Andreas Müssigbrodt

Precordial QRS amplitude ratio predicts long-term outcome after catheter ablation of electrical storm due to ventricular tachycardias in patients with arrhythmogenic right ventricular cardiomyopathy

BACKGROUND Radiofrequency catheter ablation is currently considered as the therapeutic option of choice in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) and recurrent ventricular tachycardia (VT). METHODS This study intended to assess the long-term outcome of catheter ablation in patients with ARVC and electrical storm. The specific objective was to assess the relationship between precordial QRS amplitude ratio and outcome of catheter ablation in these patients. RESULTS Twenty-eight patients (19 men, age 52.3±14.2years) underwent 48 catheter ablation procedures (range 1-6, six epicardial). During a mean follow-up of 18.7±15.1months, 13 patients (46.5%) experienced VT recurrence. Age >50years and ∑QRSmvV1-V3/∑QRSmvV1-V6≤0.48 but not right ventricular size and acute ablation outcome were associated with VT recurrence during the follow up. CONCLUSION Age >50years and ∑QRSmvV1-V3/∑QRSmvV1-V6≤0.48 predict recurrence of VT after successful radiofrequency catheter ablation of VT in patients with ARVC and electrical storm.

Diagnosis of Arrhythmias in Athletes Using Leadless, Ambulatory HR Monitors.

Exercise-related palpitations, vertigo, and syncope may be caused by benign etiologies but can also herald life-threatening arrhythmias. The precise diagnosis of these findings is therefore essential and potentially life saving but often is a challenge for sports physicians and cardiologists. Leadless, ambulatory HR monitors with chest strap transmitters have been designed to steer exercise intensity in athletes with a baseline sinus rhythm. However, they also can capture arrhythmias. Presented here are three cases of varying arrhythmias: atrial fibrillation, atrioventricular nodal reentrant tachycardia, and ectopic atrial tachycardia that demonstrate the utility of HR monitors designed for athletic purposes in facilitating the diagnosis of arrhythmias and guiding appropriate treatment.

Vernakalant-facilitated electrical cardioversion: comparison of intravenous vernakalant and amiodarone for drug-enhanced electrical cardioversion of atrial fibrillation after failed electrical cardioversion

Abstract Aims Electrical cardioversion is one cornerstone for the rhythm control strategy of atrial fibrillation (AF), which is, however, hampered by immediate AF recurrence (IRAF) or failed electrical cardioversion (FECV). We aimed to investigate the potential role of vernakalant for facilitated electrical cardioversion in cardioversion-resistant AF. Methods and results The subjects of this study were 63 patients referred to the Heart Centre Leipzig between November 2011 and May 2014 for transthoracic electrical cardioversion of AF. All patients experienced after antiarrhythmic-naïve electrical cardioversion either IRAF (n = 44; 70%) or FECV (n = 19; 30%). After drug infusion, electrical cardioversion was successful in 66.7% of vernakalant-treated as opposed to 46.7% of amiodarone-treated patients (P = 0.109). Multivariate analysis revealed treatment with vernakalant (OR 0.057, 95% CI 0.006–0.540, P = 0.013), treatment with ACEI or ARB (OR 0.101, 95% CI 0.015–0.691 P = 0.019), and IRAF after initial CV (OR 0.047, 95% CI 0.004–0.498, P = 0.011) as predictors for successful, drug-facilitated electrical cardioversion. Subgroup analysis of 18 patients with previous AF ablation revealed a significantly higher success rate of electrical cardioversion after infusion of vernakalant than after infusion of amiodarone (66.7 vs. 11.1%, P = 0.016). Conclusion Vernakalant may therefore be considered as a useful agent for facilitated electrical cardioversion in cardioversion-resistant AF.

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

BACKGROUND AND PURPOSE Approximately 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 SUBJECTS Twenty-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 CONCLUSION Radiofrequency 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.

Clinical Implications of Recent Trials on Anticoagulation in Patients with Atrial Fibrillation

The past year has seen the publication of results of the largest and arguably the most significant clinical trials of antithrombotic to prevent stroke and systemic throm-boembolism in patients with atrial fibrillation (AF) (1-3). In 2011, results of two trials concerning anticoagulation in patients with AF in addition to RE-LY study were also published (4-6). Canadian AF guidelines has been updated early this year, incorporating the new evidence (7). Also in 2012, the American College of Chest Physicians has released guidelines for the antithrombotic therapy of atrial fibril- alation (8). Similar updates of ESC and AHA/ACC guidelines are expected, which will be published in the upcoming months. Additionally in 2012, a consensus statement on interventional treatment of atrial fibrillation has been released by HRS/EHRA/ECAS (9). In the present review, new studies will be discussed in the context of current best evidence and their impact on the antithrombotic management of patients with AF will be examined. In ade-dition we present our current clinical practice regarding anticoagulation in patients with AF at Heart Centre Uni-versity of Leipzig.

