Unusual ventricular activation produced by temporary transvenous cardiac pacing: electrovectorcardiographic findings / Activación ventricular inusual producida por estimulación cardíaca transvenosa temporal: hallazgos electrovectorcardiográficos

Abstract Complete heart block (CHB) results from dysfunction of the cardiac conduction system, which results in complete electrical dissociation. The ventricular escape rhythm can have its origin anywhere from the atrioventricular node to the bundle branch-Purkinje system. CHB typically results in bradycardia, hypotension, fatigue, hemodynamic instability, syncope, or even Stokes-Adams syndrome. Escape rhythm originating above the bifurcation of the His bundle (HB) produces narrow QRSs with relatively rapid heart rate (HR) (except in cases of His system disease). We present a middle-aged man with an HR of 34 bpm, progressive fatigue, in whom a temporary pacemaker was implanted in the subtricuspid region. The post-intervention electrocardiogram had unusual features.

Resumen El bloqueo cardíaco completo (BCC) resulta de la disfunción del sistema de conducción cardíaco, lo que ocasiona una disociación eléctrica completa entre aurículas y ventrículos. El ritmo de escape resultante puede tener su origen en cualquier lugar desde el nodo auriculoventricular hasta el sistema His Purkinje. El BCC generalmente produce bradicardia, hipotensión, fatiga, inestabilidad hemodinámica, síncope o incluso el síndrome de Stokes-Adams. El ritmo de escape que se origina por encima de la bifurcación del haz de His produce intervalos QRS estrechos con frecuencia cardíaca no muy lenta (excepto en casos de enfermedad del sistema Hisiano). Presentamos a un hombre de mediana edad con una frecuencia cardíaca de 34 lpm, fatiga progresiva, en el que se implantó un marcapasos temporario en la región subtricuspídea. El electrocardiograma resultante a la intervención presentó características inusuales.

Transient left anterior and septal fascicular blocks after self-expandable percutaneous transcatheter aortic valve implantation.

Transcatheter aortic valve implantation (TAVI) is indicated in severe symptomatic aortic stenosis, when there is intermediate-high surgical risk, or a condition considered inoperable, as in the case of "porcelain aorta" that could turn clamping or cannulation of the ascending aorta hazardous in open-heart surgery. Among the complications of this less invasive procedure, intraventricular conduction disorders subsequent to the procedure stand out. TAVI causes worsening of intraventricular dromotropic disorders in more than 75% of the cases, with the presence of preexisting right bundle branch block and first-degree atrioventricular block, deep prosthesis implant, male gender, size of the aortic annulus smaller than the prosthesis, and porcelain aorta being predictive of requirement for permanent pacemaker implant.

Acute coronary syndrome of very unusual etiology.

Aortitis is one of many possible manifestations of tertiary syphilis. Aortic disease is the most common of all cardiovascular syphilitic lesions. Aortic diseases caused by tertiary syphilis include aortitis, aortic root dilation, aneurysm formation, aortic regurgitation and coronary ostial stenosis. A less common manifestation of syphilitic aortitis is coronary artery ostial narrowing related to aortic wall thickening. We report a case of a 40-year-old male patient admitted with a clinical picture of acute coronary syndrome (unstable angina). He had no risk factors for coronary artery disease. The physical examination revealed nothing remarkable. The admission electrocardiogram (ECG) showed ST segment depression in the anterolateral and inferior leads (Figure 1). The coronary angiogram showed critical ostial stenosis of the right (RCA) and left main coronary artery (Figure 2a, b). Cardiac-computed tomography showed aortic wall thickening with involvement of bilateral coronary ostia (Figure 2b, c). The patient was referred for coronary bypass surgery after treatment with two doses of penicillin G. The laboratory test was strongly positive for syphilitic infection. Postoperative treatment with benzathine penicillin, in doses recommended for tertiary syphilis, was implemented.

Brugada phenocopy caused by a compressive mediastinal tumor.

Recently, it has been shown that even experts in electrocardiography cannot differentiate the electrocardiographic pattern of genuine Brugada syndrome (BrS) from Brugada phenocopy (BrP). For this reason, this differentiation depends on the presence of established criteria both for BrS and BrP. In this manuscript, we present a patient with type 1 Brugada electrocardiographic pattern caused by expansive anterior mediastinal non-Hodgkin's lymphoma (NHL) with mechanical compression on the right ventricular outflow tract. The electrocardiographic pattern disappeared rapidly after antineoplastic measures.

Brugada phenocopy: new terminology and proposed classification.

Brugada syndrome is a channelopathy characterized on ECG by coved ST-segment elevation (≥2 mm) in the right precordial leads and is associated with an increased risk of malignant ventricular arrhythmias. The term Brugada phenocopy is proposed to describe conditions that induce Brugada-like ECG manifestations in patients without true Brugada syndrome. An extensive review of the literature identified case reports that were classified according to their suspected etiological mechanism. Future directions to learn more about these intriguing cases is discussed.

Web-based virtual cardiac symposia: a new approach for worldwide professional medical education.

AIM: The Internet is an extremely powerful tool for the transmission of data and knowledge, and the question is whether this technology can be used effectively in continuing medical education. We present our experience with worldwide, web-based virtual symposia for practicing physicians. METHODS: The International Society for Holter and Noninvasive Electrocardiography (ISHNE) decided four years ago to conduct a series of cardiology-related educational activities for physicians utilizing a web-based approach. Six educational events under the format of virtual symposia were held on the Internet during the years 2002 to 2006. These Internet events included symposia on Brugada syndrome (2002), the long QT syndrome (2004), arrhythmogenic right ventricular dysplasia (2005), atrial fibrillation (2005), heart failure (2006), and sudden cardiac death (2006). RESULTS: During the past four years, there has been a dramatic and progressive increase in the number of physician registrants, the number of countries represented, and the number of lectures downloaded with each subsequent virtual symposium. For example, during the month of October 2006, the Internet-based sudden cardiac death symposium involved 14,087 physician registrants from 120 countries with 64,939 lectures downloaded. The top lecture was downloaded 11,251 times, and over 200 e-mail questions and replies were exchanged. The average time per visit to the web site was 12.5 minutes. CONCLUSION: The progressively increasing numbers of physician registrants from around the world who participated in these web-based, virtual symposia suggest that this approach is answering an unmet professional educational need. This Internet approach adds an important, new, low-cost dimension to continuing medical education.

El síndrome del intervalo QT prolongado desde el punto de vista de un cardiólogo / Long-QT syndrome: a cardiologist's point of view

El síndrome del QT prolongado congénito está representado por un conjunto de entidades que obedecen a mutaciones genéticas que afectan los canales de potasio o de sodio del sarcolema de los cardiomiocitos. La característica común de todas las formas es la prolongación del intervalo QT que predispone a la aparición de una taquicardia ventricular polimórfica atípica denominada torsade de pointes, la cual en ocasiones puede degenerar en fibrilación ventricular y muerte súbita. Actualmente se conocen siete variantes de la enfermedad y la terapéutica incluye medidas farmacológicas y no farmacológicas. El síndrome puede responder también a causas secundarias por uso de drogas cardiológicas y no cardiológicas y siendo esta forma de presentación es más frecuente que la de origen genético. El Primer Simposio Internacional de QT Prolongado en Internet (http://www.lqts-symposium.org) ha generado un interesante debate que hace propicia la ocasión para realizar una síntesis acerca de las características de esta entidad.