Search

Aims Conduction abnormalities post-transcatheter aortic valve implantation (TAVI) are common. Post-TAVI PR prolongation was mainly studied as an adjunct to new-onset bundle branch block. The net effect of isolated PR prolongation (IPRP) without post-TAVI QRS changes is not well known. The aim of this study was to define the incidence and clinical significance of post-TAVI IPRP. Methods and results A total of 1108 consecutive TAVI patients were reviewed. Patients with IPRP were compared with patients without post-TAVI electrocardiogram (ECG) changes. Clinical outcomes included permanent pacemaker implantation (PPI) and overall mortality. A total of 146 patients with IPRP were compared with 290 patients without post-TAVI ECG changes. At 1 year follow-up, 4 (2.7%) and 7 (2.4%) patients underwent PPI (P = 0.838) and 10 (6.8%) and 25 (8.6%) died (P = 0.521), from the study and control groups, respectively. No patient with IPRP and narrow QRS underwent PPI during 1 year post-TAVI, and all death events were non-cardiac except one unknown cause. Permanent pacemaker implantation rates among patients with IPRP and wide QRS were higher (n = 4, 12.1%), compared with patients with wide QRS without post-TAVI ECG change (n = 3, 4%) however not reaching statistical significance (P = 0.126). Multivariate Cox proportional hazards model demonstrated that in patients with narrow QRS, neither PR prolongation nor baseline or maximal PR intervals was associated with the combined endpoint of PPI and mortality. However, in patients with wide QRS, baseline PR intervals and QRS width, but not PR prolongation were associated with the combined outcome. Conclusion Post-TAVI IPRP in patients with narrow QRS is not associated with adverse outcome. This finding may translate clinically into a more permissive approach to these patients. [ABSTRACT FROM AUTHOR]

This reviews the transition of remote monitoring of patients with cardiac electronic implantable devices from curiosity to standard of care. This has been delivered by technology evolution from patient-activated remote interrogations at appointed intervals to continuous monitoring that automatically flags clinically actionable information to the clinic for review. This model has facilitated follow-up and received professional society recommendations. Additionally, continuous monitoring has provided a new level of granularity of diagnostic data enabling extension of patient management from device to disease management. This ushers in an era of digital medicine with wider applications in cardiovascular medicine. [ABSTRACT FROM AUTHOR]

Background: Prior studies evaluating post-atrial fibrillation (AF) ablation pulmonary vein (PV) ostial gaps via magnetic resonance imaging (MRI) have shown circumferential PV fibrosis in a minority of patients, and their correlation with AF recurrence was weak. These studies were mostly based on radio-frequency AF ablations. Aim: We aimed to assess cryoballoon ablation-induced PV fibrosis via MRI and its correlation with AF recurrence. Methods and Results: This was a prospective study of consecutive patients with symptomatic AF who underwent pre- and post-ablation MRI to assess baseline and ablation-induced fibrosis, respectively. Post-ablation PV gaps were assessed by new semi-quantitative visual analysis assisted by computerized ADAS analysis. AF recurrence monitored via multiple ECGs and event monitoring at 6 and 12 months post ablation. Nineteen patients with 80 PVs were included, age 56 ± 11, with paroxysmal and persistent AF in 17/19 and 2/19 patients, respectively. Baseline MRI showed minimal LA fibrosis. All patients underwent successful cryoballoon PV electrical isolation. Post-ablation MRI revealed circumferential PV fibrosis among 63/80 (78.8%) PVs and partial fibrosis with major gaps among 17/80 (21.2%) PVs. AF recurred within one year in 5/9 (55.5%) patients with partial PV fibrosis, while no AF recurred among the 10 patients in whom all PVs had circumferential fibrosis (p < 0.01). Similarly, there were significantly more PVs without circumferential fibrosis (due to major gaps) among patients with AF recurrence as compared with patients without AF recurrence (42.9% vs. 13.5%; p < 0.01). Conclusion: Cryoballoon AF ablation results in circumferential PV fibrosis in the majority of PVs, as assessed by a new clinically relevant MRI-LGE analysis. Significant correlation was found between major PV gaps on post-ablation MRI and AF recurrence, suggesting that MRI might have the ability to predict AF recurrence. [ABSTRACT FROM AUTHOR]

Aims Little is known about patients with right bundle branch block (RBBB)-ventricular tachycardia (VT) and arrhythmogenic cardiomyopathy (ACM). Our aims were: (i) to describe electrocardiogram (ECG) characteristics of sinus rhythm (SR) and VT; (ii) to correlate SR with RBBB-VT ECGs; and (iii) to compare VT ECGs with electro-anatomic mapping (EAM) data. Methods and results From the European Survey on ACM, 70 patients with spontaneous RBBB-VT were included. Putative left ventricular (LV) sites of origin (SOOs) were estimated with a VT-axis-derived methodology and confirmed by EAM data when available. Overall, 49 (70%) patients met definite Task Force Criteria. Low QRS voltage predominated in lateral leads (n = 37, 55%), but QRS fragmentation was more frequent in inferior leads (n = 15, 23%). T-wave inversion (TWI) was equally frequent in inferior (n = 28, 42%) and lateral (n = 27, 40%) leads. TWI in inferior leads was associated with reduced LV ejection fraction (LVEF; 46 ± 10 vs. 53 ± 8, P = 0.02). Regarding SOOs, the inferior wall harboured 31 (46%) SOOs, followed by the lateral wall (n = 17, 25%), the anterior wall (n = 15, 22%), and the septum (n = 4, 6%). EAM data were available for 16 patients and showed good concordance with the putative SOOs. In all patients with superior-axis RBBB-VT who underwent endo-epicardial VT activation mapping, VT originated from the LV. Conclusions In patients with ACM and RBBB-VT, RBBB-VTs originated mainly from the inferior and lateral LV walls. SR depolarization and repolarization abnormalities were frequent and associated with underlying variants. [ABSTRACT FROM AUTHOR]

