Results of catheter ablation of atrial fibrillation in hypertrophied hearts – Comparison between primary and secondary hypertrophy

AbstractBackground and purposeApproximately 20–25% of the patients with hypertrophic cardiomyopathy (HCM) develop atrial fibrillation (AF) during the clinical course of the disease, a percentage significantly larger than that of the general population. The purpose of the present study was to report on the procedural results of patients with AF and either primary or secondary left ventricular hypertrophy (LVH).Methods and subjectsTwenty-two consecutive HCM patients (55% male, mean age 57±8 years) with symptomatic AF, having undergone AF ablation procedures between September 2009 and July 2012 were compared with respect to procedural outcome and follow-up characteristics with 22 matched controls with secondary cardiac hypertrophy (64% male, 63±10 years) from our prospective AF catheter ablation registry.Results and conclusionRadiofrequency catheter ablation (RFCA) was successful in restoring long-term sinus rhythm in patients with LVH due to HCM and due to secondary etiology. However, patients with HCM needed more RFCA procedures and frequently additional antiarrhythmic drug therapy in order to maintain sinus rhythm

Irrigated Tip Catheters for Radiofrequency Ablation in Ventricular Tachycardia

Radiofrequency (RF) ablation with irrigated tip catheters decreases the likelihood of thrombus and char formation and enables the creation of larger lesions. Due to the potential dramatic consequences, the prevention of thromboembolic events is of particular importance for left-sided procedures. Although acute success rates of ventricular tachycardia (VT) ablation are satisfactory, recurrence rate is high. Apart from the progress of the underlying disease, reconduction and the lack of effective transmural lesions play a major role for VT recurrences. This paper reviews principles of lesion formation with radiofrequency and the effect of tip irrigation as well as recent advances in new technology. Potential areas of further development of catheter technology might be the improvement of mapping by better substrate definition and resolution, the introduction of bipolar and multipolar ablation techniques into clinical routine, and the use of alternative sources of energy

Characteristics of left atrial remodeling in patients with atrial fibrillation and hypertrophic cardiomyopathy in comparison to patients without hypertrophy

Abstract Atrial fibrillation (AF) leads to remodeling characterized by changes in both size and shape of the left atrium (LA). Here we aimed to study the effect of hypertrophic cardiomyopathy (HCM) on the pattern of LA remodeling in AF-patients. HCM-patients (n = 23) undergoing AF ablation (2009–2012) were matched and compared with 125 Non-HCM patients from our prospective registry. Pre-procedural CT data were analyzed (EnSite Verismo, SJM, MN) to determine the maximal sagittal (anterior–posterior, AP), coronal (superior-inferior, SI and transversal, TV) dimensions and the sphericity index (LAS). Volume (LAV) was rendered after appendage (LAA) and pulmonary vein (PV) exclusion. A cutting plane, between PV ostia/LAA and parallel to the posterior wall, divided LAV into anterior- (LA­A) and posterior-LA (LA­P) parts. The ratio LA-A/LAV was defined as asymmetry index (ASI). HCM patients had a wider inter-ventricular septum and a smaller LV than Non-HCM patients. LA volume (LAV 166 ± 72 vs. 130 ± 36 ml, p = 0.03) and LA diameters were significantly larger in HCM patients. Anterior volume (LA-A: 112 ± 48 vs. 83 ± 26 ml, p < 0.001) differed significantly between groups, whereas the posterior volume LA-P (55 ± 28 vs. 47 ± 13 ml, p = 0.23) and LAS (75% vs. 78%, p = 0.089) was similar in both groups. As a result, ASI was significantly higher (67 ± 6 vs. 63 ± 6%, p = 0.01) in HCM than in Non-HCM patients. In conclusion, LA remodeling in patients with AF and HCM is characterized by asymmetric dilatation, driven by an anterior rather than a posterior dilatation. This can be characterized by three-dimensional imaging and could be used as surrogate of advanced atrial remodeling

A prodrug form of a Plasmodium falciparum glutathione reductase inhibitor conjugated with a 4-anilinoquinoline

Glutathione (GSH), which is known to guard Plasmodium falciparum from oxidative damage, may have an additional protective role by promoting heme catabolism. An elevation of GSH content in parasites leads to increased resistance to chloroquine (CQ), while GSH depletion in resistant P. falciparum strains is expected to restore the sensitivity to CQ. High intracellular GSH levels depend inter alia on the efficient reduction of GSSG by glutathione reductase (GR). On the basis of this hypothesis, we have developed a new strategy for overcoming glutathione-dependent 4-aminoquinoline resistance. To direct both a 4-aminoquinoline and a GR inhibitor to the parasite, double-drugs were designed and synthesized. Quinoline-based alcohols (with known antimalarial activity) were combined with a GR inhibitor via a metabolically labile ester bond to give double-headed prodrugs. The biochemically most active double-drug 7 of this series was then evaluated as a growth inhibitor against six Plasmodium falciparum strains that differed in their degree of resistance to CQ; the ED50 values for CQ ranged from 14 to 183 nM. While the inhibitory activity of the original 4-aminoquinoline-based alcohol followed that of CQ in these tests, the double-drug exhibited similar efficiency against all strains, the ED50 being as low as 28 nM. For the ester 7, a dose-dependent decrease in glutathione content and GR activity and an increase in glutathione-S-transferase activity were determined in treated parasites. The drug was subsequently tested for its antimalarial action in vivo using murine malaria models infected with P. berghei. A 178% excess mean survival time was determined for the animals treated with 40 mg/kg 7 for 4 days. No cytotoxicity due to this compound was observed. Work is in progress to extend and validate the strategy outlined here.info:eu-repo/semantics/publishe

