Hipertensión arterial refractaria y uso de drogas anticonvulsivantes: caso clínico / Resistant hypertension and anticonvulsant drugs: report of 1 case

Resistant arterial hypertension is uncommon when there is good compliance to antihypertensive therapy and secondary causes have been ruled out. We report a 41 years old male that suffered hypertensive encephalopathy and received prophylactic anticonvulsant therapy showing progressive raise of arterial pressure levels. Renovascular hypertension, aldosteronism and pheochromocytoma were discarded and, in spite of combined use of antihypertensive drugs, he did not achieve normal blood pressure. When phenytoin was discontinued, blood pressure temporarily normalized. Carbamazepine was started and blood pressure raised again. lt fell when this medication was discontinued. Antiepileptic agents could induce drug metabolizing system and thus reduce the effects of antihypertensive medications

Isquemia miocárdica reversible en el hipotiroidismo: comunicación de un caso / Reversible myocardial ischemia associated to hypothyroidism: report of one case

A silent, reversible myocardial ischemia with normal coronary angiography and reversible with thyroid hormone substitution, has been recently described in hypothyroid patients. We report a 49 years old male with an abnormal exercise electrocardiogram detected in a preventive medical examination. He had laboratory evidence of hypothyroidism and a history of two years of asthenia and progressive coarsening of the voice. The Thallium myocardial perfusion study, showed an alteration of coronary flow during exercise in the septum and lower wall of the left ventricle. Thyroid hormone substitution was started and three months later, a coronary angiography was normal. After six months a repeated Thallium perfusion study and exercise electrocardiogram were informed as normal

El colágeno de la reestenosis post angioplastia con stent: ¿se origina en la íntima o en la adventicia? / Origin of collagen in restenosis post stenting: intima or adventitia?

Background: Restenosis post stenting is due to the deposit of extracellular matrix, mainly collagen in the neointima. Controversy exists regarding if collagen is generated locally or by immigration from the adventitia. Aim: To study the fibrocellular response after stent implantation in rabbit iliac arteries. To observe, by immunohistochemistry and in situ hybridization, if collagen type I mRNA is expressed in the neointima, in the media or in the adventitia. Material and methods: Thirty eight white rabbits (New Zealand) of 4 kg received an hypercholesterolemic diet during 1 month. After this period, in all but 6 of them, an angioplasty with stent implantation was performed via right carotid artery in both iliac arteries, using a 1:1.3 relationship regarding the reference vessel. Angiograms were performed at day 0, 4, 21, and 40, followed by paraffin fixation of the injured segments, immunohistochemistry for a-actin and in situ hybridization to detect procollagen type I (a1R1) mRNA. Results: No hybridization was observed in non injured arteries or at day 0 (n= 6). Expression of a1R1 mRNA was observed in the neointima starting at day 4 after stenting (n= 8). At day 21 (n= 8) hybridization of procollagen type I was not only observed in the neointima, but also in the media, which became equally intense in both areas. At day 40 (n= 6) hybridization was observed similarly in the media and adventitia. Conclusions: In this model, hybridization of procollagen type I started in the neointima, then involved the media and finally the adventitia. This finding might be useful for designing therapies to be delivered locally at the end of an angioplasty to prevent collagen deposition in the neointima

Experiencia de 36 años con marcapasos implantables: un análisis histórico / A 36 year experience with implantable pacemakers