Aims: The aims of this study is to characterize the transvenous lead extraction (TLE) population with active (A) compared with passive fixation (PFix) leads and to compare the safety, efficacy, and ease of extracting active fixation (AFix) compared with PFix right atrial (RA) and right ventricular (RV) leads.Methods and Results: The European Lead Extraction ConTRolled Registry (ELECTRa) was analysed. Patients were divided into three groups; those with only AFix, only PFix, and combined Fix leads. Three outcomes were defined. Difficult extraction, complete radiological, and clinical success. Multivariate model was used to analyse the independent effect of Fix mechanism on these outcomes. The study included 2815 patients, 1456 (51.7%) with only AFix leads, 982 (34.9%) with only PFix leads, and 377 (13.4%) with combined Fix leads. Patients with AFix leads were younger with shorter lead dwelling time. Infection was the leading cause for TLE among the combined Fix group with lowest rates among AFix group. No difference in complications rates was noted between patients with only AFix vs. PFix leads. Overall, there were 1689 RA (1046 AFix and 643 PFix) and 2617 RV leads (1441 AFix and 1176 PFix). Multivariate model demonstrated that PFix is independently associated with more difficult extraction for both RA and RV leads, lower radiological success in the RA but has no effect on clinical success.Conclusion: Mechanism of Fix impact the ease of TLE of RA and RV leads and rates of complete radiological success in the RA but not clinical success. These findings should be considered during implantation and TLE procedures. [ABSTRACT FROM AUTHOR]

Background: A novel 3D mapping system (KODEX‐EPD, EPD Solutions) enables catheter localization and real‐time 3D cardiac mapping. Objective: To evaluate left atrium (LA) anatomical mapping accuracy created by the KODEX‐EPD system during pulmonary vein isolation (PVI) compared with gold standard computed tomography (CT) images acquired from the same patients before the procedure. Methods: In 15 consecutive patients who underwent PVI, 3D mapping of the LA was created on the KODEX‐EPD system using the Achieve catheter. Pulmonary vein (PV), posterior wall, and appendage anatomy and diameters, were compared to the CT 3D reconstruction measured on the CARTO 3 system. Measurements were done independently by two physicians in each method. Linear correlation and agreement between CT and EPD measurements were assessed by Spearman correlation and Bland‐Altman plot. Results: Mean LA mapping time was 7.7 ± 3.6 min. Very high interobserver correlation was found for both EPD and CT measurements (Spearman r =.9). High correlation (r =.75) was found between CT and EPD measurements. Bland‐Altman plot method revealed that measurements assessed by EPD were slightly higher than those assessed by CT. Mean difference was 3.5 mm, p <.01. In 2 (13.5%) patients each, disagreement regarding the presence of a left common PV and a right middle accessory vein anatomy was seen. Conclusion: The new KODEX‐EPD mapping system allows quick and accurate mapping of the LA with high correlation to CT imaging. Some differences in left common and accessory right middle vein anatomy were seen. [ABSTRACT FROM AUTHOR]

Aims: To develop a suite of quality indicators (QIs) for the evaluation of the care and outcomes for adults undergoing cardiac pacing.Methods and Results: Under the auspice of the Clinical Practice Guideline Quality Indicator Committee of the European Society of Cardiology (ESC), the Working Group for cardiac pacing QIs was formed. The Group comprised Task Force members of the 2021 ESC Clinical Practice Guidelines on Cardiac Pacing and Cardiac Resynchronization Therapy, members of the European Heart Rhythm Association, international cardiac device experts, and patient representatives. We followed the ESC methodology for QI development, which involved (i) the identification of the key domains of care by constructing a conceptual framework of the management of patients receiving cardiac pacing, (ii) the development of candidate QIs by conducting a systematic review of the literature, (iii) the selection of the final set of QIs using a modified-Delphi method, and (iv) the evaluation of the feasibility of the developed QIs. Four domains of care were identified: (i) structural framework, (ii) patient assessment, (iii) pacing strategy, and (iv) clinical outcomes. In total, seven main and four secondary QIs were selected across these domains and were embedded within the 2021 ESC Guidelines on Cardiac Pacing and Cardiac Resynchronization therapy.Conclusion: By way of a standardized process, 11 QIs for cardiac pacing were developed. These indicators may be used to quantify adherence to guideline-recommended clinical practice and have the potential to improve the care and outcomes of patients receiving cardiac pacemakers. [ABSTRACT FROM AUTHOR]

Objectives: A significant proportion of COVID-19 patients may have cardiac involvement including arrhythmias. Although arrhythmia characterisation and possible predictors were previously reported, there are conflicting data regarding the exact prevalence of arrhythmias. Clinically applicable algorithms to classify COVID patients' arrhythmic risk are still lacking, and are the aim of our study.Methods: We describe a single-centre cohort of hospitalised patients with a positive nasopharyngeal swab for COVID-19 during the initial Israeli outbreak between 1/2/2020 and 30/5/2020. The study's outcome was any documented arrhythmia during hospitalisation, based on daily physical examination, routine ECG's, periodic 24-hour Holter, and continuous monitoring. Multivariate analysis was used to find predictors for new arrhythmias and create classification trees for discriminating patients with high and low arrhythmic risk.Results: Out of 390 COVID-19 patients included, 28 (7.2%) had documented arrhythmias during hospitalisation, including 23 atrial tachyarrhythmias, combined atrial fibrillation (AF), and ventricular fibrillation, ventricular tachycardia storm, and 3 bradyarrhythmias. Only 7/28 patients had previous arrhythmias. Our study showed a significant correlation between disease severity and arrhythmia prevalence (P < .001) with a low arrhythmic prevalence amongst mild disease patients (2%). Multivariate analysis revealed background heart failure (CHF) and disease severity are independently associated with overall arrhythmia while age, CHF, disease severity, and arrhythmic symptoms are associated with tachyarrhythmias. A novel decision tree using age, disease severity, CHF, and troponin levels was created to stratify patients into high and low risk for developing arrhythmia.Conclusions: Dominant arrhythmia amongst COVID-19 patients is AF. Arrhythmia prevalence is associated with age, disease severity, CHF, and troponin levels. A novel simple Classification tree, based on these parameters, can discriminate between high and low arrhythmic risk patients. [ABSTRACT FROM AUTHOR]

