Corrected sinus node recovery time as a screening test in patients with typical atrial flutter post-ablation to predict pacemaker implantation.

Objective: The objective of the study was to establish the prognostic value of CSNRT regarding the necessity for pacemaker implantation in patients with atrial flutter (AFL) post-ablation.

Methods: This prospective cohort study, conducted at the National Institute of Cardiology "Ignacio Chavez" in Mexico City, assessed patients who had undergone ablation procedures to correct AFL, posterior to which an autonomic blockade was performed, and CSNRT was measured.

Results: The sample for this investigation was 40 patients.

[Comportamiento y decisión cardiovascular en el síndrome de MASS. Reporte de un caso y revisión de la literatura].

MASS syndrome (disorder of connective tissue characterized by involvement of the mitral valve, aorta, skeleton, and skin) is a rare genetic disease with a phenotype similar to that of Marfan syndrome, but with important cardiovascular differences like the absence of aortic root aneurysm and marked mitral affection. We present a case of a patient with MASS syndrome and review the limited literature addressing these differences, and we discuss the impact this information may have in decisions regarding cardiovascular surgery.

[Management of heart failure with His bundle pacing in right bundle branch block: case report].

La terapia de resincronización cardiaca mediante estimulación hisiana ha demostrado ser efectiva en pacientes con bloqueo de rama izquierda del haz de His e insuficiencia cardiaca. Paciente masculino, con 47 años de edad, con insuficiencia cardiaca, fracción de expulsión del 17% y miocardio dilatada idiopática, electrocardiograma en ritmo sinusal, bloqueo auriculoventricular de 1. grado, intervalo PR 400 ms, bloqueo completo de rama derecha del haz de His, bloqueo del fascículo anterior de la rama izquierda del haz de His, duración del QRS 200 ms.

Diagnostic challenges of Brugada Syndrome in pediatric patients.

Although most cases of Brugada syndrome have been described in adults, pediatric patients with the disease have been reported since the original article from Josep and Pedro Brugada. Herein is presented the case series of Brugada syndrome in pediatric population of the National Institute of Cardiology Ignacio Chavez. One boy and two adolescent males had palpitations as clinical presentation of the disease.

Postintervention Dyspnea after Radiofrequency Catheter Ablation: Think of a Phrenic Nerve Injury.

Phrenic nerve injury (PNI) is a rare complication of catheter ablation therapy, most commonly observed in cryoablation of the right side pulmonary veins. We present a case of PNI after radiofrequency catheter ablation that developed acute dyspnea 24 hours after the intervention. Dyspnea is the main symptom of PNI, so the diagnosis should always be suspected if it appears after any type of catheter ablation involving the trajectory of the phrenic nerve.

Left atrial cardiac myxoma. Two unusual cases studied by 3D echocardiography.

We describe two patients with cardiac tumors in the left atrium, which by their association and histopathological lineage, are extremely rare. The clinical, echocardiographic and pathological findings were analysed. The first case was asymptomatic, but in the control studies of colon adenocarcinoma, an intracardiac mass was found by chest computed tomography (CT).

Simplified progressive approach for the ablation of scar related atrial macroreentrant tachycardias.

Introduction: Radiofrequency ablation of scar related right atrial flutter is challenging. Long procedures, prolonged fluoroscopic times and high percentages of recurrences are of concern. We present a simple and progressive approach based on a single electroanatomic map of the right atrium.

[Case report: idiopathic ventricular tachycardia from the aortic sinus cusp].

Idiopathic ventricular tachycardia is identified in 10% of the patients presenting with ventricular tachycardia, and they consist of various subtypes that can originate from different areas, including the aortic cusps which represent 0.7% of the total. Electrocardiographically, these ventricular tachycardias display a left bundle branch block pattern and inferior axis, and although rare, should be considered in the differential diagnosis with tachycardias originating from the septal region of the right ventricular outflow tract, which comprise 80% of the idiopathic ventricular tachycardias.

[Supraventricular tachycardial ablation supported with an electroanatomical system].

Unlabelled: In 1992 the radiofrequency ablation program was started, with very good results in patients with supraventricular tachycardias and normal hearts or minimal structural defects. Nevertheless, the results are not as good for the patients with structural defects, that are actually seen more frequently, those are cases with more complex arrhythmias, are patients with cardiac surgery that show a complex arrhythmogenic substrate or patients previously treated with conventional ablation which tachycardia recurs. In these cases, the electroanatomic Carto system has been very useful.

Association of congenital, diffuse electrical disease in children with normal heart: sick sinus syndrome, intraventricular conduction block, and monomorphic ventricular tachycardia.

Introduction: Rhythm disturbances in children with structurally normal hearts are usually associated with abnormalities in cardiac ion channels. The phenotypic expression of these abnormalities ("channelopathies") includes: long and short QT syndromes, Brugada syndrome, congenital sick sinus syndrome, catecholaminergic polymorphic ventricular tachycardia, Lènegre-Lev disease, and/or different degrees of cardiac conduction disease.

Methods: The study group consisted of three male patients with sick sinus syndrome, intraventricular conduction disease, and monomorphic sustained ventricular tachycardia.

Non-invasive assessment of endothelial function. Intra and inter-observer variability.

Background And Objectives: Non-invasive evaluation of endothelial function with high resolution ultrasound has become a widely accepted tool in determination of high risk subjects for early atherosclerosis. Despite its simple appearance, ultrasonographic assessment of brachial artery changes, is technically challenging and has a significant learning curve. In the present study, we evaluate the intra and inter-observer variability in assessing peripheral endothelial function with high resolution ultrasound at a tertiary referral center.

[Electroanatomic mapping system (CARTO) to perform catheter ablation of atrial fibrillation].

