Search

The purpose of this paper was to highlight the importance of the anatomy of the right ventricular outflow tract (RVOT) and the proximity of the mid segment of the left anterior descending coronary artery (LAD) to the RVOT in the setting of ablation of ventricular arrhythmias in the RVOT. During the period from 2014 till 2017, five patients with injury to the LAD during ablation within RVOT were identified in three centers, in Belgium, Germany and Israel. The clinical characteristics, procedural data and follow up data, where available, are reported. The literature review over coronary artery damage during radiofrequency ablation procedures is provided and the anatomy of the RVOT and the neighboring vascular structures is discussed. We present five patients who underwent radiofrequency ablation of ventricular arrhythmias mapped to the inferior and anterior part of the RVOT, at the insertion of the right ventricular wall to the septum, whereby ablation resulted in occlusion in four and severe stenosis in one, of the mid segment of the LAD coronary artery. All patients underwent percutaneous coronary intervention and stenting, four of them immediately during the same procedure and one 3 days later because of lack of signs and symptoms of acute coronary occlusion. In conclusion, the mid segment of the LAD at the level of the second septal perforator/second diagonal branch runs in very close proximity to the endocardial aspect of the lower part of the RVOT and care should be taken during ablation of ventricular arrhythmias in this region. Additional imaging such as intracardiac echocardiography and coronary angiography may be helpful in avoiding complications., (© 2023 Wiley Periodicals LLC.)

Background: The prognosis of patients with untreated cardiac implantable electronic device (CIED) infection is poor. Whether removal of all leads by a successful transvenous lead extraction (TLE) procedure changes the prognosis is unclear., Objective: To identify predictors of mortality in patients with CIED infection despite successful TLE., Methods: Retrospective single-center analysis of prospectively collected database from consecutive patients undergoing TLE at our center. Predictors for mortality were identified and a score predicting high mortality rate was calculated., Results: A total of 371 consecutive patients underwent TLE, of whom 337 (90.8%) had complete hardware removal. Most were extracted due to infectious causes (81.3%). Approximately one-third (35%) died during a mean follow-up of 1056 ± 868 days. There was significantly higher mortality observed in the infectious group. Multivariate logistic regression models for infectious group only identified creatinine and albumin measurements as risk markers for 30 days mortality (odds ratio [OR], 1.68; 95% confidence interval [CI], 1.19-2.38; P = .003 and OR, 0.4; 95% CI, 0.16-0.97; P = .039, respectively). A risk score was created based on cutoff values of creatinine ≥2md/dL (1 point) and albumin ≤3.5 g/dL (1 point). A value of 2 points predicted a 50% chance of 30-day mortality and a 75% chance of 1-year mortality (P < .0001 for both)., Conclusions: Creatinine and albumin can be used as a combined risk score to successfully identify patients at risk of death despite undergoing a successful TLE procedure for infectious reasons. This score could help decision making when contemplating on conservative antibiotic treatment vs TLE., (© 2020 Wiley Periodicals, Inc.)

Major vessel injury during right ventricular outflow tract ablation is not something widely recognized, and routine evaluation of the left anterior descending (LAD) artery location in relation to the septal right ventricle is not routinely performed. In the present article, we report a case of acute LAD occlusion after right ventricular outflow tract ablation and then illustrate the intimately close relationship of the LAD artery to the anterior septal site of the RVOT (approximately 2-3 cm under the pulmonic valve), using a combination of intracardiac echocardiography and 3-dimensional electroanatomical mapping recorded during a second case, in order to specifically point to the area at risk., (© 2016 Wiley Periodicals, Inc.)

Background: The initial impedance decrease during radiofrequency (RF) ablation is an indirect marker of catheter contact and lesion formation. We aimed to assess feasibility, efficacy, and safety of an ablation approach guided by initial impedance decrease., Methods: A total of 25 patients with paroxysmal AF had point-by-point, wide antral pulmonary vein (PV) isolation. RF applications were aborted if a decrease of at least 5 Ω did not occur in the first 10 seconds; otherwise, ablation was continued for at least 20 seconds. Power was 30 Watts and reduced to 15-25 Watts on the posterior wall., Results: A total of 28% of RF applications were terminated because of inadequate impedance decrease. The remaining lesions showed a median decrease of 7.6 Ω (IQR 5.0-10.7) at 10 seconds and median duration of RF lesions was 38 seconds. Note that, 100 PVs were isolated with 49 rings. PVI occurred before anatomic completion of the ablation ring of adequate lesions in 39/49 (80%) and concurrent with ring completion in 7/49 (14%). Additional lesions were required in 3/49 (6%) rings. After PVI, additional lesions were required to eliminate dormant conduction in 2/47 (4%) and pace-capture on the ablation line in 24/49 vein pairs (49%). During short-term follow-up, 3 nonfatal esophageal injuries and 2 late pericardial effusions occurred. During a mean follow-up of 431 ± 87 days, 21/25 patients (84%) remained free of recurrent symptomatic atrial arrhythmias., Conclusions: PVI guided by initial impedance decrease is feasible and results in PVI concurrent with or before completion of the ablation ring in 94% of patients. Single procedure efficacy after one year of follow-up was 84%. Near-term complications suggest that deeper lesions are created, indicating that further reduction of RF-power and duration is warranted., (© 2015 Wiley Periodicals, Inc.)