Aims: Many tachy-brady syndrome (TBS) patients, are implanted a permanent pacemaker (PPM) to allow continuation of anti-arrhythmic drug (AAD) therapy to maintain sinus rhythm. Many of these PPM's are implanted as a preventive measure, in absence of symptomatic bradycardia. Our primary aim was to evaluate pacing use among these patients and find predictors for PPM use. Our secondary aim was to appreciate the portion of these patients who progress to permanent atrial fibrillation (AF).Methods: Retrospective study of TBS patients implanted a PPM as preventive measure, dividing cases into defined categories regarding highest percent atrial and ventricular pacing documented in PPM clinic visits during 3 year follow-up (F/U) period. Patients' baseline characteristics and AAD therapy were compared between cases with a major (>90%) pacing use and cases with <90% pacing use to find predictors for pacing use. Multivariable logistic regression was applied to identify independent variables associated with major pacing use.Results: Our study included 119 TBS patients. Most (86.5%) TBS patients had a moderate (>50%) pacing use and 58% had a major pacing use. Significant association was found between pre-implant severe sinus bradycardia (<40 bpm), first degree atrioventricular block and amiodarone treatment to major pacing use on univariate analysis and severe sinus bradycardia was significantly associated with major pacing on multivariate analysis as well. Only minority (16.8%) of TBS patients progressed to permanent AF during the study F/U period.Conclusion: Our study reveals most TBS patients succeed to maintain sinus rhythm using an AAD with a significant pacing use, suggesting preventive PPM implantation might be advantageous in these cases. Pre-implant severe sinus bradycardia (<40 bpm) is a possible predictor for major pacing use in this population. [ABSTRACT FROM AUTHOR]

Background: Information regarding the significance of platelet (PLT) count on outcome of atrial fibrillation (AF) patients who are treated with anticoagulants is limited. Methods: We conducted a monocentric observational retrospective cohort study of AF patients treated with either warfarin (n = 6287) or non-vitamin K antagonist oral anticoagulants (NOACs) (n = 5240). Patient were divided into 3 subgroups; low, normal and high PLT for counts < 150 K/ μl, 150–450 K/ μl and > 450 K/ μl, respectively. A multivariate Cox-regression was used to evaluate the association between PLT subgroups and clinical outcomes. Results: During follow-up [median = 40.6 months (IQR 17.6–60)], mortality (HR 1.36, 95 CI 1.1–1.74, p = 0.01) and rate of myocardial infarction (MI) (HR 2.4, 95 CI 1.28–4.57, p = 0.007) were higher in patients with high compared to normal PLT. Transient ischemic attack or cerebrovascular accident (TIA/CVA) rate was lower in patients with low compared to normal PLT (HR 0.69, 95 CI 0.51–0.93, p = 0.02). A comparison between NOACs and warfarin demonstrated a significantly better clinical outcome for patients on NOACs in both the low (lower mortality rates) and normal PLT subgroup (lower mortality, TIA/CVA and systemic emboli rates). For patients on NOACs, low and high compared to normal PLT were associated with a higher combined outcome (HR 1.12, 95 CI 1–1.38, p = 0.047), and a higher systemic emboli rate (HR 7.07, 95 CI 1.66–30.25, p = 0.008), respectively. Conclusions: Abnormal PLT count is associated with different clinical outcome of AF patients on anticoagulants. Further studies are needed in order assess whether PLT level should influence strategies of anticoagulation. [ABSTRACT FROM AUTHOR]

Aims: Data on predictors of time-to-first appropriate implantable cardioverter-defibrillator (ICD) therapy in patients with Brugada Syndrome (BrS) and prophylactically implanted ICD's are scarce.Methods and Results: SABRUS (Survey on Arrhythmic Events in BRUgada Syndrome) is an international survey on 678 BrS patients who experienced arrhythmic event (AE) including 252 patients in whom AE occurred after prophylactic ICD implantation. Analysis was performed on time-to-first appropriate ICD discharge regarding patients' characteristics. Multivariate logistic regression models were utilized to identify which parameters predicted time to arrhythmia ≤5 years. The median time-to-first appropriate ICD therapy was 24.8 ± 2.8 months. A shorter time was observed in patients from Asian ethnicity (P < 0.05), those with syncope (P = 0.001), and those with Class IIa indication for ICD (P = 0.001). A longer time was associated with a positive family history of sudden cardiac death (P < 0.05). Multivariate Cox regression revealed shorter time-to-ICD therapy in patients with syncope [odds ratio (OR) 1.65, P = 0.001]. In 193 patients (76.6%), therapy was delivered during the first 5 years. Factors associated with this time were syncope (OR 0.36, P = 0.001), spontaneous Type 1 Brugada electrocardiogram (ECG) (OR 0.5, P < 0.05), and Class IIa indication (OR 0.38, P < 0.01) as opposed to Class IIb (OR 2.41, P < 0.01). A near-significant trend for female gender was also noted (OR 0.13, P = 0.052). Two score models for prediction of <5 years to shock were built.Conclusion: First appropriate therapy in BrS patients with prophylactic ICD's occurred during the first 5 years in 76.6% of patients. Syncope and spontaneous Type 1 Brugada ECG correlated with a shorter time to ICD therapy. [ABSTRACT FROM AUTHOR]

