Role of the Electrophysiologist in the Treatment of Tachycardia-Induced Cardiomyopathy

Tachycardia-induced cardiomyopathy is a systolic cardiac dysfunction given by prolonged elevated heart rates in patients with incessant or frequent tachyarrhythmias. Arrhythmias associated with tachycardiomyopathy can be either supraventricular (atrial tachycardia, atrial flutter, atrial fibrillation, AVNRT, permanent junctional reciprocating tachycardia, high rates of atrial pacing) or ventricular (frequent premature ventricular complexes, right ventricular outflow tract tachycardia, LVOT, left ventricular fascicular tachycardia, bundle-branch reentry or high rate of ventricular pacing). Electrophysiological study confirms the clinical diagnosis of tachycardia-induced cardiomyopathy, reveals the arrhythmia mechanism and facilitates catheter ablation that results in complete recovery of ventricular function. This chapter has two parts: 1. Theoretical insight into the pathogenesis of tachycardia-induced cardiomyopathy, clinical manifestations and therapy. 2. Practical issues: we describe our EP lab’s experience on electrophysiological study and ablation in patients with tachycardia-induced cardiomyopathy. We will present five cases of ablation: PVCs >30,000/24 h, antidromic tachycardia, 2:1 atrial flutter, persistent atrial fibrillation and RVOT PVCs with nonsustained VT

ICD Electrograms in Patients with Brugada Syndrome

In patients with Brugada syndrome, implantable cardioverter‐defibrillator (ICD) is the only demonstrated treatment that prevents sudden cardiac death. The progress in ICD technology improved the diagnosis and efficacy of implantable devices in the management and treatment of ventricular tachycardia (VT) and ventricular fibrillation (VF). Recording of electrical events just before and after a delivered or aborted ICD therapy permits a more accurate characterization of the rhythm but also provides information on the electrical events preceding the arrhythmia. This chapter aims to gain insight into the mechanism of initiation and termination of spontaneous VF by analyzing intracardiac electrograms (IEGM) in Brugada patients implanted with ICDs. It has two parts: (1) update on ICD electrograms in Brugada syndrome patients, where we review the medical literature on ICD electrograms and their use for detecting electrical manifestations of Brugada syndrome, and (2) examples of ICD electrograms, from our own database of patients affected by Brugada syndrome

Cardiac Anatomy for the Electrophysiologist with Emphasis on the Left Atrium and Pulmonary Veins

This chapter aims to provide basic anatomical knowledge for the interventional electrophysiologists to understand catheter placement and ablation targets. We begin with the location of the heart inside the mediastinum, position of cardiac chambers, pericardial space and neighboring structures of the heart. We continue with the right atrium and important structures inside it: sinus node, cavotricuspid isthmus, Koch’s triangle and interatrial septum with fossa ovalis. A special part of this chapter is dedicated to the left atrium and pulmonary veins with the venoatrial junction, important structures for catheter ablation of atrial fibrillation. We finish our description with both ventricles with outflow tracts and the coronary venous system

Mapping and Ablation of Premature Atrial Section Contractions Originating from the Posterior Mitral Annulus: A Case Report

Premature Atrial Contractions (PAC) is frequent arrhythmias. Previously, regarded as a benign electrocardiographic finding, they are now linked to adverse outcomes such as, stroke and all-cause mortality. Furthermore, a high burden of PACs >1.500/24 hours has a predicted probability of atrial fibrillation occurrence. Herein, the authors presented a case of a 35-year-old male patient, with high burden PACs, originating in the posterior mitral annulus. Treatment with class IC (flecainide, propafenone) antiarrhythmic drugs and beta blockers (bisoprolol) was ineffective in controlling the tachycardia, therefore, catheter ablation was performed. The procedure was performed using the Three-Dimensional (3D) Biosense Webster Carto 3 electroanatomical mapping system. The area of the earliest atrial signal was located at the posterior mitral annulus. Successful elimination of the ectopy was obtained with Radiofrequency (RF) application on the posterior mitral ring. A single RF application of 30 W for 60 seconds abolished PACs, with no further recurrence. Holter Electrocardiogram (ECG) showed, no PACs at one, six and 12 months follow-up. Catheter ablation remains an effective approach to cure the arrhythmia, when medical treatment with antiarrhythmic drugs is ineffective or undesirable in patients with high burden PACs

COPD in Firefighters: A Specific Event-Related Condition Rather than a Common Occupational Respiratory Disorder

