCD victims than in normal subjects (0.15 ± 0.07 vs 0.09 ± 0.02, P = 0.008). During day time, the QT/RR slope differed significantly between study groups (P = 0.04), while the difference was less marked at night (P = 0.08). The slope was significantly steeper in SCD victims than in normal subjects during both day and night (P < 0.05). A marked circadian variation of QT1s was observed in normal subjects, which was blunted in Ml survivors and SCD victims. Conclusions:Abnormal repolarization behaviors, characterized by longer QT1s and impaired adaptation of QT to variations in RR intervals, were found in SCD victims. Hence, lethal ventricular tachyarrhythmias might be provoked by the altered repolarization dynamics in patients after myocardial infarction. A.N.E. 1999;4(3):286-294 [ABSTRACT FROM AUTHOR]

The study investigated the differences in five different formulae for heart rate correction of the QT interval in serial electrocardiograms recorded in healthy subjects subjected to graded exercise. Twenty-one healthy subjects (aged 37 ± 10 years, 15 male) were subjected to graded physical exercise on a braked bicycle ergometer until the heart rate reached 120 beats/min. Digital electrocardiograms (ECG) were recorded on baseline and every 30 seconds during the exercise. In each ECG, heart rate and QT interval were measured automatically (QT Guard package, Marquette Medical Systems, Milwaukee, WI, USA). Bazett, Fridericia, Hodges, Framingham, and nomogram formulae were used to obtain QTc interval values for each ECG. For each formula, the slope of the regression line between RR and QTc values was obtained in each subject. The mean values of the slopes were tested by a one-sample t-test and the comparison of the baseline and peak exercise QTc values was performed using paired t-test. Bazett, Hodges, and nomogram formulae led to significant prolongation of QTc intervals with exercise, while the Framingham formula led to significant shortening of QTc intervals with exercise. The differences obtained with the Fridericia formula were not statistically significant. The study shows that the practical meaning of QTc- interval measurements depends on the correction formula used. In studies investigating repolarization changes (e.g., due to a new drug), the use of an ad-hoc selected heart rate correction formula is highly inappropriate because it may bias the results in either direction. [ABSTRACT FROM AUTHOR]

Changes in the RR interval within episodes of paroxysmal atrial fibrillation (PAF) have not been fully characterized. A database of 177 24-hour Halter recordings were created from patients with PAF in the CRAFT studies. PAF episodes of ≥ 1 minute duration containing ≤ 20% noise and preceded by ≥ 1 minute of sinus rhythm with ≤ 20% noise were selected. Sections of each AF episode containing 10 and 25 RB intervals were identified at the onset, middle, and termination of each episode. Descriptive characteristics (mean, SD, and BMSSD of BR intervals) were calculated within each section, and compared using a nonparametric, paired Wilcoxon test. In 25 patients (17 men, 60.6 ± 12.2 years old), 232 episodes from 44 recordings met the selection criteria. The mean RR interval increased slightly between the onset and mid-portion of AF episodes (565.9 ± 128.3 vs 580.3 ± 144.7 ms, P < 0.001). The RR interval at the termination of AF was significantly greater than that at the start (627.1 ± 156.1 vs 565.9 ms, P < 10-11) or mid-portion (627.1 ± 156.1 vs 580.3 ± 144.7 ms, P < 10-13). SD of the RB interval increased significantly between onset and mid-portion (111.1 ± 60.2 vs 118.2 ± 66.7 ms, P < 0.001)and more substantially between mid-portion and termination (118.2 ± 66.7 vs 201.8 ± 93.7 ms, P < 10-21). During paroxysms of AF, the mean RR interval and the variability of RR intervals increases. Termination of a paroxysm is preceded by a marked increase in RB interval variability. [ABSTRACT FROM AUTHOR]

The atrial myocardium of patients with chronic atrial fibrillation (AF) is often abnormal in its histologic features and in its electro-physiologic properties. These abnormalities have been interpreted in some cases as the cause of AF and in others as a consequence of AF. We believe that both are the case. We will review the features of this atrial myopathy and discuss the likely mechanisms and consequences of the process. [ABSTRACT FROM AUTHOR]

The article presents information about the classification of atrial fibrillation (AF). Two overlapping systems are in common use: classification according to the underlying disease process; and classification according to the time course of the arrhythmia. In neither of these systems is there an agreed set of diagnostic criteria. The traditional classification of AF according to etiology also remains useful as coexisting disease often dictates choice of drug. The distinction between valvular and nonvalvular AF is particularly important because of the higher risk of stroke in the presence of mitral stenosis.

Left atrial isomerism (LAI) is characterized by the presence of two morphologically identical atria. It is commonly associated with conduction defects. We report a case of LAI presenting with highly symptomatic atrioventricular nodal reentrant tachycardia, which was cured by ablation. (PACE 2012; 35:e291-e292) [ABSTRACT FROM AUTHOR]

Presents a letter to the editor in response to an article discussing the classification of atrial fibrillation published in the April 1998 issue of "Pacing and Clinical Electrophysiology."