Outcomes of supraventricular tachycardia ablation: Results from the Singapore ablation and cardiac devices registry.

BACKGROUND: The Singapore Cardiac Databank was designed to monitor the performance and outcomes of catheter ablation. We investigated the outcomes of paroxysmal supraventricular tachycardia (PSVT)-ablation in a prospective, nationwide, cohort study. METHODS: Atrioventricular nodal re-entrant tachycardia (AVNRT), atrioventricular re-entry tachycardia (AVRT), or atrial tachycardia (AT)-ablations in Singapore from 2010 to 2018 were studied. Outcomes include acute success, periprocedural-complications, postoperative pacing requirement, arrhythmic recurrence and 1-year all-cause mortality. RESULTS: Among 2260 patients (mean age 45 ± 18 years, 50% female, 57% AVNRT, 37% AVRT, 6% AT), overall acute success rates of PSVT-ablation was 98.4% and increased in order of AT, AVRT, and AVNRT (p < .001). Periprocedural cardiac tamponade occurred in two AVRT patients. A total of 15 pacemakers (6 within first 30-days, 9 after 30-days) were implanted (seven AV block, eight sinus node dysfunction [SND]), with the highest incidence of pacemaker implantation after AT-ablation (5% vs. 0.6% AVNRT vs. 0.1% AVRT, p < .001). Repeat ablations (0.9% AVNRT, 7% AVRT, 4% AT, p < .001) were performed in 78 (3.5%) patients and 13 (0.6%) patients died within a year of ablation. Among outcomes considered adjusting for age, sex, PSVT-type and procedure-time, AT was independently associated with 6-fold increased odds of total (adjusted odds ratio [AOR] 6.32, 95% confidence interval [CI] 1.95-20.53) and late (AOR 6.38, 95% CI 1.39-29.29) pacemaker implantation, while AVRT was associated with higher arrhythmic recurrence with repeat ablations (AOR 4.72, 95% CI 2.36-9.44) compared to AVNRT. CONCLUSIONS: Contemporary PSVT ablation is safe with high acute success rates. Long-term outcomes differed by nature of the PSVT.

Identifying patients likely to be readmitted after transcatheter aortic valve replacement.

Hospital readmission following transcatheter aortic valve replacement (TAVR) contributes considerably to the costs of care. Readmission rates following TAVR have been reported to be as high as 17.4% at 30 days and 53.2% at 1 year. Patient and procedural factors predict an increased likelihood of readmission including non-transfemoral access, acute and chronic kidney impairment, chronic lung disease, left ventricular systolic dysfunction, atrial fibrillation, major bleeding and prolonged index hospitalisation. Recent studies have also found the requirement for new pacemaker implantation and the severity of paravalvular aortic regurgitation and tricuspid regurgitation to be novel predictors of readmission. Post-TAVR readmission within 30 days of discharge is more likely to occur for non-cardiac than cardiac pathology, although readmission for cardiac causes, especially heart failure, predicts higher mortality than readmission for non-cardiac causes. To combat the risk of readmission and associated mortality, the routine practice of calculating and considering readmission risk should be adopted by the heart team. Furthermore, because most readmissions following TAVR occur for non-cardiac reasons, more holistic approaches to readmission prevention are necessary. Familiarity with the most common predictors and causes of readmission should guide the development of initiatives to address these conditions proactively.

Syncope, conduction disturbance, and negative electrophysiological test: Predictive factors and risk score to predict pacemaker implantation during follow-up.

BACKGROUND: Patients with syncope and bundle branch block (BBB) are at risk for atrioventricular block (AVB). Electrophysiological study (EPS) can help in identifying patients at higher risk for AVB, but the false-negative rate is remarkable. Few data on the predictors of the need for pacemaker implantation during follow-up have been reported. OBJECTIVE: The purpose of this study was to analyze the rate of patients who need pacemaker implantation after negative EPS and predictive factors. METHODS: A single-center prospective study of 159 consecutive patients (73.9 ± 12.1 years; male 64.9%) with syncope and BBB (January 2012-December 2016) and negative EPS was conducted. An implantable loop recorder was implanted. RESULTS: After 27.9 ± 10.8 months of follow-up, 39 patients (24.8%) underwent pacemaker implantation because of bradyarrhythmia. In the univariate analysis, bifascicular (right BBB + left fascicular block) block, bifascicular block + long PR interval, conduction disturbance different from isolated right BBB, HV ≥60 ms, and HV ≥70 ms after class I drug challenge were predictors of pacemaker implantation. In the multivariate analysis, only bifascicular block (hazard ratio 2.5; 95% confidence interval 1.4-4.8; P = .04) and HV interval ≥60 ms (hazard ratio 3.5; 95% confidence interval 1.8-6.2; P <.001) were statistically significant. A risk score according to the multivariate model identified 3 levels of pacemaker implantation rate (13.5%, 32.7%, and 66.7%; P <.001). No death or severe trauma related to bradyarrhythmia occurred. CONCLUSION: The strategy of an implantable loop recorder in patients with syncope and BBB is safe after negative EPS, but some patients might need pacemaker implantation during follow-up. A risk score based on HV ≥60 ms and bifascicular block can be useful in identifying patients at risk for advanced AVB after negative EPS.

