Cardiac Electrophysiology

ABCIC

Editorial

Intracardiac Echocardiography: Current Status, Clinical Benefits, and Future Perspectives

Renner Augusto Raposo Pereira et al. Daniel Moreira Costa Moura

Intracardiac echocardiography (ICE) is an ultrasound imaging technique capable of providing real-time, high-quality visualization of cardiac structures and their adjacent tissues through a catheter with a transducer inserted directly into the heart chambers, typically via transfemoral venous access. By allowing direct and precise visualization of intracardiac anatomy, ICE has been increasingly used to guide structural interventions and catheter ablations for cardiac arrhythmias, as well as to enable immediate detection of intraoperative complications.

Initial clinical investigations began in the 1960s, focusing on the assessment of atrial septal defects. Since then, ICE has evolved significantly. The introduction of the phased-array transducer, the addition of color Doppler functionality, and advancements in manipulation systems have enabled its widespread clinical application. The latest version of phased-array ICE features a position sensor at the catheter tip, allowing real-time integration with three-dimensional electroanatomic mapping systems used in complex ablations. The ability to precisely maneuver the catheter, combined with its versatile positioning, makes ICE a valuable tool for anatomic navigation and real-time monitoring during complex interventions.

[…]

Read Full Article

ABC

Review Article

Analysis of Ventricular Repolarization in Hypertensive Patients: Influence of Nocturnal Blood Pressure Dipping

Marco Aurélio Goulart et al. Dalmo Antonio Ribeiro Moreira Fernando Yue Cesena Jonathan Batista Souza … Antonio Gabriele Laurinavicius Fernanda Marciano Consolim-Colombo Márcio Gonçalves de Sousa

Abstract

Changes in ventricular repolarization are associated with ventricular arrhythmias and higher mortality. The association between a non-dipper blood pressure pattern and changes in ventricular repolarization remains controversial. This study sought to compare ventricular repolarization measurements (QT interval, QTc, Tp-Te, Tp-Te/QT, and QTd) in hypertensive dippers and non-dippers. Secondary objectives are to compare measurements between controlled and uncontrolled hypertensive patients, as well as resistant and non-resistant hypertensive patients. This observational, cross-sectional study involved patients monitored in a Hypertension Service. The level of significance adopted in the statistical analysis was 5%. A total of 130 participants were admitted. The mean age was 67.4 years, with 72% presenting some form of target organ damage. Repolarization measurements did not differ between dippers and non-dippers. However, within the resistant hypertension group, when compared to the non-resistant, differences were observed in the QT interval in V5 (433.3 ms vs. 420.9 ms, p = 0.046), Tp-Te in both V2 (85.4 ms vs. 78.7 ms, p = 0.049) and V5 (84.6 ms vs. 74.6 ms, p = 0.006), Tp-Te/QT in V5 (0.19 vs. 0.18, p = 0.019), Sokolow-Lyon index (18.8 mm vs. 15.7 mm, p = 0.011), and Cornell index (14.2 mm vs. 11.2 mm, p = 0.002), aged-adjusted values. In this high cardiovascular risk hypertensive population, no difference in repolarization measures was found between dippers and non-dippers. However, this is the first study to demonstrate increased ventricular repolarization measures in patients with resistant hypertension.

Read Full Article

ABC

Original Article

Efficacy and Safety of Adjunctive Posterior Wall Isolation in Patients with Persistent Atrial Fibrillation: A Systematic Review and Meta-Analysis

João Vitor Levindo Coelho Novaes et al. David de Pádua Brasil Flavia Maria de Freitas Faria Isadora Soares Bicalho Garcia … Camila Ribeiro Pimenta Nathalia Sernizon Guimarães Marcus Vinicius Bolivar Malachias

Abstract

Background

In patients with persistent atrial fibrillation (AF), addition of posterior wall isolation (PWI) to pulmonary vein isolation (PVI) is controversial.

Objective

Compare PVI plus PWI versus PVI alone in patients with persistent AF.