Purpose: Multisite cardiac resynchronization therapy (MSCRT) with dual-vein left ventricular (LV) pacing has theoretical advantages over conventional CRT in faster and more physiological LV activation. We aimed to define indications, feasibility, safety, acute, and long-term results of MSCRT.Methods: All patients implanted with MSCRT during 2008-2014 in a single center were reviewed and analyzed.Results: Thirty-nine patients (90% CRT-defibrillators, 64 ± 9 years, 85% male, 74% ischemic etiology) were included. Four groups of indications were recognized: (1) significant tricuspid regurgitation (TR) in patients planned for device implantation without right ventricular lead (n = 3). Follow-up (f/u) of 4 ± 3 years showed major symptomatic improvement in all, with stable LV size and function and deferral of valve surgery; (2) severe heart failure with reduced ejection fraction (HFrEF) and refractory ventricular tachycardia (VT) (n = 4). Except for 1 early death for acute renal failure, all others showed no VT episodes and HF improvement (f/u 4.5 ± 0.5 years); (3) severe HFrEF and wide QRS (≥ 150 ms) or failure of biventricular pacing to narrow QRS during implantation (n = 5). One patient had periprocedural mortality. The others had major clinical improvement; (4) severe HF and narrow QRS/RBBB (n = 27). 23/24 patients with available f/u of 3 ± 1.7 years improved clinically and 57% had EF improvement. In 3 patients, LV1 was disabled and one had LV2 dislodgement.Conclusions: MSCRT is feasible, safe, and valuable in selected patients with a need to avoid RV lead during device implantation, refractory VT with no other solution, severe HFrEF with wide QRS or CRT non-responsiveness, and severe HF without LBBB. Randomized controlled studies are required. [ABSTRACT FROM AUTHOR]

Background: Cardiac resynchronization therapy (CRT) is an effective treatment for heart failure (HF); however, a third of patients are non-responders. The development of quadripolar left ventricular (LV) lead was shown, mainly in single manufactures' registry, to improve LV remodeling and overall mortality. However, limited reports exist on the impact of quadripolar LV leads on HF hospitalization rates in real-life cohorts. We evaluated the clinical outcomes associated with quadripolar LV leads in a large nation-wide registry including all patients implanted with a cardiac resynchronization therapy with defibrillator (CRT-D).Methods: Between July 2010 and October 2016, 2913 consecutive patients were implanted with a CRT-D and all were prospectively enrolled in the Israeli ICD Registry. Quadripolar LV leads were implanted in 973 (33.4%) patients during this period, and their clinical outcomes were compared to CRT-D recipients implanted with a bipolar LV lead. Primary endpoint was HF hospitalization rate.Results: Quadripolar leads were implanted more in patients with non-ischemic cardiomyopathy and for primary prevention indication and less in post-infarction patients and for secondary prevention of sudden death. Longer QRS duration was observed with quadripolar leads (147 ± 23 vs 143 ± 25; p < 0.001). Outcome event rate for 100 patient years revealed no difference in HF hospitalization rates between bipolar and quadripolar LV leads. Quadripolar lead implant led to lower cardiac mortality, with no influence on overall mortality. Multivariate analysis revealed no significant differences in study endpoints between bipolar and quadripolar LV leads.Conclusion: In a large real-life registry, implantation of quadripolar LV leads in patients with CRT-D did not influence HF hospitalization rates. [ABSTRACT FROM AUTHOR]

Aims: Dual-coil leads were traditionally considered standard of care due to lower defibrillation thresholds (DFT). Higher complication rates during extraction with parallel progression in implantable cardioverter defibrillator (ICD) technology raised questions on dual coil necessity. Prior substudies found no significant outcome difference between dual and single coils, although using higher rates of DFT testing then currently practiced. We evaluated the temporal trends in implantation rates of single- vs. dual-coil leads and determined the associated adverse clinical outcomes, using a contemporary nation-wide ICD registry.Methods and Results: Between July 2010 and March 2015, 6343 consecutive ICD (n = 3998) or CRT-D (n = 2345) implantation patients were prospectively enrolled in the Israeli ICD Registry. A follow-up of at least 1 year of 2285 patients was available for outcome analysis. The primary endpoint was all-cause mortality. Single-coil leads were implanted in 32% of our cohort, 36% among ICD recipients, and 26% among CRT-D recipients. Secondary prevention indication was associated with an increased rate of dual-coil implantation. A significant decline in dual-coil leads with reciprocal incline of single coils was observed, despite low rates of DFT testing (11.6%) during implantation, which also declined from 31 to 2%. In the multivariate Cox model analysis, dual- vs. single-coil lead implantation was not associated with an increased risk of mortality [hazard ratio (HR) = 1.23; P= 0.33], heart failure hospitalization (HR = 1.34; P=0.13), appropriate (HR = 1.25; P= 0.33), or inappropriate ICD therapy (HR = 2.07; P= 0.12).Conclusion: Real-life rates of single-coil lead implantation are rising while adding no additional risk. These results of single-coil safety are reassuring and obtained, despite low and contemporary rates of DFT testing. [ABSTRACT FROM AUTHOR]

Aims: Cardiac resynchronization therapy (CRT) with a defibrillator (CRT-D) has downsides of high cost and inappropriate shocks compared to CRT without a defibrillator (CRT-P). Recent data suggest that the survival benefit of implantable cardioverter defibrillator (ICD) therapy is attenuated in the older age group. We hypothesized that, among octogenarians eligible for cardiac resynchronization therapy, CRT-P confers similar morbidity and mortality benefits as CRT-D.Methods and Results: We compared morbidity and mortality outcomes between consecutive octogenarian patients eligible for CRT therapy who underwent CRT-P implantation at Barzilai MC (n = 142) vs. those implanted with CRT-D for primary prevention indication who were prospectively enrolled in the Israeli ICD Registry (n = 104). Among the 246 study patients, mean age was 84 ± 3 years, 74% were males, and 66% had ischaemic cardiomyopathy. Kaplan-Meier survival analysis showed that at 5 years of follow-up the rate of all-cause mortality was 43% in CRT-P vs. 57% in the CRT-D group [log-rank P = 0.13; adjusted hazard ratio (HR) = 0.79, 95% CI 0.46-1.35, P = 0.37]. Kaplan-Meier analysis also showed no significant difference in the rates of the combined endpoint of heart failure or death (46 vs. 60%, respectively, log-rank P = 0.36; adjusted HR was 0.85, 95% CI 0.51-1.44, P = 0.55). A Cox proportional hazard with competing risk model showed that re-hospitalizations for cardiac cause were not different for the two groups (adjusted HR 1.35, 95% CI 0.7-2.6, P = 0.37).Conclusion: Our data suggest that, in octogenarians with systolic heart failure, CRT-P therapy is associated with similar morbidity and mortality outcomes as CRT-D therapy. [ABSTRACT FROM AUTHOR]

