Automated conduction velocity estimation based on isochronal activation of heart chambers

Background Spatial differences in conduction velocity (CV) are critical for cardiac arrhythmias induction. We propose a method for an automated CV calculation to identify areas of slower conduction during cardiac arrhythmias and sinus rhythm.Methods Color-coded representations of the isochronal activation map using data coming from the RHYTHMIA (TM) Mapping System were reproduced by applying a temporal isochronal window at 20 ms. Geodesic distances of the 3D mesh were calculated using an algorithm selecting the minimum distance pathway (MDP). The CV estimation was performed considering points on the boundary of two spatially and temporally adjacent isochrones. For each of the boundary points of a given isochrone, the nearest boundary point of the consecutive isochrone was chosen, the MDP was evaluated, and a map of CV was created. The proposed method has been applied to a population of 29 patients.Results In all cases of perimitral atrial flutter (16 pts out of 29 (55%)), areas with significantly low CV (< 30 cm/s) were found. Half of the cases present regions with low CV located in the anterior wall. No case with low CV at the so-called LA isthmus was observed. Right atrial maps during common atrial flutters showed low CV areas mainly located in the inferior inter-atrial septum. No areas of low CV were observed in subjects without a history of atrial arrhythmia while pts affected by paroxysmal AF showed areas with a limited extension of low CV.Conclusions The proposed software for automated CV estimation allows the identification of low CV areas, potentially helping electrophysiologists to plan the ablation strategy

EP Testing in Asymptomatic Brugada Patients with Recurrent Palpitations. Just do it

Brugada syndrome is a rare heritable arrhythmogenic disease characterized by a coved ST segment elevation in the right precordial leads and by an increased risk of sudden cardiac arrest as a result of polymorphic ventricular tachyarrhythmias or ventricular fibrillation (1). Although implantable cardioverter defibrillators are considered to be the main therapy in patients with a history of ventricular arrhythmias or syncope, risk stratification in cases without these symptoms remains controversial. Patients with confirmed Brugada pattern and a history of palpitations without major events should be scheduled for risk stratification. Even though its value has been questioned, inducibility of VTs/VF at programmed electric stimulation is widely used to select candidates to receive a prophylactic implantable cardiac defibrillator in these categories. Herein, we report a patient with type I Electrocardiogram (ECG) pattern induced at the Ajmaline test and a family history of sudden cardiac death who had episodes of palpitations. We describe and discuss our management proving the importance of complete electrophysiological testing in the setting of Brugada asymptomatic patients' risk stratification

Chronotropic Incompentence and Functional Capacity in CHF

SUMMARY Aim: To assess the effect of chronotropic incompetence on functional capacity in chronic heart failure (CHF) patients, as evaluated as NYHA and peak oxygen consumption (pVO2), focusing on the presence and dose of β-blocker treatment. Methods: Nine hundred and sixty-seven consecutive CHF patients were evaluated, 328 of whom were discarded because they failed to meet the study criteria. Of the 639 analyzed, 90 were not treated with β-blockers whereas the other 549 were. The latter were further subdivided in high (n = 184) and low (n = 365) β-blockers daily dose group in accordance with an arbitrary cut-off of 25 mg for carvedilol and of 5 mg for bisoprolol. Failure to achieve 80% of the percentage of maximum age predicted peak heart rate (%Max PHR) or of HR reserve (%HRR) constituted chronotropic incompetence. Results: No differences were found in NYHA or pVO2 between patients with and without β-blockers and, similarly, between high and low β-blocker dose groups. Twenty and sixty-nine percent of not β-blocked patients showed chronotropic incompetence according to %Max PHR and %HRR, respectively, whereas this prevalence rose to 61% and 84% in those on β-blocker therapy. Patients taking β-blockers without chronotropic incompetence, as inferable from both %Max PHR and %HRR, showed higher NYHA and pVO2 regardless of drug dose, whereas, in not β-blocked patients, only %HRR revealed a difference in functional capacity. At multivariable analysis, HR increase during exercise (ΔHR) was the variable most strongly associated to pVO2 (β: 0.572; SE: 0.008; P < 0.0001) and NYHA class (β: −0.499; SE: 0.001; P < 0.0001). Conclusions: ΔHR is a powerful predictor of CHF severity regardless of the presence of β-blocker therapy and of β-blocker daily dose

The sympathetic nervous system and ventricular arrhythmias: an inseparable union

The sympathetic nervous system and ventricular arrhythmias: an inseparable unio

Techniques for Temperature Monitoring of Myocardial Tissue Undergoing Radiofrequency Ablation Treatments: An Overview

Cardiac radiofrequency ablation (RFA) has received substantial attention for the treatment of multiple arrhythmias. In this scenario, there is an ever-growing demand for monitoring the temperature trend inside the tissue as it may allow an accurate control of the treatment effects, with a consequent improvement of the clinical outcomes. There are many methods for monitoring temperature in tissues undergoing RFA, which can be divided into invasive and non-invasive. This paper aims to provide an overview of the currently available techniques for temperature detection in this clinical scenario. Firstly, we describe the heat generation during RFA, then we report the principle of work of the most popular thermometric techniques and their features. Finally, we introduce their main applications in the field of cardiac RFA to explore the applicability in clinical settings of each method

High Risk for Sudden Death Identified by Electrocardiographic Loop Recording in a Patient With Hypertrophic Cardiomyopathy Without Major Risk Factors

Recurrent presyncope is occasionally reported by patients with hypertrophic cardiomyopathy (HC). However, it is difficult to identify on 24-hour Holter recordings the mechanisms responsible for these infrequent symptoms. We report the case of a patient with HC with recurrent presyncope and without major sudden death risk factors, in whom electrocardiographic loop recording identified life-threatening arrhythmias as the mechanism responsible for these symptoms. Documentation of these arrhythmias justified implantation of a cardioverter-defibrillator in the absence of other risk factors. (C) 2011 Elsevier Inc. All rights reserved. (Am J Cardiol 2011;107:1558-1560