Differences in ventricular tachyarrythmias and antitachycardia pacing effectiveness according to the ICD indication (primary versus secondary prevention): an analysis based on the stored electrograms.

PURPOSE: To determine whether monomorphic ventricular tachycardias (VTs) have different characteristics and/or responses to antitachycardia pacing (ATP) with respect to the indication-primary prevention (PP) versus secondary prevention (SP)-among ICD patients with left ventricular dysfunction. METHODS: We prospectively studied 551 VT (cycle length [CL] 329 ± 35 ms; PP 34%) occurring in 67 ICD patients with left ventricular dysfunction (LVEF 35 ± 8%). ICD programming was standardized, including ATP for slow (CL 400-321 ms) and fast VT (CL 250-320 ms). We analyzed the following aspects: CL, percentage of variability of the 12 RR intervals prior to ATP (P-RR)-which was calculated by dividing the mean difference between each R-R interval with the next one by the CL × 100-and type of termination: immediate (VT ceased immediately upon ATP completion) or delayed (VT persisted after ATP). RESULTS: ATP was successful in 86% of VTs. VTs occurring in SP patients had a lower P-RR, median (IQR) 2.7% (1.2-3.7) versus 1.9% (0.9-3.2); p = 0.002; they terminated immediately after ATP less frequently (27% versus 12%; p < 0.001), and although they were more frequently slow (51% versus 67%; p = 0.01), ATP was less effective in them, 92 versus 80% (p = 0.02). CONCLUSIONS: VTs occurring in SP patients are slower, more stable, and they terminate less frequently at ATP. Therefore, compared with PP, SP patients seem to have fewer self-terminating VTs.

Incidence and prognostic significance of spontaneous and inducible antidromic tachycardia.

AIMS: Orthodromic atrioventricular reentrant tachycardia (ORT) is the most common arrhythmia at electrophysiological study (EPS) in patients with pre-excitation. The purpose of the study was to determine the clinical significance and the electrophysiological characteristics of patients with inducible antidromic tachycardia (ADT). METHODS AND RESULTS: Electrophysiological study was performed in 807 patients with a pre-excitation syndrome in control state and after isoproterenol. Antidromic tachycardia was induced in 63 patients (8%). Clinical and electrophysiological data were compared with those of 744 patients without ADT. Patients with and without ADT were similar in term of age (33 ± 18 vs. 34 ± 17), male gender (68 vs. 61%), clinical presentation with spontaneous atrioventricular reentrant tachycardia (AVRT) (35 vs. 42%), atrial fibrillation (AF) (3 vs. 3%), syncope (16 vs. 12%). In patients with induced ADT, asymptomatic patients were less frequent (24 vs. 37%; <0.04), spontaneous ADT and spontaneous malignant form more frequent (8 vs. 0.5%; <0.001) (16 vs. 6%; <0.002). Left lateral accessory pathway (AP) location was more frequent (51 vs. 36%; P < 0.022), septal location less frequent (40 vs. 56%; P < 0.01). And 1/1 conduction through AP was more rapid. Orthodromic AVRT induction was as frequent (55.5 vs. 55%), but AF induction (41 vs. 24%; P < 0.002) and electrophysiological malignant form were more frequent (22 vs. 12%; P < 0.02). The follow-up was similar; four deaths and three spontaneous malignant forms occurred in patients without ADT. When population was divided based on age (<20/≥20 years), the older group was less likely to have criteria for malignant form. CONCLUSION: Antidromic tachycardia induction is rare in pre-excitation syndrome and generally is associated with spontaneous or electrophysiological malignant form, but clinical outcome does not differ.

Implantation and patient profiles for pacemakers and cardioverter-defibrillators in France (2008-2009).

BACKGROUND: An ageing population and the extension of indications will in all probability result in an increasing number of cardiac device implantations. METHODS: Patients implanted in 2008 and 2009 were identified by means of the French National Hospital Discharge database to establish the implantation rate and the National Health Insurance (NHI) Information System database for patient profiles (76% of the population). RESULTS: Of the 64,306 pacemaker implantations (1003.7 per million inhabitants [pmi]) in 2009, 21.4% were single chamber, 75.4% double chamber and 3.2% triple chamber (CRT-P). Of the 9028 cardioverter-defibrillator implantations (140.8 pmi) in 2009, 30.1% were single chamber, 27.5% double chamber and 42.5% triple chamber (CRT-D), accounting for 65% of cardiac resynchronization therapy (CRT) implants. Among NHI beneficiaries, 58.6% of cardioverter-defibrillators were implanted for primary prevention. Between 2008 and 2009, CRT-P implantations increased by 8.8% and CRT-D implantations by 29.3%. Regional variations in implantation rates were observed regarding single-chamber pacemakers (15-33%) and CRT-D among CRT (46.2-73.8%). Pacemaker implantations cost €158.4 million overall, 4.5% of which was for CRT-P; cardioverter-defibrillator implantations cost €96 million, 49% of which was for CRT-D. For NHI beneficiaries, 11.9% of CRT-P patients and 6.5% of CRT-D patients already had a device of the same type implanted in the 3 preceding years. CONCLUSION: The results confirm the increase in cardioverter-defibrillator implantations in France. The implantation rate remains lower than that in the USA but falls within the European average. Reasons behind significant regional variations in implantation rates need further study.