Background: The implantation of pacemakers improves cardiac function and quality of life, in particular with dual chamber DDD and DDDR modes. Aim: To evaluate our clinical experience and results on pacemaker implantation, from 1963 to 1998. Material and methods: Computerized data collected from 2,445 consecutive paced patients was reviewed. A total of 3,554 operative procedures were performed, including 412 procedures for complications and 697 pacemaker replacement. Patient survival was determined from clinical records, inquiry to pacemaker manufacturers and death certificates from Servicio de Registro Civil e Identificaci-n de Chile (Chilean Civil and Identification Registry). Results: Use of dual chamber (DDD and DDDR) pacemakers increased progressively up to 74 percent from 1988 to 1998. Complication rate was 42 percent in the 1963-1976 study period, it decreased to 10.6 percent in the 1977-1987 study period, and to 5.6 percent by 1988-1998. Only two patients died during surgery in the study period (0.08 percent). In the 1977-1987 period, pacemakers lasted 10.6 years. Survival rates were 52 percent at ten years, 33 percent at 15 years, and 21 percent at 20 years, with a median survival of 11.7 years, and 7.24 years in patients over 80 years old. Conclusions: Transvenous permanent pacing can be accomplished today with a low complication rate, mainly due to better technology and surgical procedures

Tratamiento de la insuficiencia cardíaca avanzada mediante trasplante de corazón / Heart transplantation as a treatment for advanced heart failure

Background: Heart transplantation currently provides the most effective treatment for advanced heart failure. However, medical therapy for this condition has also improved, heart donors are scarce and the cost of the procedure is high. Therefore the indications and management of these patients need reevaluation. Aim: To analyze the results of 24 patients submitted to heart transplantation for end-stage heart failure needing repeated hospitalizations and i.v. inotropes for compensation. Patients and methods: The group was comprised by 21 men and 3 women with a mean age of 36.8 years, mean left ventricular ejection fraction 19ñ4.5 percent, mean systolic pulmonary artery pressure 48ñ13 mmHg (24-70) and mean pulmonary vascular resistance 2.6 Wood Units (1-5). Fourteen patients (58 percent) had a previous median sternotomy. Immunosupression did not include induction therapy and steroids were discontinued early...

Amiodarona y efectos secundarios cutáneos / Amiodarone and secondary cutaneous effects

El clorhidrato de amiodarona es un agente antiarrítmico con efectos secundarios cutáneos conocidos. Un grupo multidisciplinario de especialistas estudió durante 2 años a 148 pacientes en tratamiento crónico con amiodarona, con el propósito de evaluar los efectos secundarios del fármaco. Todos los pacientes fueron examinados por el mismo dermatólogo, buscando la presencia de alteraciones cutáneas y su correlación con la dosis y duración del tratamiento; 79 eran mujeres, con un promedio de edad de 65 años. Las dosis de amiodarona comprendían un rango de 100 a 400 mg/día. Los pacientes fueron controlados durante 2 años, pero el período de terapia con amiodarona fue de 1 a 9 años. Se encontró fotosensibilidad en 39,3 por ciento de los pacientes, hiperpigmentación azul-grisácea en 10 por ciento , ambos sin relación con la dosis. La presencia de eritema facial se constató en el 24 por ciento de los casos y se estableció que existía relación con la dosis. Un paciente debió suspender la terapia debido a una erupción pruriginosa de placas infiltrativas, las que regresaron completamente al suspender fármacos. 76 por ciento de los pacientes presentaban uno o más trastornos cutáneos diferentes de los relacionados con la miodarona. Estos incluyen micosis de pies y uñas, queratosis actínicas y seborreicas, xerosis y distrofias ungueales. Los efectos secundarios cutáneos son muy comunes y bien tolerados en los pacientes en terapia con amiodarona. La suspensión del tratamiento debido a los efectos secundarios cutáneos fue poco frecuente

Angina inestable: resultados inmediatos y a un año del tratamiento con angioplastía coronaria transluminal percutánea / Immediate and late results of transluminal coronary angioplasty in patients with unstable angina