Efficacy of Catheter Ablation for Atrial Arrhythmias in Patients with Arrhythmogenic Right Ventricular Cardiomyopathy-A Multicenter Study

Background: Atrial arrhythmias are present in up to 20% of patients with arrhythmogenic right ventricular cardiomyopathy (ARVC). Catheter ablation (CA) is an effective treatment for atrial arrhythmias in the general population. Data regarding CA for atrial arrhythmias in ARVC are scarce. Objective: To assess the safety and efficacy of CA for atrial arrhythmias in patients with ARVC. Methods: In this international collaborative effort, all patients with a definite diagnosis of ARVC undergoing CA for atrial fibrillation (AF), focal atrial tachycardia (AT), or cavotricuspid isthmus (CTI)-dependent atrial flutter (AFl) were extracted from twelve ARVC registries. Demographic, periprocedural, and long-term arrhythmic outcome data were collected. Results: Thirty-seven patients were enrolled in the study (age 50.2 ± 16.6 years, male 84%, CHA2DS2VASc 1 (1,2), HAS-BLED 0 (0–2)). The arrhythmia leading to CA was AF in 23 (62%), focal left AT in 5 (14%), and CTI-dependent AFl in 9 (24%). Acute procedural success was achieved in all procedures but one (n = 1 focal left AT; 97% acute success). The median follow-up period was 27 (13–67) months, and 96%, 74%, and 61% of patients undergoing AF ablation were free from any atrial arrhythmia recurrence after a single procedure at 6 months, 12 months, and last follow-up, respectively. After focal AT ablation, freedom from atrial arrhythmia recurrence was 80%, 80%, and 60% at 6 months, 12 months, and last follow-up, respectively. All patients undergoing CTI ablation were free from atrial arrhythmia recurrences at 6 months, with 89% single-procedural arrhythmic freedom at last follow-up. One major complication (2.7%; PV stenosis requiring PV stenting) occurred. Conclusions: CA is safe and effective in managing atrial arrhythmias in patients with ARVC, with success rates comparable to the general population

Intensive recreational athletes in the prospective multinational ICD Sports Safety Registry : results from the European cohort

Background: In the ICD Sports Safety Registry, death, arrhythmia- or shock-related physical injury did not occur in athletes who continue competitive sports after implantable cardioverter-defibrillator (ICD) implantation. However, data from non-competitive ICD recipients is lacking. This report describes arrhythmic events and lead performance in intensive recreational athletes with ICDs enrolled in the European recreational arm of the Registry, and compares their outcome with those of the competitive athletes in the Registry. Methods: The Registry recruited 317 competitive athletes >= 18 years old, receiving an ICD for primary or secondary prevention (234 US; 83 non-US). In Europe, Israel and Australia only, an additional cohort of 80 'auto-competitive' recreational athletes was also included, engaged in intense physical activity on a regular basis (>= 2x/week and/or >= 2 h/week) with the explicit aim to improve their physical performance limits. Athletes were followed for a median of 44 and 49 months, respectively. ICD shock data and clinical outcomes were adjudicated by three electrophysiologists. Results: Compared with competitive athletes, recreational athletes were older (median 44 vs. 37 years; p = 0.0004), more frequently men (79% vs. 68%; p = 0.06), with less idiopathic ventricular fibrillation or catecholaminergic polymorphic ventricular tachycardia (1.3% vs. 15.4%), less congenital heart disease (1.3% vs. 6.9%) and more arrhythmogenic right ventricular cardiomyopathy (23.8% vs. 13.6%) (p < 0.001). They more often had a prophylactic ICD implant (51.4% vs. 26.9%; p < 0.0001) or were given a beta-blocker (95% vs. 65%; p < 0.0001). Left ventricular ejection fraction, ICD rate cut-off and time from implant were similar. Recreational athletes performed fewer hours of sports per week (median 4.5 vs. 6 h; p = 0.0004) and fewer participated in sports with burst-performances (vs. endurance) as their main sports: 4% vs. 65% (p < 0.0001). None of the athletes in either group died, required external resuscitation or was injured due to arrhythmia or shock. Freedom from definite or probable lead malfunction was similar (5-year 97% vs. 96%; 10-year 93% vs. 91%). Recreational athletes received fewer total shocks (13.8% vs. 26.5%, p = 0.01) due to fewer inappropriate shocks (2.5% vs. 12%; p = 0.01). The proportion receiving appropriate shocks was similar (12.5% vs. 15.5%, p = 0.51). Recreational athletes received fewer total (6.3% vs. 20.2%; p = 0.003), appropriate (3.8% vs. 11.4%; p = 0.06) and inappropriate (2.5% vs. 9.5%; p = 0.04) shocks during physical activity. Ventricular tachycardia/fibrillation storms during physical activity occurred in 0/80 recreational vs. 7/317 competitive athletes. Appropriate shocks during physical activity were related to underlying disease (p = 0.004) and competitive versus recreational sports (p = 0.004), but there was no relation with age, gender, type of indication, beta-blocker use or burst/endurance sports. The proportion of athletes who stopped sports due to shocks was similar (3.8% vs. 7.5%, p = 0.32). Conclusions: Participants in recreational sports had less frequent appropriate and inappropriate shocks during physical activity than participants in competitive sports. Shocks did not cause death or injury. Recreational athletes with ICDs can engage in sports without severe adverse outcomes unless other reasons preclude continuation