Background: Insertable cardiac monitors (ICMs) require an invasive procedure and are used for purely diagnostic purposes. Therefore, simplicity of the insertion procedure, low complication rate, ...long-term patient acceptance, sensing quality, and reliable remote monitoring are of great importance.Objective: To evaluate a novel ICM (BIOMONITOR III) regarding all these aspects.Methods: BIOMONITOR III has a miniaturized profile, long sensing vector (≈70 mm), a fast insertion tool for pocket formation and ICM placement in 1 step, and daily automatic Home Monitoring (HM) function. We evaluated the insertion procedure, complication rate, patient acceptance, sensing quality, and HM performance in 653 patients with BIOMONITOR III inserted for any ICM indication within 2 ongoing studies involving 51 sites in 11 countries.Results: The median time from skin incision to wound closure was 4.0 minutes (interquartile range, 2.3-6.2 minutes). Median follow-up period was 274 days (interquartile range, 175-342 days). Serious adverse device-related events occurred in 6 patients (0.9%). No deep infections were reported in 334 patients without antibiotic prophylaxis. The wearing comfort was good or excellent in ≈95%. The mean R-wave amplitude (0.73 mV) and HM transmission rate (≈94% of days) were stable over 1.5 years. R-wave amplitudes were larger (mean 0.80 vs 0.62 mV, P < .001) and noise burden was lower (median 3.7 vs 14.5 minutes/day, P < .001) for ICM insertions parallel to the heart's long axis (54.2%) vs parasternal (41.3%). A gross visibility of P waves was 95.1%.Conclusion: The study demonstrated fast insertion times, low complication rate, high patient acceptance, and favorable long-term sensing and HM performance of the ICM.
Electro-anatomical maps (EAMs) are commonly acquired in clinical routine for guiding ablation therapies. They provide voltage and activation time information on a 3-D anatomical mesh representation, ...making them useful for analyzing the electrical activation patterns in specific pathologies. However, the variability between the different acquisitions and anatomies hampers the comparison between different maps. This paper presents two contributions for the analysis of electrical patterns in EAM data from biventricular surfaces of cardiac chambers. The first contribution is an integrated automatic 2-D disk representation (2-D bull's eye plot) of the left ventricle (LV) and right ventricle (RV) obtained with a quasi-conformal mapping from the 3-D EAM meshes, that allows an analysis of cardiac resynchronization therapy (CRT) lead positioning, interpretation of global (total activation time), and local indices (local activation time (LAT), surrogates of conduction velocity, inter-ventricular, and transmural delays) that characterize changes in the electrical activation pattern. The second contribution is a set of indices derived from the electrical activation: speed maps, computed from LAT values, to study the electrical wave propagation, and histograms of isochrones to analyze regional electrical heterogeneities in the ventricles. We have applied the proposed methods to look for the underlying physiological mechanisms of left bundle branch block (LBBB) and CRT, with the goal of optimizing the therapy by improving CRT response. To better illustrate the benefits of the proposed tools, we created a set of synthetically generated and fully controlled activation patterns, where the proposed representation and indices were validated. Then, the proposed analysis tools are used to analyze EAM data from an experimental swine model of induced LBBB with an implanted CRT device. We have analyzed and compared the electrical activation patterns at baseline, LBBB, and CRT stages in four animals: two without any structural disease and two with an induced infarction. By relating the CRT lead location with electrical dyssynchrony, we evaluated current hypotheses about lead placement in CRT and showed that optimal pacing sites should target the RV lead close to the apex and the LV one distant from it.
Introduction: Brugada syndrome is characterized by sudden death secondary to malignant arrhythmias and the presence of ST segment elevation in leads V1 to V3 of patients with structurally normal ...hearts. This ECG pattern often is concealed but can be unmasked using potent sodium channel blockers. Like congenital long QT syndrome type 3 (LQT3) and sudden unexpected death syndrome, Brugada syndrome has been linked to mutations in SCN5A.