Since the first report of radiofrequency catheter ablation curing atrial fibrillation (AF) nearly a decade ago, numerous techniques have evolved, from linear ablation to modify the reentrant sustrate for AF, to electrical isolation of pulmonary vein to eliminate triggers of AF, to hibrid approaches of circunferential ablation around and between the pulmonary veins and mitral valve annulus to modify both the triggers and sustrate for AF. We describe the electroanatomic mapping system (CARTO, Biosense Webster) and its use in patients undergoing catheter ablation for AF.

[Electrophysiologic study and ablation therapy in idiopathic paroxystic atrial fibrillation].

Objective: To analyze the results of radiofrequency catheter ablation (RFCA) of the pulmonary veins (PV) in patients with paroxysmal atrial fibrillation (PAF).

Material And Methods: We describe 4 patients (38 +/- 12 years, interval 8-52; 11 men) with symptomatic PAF, refractory to antiarrhythmic drugs. Special mapping catheters were used and ablation was performed at the ostium/antrum of those veins with abnormal electrical activity (AEA).

Neurocardiogenic syncope in chronic atrioventricular block.

We report a 37-year-old man with type I second-degree atrioventricular (AV) block (atypical Wenckebach's periodicity) referred to our department for pacemaker implantation because of an episode of syncope. After exhaustive evaluation, including electrophysiological test, in which Wenckebach's cycles with block within the AV node was demonstrated, syncope was considered to be neurally mediated. Head-up tilt testing with sublingual isosorbide dinitrate was positive.

[Electrocardiogram in the differential diagnosis of wide-QRS tachycardias].

The surface ECG constitutes an invaluable tool for the differential diagnosis in those cases in which the QRS complex exceeds the normal duration (120 mseg or more) and a heart rate of 100 bpm or more. Most of the arrhythmias with wide QRS complexes are ventricular in origin, and frequently related to heart disease; nevertheless, in those patients with hemodynamic stability it is frequently misdiagnosed as supraventricular tachycardia. The importance of the surface ECG resides in the fact that the correct diagnosis can be done with high probability when the analysis is orderly made.

[Long-term follow-up of 413 patients with atrioventricular accessory pathway who underwent radiofrequency catheter ablation].

Objective: The aim of this study was shown clinical characteristics and follow-up of patients with atrioventricular reentrant tachycardia (AVRT) who underwent radiofrequency catheter ablation (RCA) therapy.

Material And Methods: From April 1992 to December 1995, 413 patients with AVRT underwent RCA therapy.

Results: Two hundred thirty four men (57%) and one hundred seventy nine women (43%) aged 31.

[Trans-septal puncture for radiofrequency ablation of left accessory pathway].

We present the case of an 18-year-old male patient with diagnosis of Wolff Parkinson-White syndrome due to a left free wall accessory pathway. We performed an electrophysiology study and transseptal punction guided by transesophageal echocardiogram to via access to the left atrium. We performed successful radiofrequency ablation of the accessory pathway, observing disappearance of the delta wave on the first attempt.

[Hypertrophic cardiomyopathy. Arrhythmia in hypertrophic cardiomyopathy].

Hypertrophic cardiomyopathy is a relatively common genetic disorder with heterogeneity in mutations, forms of presentation, prognosis and treatment strategies. Hypertrophic cardiomyopathy is recognized as the most common cause of sudden cardiac death that occurs in young people, including athletes. The clinical diagnosis is complemented with the ecocardiographic study, in which an abnormal myocardial hypertrophy of the septum can be observed in the absence of a cardiac or systemic disease (arterial systemic hypertension, aortic stenosis).

[Atrioventricular nodal reentrant tachycardia: Radiofrequency ablation].

Atrioventricular nodal reentrant tachycardia is the most frequent regular supraventricular tachycardia. It is generally a benign arrhythmia and usually it is no associated with heart disease. It is more often seen in middle-aged women but it is no infrequent in younger and older patients.

[Usefulness of adenosine to detect advanced paroxysmal atrioventricular block as a cause of syncope].

We present the case of a 66 years old man with recurrent episodes of syncope, up to three times during the last two months without previous symptoms. An ECG after the syncope showed a bilateral block (left anterior fascicle block and right bundle branch block) and first grade atrioventricular block. The exercise test did not demonstrate either AV conduction disorders or tachyarrhythmia episodes.

[Follow-up of a group of patients with automatic implantable defibrillator].

Unlabelled: The automatic implantable defibrillator (AID) is the treatment of choice for primary and secondary prevention of sudden death. At the Instituto Nacional de Cardiología, since October 1996 until January 2002, 25 patients were implanted with 26 AID. There were 23 men (92%) and the mean age of the whole group, was 51.

[Sudden death. Role of the electrophysiologic study].

At present, sudden death is considered a major health problem, DeBoer in 1935, recognized the clinical importance of ventricular fibrillation as the cause of sudden cardiac death. Sudden death due to cardiovascular problems has been established as one of the main causes of death in the developed countries and in developing countries as ours, where the deaths caused by cardiovascular diseases represent 15% of the total, exceeding other causes of death. The frequency of sudden death in our country is unknown, but more frequently we hear about cases of patients that have been reanimated for cardiac arrest; in the United States of America the frequency has been estimated between 400,000 at 500,000 per year although, recently, 250,000 at 300,000 events are being mentioned.

[Disclosure of "Brugada's syndrome" with intravenous propafenone].

We present the case of a woman with familial antecedents of a brother who died suddenly at the age of 39 years, and an other with Brugada syndrome. The ECG had not shown the typical pattern of the Brugada syndrome. Based on these antecedents, we decided to perform a pharmacological test with endovenous propafenone, which revealed the electrocardiographic alterations at 10 min after the administration.