Methods

We searched PubMed (by MEDLINE), Embase, LILACS, CENTRAL (by Cochrane Library), and Clinicaltrials.gov databases for randomized trials comparing PVI + PWI and PVI alone in persistent AF. The outcomes were: (i) AF recurrence; (ii) composite of recurrent atrial arrhythmias (i.e., AF, atrial tachycardia, or atrial flutter); (iii) major clinical complications (i.e., pericardial effusion or tamponade, sinus node dysfunction, or atrioesophageal fistula); (iv) mean ablation time. Risk of bias and quality of evidence were evaluated using the Cochrane Risk of Bias 2.0 tool and GRADE, respectively. Statistical significance was set at 5%, and subgroup and sensitivity analyses were performed.

Results

We included eight studies and 1119 patients, of which 561 underwent PVI + PWI. During follow-up (12 – 24 months), recurrence of AF was significantly reduced with adjunctive PWI (RR 0.66, 95% CI 0.44-0.98). Composite of recurrent atrial arrhythmias did not differ significantly (RR 0.83, 95% CI 0.65-1.06). Major clinical complications (RR 0.81, 95% CI 0.42-1.58) were similar, with PVI alone having a shorter mean procedure time (mean difference -23.37 minutes, 95% CI -30.23, -16.50).

Conclusion

Adjunctive PWI appears to be effective in improving recurrent AF, but not recurrence of all atrial arrhythmias. Procedure time was longer with PVI + PWI without significant change in overall safety. Further studies should focus on long-term benefit.

Read Full Article

IJCS

Editorial

Intracardiac Conduction Intervals: An Electrophysiological Mirror of the Brazilian Population

Erivelton A. do Nascimento

In the current edition of the International Journal of Cardiovascular Sciences, Leiria et al. have published a historical cohort of 124 electrophysiological studies considered normal, and evaluated three parameters of intracardiac conduction: (1) PA interval; (2) AH interval and (3) HV interval. The reference values for baseline electrophysiological parameters in the Brazilian population are of great interest due to their unique characteristics.

Since the description of the electrical potential in the end portion of the atrioventricular (AV) node by, Dandamudi and Vijayaraman related Wilhelm His Jr., in 1893, which would come to be named the bundle of His, cardiac electrophysiology has added knowledge to both the diagnosis and treatment of the different forms cardiac arrhythmias, and to the field of artificial cardiac stimulation.

[…]

Read Full Article

ABC

Case Report

Painful Left Bundle Branch Block Syndrome in a Patient Referred to Electrophysiologic Study: A Case Report

José Nunes de Alencar Neto et al. Marcel Henrique Sakai Saulo Rodrigo Ramalho de Moraes Elano Sousa da Frota … Claudio Cirenza Angelo Amato Vincenzo de Paola

Introduction

The development of chest pain associated with intermittent left bundle branch block (LBBB) in the absence of coronary artery disease has been described in the literature as painful left bundle branch block syndrome. The mechanism responsible for the chest pain is unknown, but the main current hypothesis is related to acute cardiac dyssynchrony.

In this syndrome, the LBBB occurs when the cycle length is equal to or less than the refractory period of the left bundle, mainly during physical effort. The chest pain in the case of the painful LBBB syndrome may range from a mild discomfort to a disabling condition.

[…]

Read Full Article

IJCS

Case Report

Case Report: Myocardial Bypass in Left Descending Artery – A Rare Congenital Anomaly

Vergílio Pereira Carvalho et al. Eraldo Ribeiro Ferreira Leão de Moraes João Emílio Hanum Paes Daniela Textor … Hugo Leonardo Shigenaga Ribeiro Amara Chebli Baptista Stephanie Borges Vilela Ana Paula Fontana Isabella Beatriz Silva Rocha Jair Pereira Melo Junior

Abstract

Myocardial bypass (MB) is known to have scientific relevance and is present in several studies with great statistical significance regarding its clinical manifestations and complications. There are still questions about MB in its relationship with heart disease and repercussion in life-threatening conditions. We present a case report of a MB in the left anterior descending coronary artery, whose objective is to identify this rare congenital anomaly and to highlight the patient’s clinical outcome in order to elicit greater contributions about the presence of this variant in the emergency room, its diagnosis by angiography and therapeutic management.

Read Full Article

ABC

Original Article

Paroxysmal Atrial Fibrillation in Females: Understanding gender diferences

Gabriel Odozynski et al. Alexander Romeno Janner Dal Forno Andrei Lewandowski Hélcio Garcia Nascimento André d'Avila

Abstract

Background:

The catheter ablation of atrial fibrillation (AF) is performed less frequently in women. In addition, there is divergent information in the literature regarding the effectiveness and safety for the ablative procedure to females.

