The second Latin American catheter ablation registry ("II LAHRS EP registry").

Background: Patient's clinical characteristics, technical resources, center and operator volume, and operator experience and training are known variables impacting outcomes. Although international standards have been agreed to maximize the benefits of this therapy, regional and global differences still exist. Latin American information has not been updated in the last 10 years.

Associated factors with the occurrence of in-hospital cardiac arrest in patients admitted to internal medicine wards for non-cardiovascular causes.

Background And Objective: In-hospital cardiac arrest (IHCA) has a low survival rate, so it is essential to recognize the cases with the highest probability of developing it. The aim of this study is to identify factors associated with the occurrence of IHCA.

Material And Methods: A single-center case-control study was conducted including 65 patients admitted to internal medicine wards for non-cardiovascular causes who experienced IHCA, matched with 210 admitted controls who did not present with IHCA.

Would a complete electrophysiological study allow us to make a correct diagnosis? Case report.

Background: Oblique course of some left accessory pathways is rare An incomplete electrophysiological study may confuse us between an oblique accessory pathway or the presence of two accessory pathways. The proximity of all atrial and ventricular electrograms, at each pole of the catheter, within the coronary sinus may be a novel finding.

Case Presentation: A 68-year-old woman patient presented arrhythmias with hypotension requiring electrical cardioversion.

QRS and QT Interval Modifications in Patients with Type 2 Diabetes Mellitus.

Introduction: Diabetes Mellitus imbricates inflammatory processes on their pathophysiology, it could affect cardiac electrophysiology. Cardiac inflammatory process leads electrocardiogram changes. Nevertheless, there are discrepancies about whether it prolongs or decreases waves and intervals such as QRS and QT.

Uneven vectorial projection is the best explanation for QRS dispersion, not the asynchronic ventricular activation.

Background: It is believed that QRS dispersion (QRSd) is caused by asynchrony of ventricular activation, but there are no studies that prove it.

Objectives: To determine the mechanism that best explains QRSd in surface electrocardiogram (ECG).

Methods: Cross-sectional study in 95 consecutive patients (median age: 31.

Ventricular arrhythmias are associated with increased QT interval and QRS dispersion in patients with ST-elevation myocardial infarction.

Introduction And Objectives: The electrocardiogram continues to be essential in the diagnosis of acute myocardial infarction, and a useful tool in arrhythmic risk stratification. We aimed to determine which electrocardiographic variables can successfully predict the occurrence of ventricular arrhythmias (VA) in patients following ST-segment elevation myocardial infarction (STEMI).

Methods: We performed an observational study including 667 patients with STEMI admitted to the University Hospital in Sancti Spíritus, Cuba.

Increased QRS duration and dispersion are associated with mechanical dyssynchrony in patients with permanent right ventricular apical pacing.

Background: Permanent right ventricular apical pacing may have negative effects on ventricular function and contribute to development of heart failure. We aimed to assess intra- and interventricular mechanical dyssynchrony in patients with permanent right ventricular apical pacing, and to establish electrocardiographic markers of dyssynchrony.

Methods: 84 patients (46:38 male:female) who required permanent pacing were studied.

New Parameter of the Second Half of the P-Wave, P-Wave Duration, and Atrial Conduction Times Predict Atrial Fibrillation during Electrophysiological Studies.

Objective: Several P-wave parameters reflect atrial conduction characteristics and have been used to predict atrial fibrillation (AF). The aim of this study was to determine the relationship between maximum P-wave duration (PMax) and new P-wave parameters, with atrial conduction times (CT), and to assess their predictive value of AF during electrophysiological studies (AF-EPS).

Subjects And Methods: This was a cross-sectional study in 153 randomly selected patients aged 18-70 years, undergoing EPS.

Vectorial theory surpasses the local theory in explaining the origin of P-wave dispersion.

Background: Local theory and the vectorial theory are used to explain the origin of P-wave dispersion (PWD). There are no previous studies that analyze both at the same time.

Objectives: We set out to determine the implication of local and vectorial theories in the origin of PWD.

Atrial conduction explains the occurrence of the P-wave dispersion phenomenon, but weakly.

Background: P-wave dispersion (PWD) is believed to be caused by inhomogeneous atrial conduction. This statement, however, is based on limited little solid evidence. The aim of this study was to determine the relationship between atrial conduction and PWD by means of invasive electrophysiological studies.

Prognostic Scale to Stratify Risk of Intrahospital Death in Patients with Acute Myocardial Infarction with ST-Segment Elevation.

INTRODUCTION The scales available to predict death and complica-tions after acute coronary syndrome include angiographic studies and serum biomarkers that are not within reach of services with limited resources. Such services need specifi c and sensitive instruments to evaluate risk using accessible resources and information. OBJECTIVE Develop a scale to estimate and stratify the risk of intra-hospital death in patients with acute ST-segment elevation myocardial infarction.

Tpeak-Tend, Tpeak-Tend dispersion and Tpeak-Tend/QT in children and its relationship with clinical variables.

Aim: To characterize the Tpeak-Tend, the Tpeak-Tend dispersion and Tpeak-Tend/QT in children and its relationship with clinical variables.

Methods: Cross-sectional study in 126 children between 9 and 12 years of the Camilo Cienfuegos School in Santa Clara, Cuba. Clinical and anthropometric variables were obtained to determine their relationship with electrocardiographic parameters: Tpeak-Tend V5, Tpeak-Tend dispersion and Tpeak-Tend/QT ratio V5.

Corrected QT-Interval Dispersion: An Electrocardiographic Tool to Predict Recurrence of Myocardial Infarction.

INTRODUCTION Many clinical settings lack the necessary resources to complete angiographic studies, which are commonly used to predict complications and death following acute coronary syndrome. Corrected QT-interval dispersion can be useful for assessing risk of myocardial infarction recurrence. OBJECTIVE Evaluate the relationship between corrected QT-interval dispersion and recurrence of myocardial infarction in patients with ST-segment elevation.

Biochemical Markers and Hypertension in Children.

INTRODUCTION Hypertension is one of the most studied risk factors for cardiovascular disease in adults; in children and adolescents, its global prevalence changes with age, from 1%-3% in children to 3.2% in adolescents. In adults, in addition to hypertension, several biochemical markers of cardiovascular risk have been identified.

[Permanent septal pacing in patients suffering secondary heart failure compared to right ventricular apical pacing].

Introduction: Regardless of the type of electrical stimulation (VVI or DDD) the highest percentage of right ventricular apical pacing can cause left ventricular failure. For this reason, studies have been performed in different sites on right ventricle pacing.

Objective: To describe differences between electrocardiography and echocardiography variables during right ventricular apical pacing and septal pacing.

[P wave dispersion increased in childhood depending on blood pressure, weight, height, and cardiac structure and function].

Introduction: Increased P wave dispersion are identified as a predictor of atrial fibrillation. There are associations between hypertension, P wave dispersion, constitutional and echocardiographic variables. These relationships have been scarcely studied in pediatrics.