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. Smoking remains the most important risk factor, but occupational exposures may play an essential role as well. Firefighters are among occupations regularly exposed to a variety of irritative inhalational products, and they may be expected to develop respiratory health problems because of such an occupational exposure. To better understand and characterize this relationship, we performed an extensive search of the scientific literature, and we identified two major research areas: firefighters exposed to wildland fire smoke and firefighters involved in the World Trade Centre disaster-related operations. Most of the studies did not report a significant increase in COPD diagnosis in firefighters. An accelerated rate of decline in lung function was seen, a short time after major exposure events. This is the reason for an increased rate of exacerbations observed in individuals already diagnosed with obstructive respiratory disorders. A limited number of studies not covering these specific circumstances of exposure were found. They reported long-term morbidity and mortality data, and the results are controversial. Major confounding factors for most of the studies were the “healthy worker effect” and the lack of useful data regarding smoking habits. Efforts should be made in the future to better characterize specific biomarkers for the progression of COPD; to establish exposure limits; and to implement preventive strategies like rotation of workers, smoking cessation programs, and long-term monitoring programs for respiratory disorders

Validation of Normal P-Wave Parameters in a Large Unselected Pediatric Population of North-Western Romania: Results of the CARDIOPED Project

Aims. Reference values of the P-wave on 12 lead electrocardiograms are lacking for children and adolescents in Eastern Europe. Hence, the present study is aimed at determining the standard values of the P-wave in children and adolescents based on ECG data from the CARDIOPED project, a large-scale general population of children who participated in a screening program in Transylvania, Romania. Methods and Results. A total of 22,411 ECGs of participants aged 6 to 18 years old from a school-based ECG screening were obtained between February 2015 and December 2015 in Transylvania, Romania. Three pediatric cardiologists manually reviewed each ECG. P-wave duration, voltage, axis, and correlation with gender and age were analyzed. The mean P-wave duration was 88±10.7 ms, with a maximum duration of 128 ms. P-wave showed a positive correlation with age but did not differ between sexes. There was a positive correlation between the P-wave duration and the heart rate, but not with the body max index. The mean P-wave axis was 40.4±31.1, and the mean P-wave amplitude was 0.12±0.03 mV. Conclusion. In this study on many pediatric subjects, we have provided normal limits for the P-wave in Romanian children aged 6-18 years. Our findings are useful for creating interpretation guidelines for pediatric ECG

Catheter ablation of idiopathic ventricular fibrillation using the CARTO 3 mapping system

Ventricular fibrillation in the absence of structural heart disease represents an important mechanism of sudden cardiac death. It is initiated by triggers originating in the distal Purkinje fibers, arising from either the right or the left ventricle. Catheter ablation of these triggers has the potential of terminating the arrhythmia and preventing recurrence. We present the case of an electrical storm in a 39-year old female patient with no cardiac past medical history, with recurrent episodes of idiopathic ventricular fibrillation, who was referred to our hospital for repeated episodes of syncope. The 12-lead ECG showed the presence of frequent ventricular premature beats (VPB), having a left-bundle branch block morphology and superior axis, with an “R on T” phenomenon, initiating non-sustained episodes of ventricular fibrillation. Using a three-dimensional, non-fluoroscopic mapping system (CARTO 3, Biosense Webster), the origin of the ventricular premature beat responsible for the initiation of VFib was identified and successfully ablated. Catheter ablation of idiopathic ventricular fibrillation using a 3-dimensional mapping system is a feasible therapeutic option for patients with this type of arrhythmia

Galectin-3, Inflammation, and the Risk of Atrial High-Rate Episodes in Patients with Dual Chamber Pacemakers

Atrial high-rate episodes (AHREs) are atrial tachyarrhythmias that are exclusively detected by cardiac implantable electronic devices (CIEDs) with an atrial lead. The objective of this study was to investigate the incidence and predictive factors for AHREs, and to evaluate the ability of inflammation biomarkers to predict the occurrence of AHREs. 102 patients undergoing CIED procedure who received a dual chamber pacemaker were included. CIED interrogation was performed 1 year after the implantation procedure. Patients were divided into groups according to the occurrence of AHREs, which was the primary endpoint of the study. The mean age of the patients was of 73 ± 8.6 years and 48% were male. The incidence of AHREs was 67% at 1 year follow-up. Patients with AHREs were older, had higher left atrial indexed volume (LAVi), higher baseline galectin-3 levels (1007.5 ± 447.3 vs. 790 ± 411.7 pg/mL) and received betablockers more often, along with amiodarone and anticoagulants. Interestingly, the CHADSVASC score did not differ significantly between the two groups. A cut-off value of galectin > 990 pg/mL predicted AHREs with moderate accuracy (AUC of 0.63, 95% CI 0.52 to 0.73, p = 0.04), and this association was confirmed in the univariate regression analysis (OR 1.0012, 95% CI 1.0001 to 1.0023, p = 0.0328). However, based on the multivariate regression analysis, galectin lost its prognostic significance under the effect of LAVi, which remained the only independent predictor of AHREs (OR 1.0883, 95% CI 1.0351 to 1.1441, p = 0.0009). AHREs are common in CIEDs patients. Galectin-3 may bring additional data in the prediction of AHREs