[Ventricular tachycardia associated with isolated right ventricular dysfunction as indicator of arrhythmogenic dysplasia of the right ventricle]. / Taquicardia ventricular asociada a disfunción del ventrículo derecho aislada como indicador de displasia arritmogénica del ventrículo derecho.

We report the case of a 21 year-old patient with arrhythmogenic right ventricular dysplasia manifested by episodes of QRS tachycardia greater than 0.12 sec and isolated dysfunction of the right ventricle. The patient treated with amiodarone however, the tachycardia episodes persisted. The surface electrocardiogram showed left branch block with the axis down, which suggested a right ventricle origin, and was therefore considered an arrhythmogenic dysplasia. Echocardiography and cardioangiography showed alterations in the anatomy of the outflow tract of the right ventricle. A myocardial gammagraphy revealed no perfusion alterations. The endomyocardial biopsy showed perivascular fibrosis. An electrophysiology study was performed, stimulating the outflow tract of the right ventricle, which induced two types of ventricular tachycardias, one of them identical to that recorded clinical. The patient was treated with sotalol, and has been being free of ventricular tachycardia episodes for 18 months of follow-up. We consider that this entity should be studied in a systematic way in those patients with ventricular tachycardia originated in the outflow of the right ventricle and with primary cardiac illness.

[Trans-surgical ablation of atrial flutter in patients treated with closure of atrial septal defect. Pilot project]. / Ablación transquirúrgica del flutter atrial en pacientes sometidos a cierre de comunicación interauricular. Estudio piloto.

Atrial flutter is one of the most common arrhythmias in patients with atrial septal defect, after surgery 14% of patients can develop it and may be associated with high morbidity. In this study we performed prophylactic and therapeutic ablation of atrial flutter during atrial septal closure surgery drawing 4 lines; line 1, isthmus cavo-tricuspid, the area between the inferior vena cava and the tricuspid ring; line 2, the area between coronary sinus ostium and inferior vena cava; line 3, the area between tricuspid valve annulus and coronary sinus ostium; and line 4, the area between lateral atriotomy and atrial septal defect. Twenty-one patients were included, 6 (28.5%) patients had atrial flutter before surgery and 15 (71.4%) were in sinus rhythm. There were no new cases of atrial flutter, but at six months follow up 2 (33.3%) patients recidivated with atrial flutter. One patient developed high degree atrio-ventricular block and a pacemaker had to be implanted. Older age at the time of surgery and high systolic pulmonary pressure were significantly higher in those patients with atrial flutter before surgery and in patients with arrhythmias recurrence. Ablation of atrial flutter during atrial septal closure surgery can be a good option for the treatment and prevention of atrial arrhythmias, but more studies are still needed.

[Electrocardiographic changes during stress test in a patient with "Brugada syndrome"]. / Alteraciones electrocardiográficas durante el esfuerzo en un paciente con "síndrome de Brugada".

We report a 28 year old man with the Brugada syndrome characterised by an electrocardiographic pattern of a right bundle branch block and an ST segment elevation in the right precordial leads as well as syncope. During an exercise test, we observed a normalization of the ST segment in V2+ while in the postexercise phase, the ST segment elevation in the right leads was established. This is the first case reported of the Brugada syndrome in Mexico, with spontaneous changes on the EKG masked during exercise and apparent during postexercise phase.

[Radiofrequency ablation and simultaneous insertion of an Amplatzer device in a patient with atrial septal defect and nodal reentry tachycardia]. / Ablación con radiofrecuencia y colocación simultánea de un dispositivo Amplatzer en un paciente con comunicación interatrial y taquicardia por reentrada intranodal.

The association of AV nodal reentry tachycardia and interatrial septal defect has not been described previously. This article reports a 47-year-old woman with an atrial septal defect (ostium secundum) and history of palpitations without documental tachycardia through resting and ambulatory electrocardiography. Rapid atrial pacing under the influence of isoproterenol, during an electrophysiology study, elicited and AV nodal reentry tachycardia of the common type. Successful radiofrequency catheter ablation was performed targeting the slow pathway. Immediately an Amplatzer device was used for closure of the septal defect. Both procedures were successful and without complications. What makes this case unusual is that both interventional procedures were performed during the same session.

[Double tachyarrhythmia: left anterior fascicular ventricular tachycardia associated with atrial flutter and fibrillation. Report of a case]. / Doble taquiarritmia: taquicardia ventricular fascicular anterior izquierda asociada a fibrilación y flutter auriculares. Reporte de un caso.

A patient with episodes of palpitation in whom the electrocardiogram showed a right bundle branch (RBBB) configuration and right axis deviation underwent electrophysiologic study and radiofrequency ablation. Left ventricular endocardial mapping during ventricular tachycardia (VT) identified the earliest ventricular activation in the anterolateral wall of the left ventricle. The fused Purkinje potential was recorded at that site, and preceded the QRS complex by 47 mseg, with pace mapping showing an optimal match between the paced rhythm and the clinical VT. The stimulus to QRS time was equal to the Purkinje potential-QRS time. Several radiofrequency lesions were applied in this region, one of them resulted with termination of the tachycardia. Following delivery of this lesion the ventricular tachycardia couldn't be induced either at baseline or during isoproterenol infusion. During VT, atrial fibrillation and atrial flutter were observed, cardioversion was performed reverting to sinus rhythm.