Opposite behavior of plasma levels surfactant protein type B and receptor for advanced glycation end products in pulmonary sarcoidosis

Background: No biological marker is currently available for evaluating pulmonary involvement and/or for monitoring the clinical course of sarcoidosis. The present pilot study focused on possible relationships between circulating plasma levels of surfactant protein type B (SP-B) and plasma receptor for advanced glycation end products (RAGE) and lung function abnormalities in patients with pulmonary sarcoidosis, since both SP-B and RAGE have been previously suggested as lung injury markers. The plasmatic levels of these two proteins were also investigated with respect to functional capacity, as assessed by a cardiopulmonary exercise test (CPET). Methods: Thirty pulmonary sarcoidosis outpatients and fifteen volunteers (Control Group) underwent lung function tests and CPET. Resting SP-B and RAGE plasma levels were also determined. Patients were then categorized according to the severity of their pulmonary involvement, as assessed in terms of lung diffusion for carbon monoxide (DLCO) values. Results: Group B showed SP-B levels higher and RAGE levels lower than Group A and Control Group (p < 0.01). Group A showed lower RAGE levels than Control Group (p < 0.01), whereas SP-B levels did not differ between these two groups. A significant univariate relationship was found between both SP-B and RAGE and several lung function data, particularly with DLCO (SP-B Vs DLCO: r: -0.437, p = 0.016; RAGE Vs DLCO: r: -0.451, p = 0.012). Conclusions: Circulating plasma levels of SP-B and RAGE showed an opposite behavior in patients with pulmonary sarcoidosis. SP-B values are directly related to alveolar unit damage, supporting a possible role of SP-B as a marker of disease severity in these patients. Differently, RAGE decreases in severe sarcoidosis, suggesting more complex underlying mechanisms. (C) 2013 Elsevier Ltd. All rights reserved

Interatrial conduction times in paroxysmal atrial fibrillation patients with normal atrial volume and their correlation with areas of local prolunged bipolar electrocardiograms

Recent evidence has shown that the presence of abnormal substrate can be demonstrated also among patients with “lone” AF. Objectives: Interatrial conduction slowing is likely to characterize patients with paroxysmal atrial fibrillation (AF) and it could be correlated to the left atrium area of prolonged local bipolar endocardial electrograms. P-wave duration (PWD), amplified PWD and endocavitary interatrial conduction time (IACT), were analyzed in 60 patients; 30 undergoing de novo ablation for paroxysmal AF with normal atrial volumes and without any other cardiac disease and 30 of similar age undergoing electrophysiological study for atrioventricular nodal reentrant tachycardia or atrioventricular re- entrant tachycardia. In patients with AF, voltage maps and local bipolar electrograms (LBE) duration map were evaluated. Although PWD was &lt;120 ms in 28 patients with AF and in 29 controls, patients with AF exhibited longer PWD, amplified-PWD and IACT. Although low-voltage areas (&lt;0.5 mV) were not found in the study population, 28 of them demonstrated areas with LBE longer than 60 ms. These LBE were found mainly in the roof of the left atrium and their extension was correlated to IACT (R = 0.51, p = 0.004). IACT &gt;135.5 ms identified the subjects who experienced AF with 90% sensitivity and 97% specificity. A subclinical interatrial conduction disturbance is demonstrable in subjects with paroxysmal AF and normal left atrial volume. IACT has a good correlation to the areas of abnormal LBE in the left atrium. IACT &gt;135 ms identified subjects who have experienced AF. © 201

NT-proAtrial Natriuretic Peptide as a possible biomarker of cardiopulmonary involvement in sarcoidosis

Background: Lung diffusion for carbon monoxide (DLCO) has been shown to associate with the risk of pulmonary arterial hypertension development and, most likely, with right ventricular (RV) myocardial dysfunction in sarcoidosis patients. Besides its known role as a marker of left ventricular dysfunction, experimental evidence suggests a role of NT-proAtrial Natriuretic Peptide (NT-proANP) also in modulating pulmonary circulation. We therefore investigated possible relationships between NT-proANP, lung diffusion impairment and RV dysfunction. Methods: Thirty-two pulmonary sarcoidosis outpatients and eighteen volunteers underwent full clinical assessment, including full lung function tests and Doppler echocardiography integrated with tissue Doppler imaging (TDI) study. Resting circulating NT-proBNP and NT-proANP plasma levels were also determined. Results: NT-proANP and RV-myocardial performance index (RV-MPI) were significantly higher in those patients with the greatest DLCO impairment, whereas no differences were found for NT-proBNP values. At multivariable analysis, only DLCO (beta: -0.496; standard error: 3.38; p = 0.000) and RV-MPI (beta: 0.373; standard error: 6.56; p = 0.031) remained significantly associated with NT-proANP levels. Conclusions: Our finding may support a key role of NT-proANP in the complex mechanisms underlying modulation of lung function. An early increase in pulmonary vascular resistance may stimulate NT-proANP increase, thus explaining its association with signs of early RV myocardial dysfunction. This hypothesis warrants further confirmation. (C) 2012 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved

Cardiac sympathetic denervation for untreatable ventricular tachycardia in structural heart disease. Strengths and pitfalls of evolving surgical techniques

Cardiac sympathetic denervation (CSD) is a valuable option in the setting of refractory ventricular arrhythmias in patient with structural heart disease. Since the procedure was introduced for non structural heart disease patients the techniques evolved and were modified to be adopted in several settings. In this state-of-the-art article we revised different techniques, their rationale, strengths, and pitfalls