Objectives: Transcatheter aortic valve implantation (TAVI) is frequently associated with the development of conduction abnormalities. We assessed the effect of conduction abnormalities on diastolic function following TAVI. Methods: In total, 101 consecutive post-TAVI patients were included, each with echocardiographic follow-up at 1 and 6 months. Diastolic properties were correlated with the occurrence of a long PR interval and wide QRS, and their change from baseline. The measured diastolic parameters included E/A ratio, E wave deceleration time, E wave to e ' ratio, left atrial (LA) volume, and systolic pulmonary artery pressure (SPAP). The clinical outcome was all-cause mortality. Results: Overall, TAVI was associated with a consistent decrease in SPAP at the 1- and 6-month follow-up. LA volumes were increased at 1 month post-TAVI in patients with a wide compared to normal QRS (p = 0.03) and at 6 months in patients with a normal compared to prolonged PR (p = 0.03). PR prolongation above 40 ms was associated with lower SPAP at the 1- but not 6-month follow-up. Survival was not influenced by conduc-tion abnormalities. Conclusions: TAVI is associated with a reduction in SPAP. A postprocedural wide QRS and normal PR interval may unfavorably influence the left-sided filling performance, resulting in an increased LA volume. Other diastolic parameters, as well as survival, are not significantly affected by postprocedural conduction abnormalities. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to evaluate electrophysiologic study (EPS) in risk stratification of relative indications for pacemaker implantation (PMI) after transcatheter aortic valve implantation (TAVI).Methods: We reviewed files of all patients who had a left bundle branch block (LBBB) and underwent EPS after TAVI between 3/2009 and 5/2015. The indications for EPS were new-onset LBBB and the presence of an old or a new-onset LBBB associated with either PR prolongation after TAVI (∆PR >20 ms) or with "slow" atrial fibrillation (<100/min). Pacemakers were implanted when significant infranodal disease was demonstrated. The control group comprised of 55 consecutive patients who underwent TAVI and had an indication for an EPS per our definitions. These patients were discharged without further intervention. All patients were followed during 1 year for the composite endpoint of mortality or PMI after hospital discharge.Results: Indications for EPS were new LBBB (n = 8, 30.8%), new LBBB + ∆PR >20 ms (n = 9, 34.6%), baseline LBBB + ∆PR >20 ms (n = 7, 26.9%) and new LBBB + slow AF <100 bpm (n = 2, 7.7%). Multilevel conduction disturbances involving the AV node (n = 19, 73.1%), the His (n = 3, 11.5%), and the infra-His system (n = 4, 15.4%) were found. Post discharge, there were 5 (9%) deaths and 3 (5.5%) PMI in the control group compared to none in the EPS group corresponding to event-free survival of 85 and 100%, respectively (p = 0.04).Conclusions: Patients with LBBB with or without ∆PR >20 ms are at a higher risk of mortality and late PMI at 1-year follow-up. EPS can be used to safely identify patients in whom a PMI is needed. [ABSTRACT FROM AUTHOR]

A New CARTO Software for Ablating Ventricular Arrhythmias Introduction A new imaging software (CARTO® Segmentation Module, Biosense Webster) allows preprocedural 3-D reconstruction of all heart chambers based on cardiac CT. We describe our initial experience with the new module during ablation of ventricular arrhythmias. Methods and Results Eighteen consecutive patients with idiopathic ventricular arrhythmias or ischemic ventricular tachycardia (VT) were studied. In the latter group, a combined endocardial and epicardial ablation was performed. Of the 14 patients with idiopathic arrhythmias, 12 were ablated in the outflow tract (OT), 1 in the midseptal left ventricle, and 1 at the left posterior fascicular area; acute successful ablation was achieved in 11 (78.6%) patients. The procedure was discontinued due to close proximity of the arrhythmia origin to the coronary arteries (CA) in 2 patients. Acute successful uncomplicated ablation was achieved in all 4 patients with ischemic VT. During ablation in the coronary cusps commissures, the CARTO® Segmentation Module accurately defined the cusps anatomy. The precise anatomic location provided by the module assisted in successfully ablating when information from activation mapping was not optimal, by ablating at the opposite side of the cusps. In addition, by demonstrating the precise location of the CA, it allowed safe ablation of arrhythmias that originated in close proximity to the CA both in the OT area and the epicardium, eliminating the need for repeat angiography. Conclusions The CARTO® Segmentation Module is useful for accurate definition of the exact anatomic location of ventricular arrhythmias and for safely ablating them especially in close proximity to the CA. [ABSTRACT FROM AUTHOR]