Methods and Results: We screened a large European family with Brugada syndrome. Three members (two female) had suffered malignant ventricular arrhythmias. Ten members showed an ECG pattern characteristic of Brugada syndrome at baseline, and eight showed the pattern only after administration of ajmaline (total 12 female). Haplotype analysis revealed that all individuals with positive ECG at baseline shared the SCN5A locus. Sequencing of SCN5A identified a missense mutation, R367H, previously associated with sudden unexpected death syndrome. Two of the eight individuals who displayed a positive ECG after the administration of ajmaline, but not before, did not have the R367H mutation, and sequencing analysis failed to identify any other mutation in SCN5A. The R367H mutation failed to generate any current when heterologously expressed in HEK cells.
Conclusion: Our results support the hypothesis that (1) sudden unexpected death syndrome and Brugada syndrome are the same disease; (2) male predominance of the phenotype observed in sudden unexpected death syndrome does not apply to this family, suggesting that factors other than the specific mutation determine the gender distinction; and (3) ajmaline may provide false‐positive results. These findings have broad implications relative to the diagnosis and risk stratification of family members of patients with the Brugada syndrome. (J Cardiovasc Electrophysiol, Vol. 15, pp. 64‐69, January 2004)
Background Isolation of the pulmonary veins (PVs) for the treatment of atrial fibrillation (AF) is often supplemented with linear lesions within the left atrium (LA). However, there are conflicting ...data on the effects of creating a roof line (RL) joining the superior PVs in paroxysmal atrial fibrillation (PAF). Methods and Results A cohort of 120 patients with drug-refractory PAF referred for ablation were prospectively randomized into 2 strategies: (1) PV isolation in combination with RL ablation (LA roof ablation LARA-1: 59 patients) or (2) PV isolation (LARA-2: 61 patients). Follow-up was performed at 1, 3, and 6 months after the procedure and every 6 months thereafter. After a 3-month blanking period, recurrence was defined as the ocurrence of any atrial tachyarrhythmia lasting ≥30 seconds. PV isolation was achieved in 89% and complete RL block in 81%. RF duration, fluoroscopy, and procedural times were slightly, but not significantly, longer in the LARA-1 group. After 15±10 months, there was no difference in the arrhythmia-free survival after a single AF ablation procedure (LARA-1: 59% vs. LARA-2: 56% at 12 months; log rank P=0.77). The achievement of complete RL block did not influence the results. The incidence of LA macroreentrant tachycardias was 5.1% in the LARA-1 group (n=3) versus 8.2% in the LARA-2 (n=5) (P=ns). Univariate analysis only identified AF duration as a covariate associated with arrhythmia recurrence (hazard ratio, 1.01 95% confidence interval, 1.002 to 1.012; P<0.01). Conclusion The linear block at the LA roof is not associated with an improved clinical outcome compared with PV isolation alone.
Premature ventricular complex (PVC) ablation has been shown to improve left ventricular ejection fraction (LVEF) and New York Heart Association functional class in patients with left ventricular ...dysfunction. Both are considered key variables in predicting risk of sudden cardiac death.
The objective of this study was to assess whether ablation might remove the primary prevention (PP) implantable cardioverter-defibrillator (ICD) indication in patients with frequent PVC.
Sixty-six consecutive patients with PP-ICD indication and frequent PVC 33 (50%) men; mean age 53 ± 13 years; 11 (17%) with ischemic heart disease underwent PVC ablation. The ICD was withheld and the indication was reevaluated at 6 and 12 months.
LVEF progressively improved from 28% ± 4% at baseline to 42% ± 12% at 12 months (P < .001). New York Heart Association functional class improved from 2 patients with NYHA functional class I (3%) at baseline to 35 (53%) at 12 months (P < .001). The brain natriuretic peptide level decreased from 246 ± 187 to 176 ± 380 pg/mL (P = .004). The PP-ICD indication was removed in 42 patients (64%) during follow-up, from 38 (92%) of them at 6 months, showing an independent association with baseline PVC burden and successful sustained ablation. In patients with successful sustained ablation, a cutoff value of 13% PVC burden had a sensitivity of 100% and a specificity of 93% (area under the curve 99%) for removing ICD indication postablation. No sudden cardiac deaths or malignant ventricular arrhythmias were observed.