Introduction: Renal dysfunction is associated with increased morbi-mortality in heart failure patients. Data regarding functional and clinical efficacy of cardiac resynchronization therapy (CRT) in this population are limited., Methods and Results: We aimed to evaluate the rate of functional response to CRT in patients with renal dysfunction and its association with long-term mortality. Our study included a total of 179 consecutive patients implanted between 2007 and 2010. The rate of functional response to CRT (defined by a composite score using New York Heart Association functional class, 6-minute walk test, and quality of life) was compared between patients with and without renal dysfunction (defined as eGFR < or ≥60 mL/min/1.73 m(2) ). Survival analysis estimates were constructed according to the Kaplan-Meier method, with results comparison using the log-rank test. During a median follow-up of 4.2 years, 73 patients (40%) died. Patients with low eGFR were older (72 ± 8 years vs. 64 ± 12 years; P < 0.001), and had higher prevalence of ischemic heart disease (75% vs. 53%; P = 0.003). Functional response rates did not differ significantly between patients with and without renal dysfunction (58% and 69%, respectively; P = 0.14). Despite overall higher mortality in patients with low eGFR (53.8% vs. 22.7%; P < 0.001), the presence of functional response at 1 year among patients with renal dysfunction was still independently associated with an improved long-term survival (HR = 0.49 [95%CI: 0.28-0.83]; P = 0.009)., Conclusion: Functional response to CRT at 1 year does not differ significantly between patients with or without kidney disease, and is an independent predictor of improved long-term survival in patients with renal dysfunction., (© 2014 Wiley Periodicals, Inc.)

Introduction: Magnetic resonance (MR)-imaging has shown that infarct scars causing ventricular tachycardia (VT) can extend deep to and beyond bipolar low-voltage areas (LVAs) and may be a source of ablation failure. We hypothesized that the size of the unipolar LVA "penumbra" beyond the overlying bipolar scar may predict outcome of endocardial VT ablation., Methods: Twenty consecutive patients with ischemic cardiomyopathy who underwent endocardial VT ablation were retrospectively reviewed. Bipolar (30-500 Hz) LVA defined as <1.5 mV and unipolar (0.5-500 Hz) LVA defined as <8.3 mV were reviewed on an electroanatomic mapping system. VT isthmus sites were identified from entrainment mapping, VT termination by ablation, or pace-mapping with abolition of VT inducibility by ablation., Results: All bipolar LVAs (70.5 ± 20 cm(2) ) had unipolar LVAs that surrounded the bipolar LVA (147 ± 47 cm(2) ). Only 58% of the induced VTs could be mapped and ablated. During a 3-month follow-up 8/20 patients had VT recurrence. The size of the LVA penumbra was not different for those with (88 ± 47 cm(2) ) versus without (69 ± 35 cm(2) ) recurrences. However, all (8/8) of the group that recurred had isthmus/exits in the bipolar LVA border compared to only 3/12 that did not recur (100% vs. 25%; P < 0.05). Furthermore, 5/8 patients who recurred harbored VT isthmuses in the unipolar LVA penumbra than 1/12 who did not recur (63% vs. 8%; P = 0.01)., Conclusion: In ischemic cardiomyoapthy, unipolar LVA penumbra of varying size surrounds endocardial bipolar LVA, indicating intramural/epicardial scar. Although the size of this area did not predict early recurrence after endocardial ablation, frequent recurrences after VT ablation at scar periphery suggests deeper substrate toward the infarct border., (© 2014 Wiley Periodicals, Inc.)