Ventricular arrhythmia inducibility predicts subsequent ICD activation in nonischemic cardiomyopathy patients: a DEFINITE substudy.

OBJECTIVES: We evaluated whether electrophysiologic (EP) inducibility predicts the subsequent occurrence of spontaneous ventricular tachycardia (VT) or ventricular fibrillation (VF) in the Defibrillators in Nonischemic Cardiomyopathy Treatment Evaluation (DEFINITE) trial. BACKGROUND: Inducibility of ventricular arrhythmias has been widely used as a risk marker to select implantable cardioverter defibrillator (ICD) candidates, but is believed not to be predictive in nonischemic cardiomyopathy patients. METHODS: In DEFINITE, patients randomized to the ICD arm, but not the conventional arm, underwent noninvasive EP testing via the ICD shortly after ICD implantation using up to three extrastimuli at three cycle lengths plus burst pacing. Inducibility was defined as monomorphic or polymorphic VT or VF lasting 15 seconds. Patients were followed for a median of 29 +/- 14 months (interquartile range = 2-41). An independent committee, blinded to inducibility status, characterized the rhythm triggering ICD shocks. RESULTS: Inducibility, found in 29 of 204 patients (VT in 13, VF in 16), was associated with diabetes (41.4% vs 20.6%, P = 0.014) and a slightly higher ejection fraction (23.2 +/- 5.9 vs 20.5 +/- 5.7, P = 0.021). In follow-up, 34.5% of the inducible group (10 of 29) experienced ICD therapy for VT or VF or arrhythmic death versus 12.0% (21 of 175) noninducible patients (hazard ratio = 2.60, P = 0.014). CONCLUSIONS: In DEFINITE patients, inducibility of either VT or VF was associated with an increased likelihood of subsequent ICD therapy for VT or VF, and should be one factor considered in risk stratifying nonischemic cardiomyopathy patients.

Utility of T-wave alternans in congestive heart failure.

The use of implantable cardioverter defibrillator (ICD) in heart failure patients decreases the arrhythmic mortality with the cost of increasing the number of patients to be treated, and microvolt T-wave alternans (MTWA) testing can be used as a good criteria to better select the candidate for such a therapy. This article examines generalities about the mechanism of alternans, definitions of positive, negative, and indeterminate MTWA tests, and factors that can modify these results. We review clinical studies that have found MTWA as a marker of ventricular arrhythmias in patients with heart failure, independent of etiology, ischemic or idiopathic. Microvolt T-wave alternans permits the selection of low risk patients who may not benefit of ICD implantation by standard criteria, due to high negative predictive values in most studies.

Avaliação clínica do desempenho de um cabo-eletrodo bipolar endocárdico atrial de fização passiva revestido com esteróide / Clinical avaliation of the atrial bipolar pacing lead with passive fixation and steroid eluting

Cabos elétrodos revestidos com esteróides foram desenvolvidos com o propósito de obter baixos limiares crônicos de estimulação. O objetivo deste estudo clínico foi testar a segurança e a efetividade do cabo-eletrodo bipolar Medtronic modelo 5592, tanto na estimulação como na sensibilidade, usando como referência o modelo 5524M do mesmo fabricante. Realizou-se uma avaliação prospectiva do modelo mediante o implante de 87 cabos-eletrodos em 87 pacientes, 44 (51 por cento) dos quais eram homens. Os dados foram coletados no momento do implante, na pré-alta, duas semanas e um mês após o implante. Ao final de um mês de acompanhamento foram constatadas 7 por cento de complicações que necessitaram de correção cirúrgica e 3,5 por cento que foram solucionadas com reprogramação do gerador de pulsos. A análise dos resultados mostrou que a despeito do desempenho elétrico aceitável, não foi atingido o objetivo de promover maior segurança com relação a complicações e eventos adversos relacionados ao cabo-eletrodo. Conclui-se que o cabo-eletrodo estudado apresentou menor segurança que o modelo de referência

[Cardiac electrostimulation methods in the treatment, drug therapy selection and assessment of their antirelapse effect in atrial flutter]. / Elektrokardiostymuliatsiini metody u likuvanni, pidbori medykamentoznoï terapiï ta otsinky ïï protyvretsydyvnoho efektu pry tripotinni peredserd'.

Preliminary preparation of patients with atrial flutter (AF) using antiarrhythmic drugs permits enhancing efficiency of electrocardiostimulating method to arrest AF (up to 93.75%). The size of the amplitude F in transesophageal electrogramme (TEEG) and duration of the cycle of auricular contractions permit the results of the electrocardiostimulating arrest of AF to be predicted. AF of low amplitude wave F in TEEG turns, as a rule, to atrial fibrillation.