Background: Unstable angina is characterized by angina at rest, angina of recent onset or accelerating angina. It is caused by a fissure or ulceration of an atheromatous plaque leading to thrombi formation and coronary spasm. Aim: To report the immediate and late results of coronary angioplasty in patients with unstable angina. Patients and methods: Eight hundred twenty eight patients were subjected to coronary arteriography between January 1994 and June 1996. Of these, 242 were subjected to a transluminal coronary angioplasty, 245 patients were subjected to surgical revascularization and 341 patients were treated without revascularization. Results: A total of 323 stenotic lesions (1.3 lesions per patient) were subjected to angioplasty. Angiographic success was obtained in 93 percent of patients. Angiographic success and lack of major complications such as death, infarction of the need for surgery, was obtained in 90 percent of patients. Five patients (2.1 percent) had a non fatal infarction and five required emergency surgery. Hospital mortality was 1.2 percent. During the year of follow up, 15 percent required a new revascularization, 3.3 percent had a non fatal infarction and 3.3 percent died. Conclusions: Coronary angioplasty had a 90 percent immediate success and 78 percent of patients were free of ischemic events after one year of follow up

Displasia arritmogénica de ventrículo derecho: opciones de tratamiento durante 12 años de seguimiento en un caso / Arrhythmogenic right ventricular dysplasia: Therapeutic options during 12 years follow up in 1 case

The replacement of muscle by fibrous and adipose tissue leads to arrhythmogenic right ventricular dyaplasia. We report the clinical features and therapeutic options of a 50 years old male with the disease followed during 12 years. The latter included pharmacological therapy, surgical pseudoaneurysmal resection and radiofrequency fulguration of a second arrhythmogenic focus that appeared 10 after the surgical procedure. The patient remained asymptomatic after each therapy, until the disease progressed again. This follow up is one of the longest reported and documents the disease's clinical presentation, evolution and treatment

Taquicardia incesante de la unión: características clínicas, electrofisiológicas y rol de la fulguración en 5 casos / Permanent form of junctional tachycardia: clinical and electrophysiological characteristics and fulguration role in 5 cases

The permanent form is a variety of functional reciprocating tachycardia that is refractory to medical treatment. The anterograde arm of the circuit is formed by the His Purkinje bundle and the retrograde conduction is through a slow conduction accesory atrioventricular pathway. We report five patients with this type of arrhythmia, subjected to electrophysiological assessment. Their mean age was 37 years, all suffered from palpitations and several medical treatments had failed. During tachycardia, electrocardiogram had a negative P wave in inferior leads and RP interval was bigger than PR interval. Accesory Pathway were located in the right postero-septal region in three patients, in the left postero-septal region in one and in the left lateral in one. Specific bundle fulguration was succesfully attempted in four patients, in whom arrythmias did not recur without medical treatment

Fulguración con radiofrecuencia en pacientes con flutter auricular típico / Radiofrequency fulguration in patients with common atrial flutter

Nine patients (8 males) whose ages ranged from 6 to 72 years old were studied. Two patients had an operated congenital cardiopathy, 2 had high blood pressure, 1 has no subject previously to radiofrequency ablation due to a left paraspecific pathway; 1 developed a cardiac failure secondary to tachycardia and 3 relapses in the first month after the procedure, of these, 2 patients were succesfully treated again. After a mean follow up of 4.5 months, these patients are asymptomatic and without antiarrythmic drugs. Analyzis of obtained signals, showed that radiofrequency that interrupted atrial flutter always occurred in zones of double potentials. Radiofrequency ablation is an effective tretament for atrial flutter and the zone of succesful ablation is associated to the presence of double atrial potentials

Variantes electrofisiológicas de la taquicardia incesante / Electrophysiological variations of incesant tachycardia