In patients with frequent PVC and PP-ICD indication, ablation improves LVEF and, in most cases, allows removal of the indication. Withholding the ICD and reevaluating within 6 months of ablation seems to be a safe and appropriate strategy.
Substrate-based ventricular tachycardia (VT) ablation is a first-line treatment in patients with structural cardiac disease and sustained VT refractory to medical therapy. Despite technological ...improvements and increased knowledge of VT substrate, recurrence still is frequent. Published data are lacking on the possible reduction in VT burden after ablation despite recurrence.
The purpose of this study was to assess VT burden reduction during long-term follow-up after substrate ablation and identify predictors of VT recurrence.
We analyzed 234 consecutive VT ablation procedures in 207 patients (age 63 ± 14.9 years; 92% male; ischemic heart disease in 65%) who underwent substrate ablation in a single center from 2013 to 2018.
After follow-up of 3.14 ± 1.8 years, the VT recurrence rate was 41.4%. Overall, a 99.6% reduction in VT burden (median VT episodes per year: preprocedural 3.546 1.347–13.951 vs postprocedural 0.001 0–0.689; P = .001) and a 96.3% decrease in implantable cardioverter-defibrillator (ICD) shocks (preprocedural 1.145 0.118–4.467 vs postprocedural 0.042 0–0.111 per year; P = .017) were observed. In the subgroup of patients who experienced VT recurrences, VT burden decreased by 69.2% (median VT episodes per year: preprocedural 2.876 1.105–8.801 vs postprocedural 0.882 0.505–2.283; P <.001). Multivariable analysis showed persistence of late potentials (67% vs 19%; hazard ratio 3.18 2.18–6.65; P <.001) and lower left ventricular ejection fraction (EF) (30 25–40 vs 39 30–50; P = .022) as predictors of VT recurrence.
Despite a high recurrence rate during long-term follow-up, substrate-based VT ablation is related to a large reduction in VT burden and a decrease in ICD therapies. Lower EF and persistence of late potentials are predictors of recurrence.
Reseñas de libros Jose Manuel Pedrosa; Marc Vitse; Antonio Sánchez Jiménez ...
Revista de literatura,
12/2012, Letnik:
74, Številka:
148
Journal Article
The earliest activation site (EAS) location in the septal right ventricular outflow tract (RVOT) could be an additional mapping data predictor of left ventricular outflow tract (LVOT) vs RVOT origin ...of idiopathic ventricular arrhythmias (VAs).
The purpose of this study was to assess the impact of EAS location in predicting LVOT vs RVOT origin.
Macroscopic and histologic study was performed in 12 postmortem hearts. Electroanatomic maps (EAMs) from 37 patients with outflow tract (OT) VA with the EAS in the septal RVOT were analyzed. Pulmonary valve (PV) was defined by voltage scanning after validation of voltage thresholds by image integration. EAM measurements were correlated with those of macroscopic/histologic study.
A cutoff value of 1.9 mV discriminated between subvalvular and supravalvular positions (90% sensitivity, 96% specificity). EAS ≥1 cm below PV excluded RVOT site of origin (SOO). According to anatomic findings (distance PV-left coronary cusp = 5 ± 3 vs PV-right coronary cusp = 11 ± 5 mm), EAS-PV distance was significantly shorter in VAs arising from left coronary cusp than from the other LVOT locations (4.2 ± 5.4 mm vs 9.2 ± 7 mm; P = .034). The 10-ms isochronal longitudinal/perpendicular diameter ratio was higher in the RVOT vs the LVOT SOO group (1.97 ± 1.2 vs 0.79 ± 0.49; P = .001). An algorithm based on EAS-PV distance and the 10-ms isochronal longitudinal/perpendicular diameter ratio predicted LVOT SOO with 91% sensitivity and 100% specificity.
An algorithm based on the EAS-PV distance and the 10-ms isochronal longitudinal/perpendicular diameter ratio accurately predicts LVOT vs RVOT SOO in outflow tract VAs with EAS in the septal RVOT.
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