Influence of baseline inducibility and activation mapping on ablation outcomes in patients with structural heart disease and ventricular tachycardia.

INTRODUCTION: Stand-alone substrate ablation has become a standard ventricular tachycardia (VT) ablation strategy. We sought to evaluate the influence of baseline VT inducibility and activation mapping on ablation outcomes in patients with structural heart disease (SHD) undergoing VT ablation. METHODS: Single center, observational and retrospective study including consecutive patients with SHD and documented VT undergoing ablation. Baseline VT induction was attempted before ablation in all patients and VT activation mapping performed when possible. Ablation was guided by activation mapping for mappable VTs plus substrate ablation for all patients. Ablation outcomes and complications were evaluated. RESULTS: One hundred and sixty patients were included and were classified in three groups according to baseline VT inducibility:group 1 (non inducible, n = 18), group 2 (1 VT morphology induced, n = 53), and group 3 (>1 VT morphology induced, n = 89). VT activation mapping was possible in 35%. After a median follow-up of 38.5 months, baseline inducibility of greater than 1 VT morphology was associated with a significant incidence of VT recurrence (42% for group 3 vs. 15.1% for group 2% and 5.6% for group 1, Log-rank p < .0001) and activation mapping with a lower rate of VT recurrence (24% vs. 36.3%, Log-rank p = .035). Baseline inducibility of greater than 1 VT morphology (hazards ratio [HR]: 12.05, 95% confidence interval [CI]: 1.60-90.79, p = .016) was an independent predictor of VT recurrence while left ventricular ejection fraction less than 30% (HR: 1.93, 95% CI: 1.13-3.25, p = .014) and advanced heart failure (HR: 4.69, 95% CI: 2.75-8.01, p < .0001) were predictors of mortality or heart transplantation. Complications occurred in 11.2% (5.6% hemodynamic decompensation). CONCLUSION: Baseline VT inducibility and activation mapping may add significant prognostic information during VT ablation procedures.

Safety and feasibility of conduction system pacing in patients with congenital heart disease.

INTRODUCTION: Conduction system pacing (CSP) has emerged as an ideal physiologic pacing strategy for patients with permanent pacing indications. We sought to evaluate the safety and feasibility of CSP in a consecutive series of unselected patients with congenital heart disease (CHD). METHODS: Consecutive patients with CHD in which CSP was attempted were included. Safety and feasibility, implant tools and electrical parameters at implant and at follow-up were evaluated. RESULTS: A total of 20 patients were included (10 with a previous device). A total of 10 patients had complex forms of CHD, 9 moderate defects and 1 a simple defect. CSP was achieved in 75% of cases (10 His bundle pacing, 5 left bundle branch pacing) with left ventricular septal pacing in the remaining 5 patients. Procedure times and fluoroscopy times were prolongued (126 ± 82 min and 27 ± 30 min, respectively). Ventricular lead implant times widely varied ranging from 4 to 115 min, (mean 31 ± 28 min) and the use of multiple delivery sheaths was frequent (50%). The QRS width was reduced from 145 ± 36 ms at baseline to 116 ± 18 ms with CSP. Implant electrical parameters included: CSP pacing threshold 0.95 ± 0.65 V; R wave amplitude 9.2 ± 8.8 mV and pacing impedance 632 ± 183 Ohms, and remained stable at a median follow-up of 478 days (interquartile range: 225-567). Systemic ventricle systolic function and NYHA class (1.50 ± 0.51 vs. 1.10 ± 0.31; p = .008) significantly improved at follow-up. Lead revision was required in one patient at Day 4. CONCLUSIONS: Permanent CSP is safe and feasible in patients with CHD although implant technique is complex.

Impact of Circulatory Assistance in the Early Evolution After Heart Transplantation. Unicentric Experience.

BACKGROUND: Heart transplantation (HT) is the reference treatment for patients with terminal heart failure. In recent years there has been a progressive increase in HT procedures in patients who have a circulatory support (CS). METHODS: This is a retrospective single-center study of 293 consecutive patients who underwent HT from 2009 to 2018, analyzing the evolution of the 2 cohorts: patients with and without CS as a bridge to HT. Baseline and evolutionary clinical data collected following the usual follow-up protocol were recorded, including clinical events observed during the follow-up 1 year after the procedure. RESULTS: The subgroup of patients transplanted with CS showed a higher incidence of primary graft failure, frequent infection, and mortality. A tendency toward lower cardiac allograft vasculopathy was observed in this subgroup. Mechanical ventilation added to the CS resulted in a higher incidence of primary graft failure, infection, and renal dysfunction. The CS variable as a bridge to HT was shown to be predictive of 1-year mortality in both univariate (odds ratio, 1.84; 95% confidence interval, 1.03-3.3; P = .038) and multivariate (odds ratio, 2.1; 95% confidence interval, 1.01-4.3; P = .047) analyses. CONCLUSIONS: In our experience, CS as a bridge to HT results in a higher incidence of primary graft failure, frequent infection, and mortality at 1-year follow-up. Mechanical ventilation added to CS has a clear unfavorable prognostic impact. CS as a bridge to HT was shown to be predictive of 1-year mortality in both univariate and multivariate analyses.

Early prediction of cardiac resynchronization therapy response by non-invasive electrocardiogram markers.

Cardiac resynchronization therapy (CRT) is an effective treatment for those patients with severe heart failure. Regrettably, there are about one third of CRT "non-responders", i.e. patients who have undergone this form of device therapy but do not respond to it, which adversely affects the utility and cost-effectiveness of CRT. In this paper, we assess the ability of a novel surface ECG marker to predict CRT response. We performed a retrospective exploratory study of the ECG previous to CRT implantation in 43 consecutive patients with ischemic (17) or non-ischemic (26) cardiomyopathy. We extracted the QRST complexes (consisting of the QRS complex, the S-T segment, and the T wave) and obtained a measure of their energy by means of spectral analysis. This ECG marker showed statistically significant lower values for non-responder patients and, joint with the duration of QRS complexes (the current gold-standard to predict CRT response), the following performances: 86% accuracy, 88% sensitivity, and 80% specificity. In this manner, the proposed ECG marker may help clinicians to predict positive response to CRT in a non-invasive way, in order to minimize unsuccessful procedures.