Objectives:

The objective of this study was to compare the clinical characteristics and outcomes in men and women undergoing paroxysmal atrial fibrillation (PAF) ablation.

Methods:

Cohort study of patients undergoing first-ever PAF catheter ablation procedure refractory to antiarrhythmic drugs. The information was taken from patients’ records by means of a digital collection instrument and indexed to an online database (Syscardio®). Clinical characteristics and procedures were compared between each gender (M x F), adopting a level of statistical significance of 5%. The primary endpoint associated with efficacy was freedom from atrial arrhythmia over the follow-up time.

Results:

225 patients were included in the study, 64 (29%) women and 161 (71%) men. Women presented more symptoms due to AF according to the CCS-SAF score (1.8 ± 0.8M x 2.3 ± 0.8F p = 0.02) and higher CHADS2 score compared to men (0.9 ± 0.8M x 1.2 ± 1F). Post-ablation recurrence occurred in 20% of the patients, with no difference based on gender (21% M x 20% F p = 0.52). The rate of complications was less than 3% for both groups (p = 0.98).

Conclusion:

Women undergoing the first-ever PAF catheter ablation procedure present similar complication rate and clinical outcome compared to men. These findings suggest that the current underutilization of AF catheter ablation in women may represent a discrepancy in care.

Read Full Article

ABC

Original Article

Bone-Marrow-Derived Mesenchymal Stromal Cells (MSC) from Diabetic and Nondiabetic Rats Have Similar Therapeutic Potentials

Vitória Santório de São José et al. Gustavo Monnerat Barbara Guerra Bruno Dias Paredes … Tais Hanae Kasai-Brunswick Antonio Carlos Campos de Carvalho Emiliano Medei

Abstract

Background:

Diabetes mellitus is a severe chronic disease leading to systemic complications, including cardiovascular dysfunction. Previous cell therapy studies have obtained promising results with the use bone marrow mesenchymal stromal cells derived from healthy animals (MSCc) in diabetes animal models. However, the ability of MSC derived from diabetic rats to improve functional cardiac parameters is still unknown.

Objectives:

To investigate whether bone-marrow-derived MSC from diabetic rats (MSCd) would contribute to recover metabolic and cardiac electrical properties in other diabetic rats.

Methods:

Diabetes was induced in Wistar rats with streptozotocin. MSCs were characterized by flow cytometry, morphological analysis, and immunohistochemistry. Cardiac electrical function was analyzed using recordings of ventricular action potential. Differences between variables were considered significant when p < 0.05.

Results:

In vitro properties of MSCc and MSCd were evaluated. Both cell types presented similar morphology, growth kinetics, and mesenchymal profile, and could differentiate into adipogenic and osteogenic lineages. However, in an assay for fibroblast colony-forming units (CFU-F), MSCd formed more colonies than MSCc when cultured in expansion medium with or without hydrocortisone (1 µM). In order to compare the therapeutic potential of the cells, the animals were divided into four experimental groups: nondiabetic (CTRL), diabetic (DM), diabetic treated with MSCc (DM + MSCc), and diabetic treated with MSCd (DM + MSCd). The treated groups received a single injection of MSC 4 weeks after the development of diabetes. MSCc and MSCd controlled hyperglycemia and body weight loss and improved cardiac electrical remodeling in diabetic rats.

Conclusions:

MSCd and MSCc have similar in vitro properties and therapeutic potential in a rat model of diabetes induced with streptozotocin.

Read Full Article

ABC

Case Report

Electrophysiological Study in Ebstein's Anomaly With no Evidence of Accessory Pathway

Larissa de Oliveira et al. Ana Karyn E. de Freitas Niraj Mehta Marcio Rogério Ortiz … Leonardo A. Mulinari Cláudio L. Pereira da Cunha

Introduction

Ebstein’s anomaly (EA) is characterized by low implantation of the tricuspid valve, and corresponds to less than 1% of all congenital heart defects^–. It is often associated with other malformations, such as ventricular septal defect, and Wolff-Parkinson-White syndrome often accompanies.

Its clinical manifestation depends on the severity of the anatomical changes, and the indications for surgery have been well established^,.

[…]

Read Full Article