Background A few series of focal atrial tachycardia (AT) originating from the noncoronary sinus of Valsalva (NCSV) have been reported in the literature during the last decade. Methods and Results Of 147 patients with AT referred for radiofrequency ablation (RFA), we identified nine (6%) originating in the vicinity of the NCSV. Clinical AT was induced during electrophysiological study in all patients without (n = 6) and with (n = 3) isoproterenol infusion. Mean cycle length of the induced tachycardia was 399 ± 85 ms. Mapping of the right atrium and of the left atrium (LA) was initially performed in all nine patients and in four patients, respectively. Earliest tachycardia activation occurred at the His bundle area in all cases. Earliest activations in the LA were at the low paraseptal regions. In two patients with antegrade dual atrioventricular (AV) node physiology that rendered difficult accurate distinction between atrial and ventricular activation, slow pathway ablation was necessary. A retrograde aortic approach was used for mapping the aortic cusps. The earliest local atrial activation in the NCSV preceded the atrial activation in the His area in all patients by 27 ± 8 ms. RFA was performed in all nine patients and was acutely successful in eight. Two patients required radiofrequency (RF) energy outputs of 50 W in order to terminate the arrhythmia. In one patient, successful AT ablation was associated with complete AV block requiring implantation of permanent pacemaker. Conclusions Focal AT can be successfully mapped and ablated in the NCSV. Higher than usual RF energy levels are sometimes required. Complete AV block is a possible complication. [ABSTRACT FROM AUTHOR]

Clinical Outcome of Single- versus Dual-Chamber ICDs Objective To compare the clinical outcomes of a single- versus dual-chamber ICD for primary prevention of sudden cardiac death in a large, national ICD registry. Methods Data were collected from the prospective Israeli ICD Registry. Baseline characteristics and clinical outcomes including mortality, admissions for heart failure (HF), and ICD therapy were compared between the two groups. Results A total of 1,125 subjects, 37% with a single-chamber and 63% with a dual-chamber ICD, constructed the baseline cohort. Approximately 80% had ischemic heart disease (IHD). Mean follow-up was 22 months, mean ejection fraction was 30%, and mean QRS width was 103 milliseconds in both groups. During follow-up, there were no significant differences in the rate of mortality, admissions for HF, appropriate or inappropriate therapy, or in time to any of the clinical outcomes. Using multivariate analysis, single-chamber ICD was not associated with increased risk of death or admission for HF. In a subgroup of patients with IHD, single-chamber ICD was associated with a higher rate of inappropriate therapy. Conclusions In this large retrospective population-based cohort, dual-chamber ICD showed no benefit in reducing the incidence of death or HF admissions, whereas in a subgroup of patients with IHD, single-chamber ICD was associated with increased inappropriate therapy. Further prospective studies are necessary to assess the benefit of dual-chamber ICD in reducing the rate of inappropriate therapy. [ABSTRACT FROM AUTHOR]

Ablation Effectiveness and Biophysical Parameters Background There is a paucity of data on biophysical parameters during radiofrequency ablation of scar-mediated ventricular tachycardia (VT). Methods and Results Data were collected from consecutive patients undergoing VT ablation with open-irrigation. Complete data were available for 372 lesions in 21 patients. The frequency of biophysical parameter changes were: >10Ω reduction (80%), bipolar EGM reduction (69%), while loss of capture was uncommon (32%). Unipolar injury current was seen in 72% of radiofrequency applications. Both EGM reduction and impedance drop were seen in 57% and a change in all 3 parameters was seen in only 20% of lesions. Late potentials were eliminated in 33%, reduced/modified in 56%, and remained after ablation in 11%. Epicardial lesions exhibited an impedance drop (90% vs. 76%, P = 0.002) and loss of capture (46% vs. 27%, P < 0.001) more frequently than endocardial lesions. Lesions delivered manually exhibited a >10Ω impedance drop (83% vs. 71%, P = 0.02) and an EGM reduction (71% vs. 40%, P < 0.001) more frequently than lesions applied using magnetic navigation, although loss of capture, elimination of LPs, and a change in all 3 parameters were similarly observed. Conclusions VT ablation is inefficient as the majority of radiofrequency lesions do not achieve more than one targeted biophysical parameter. Only one-third of RF applications targeted at LPs result in complete elimination. Epicardial ablation within scar may be more effective than endocardial lesions, and lesions applied manually may be more effective than lesions applied using magnetic navigation. New technologies directed at identifying and optimizing ablation effectiveness in scar are clinically warranted. [ABSTRACT FROM AUTHOR]

Introduction: The usefulness of unipolar electrograms (EGMs) has been reported in assessing lesion transmurality and conduction block along ablation lines. It is unknown whether unipolar and bipolar EGM characteristics predict exit block during pulmonary vein isolation (PVI) procedures. Methods and Results: Twenty patients (63 ± 7 years; 14 males [70%]) undergoing PVI with a circular mapping catheter (CMC) placed outside each PV ostium were retrospectively studied. After entrance block was achieved, pacing at each bipole around the CMC was performed to assess for absence of atrial capture (exit block). Bipolar EGMs recorded before pacing were examined for voltage, duration, fractionation, and monophasic morphology. Unipolar EGMs were examined for positive and negative amplitude, PQ segment elevation, fractionation, and monophasic morphology. The association of these parameters with atrial capture (absence of exit block) at each site was analyzed. After achievement of entrance block, only 23 of 64 PV antra (36%) exhibited exit block. Unipolar EGMs at sites with persistent capture were more likely to be fractionated and had larger negative deflections. Bipolar EGMs at sites with persistent capture showed higher amplitude, longer duration, were more likely to be fractionated, and were less likely to be monophasic. In a multivariate logistic regression model, bipolar and unipolar fractionation, bipolar duration, and lack of bipolar monophasic morphology were independently associated with persistent atrial capture. Conclusion: Specific unipolar and bipolar EGM characteristics are associated with left atrium capture after PV antral isolation. These parameters might be useful in predicting the need for further ablation to achieve exit block. (PACE 2012; 35:1294-1301) [ABSTRACT FROM AUTHOR]

Ventricular tachycardia as a late complication of blunt chest trauma has never been reported. We present a case of combined endocardial and epicardial delineation of the right ventricular arrhythmogenic substrate, where other causes of cardiomyopathy were excluded. The epicardial scar was more extensive than endocardial scar, and the central isthmus was likely intramural. A history of blunt chest trauma should be considered in patients with right ventricular cardiomyopathy. (PACE 2012; 35:e127-e130) [ABSTRACT FROM AUTHOR]

