Biventricular / Left Ventricular Pacing in Hypertrophic Obstructive Cardiomyopathy: An Overview

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant inherited genetic disease characterized by compensatory pathological left ventricle (LV) hypertrophy due to sarcomere dysfunction. In an important proportion of patients with HCM, the site and extent of cardiac hypertrophy results in severe obstruction to LV outflow tract (LVOT), contributing to disabling symptoms and increasing the risk of sudden cardiac death (SCD). In patients with progressive and/or refractory symptoms despite optimal pharmacological treatment, invasive therapies that diminish or abolish LVOT obstruction relieve heart failure-related symptoms, improve quality of life and could be associated with long-term survival similar to that observed in the general population. The gold standard in this respect is surgical septal myectomy, which might be supplementary associated with a reduction in SCD. Percutaneous techniques, particularly alcohol septal ablation (ASA) and more recently radiofrequency (RF) septal ablation, can achieve LVOT gradient reduction and symptomatic benefit in a large proportion of HOCM patients at the cost of a supposedly limited septal myocardial necrosis and a 10-20% risk of chronic atrioventricular block. After an initial period of enthusiasm, standard DDD pacing failed to show in randomized trials significant LVOT gradient reductions and objective improvement in exercise capacity. However, case reports and recent small pilot studies suggested that atrial synchronous LV or biventricular (biV) pacing significantly reduce LVOT obstruction and improve symptoms (acutely as well as long-term) in a large proportion of severely symptomatic HOCM patients not suitable to other gradient reduction therapies. Moreover, biV/LV pacing in HOCM seems to be associated with significant LV reverse remodelling

Analysis of ECG in athletes running in mountain route conditions

The purpose of this work is to analyse changes in ECG and heart rate variability (HRV) metrics in athletes during 10 km running in mountain route conditions. Eighteen healthy athletes carrying a 12-lead ECG GE Holter recorder and a heart rate monitor ran a route with slopes similar as trail races. QRS duration, QRS area, R-wave peak, ST elevation at J-point and J+60 ms, ST slope and T-wave peak indices were computed after signal-averaging ECG segments at different sloping stages of running (S1-S6) and at a control stage (S0) before running. HRV analysis included standard time and frequency metrics: mean RR (normal, N) interval, SDNN, RMSSD, low and high frequency absolute and normalized power (LF, HF, LFn, HFn) and LF/HF ratio. QRS area and R-peak were reduced during stage 1 in lateral leads, comparing to rest before running. ST slope was significantly higher during upslope stages in leads II, V4 and V5. T-wave amplitude increased significantly in precordial leads during upload running. ST segment depressed in leads II, III and V5 respect control. Mean RR, SDNN, LF and LFn showed high significant differences (p<0.01) among stages and HF and LF/HF were also varying (p<0.05). Changes of ECG and HRV indices can help understanding the cardiac function in runners performing extreme stress.Postprint (published version

Nonsurgical transthoracic epicardial radiofrequency ablation An alternative in incessant ventricular tachycardia

AbstractObjectivesThe purpose of this study was to analyze the feasibility, efficacy, and safety of epicardial radiofrequency (RF) ablation in patients with incessant ventricular tachycardia (VT).BackgroundManagement of patients with incessant VT is a difficult clinical problem. Drugs and RF catheter ablation are not always effective. A nonsurgical transthoracic epicardial RF ablation can be an alternative in patients refractory to conventional therapy.MethodsEpicardial RF ablation was performed in 10 patients who presented with incessant VT despite the use of two or more intravenous antiarrhythmic drugs.ResultsIn eight patients, endocardial ablation (EdA) failed to control the tachycardia. In the remaining two patients, epicardial ablation (EpA) was first attempted because of left ventricular thrombus and severe artery disease, respectively. Eight patients had a diagnosis of coronary artery disease with healed myocardial infarction. One patient had dilated cardiomyopathy, and one patient had idiopathic, incessant VT. In patients with structural heart disease, the mean ejection fraction was 0.28 ± 0.10%. Four patients previously received an implantable defibrillator. The EpA effectively terminated the incessant tachycardia in eight patients, which represents a success rate of 80%. In them, after a follow-up of 18 ± 18 months, a single episode of a different VT was documented in one patient. No significant complications occurred related to the procedure.ConclusionsIn patients with incessant VT despite the use of drugs or standard EdA, the epicardial approach was very effective and should be considered as an alternative in this life-threatening situation

Manifold learning characterization of abnormal myocardial motion patterns: application to CRT-induced changes

International audienceThe present paper aims at quantifying the evolution of a given motion pattern under cardiac resynchronization therapy (CRT). It builds upon techniques for population-based cardiac motion quantifica-tion (statistical atlases, for inter-sequence spatiotemporal alignment and the definition of normal/abnormal motion). Manifold learning is used on spatiotemporal maps of myocardial motion abnormalities to represent a given abnormal pattern and to compare any individual to that pattern. The methodology was applied to 2D echocardiographic sequences in a 4-chamber view from 108 subjects (21 healthy volunteers and 87 CRT candidates) at baseline, with pacing ON, and at 12 months follow-up. Experiments confirmed that recovery of a normal motion pattern is a necessary but not su cient condition for CRT response

Atlas-Based Quantification of Myocardial Motion Abnormalities: Added-Value for Understanding the Effect of Cardiac Resynchronization Therapy

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Atlas-based Quantification of Myocardial Motion Abnormalities: Added-value for the Understanding of CRT Outcome?

International audienceIn this paper, we present the use of atlas-based indexes of abnormality for the quantification of cardiac resynchronization therapy (CRT) outcome in terms of motion. We build an atlas of normal motion from 21 healthy volunteers to which we compare 88 CRT candidates before and after the therapy. Abnormal motion is quantified locally in time and space using a statistical distance to normality, and changes induced by the therapy are related with clinical measurements of CRT outcome. Results correlate with recent clinical hypothesis about CRT response, namely that the correction of specific mechanisms responsible for cardiac dyssynchrony conditions the response to the therapy

Practical ways to reduce radiation dose for patients and staff during device implantations and electrophysiological procedures

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