La taquicardia incesante puede ser causada por diferentes mecanismos electrofisiológicos. Desde 1986, hemos estudiado 13 pacientes con taquicardia incesante, 9 hombres y 4 mujeres (edad promedio 35a). Diez pacientes habían recibido múltiples antiarrítmicos y 4 habían desarrollado insuficiencia cardíaca secundaria a taquicardia. Se efectuó estudio electrofisiológico en 11 pacientes, encontrando: 1) haces accesorios con conducción lenta y decremental en 5 pacientes. Se encontró un haz derecho posteroseptal en 3, un haz izquierdo posterolateral en 1 y un haz izquierdo posteroseptal en 1. La ablación por radiofrecuencia fue exitosa en 4 de estos 5 pacientes. 2) la taquicardia auricular ectópica fue el mecanismo de la arritmia en 4 pacientes. Se efectuó una resección quirúrgica exitosa del foco auricular en 1 paciente y ablación del his en otro. Fracasó la ablación por radiofrecuencia del foco auricular en un paciente. 3) Reentrada nodal atípica existió en 2 pacientes que fueron tratados con antiarrítmicos, cuando carecíamos de radiofrecuencia. 4) Un foco ectópico del his existía en un niño de 1 mes de edad, cuya arritmia se encuentra parcialmente controlada con drogas. 5) Un paciente tenía una taquicardia incesante atípica debida a un haz accesorio lento con intervalos A-H y H-V prolongados. Un intento de ablación con corriente continua se complicó de hemopericario que se trató con cirugía y la arritmia respondió posteriormente a antiarrítmicos. Por tanto, el estudio electrofisiológico es valioso en pacientes con taquicardia incesante y conduce a tratamiento exitoso con ablación por radiofrecuencia en muchos de ellos

Características del electrograma local en fulguraciones exitosas de haces paraespecíficos / Characteristics of the local electrogram in successfuly fulgurations of paraspecific bundles

La ablación por radiofrecuencia de haces paraespecíficos es un aterapia muye efectiva para el tratamiento de las taquicardías paroxíticas supraventriculares. Con el objeto de evaluar la utilidad del electrograma local en la identificación del sitio correcto para efecturar la ablación por radiofrecuencia, se analizaron las características de éstos en 20 pacientes con haces paraespecíficos fulgurados exitosamente. 16 pacientes tenían un haz paraespecífico izquierdo (10 ocultos), 2, haz paraespecífico anteroseptal y 1, un haz paraespecífico lateral derecho. En 15 pacientes la fulguración se realizó durante taquicardia paroxítica supraventricular y en 5, durante ritmo sinusal. En los 20 electrogramas analizados, el hallazgo más frecuente fue el de complejos fusionados. Se registró un probable electrograma de Kent en 3 pacientes fulgurados en taquicardia y en 4 pacientes fulgurados en ritmo sinusal. Pensamos que ninguna de las características del electrograma local tiene un valor predictivo alto para precisar el sitio de la fulguración exitosa

Incidencia y características del shock cardiogénico en el IAM: comparación de las eras pre y post trombolíticas / Incidence and features of cardiogenic shock in AMI: a comparison of the pre and post thrombolytic periods

El shock cardiogénico secundario al infarto del miocardio (IAM) ocurre en realción a infartos muy extensos y tiene alta mortalidad. Para evaluar el impacto del tratamiento actual del infarto, hemos comparado la incidencia y características del shock cardiogénico entre 252 pacientes admitidos por IAM entre 1983-1985 (Grupo 1), con 228 pacientes admitidos después de 1990 (Grupo 2). Mientras en el Grupo 1 sólo se trataron las complicaciones del infarto, en el Grupo 2 hubo 69 pacientes (31 por ciento ) que se sometieron a trombolisis o angioplastía en las primeras seis horas y todos recibieron heparina, antiagregantes plaquetarios y nitroglicerina i.v. La incidencia de shock cardiogénico fue la misma en Grupo 1 y Grupo 2 (13 por ciento y 12,8 por ciento ). Tampoco hubo diferencias en la incidencia de shock no relacionada a ruptura cardiaca (8,3 por ciento para el Grupo 1 y 7,9 por ciento para el grupo 2). Los grupos se diferenciaron, sin embargo, en el momento de aparición del shock. Mientras en el Grupo 1 el 53 por ciento de los casos lo desarrollaron después de 24 horas de iniciado el infarto, en el Grupo 2 la mayor parte lo presentó en las primeras 24 horas del infarto (88 por ciento ), período en el que se concentra la mayor mortalidad. En conclusión, el tratamiento actual del IAM ha disminuido la incidencia de shock cardiogénico por falla miocárdica tardía, pero no ha influido en la incidencia del shock que se presenta en las primeras horas del infarto