Aims To evaluate the incidence, mechanism, and clinical implications of atrioventricular (AV) block during catheter radiofrequency (RF) ablation of the cavotricuspid isthmus (CTI). Although RF ablation of atrial flutter is the most frequently performed ablation procedure, data on the incidence and significance of an AV block occurring during the procedure are scarce. Methods and results Consecutive patients (n = 845, 73.5% male) undergoing CTI ablation (913 procedures) between 1998 and 2010 were studied. Data on the occurrence of complete AV block (lasting ≥3 s) during the procedure were prospectively collected. Sixteen (1.9%) patients experienced AV block, 12 during delivery of RF pulses (Group 1) and 4 (Group 2) during manipulation of catheters in the cardiac chambers. The AV block was short lived (<1 min), located in the AV node, and associated with septal isthmus RF lines in 11 Group 1 patients. It was long-lasting and led to pacemaker implantation in one Group 1 patient. Atrioventricular blocks had an infranodal location in four Group 2 patients, all of whom had a pre-existing complete left bundle branch block (LBBB). One Group 2 patient had an AV block during his two ablation procedures. Permanent pacemakers were implanted in five (0.6%) patients (one from Group 1 and four from Group 2). Conclusions Atrioventricular blocks requiring pacemaker implantation following administration of RF pulses at the CTI are rare (0.12%). The occurrence rate of AV block related to the procedure and requiring pacemaker implantation is, however, not negligible (0.6%) and mostly affects patients with a pre-existing complete LBBB. [ABSTRACT FROM PUBLISHER]

Background The utility of defibrillation threshold testing in patients undergoing implantable cardioverter–defibrillator (ICD) implantation is controversial. Higher defibrillation thresholds have been noted in patients undergoing implantation of cardiac resynchronization therapy defibrillators (CRT-D). Since the risks and potential benefits of testing may be higher in this population, we sought to assess the impact of defibrillation safety margin or vulnerability safety margin testing in CRT-D recipients. Methods and results A total of 256 consecutive subjects who underwent CRT-D implantation between January 2003 and December 2007 were retrospectively reviewed. Subjects were divided into two groups based on whether (n= 204) or not (n= 52) safety margin testing was performed. Patient characteristics, tachyarrhythmia therapies, procedural results, and clinical outcomes were recorded. Baseline characteristics, including heart failure (HF) severity, were comparable between the groups. Four cases of HF exacerbation (2%), including one leading to one death, were recorded in the tested group immediately post-implantation. No complications were observed in the untested group. After a mean follow-up of 32 ± 20 months, the proportion of appropriate shocks in the two groups was similar (31 vs. 25%, P = 0.49). There were three cases of failed appropriate shocks in the tested group, despite adequate safety margins at implantation, whereas no failed shocks were noted in the untested group. Survival was similar in the two groups. Conclusion Defibrillation efficacy testing during implant of CRT-D was associated with increased morbidity and did not predict the success of future device therapy or improve survival during long-term follow-up. [ABSTRACT FROM PUBLISHER]

Electrophysiological properties of the atrial endocardium compared to epicardium are not well understood. The purpose of this study was to compare the electrophysiological properties and vulnerability to arrhythmia induction from these regions. Transseptal endocardial and percutaneous epicardial mapping were performed in a porcine model (n = 7). Two opposing 4-mm electrophysiological catheters were positioned endocardially and epicardially. A circular mapping catheter (CMC) was positioned at the ostium of the common inferior pulmonary vein (CIPV) recording left atrial (LA)-PV potentials. Endocardial and epicardial effective refractory periods (ERPs) at two basic cycle lengths (CLs) of 600 and 400 ms were recorded from four anatomic locations (CIPV, LA appendage, right superior PV, and LA posterior wall). Atrial repetitive response (ARR) induction was also tested from endocardial and epicardial sites. Overall, 254 ERP measurements (mean 36.3 per animal) and 84 induction attempts (mean 12 per animal) were performed. The ERP was significantly shorter in the epicardium compared to the endocardium at basic CL of 400 ms (P = 0.006) but not at CL of 600 ms (P = 0.2). In addition, only the epicardium demonstrated ERP shortening when the CL of the basic drive was shortened (P = 0.03). ARR could be induced more often from the epicardium (P = 0.002) and fibrillatory activity with epicardial/endocardial dissociation was recorded (n = 3). Also, the earliest PV activation site on the CMC was noted to be different in 16.5% of cases during epicardial and endocardial pacing. The electrophysiological characteristics of the atrial epicardium are different from the endocardium with a shorter ERP and more frequent ARR induction by programed stimulation. (PACE 2011; 37-46) [ABSTRACT FROM AUTHOR]

We present a 34-year-old patient with recurrent episodes of drug refractory paroxysmal atrial fibrillation referred for pulmonary vein (PV) isolation at our institution. During isolation of the right superior PV, a dissociated escape rhythm was observed on a portion of the PV that was disconnected, while the rest of the PV showed clear left atrium to PV conduction. This report demonstrates the rare possibility of escape PV rhythm from only partially disconnected PV, highlighting that dissociated PV rhythm does not necessarily reflect complete PV isolation. [ABSTRACT FROM PUBLISHER]

The article discusses the 2021 cardiac pacing and cardiac resynchronization therapy guidelines issued by the European Society of Cardiology (ESC). Topics explored include the initial patient evaluation process which consists of medical history taking and electrocardiogram, the need to consider pacing for reflex syncope in middle-aged patients, and the pacing procedures following transcatheter aortic valve implantation (TAVI) and cardiac surgery.