Cardiac resynchronization therapy in the ageing population – With or without an implantable defibrillator?

BACKGROUND Cardiac resynchronization therapy (CRT) is an effective treatment option for systolic heart failure, but the benefit of an additional implantable cardioverter-defibrillator (ICD) in elderly patients is not well established. The aim of our study was to evaluate the impact of an additional ICD on survival in elderly CRT recipients. METHODS Patients aged ≥75 years with an indication for CRT and primary preventive ICD therapy, which underwent implantation of either a CRT-pacemaker (CRT-P) or CRT-defibrillator (CRT-D) were included in the study. Patient characteristics, procedural and follow-up data, and subsequent all-cause mortality were analyzed. RESULTS A total of 775 consecutive patients underwent CRT implantation, whereof 177 patients fulfilled the inclusion criteria. Of these, 80 patients with CRT-P and 97 with CRT-D formed the two study groups. Patients in the CRT-P group were significantly older (82.6 ± 4.5 vs. 77.8 ± 1.9 years, p < 0.001) and more often female (44 vs. 25%; p < 0.001), had a better left ventricular ejection fraction (29.5 ± 5.7 vs. 27.4 ± 6.0%; p = 0.019) and narrower QRS-complex (150 ± 19 vs. 158 ± 18 ms; p = 0.025). During a mean follow-up of 26 ± 19 months, 62 (35%) study patients died, 28 (35%) in the CRT-P and 34 (35%) in the CRT-D group (p = 0.994). The Kaplan-Meier analysis of survival probability showed no significant difference between the two groups (p = 0.562). CONCLUSION In our study, an additional ICD had no impact on survival in elderly patients undergoing implantation of a CRT device. Randomized controlled trials have to confirm this finding.

Excess of exercise increases the risk of atrial fibrillation

An interesting and still not well‐understood example for old medical wisdom “Sola dosis facit venenum” is the increased prevalence of atrial fibrillation (AF) in athletes. Numerous studies have shown a fourfold to eightfold increased risk of AF in athletes compared to the normal population. Analysis of the existing data suggests a dose‐dependent effect of exercise. Moderate exercise seems to have a protective effect and decreases the risk of AF, whereas excessive exercise seems to increase the risk of AF. The described cases illustrate clinical manifestations within the spectrum of AF in elderly athletes, that is, exercise‐induced AF, vagal AF, chronic AF, and atrial flutter. As the arrhythmia worsened quality of life and exercise capacity in all patients, recovery of sinus rhythm was desired in all described cases. As the atrial disease was advanced on different levels, different treatment regimes were applied. Lifestyle modification and temporary anti‐arrhythmic drug therapy could stabilize sinus rhythm in one patient, whereas others needed radiofrequency ablation to achieve a stable sinus rhythm. The patient with the most advanced atrial disease necessitated anti‐arrhythmic drug therapy and another left atrial ablation. All described patients remained in sinus rhythm during the long‐term follow‐up.

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.

Battery Malfunction of a Leadless Cardiac Pacemaker: Worrisome Single-Center Experience

Leadless cardiac pacemaker (LCP) therapy has been established clinically as a feasible and safe alternative to conventional transvenous pacemaker therapy for patients with an indication for single-chamber right-ventricular pacing.1-3 However, reports on loss of telemetry and pacing output due to abrupt battery failure called the safety of one of the two commercially available systems seriously into question. The initial battery advisory with the Nanostim™ LCP was issued by the manufacturer in October 2016, who instantly called a global stop to Nanostim™ implants. To this day, similar battery issues have not been described for the Micra™ transcatheter pacing system. Therefore, we thought to analyze the long-term pacemaker performance and rate of battery malfunction of the Nanostim™ LCP in our patient population.

Respiratory cycle-dependent left atrial tachycardia in a former Tour de France cyclist.

A former elite cyclist presented with palpitations, often induced by exercise. Electrophysiological study revealed an atrial tachycardia of 280–420 ms cycle length ( Panel A ). Activation mapping revealed an origin from LSPV ( Panel B ). Deep inspiration triggered ‘firing’ of the ectopic atrial focus. The patient underwent isolation of the LSPV by radiofrequency ablation (RFA) and remained symptom-free …