Aterectomía rotacional (rotablator) en la angioplastía coronaria percutánea transluminal / Rotational atherectomy (rotablator) for percutaneous transluminal coronary angioplasty

Background: The use of Rotablator in percutaneous transluminal coronary angioplasty attempts to reduce the atheromatous plaque abrading it and fragmenting the pariental calcium of the artery. Aim: To report our experience with the use of Rotablator: Patients and methods: Rotational atherectomy was performed in 189 patients aged 60.8 ñ 11 years (154 men). The clinical indication for the procedure was chronic angina in 22 percent, unstable angina in 44 por ciento, myocardial infarction in 21 percent, silent angina in 7 percent and re-stenosis in 6 percent. One bundred seventy seven patiens were followed for a mean of 15.9 ñ 6.3 months. Results: Two hundred thirty six stenoses in 215 coronary arteries were treated with a 98.7 percent angiographic success rate. One patient had a Q infarction and no patient died or required emergency surgery. Fourteen patients had rises in CK MB enzymes (non Q infarction). Thee patients had a pseudoaneurism and three had bleedings that required transfusion. Of the followed patients, 33 had a clinically suspected re-stenosis, that was angiographically confirmed in 23. Cardiac mortality was 2.3 percent. Seventy nine percent of patients had an evolution without angina or coronary events. Conclusions: Percutaneous transluminal coronary angioplasty with the use of Rotablator had a high immediate success rate and a low incidence of complications. The clinical evolution of patients has been favorable with a low incidence of mortality and ischemic events

Flutter auricular crónico: una manifestación infrecuente de enfermedad del nódulo sinusal: caso clínico / Chronic atrial flutter as an infrequent manifestation of sick sinus syndrome: report of 1 case

We report a 41 years old female, previously operated of an atrial septal defect, presenting with a persisting atrial flutter. Sinus node dysfunction became evident during an electrophysiological study at the moment of interrupting the flutter with electrical stimulation. The patient was treated with his bundle ablation and implantation of a definitive pacemaker. After one year of follow up, she is devoid of symptoms

Miocardiopatía hipertrófica y doble episodio de muerte súbita recuperada: primer cardiovertor desfibrilador automático implantable colocado en Chile / Hypertrophic cardiomyopathy and double episodes of recupered sudden death: first implantable defibrillator cardiovertor installed in Chile

We report a 29 years old male with a non obstructive hypertrophic cardiomyopathy that survived two episodies of cardiac arrest and with a familiar history of the disease and sudden death. He had an implant of an automatic implantable cardioverter defibrillator by a left anterior thoracotomy with intraoperative electrophysiology. The postoperative outcome was uneventful. After one year of follow up, the patient is in good functional capacity and the implanted device has not performed defibrillations

Fulguración con radiofrecuencia de la vía nodal lenta: experiencia en 30 casos consecutivos / Radiofrequency fulguration of the slow nodal pathway: experience in 30 consecutives cases

Atrioventricular nodal reentry tachycardia (AVNRT) is one of the most mechanisms of paroxysmal supraventricular tachycardia. In these patients tachycardia is maintained due to anterograde conduction through a slow pathway and retrograde conduction to the atrium via a fast pathway. We present here our experience in ablation of the slow pathway. Since January 1993, 30 consecutive patients with AVNRT underwent attempted catheter ablation of the slow pathway. Mean age was 37ñ3.7 years. All patients had symptomatic tachycardia and six had history of syncope. Electrophysiological studies revealed AVNRT in all patients, in addition, 2 patients had a left accesory pathway. Slow pathway ablation was performed with Mansfield 7 F catheter, guided by both fluoroscopic positioning and endocardial signals. A mean of 13 burst were applied. In the 30 patients conduction though the slow pathway was interrupted and thus tachycardia was no longer inductible. Retrograde conduction post ablation was evaluated in 17 of the 30 patients, significant changes were observed in three of them. One patient developed second degree AV block and a permanent pacemaker was implanted. Another patient had recurrence of tachycardia three months post ablation. After a second attempt she is arrhythmia free. Patients have been followed for a mean of 15.7ñ2.5 months and are asymptomatic in the absence of antiarrhythmic therapy