Background: Management of atrial arrhythmias (AA) in orthotopic heart transplant (OHT) patients is challenging., Objective: The purpose of this study was to define the mechanisms of these arrhythmias and to evaluate the role of ablation., Methods: Patients with OHT referred for ablation of AA from 1999 to 2011 were included (n = 15). Entrainment and anatomic 3-D mapping were utilized to identify AA mechanism and guide ablation., Results: The median time from OHT to ablation was 8 years (range: 1 month-16 years). AA types included 1 (7%) AVNRT, 5 (33%) cavotricuspid isthmus (CTI) dependent donor atrial flutter (AFl), 3 (20%) non-CTI-dependent donor AFL (n = 3), focal atrial tachycardia (AT) (n = 2) and in 4 (27%) recipient to donor atria conduction (RDC) that involved the right atrial anastomosis in 3 and left atrial anastamosis in 1 patient. In RDC tachycardia, ablation was performed at the site of earliest donor atrial activation on the suture line. AA in the recipient atria were not targeted. This resulted in acute success in all cases. In most patients 12/15 (80%) only right atrial ablation was necessary. Regardless of surgical technique (bicaval vs biatrial) right-sided AA was most common. Acute success occurred in 14/15 (93%) patients and 3/15 (20%) required repeat Abl for recurrence. There were no major complications., Conclusion: AA after OHT are most commonly due to atrial macroreentry, but focal arrhythmias and RDC atrial conduction also occur. Ablation of organized AA is usually successful with low risk, warranting early consideration in preference to medical treatment., (© 2012 Wiley Periodicals, Inc.)

Introduction: NS5806 activates the transient outward potassium current (I(to) ) in canine ventricular cells. We compared the effects of NS5806 on canine atrial versus ventricular tissues and myocytes., Methods and Results: NS5806 (10 μM) was evaluated in arterially perfused canine right atrial and right ventricular wedge preparations. In ventricular wedges NS5806 (10 μM) accentuated phase 1 in epicardium (Epi), with little effect in endocardium (Endo), resulting in augmented J-waves on the ECG. In contrast, application of NS5806 (10 μM) to atrial preparations had no effect on phase 1 repolarization but significantly decreased upstroke velocity (dV/dt) and depressed excitability, consistent with sodium channel block. Current and voltage-clamp recordings were made in the absence and presence of NS5806 in (10 μM) enzymatically dissociated atrial and ventricular myocytes. In ventricular myocytes, NS5806 increased I(to) magnitude by 80% and 16% in Epi and Endo, respectively (at +40 mV). In atrial myocytes, NS5806 increased peak I(to) by 25% and had no effect on the sustained current, I(Kur) . Under control conditions, I(Na) density in atrial myocytes was nearly double that in ventricular myocytes. NS5806 caused a shift in steady-state mid-inactivation (V(1/2)) from -73.9 ± 0.27 to -77.3 ± 0.21 mV in ventricular and from -82.6 ± 0.12 to -85.1 ± 0.11 mV in atrial cells, resulting in reduction of I(Na) in both cell types. Expression of mRNA encoding putative I(Na) and I(to) channel subunits was evaluated by qPCR., Conclusion: NS5806 produces a prominent augmentation of I(to) with little effect on I(Na) in the ventricles, but a potent inhibition of I(Na) with little augmentation of I(to) in atria., (© 2011 Wiley Periodicals, Inc.)

Objectives: to conduct a clinical, genetic, and functional analysis of 3 unrelated families with familial sinus bradycardia (FSB)., Background: mutations in the hyperpolarization-activated nucleotide-gated channel (HCN4) are known to be associated with FSB., Methods and Results: three males of Moroccan Jewish descent were hospitalized: 1 survived an out-of-hospital cardiac arrest and 2 presented with weakness and presyncopal events. All 3 had significant sinus bradycardia, also found in other first-degree relatives, with a segregation suggesting autosomal-dominant inheritance. All had normal response to exercise and normal heart structure. Sequencing of the HCN4 gene in all patients revealed a C to T transition at nucleotide position 1,454, which resulted in an alanine to valine change (A485V) in the ion channel pore found in most of their bradycardiac relatives, but not in 150 controls. Functional expression of the mutated ion channel in Xenopus oocytes and in human embryonic kidney 293 cells revealed profoundly reduced function and synthesis of the mutant channel compared to wild-type., Conclusions: we describe a new mutation in the HCN4 gene causing symptomatic FSB in 3 unrelated individuals of similar ethnic background that may indicate unexplained FSB in this ethnic group. This profound functional defect is consistent with the symptomatic phenotype.