Background: Circulating endothelial progenitor cells (EPCs) are increased in conditions associated with ischaemia and can potentially support angiogenesis and vasculogenesis. EPC levels were also shown to predict outcome in patients with atherosclerotic vascular disease. We tested the hypothesis that circulating EPC can predict outcome in patients with congestive heart failure (CHF). Methods: EPC-colony-forming units were measured in the peripheral blood of 107 consecutive patients with CHF with New York Heart Association (NYHA) functional class II-IV. Serum levels of vascular endothelial growth factor (VEGF), N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) and high-sensitivity C-reactive protein (hsCRP) were also measured. End points were defined as CHF-related hospital admissions and all- cause mortality. Results: Age (p=0.01), diabetes mellitus (p=0.002) and EPC levels (p=0.02) were found to be independent predictors of all-cause mortality. EPC levels did not predict CHF-related hospitalisations. EPC levels correlated positively with NYHA (p = 0.05, r = 0.19), but did not correlate with VEGF, NT-pro-BNP or hsCRP. EPC levels did not differ by the aetiology of CHF. Conclusions: EPC levels are independent predictors of all-cause mortality among patients with CHF. [ABSTRACT FROM AUTHOR]

Subacute stent thrombosis (SAST) is a major thrombotic complication of coronary stenting. Its occurrence has been substantially reduced by thienopyridine treatment. However, information on clinical profile of patients with SAST in clopidogrel era is limited. In order to define the incidence and factors predisposing to stent thrombosis, we analyzed the computerized angiographic database of three interventional cardiology centers. Out of a total number of 5903 percutaneous coronary interventions (PCIs) with stent implantation, we found 10 patients with SAST (0.17%). The indication for PCI was usually an early invasive approach (90%) during an acute coronary syndrome . All patients were treated with an apparently optimal antithrombotic regimen (90% received heparin or LMWH and 70% received IIb/IIIa receptor inhibitors and all given aspirin). In each of the patients, we could identify high-risk angiographic findings. SAST presentation was always clinically significant with definite myocardial infarction in 100% of cases. 80% of cases occurred during the first six days post PCI. Two patients had a recurrent event. Finally, despite earlier reports of atorvastatin-mediated inhibition of clopidogrel activation we did not find any patient with SAST taking both drugs. Thus, patients with stent thrombosis during thienopyridine treatment usually exhibit high-risk angiographic features. Prospective studies should be performed to elucidate drug interactions that may reduce clopidogrel efficacy and contribute to stent thrombosis. (Int J Cardiovasc Intervent 2004; 6: 160-164) [ABSTRACT FROM AUTHOR]

Objective Data on low molecular weight heparin (LMWH) and induction of hyperkalemia is scarce. Therefore, we conducted a prospective study evaluating potassium levels before and after three days of treatment with the LMWH Enoxaparin. Methods Patients treated with the LMWH Enoxaparin in the standard therapeutic dosages were included. Levels of potassium, sodium, urea, creatinine, AST, ALT bicarbonate, pH and platelet counts were examined before and after three days of LMWH treatment. Plasma renin activity (PRA) and aldosterone levels were examined in a subgroup of patients. Potassium levels were correlated with disease states and medications known to affect potassium homeostasis. Results Ninety-seven consecutive patients were enrolled in the study, however, 12 patients were excluded from analysis; therefore 85 patients comprised the study group. The most common reason for exclusion (in 9 patients) was the absence of a second potassium result. We found an increase in potassium levels from 4.26±0.04 mmol/L at baseline to 4.43±0.04 mmol/L on the third day of treatment (mean±SE), with potassium levels exceeding 5.0 mmol/L in 9% of treated patients. There was no life threatening or symptomatic hyperkalemia. PRA and aldosterone levels did not change significantly during the treatment period. There was no correlation between the increase in potassium levels and diabetes mellitus or treatment with angiotensin converting enzymes inhibitors, angiotensin receptor blockers, β-blockers and non-potassium sparing diuretics. Conclusions Potassium levels increase on the third day of treatment with the LMWH Enoxaparin. This effect may be aldosterone independent. Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Aim: Evaluate prevalence of heart failure (HF) medications and their association with ventricular arrhythmia (VA) and survival among patients implanted with primary prevention implantable cardiac defibrillator (ICD)/cardiac resynchronization therapy + defibrillator (CRTD) devices. Methods: Association of treatment and dose (% guideline recommended target) of beta-adrenergic receptor antagonist (BB), angiotensin-antagonists (AngA), and mineralocorticoid-antagonists (MRA), after ICD/CRTD implant with VA and mortality was retrospectively analyzed. Results: Study included 186 HF patients; 42.5% and 57.5% implanted with ICD and CRTD, respectively. During 3.8 (2.1;6.7) years; 52 (28%) had VA and 77 (41.4%) died. Treatment (% of patients) included: BB (83%), AngA (87%), and MRA (59%). Median doses were 25(12.5;50)% of target for all medications. BB treatment >25% target dose was associated with reduced VA incidence. In the multivariable model including age, gender, diabetes, heart rate, and medication doses, increased BB dose was associated with reduced VA (hazard ratio (HR) 0.443 95% CI 0.222–0.885; p = 0.021). In the multivariable model for overall mortality including age, gender, renal disease, VA, and medical treatment, VA was associated with increased mortality (HR 2.672; 95% CI 1.429–4.999; p = 0.002) and AngA treatment was associated with reduced mortality (HR 0.515; 95% CI 0.285–0.929; p = 0.028). Conclusions: In this cohort of real-life HF patients discharged after ICD/CRTD implant, prevalence of guideline-based HF medications was high, albeit with low doses. Higher BB dose was associated with reduced VA, while AngA was associated with improved survival. [ABSTRACT FROM AUTHOR]

The article reports on a electrophysiology study of a nine-year-old child who presented with syncope and wide complex tachycardia. The discussion topics include dilated cardiomyopathy, infraHisian conduction system disease, ventricular tachycardia, atrioventricular node reentry tachycardia (AVNRT), and diagnosis of bundle branch (BB) reentry.