Fulguración por radiofrecuencia de las taquicardias supraventriculares en pediatría / Radiofrequency ablation of supraventricular tachycardias in pediatrics

Supraventricular tachycardias (SVT) are the most frequent cause of tachycardia in children. Its pharmacological treatment has adverse effects, is not curative and is not always effective. During the last few years radiofrequency ablation (RF-A) has changed the treatment. The purpose of this study is to evaluate our experience in RF-A in children with SVT. Between 1990 and 1995, 92 patients (1 mont to 17 years old) underwent electrophysiological study after the diagnosis of SVT. RF-A was attempted in 55 patients with accessory pathways (AP), slow-pathway of the atrioventricular node, or ectopic focus. The site of ablation was decided according to the electrical signals and the catheter position. The success of the RF-A was confirmed by the interruption of the tachychardia, the change in the sequence of activation of the intracardiac signals, the regression of the preexcitation and the inability to reinduce tachycardia. RF-A was succesful in 81 percent of the patients; 88 percent in those with a left AP 56 percent in those with a right arterial obstruction, one with a minimal pneumothorax and one with cardiac tamponade. During a follow up of 16.6 months there was no relapse nor late complications. We conclude that RF-A is a safe and effective procedure in pediatric patients with SVT

Edema pulmonar no-cardiogénico relacionado con la hidroclorotiazida / Non-cardiogenic pulmonary edema related to hidrochlorothiazide

A 54 years old female patient with a mitral valve prolapse and a rheumatic arthritis with steroids was admitted with dysnea and hypotension, that started 30 min after taking a pill containing enapril and hydroclorothiazide. Hemodynamic monitoring with a Swan-Ganz catheter showed a pulmonary capillary pressure of 5 mm Hg, a systemic vascular resistance of 887 (dyn sec)/cm5 and a cardiac output of 10 1/min. Tha patient had a history of adverse reactions to thiazides and responded to volume replacement, dopamine and steroids

La importancia de la reprogramación en la vida útil y costo de implante de los marcapasos bicamerales / The importance of adjusting parameters for the duration and cost of dual chamber pacemakers

Antecedentes: realizamos un estudio prospectivo de 236 pacientes sometidos a implante de marcapaso DDD bicameral. Los parámetros nominales de implante permiten márgenes de seguridad de estimulación más que suficientes. Las mejoras en la tecnología de marcapasos y electrodos han permitido reducir los umbrales de captura y, por lo tanto, la programación de los parámetros de salida. Dichos cambios pueden significar una reducción en el consumo de la batería a largo plazo, produciendo una mayor durabilidad del generador. Métodos y resultados: se estudió 236 pacientes consecutivos implantados con marcapasos Pacesetter DDD para determinar el impacto de la reprogramación en la durabilidad y costo del implante del marcapaso. Se excluyó a 36 pacientes, 19 murieron, 13 no tuvieron suficientes controles y 4 fueron reprogramados a modo VVI. Los 200 pacientes restantes completaron al menos 18 meses de seguimiento y se les implantó generadores capaces de medir umbrales de estimulación crónico, ancho de pulso, impedancia y energía de la batería. Comparamos la durabilidad estimada basada en la energía de la batería bajo parámetros de implante nominales, con aquella basada en los parámetros obtenidos tras la reprogramación durante el seguimiento. La estimación de durabilidad fue de 6,89 años bajo parámetros nominales y de 10,5 años bajo parámetros de programación final (p<0,001). Conclusiones: la reprogramación podría aumentar la durabilidad y reducir el costo de implante de los marcapasos. En nuestro estudio la reprogramación aumentó la durabilidad del marcapaso en 3,6 años y ocasionó una reducción promedio en sus costos de 330 dólares por año