Ismael Vergara S

Implante de marcapaso definitivo en pacientes con vena cava superior izquierda persistente y ausencia de vena cava superior derecha: Caso clínico

Persistent left superior vena cava and absent right superior venacava is an uncommon anatomical association. This is a challenging situation for permanentpacemaker implantation. We report three patients with this anomaly and a permanentpacemaker successfully implanted through the left superior vena cava and coronary sinus,without acute or chronic complications (Rev Med Chile 2006; 134: 767-71).(

Seguimiento en fase aguda de catéteres electrodos de estimulación endocavitaria permanente: Comparación de tres modelos

, los cuales fueron comercializados enChile a partir de febrero de 2002, marzo de 2000 yagosto 2002, respectivamente. Estos modelos decateteres electrodos se utilizan rutinariamente enlos implantes realizados en nuestro laboratorio ylas especificaciones tecnicas de cada uno de ellosse detallan en la Tabla 1.El objetivo de este trabajo es comparar losresultados del implante y los parametros deestimulacion en fase aguda de los tres modelos decateteres electrodos utilizados en los pacientessometidos a implante de marcapaso o desfibrila-dor en el Laboratorio de Electrofisiologia Cardiacadel Hospital Clinico de la Pontificia UniversidadCatolica de Chile.M

Fulguración con radiofrecuencia de taquicardia ventricular después de corrección quirúrgica de Tetralogía de Fallot: Caso Clínico

Ventricular tachycardia is one of the most feared complications after surgical repair of Tetralogy of Fallot and it is associated with sudden death. We report a 26 years old female with a history of surgical repair of Tetralogy of Fallot at age of 4 year-old, who developed sustained ventricular tachycardia despite antiarrhythmic drugs. She was successfully treated with radiofrequency catheter ablation. Radiofrequency catheter ablation is a valid treatment for these patients.

Síndrome de Twiddler: una causa infrecuente de disfunción de marcapaso definitivo. Caso clínico

We report a 26 year old patient who had a single chamber pacemaker implantation one year before. During a routine pre-operative evaluation, pacemaker dysfunction was demonstrated due to sensing and pacing failure, associated to left pectoral muscle rhythmic contraction. Chest X-ray confirmed Twiddler syndrome, in which twisting or rotation of the device inside the pocket results in lead dislodgement and device malfunction.

Criocoagulación de venas pulmonares como tratamiento complementario de la fibrilación auricular en cirugía valvular

Twenty onepatients had simultaneous valvular surgery and CPV, 81% of them had permanent AF for an average of5 years. Twenty patients had mitral valve disease. The etiology was rheumatic in 14. Average left atrialdiameter was 60 mm. In 7 patients the mitral valve was replaced, in 5 it was repaired, in 7 both mitraland aortic valve were replaced, in 1 the mitral valve was repaired and the aortic valve was replacedand in 1 only the aortic valve was replaced. A combined transeptal and superior approach was used forall patients. The CPV was performed after the valvular procedure with cryothermy at -60

Flutter auricular: Resultados inmediatos y alejados de la fulguración con radiofrecuencia del istmo cavo-tricuspídeo

Of all the patients treated, five died and fivewere lost from follow up, thus 76 patients (mean age 56 years, 58 males) were contacted forreassessment. At the moment of the procedure, 51% had an underlying cardiac disease and25% had high blood pressure. All referred palpitations, 25% had dyspnea, 84% were receivingantiarrhythmic drugs and 33% were on oral anticoagulants. Flutter was paroxystic in 83%and chronic in 17%. Fulguration was successful in all patients; one patient presented a highgrade atrioventricular block as a complication of the procedure. At reassessment, 82% ofpatients were in sinus rhythm, 16% had atrial fibrillation and 2%, an atypical flutter.

Taquicardia recíproca de la unión auriculoventricular: características electrofisiológicas en un paciente con la variedad paroxística. Caso clínico

Junctional reciprocating tachycardia is an atrioventricular reentrant tachycardia whose anterograde conduction occurs via the His Purkinje and the retrograde conduction via an accessory pathway with slow conduction. The most common form is incessant tachycardia but a paroxysmal form also exists. We report a 35 years old female with recurrent paroxysmal tachycardia, that underwent electrophysiological evaluation. A left posterolateral accessory pathway was documented. Reciprocating paroxysmal tachycardia was induced by electrical stimulation and a successful pathway ablation was performed.

Terapia de resincronización cardiaca en paciente con vena cava superior izquierda persistente: Caso clínico

Persistent left superior vena cava is the most common venous congenital malformation and is usually asymptomatic. Its presence could increase the difficulty for transvenous lead implantation. We report a 71-year-old woman with an idiopathic dilated cardiomyopathy, atrial fibrillation and heart failure that required biventricular resynchronization therapy. During the placement of the device a persistent left superior vena cava was detected. The device was placed without problems and the patient had a satisfactory postoperative evolution.

Necesidad de estimulación ventricular rápida en la inducción de taquicardia por reentrada del nodo aurículo-ventricular: Caso clínico

We report a 59 year-old woman who had recurrent episodes ofparoxystic supraventricular tachycardia despite pharmacologic therapy. A previouselectrophysiological study (EPS) was done two years earlier without induction of any sustainedarrhythmia. A new EPS was performed, during which atrial and ventricular programmedstimulation failed to induce tachycardia, and only by fast ventricular stimulation duringintravenous isoproterenol infusion, a typical atrio ventricular nodal reentrant tachycardia(AVNRT) was induced. We successfully ablated the slow nodal pathway. After ablation thetachycardia was not inducible. We comment the occasional difficulties to induce AVNRT andthe importance of a complete induction protocol to avoid false negative studies during the EPS(Rev Med Chile 2007; 135: 764-7).(

Estimulación ventricular derecha multisitio en insuficiencia cardíaca refractaria a tratamiento con resincronización biventricular

The prevalence of congestive heart failure has increased in the world. Despite advances in pharmacological treatment, some patients have progression of the disease and deterioration of their functional class. In this group of patients cardiac resynchronization therapy has been accepted as a treatment option. However, some patients are non-responders to cardiac resynchronization, and others who respond favorably, will experience reappearance of their symptoms. For these patients, multisite stimulation with the implant of a second electrode in the right ventricle has been published as a new option. We report a 76 year-old woman with a dilated cardiomyopathy, who was treated with resynchronization therapy with good clinical response during two years, but symptoms of congestive heart failure reappeared and her functional class deteriorated to NYHA class IV. She was successfully treated with right ventricular multisite stimulation, with a reduction of symptoms that has lasted during the two months of follow up after the procedure.