P and R wave detection in complete congenital atrioventricular block.

Complete atrioventricular block (type III AVB) is characterized by an absence of P wave transmission to ventricles. This implies that QRS complexes are generated in an autonomous way and are not coordinated with P waves. This work introduces a new algorithm for the detection of P waves for this type of pathology using noninvasive electrocardiographic surface leads. The proposed algorithm is divided into three stages. In the first stage, the R waves located by a QRS detector are used to generate the RR series and time references for the other stages of the algorithm. In the second stage, the ventricular activity (QT segment) is removed by using an adaptive filter that obtains an averaged pattern of the QT segment. In the third stage, a new P wave detector is applied to the residual signal obtained after QT cancellation in order to detect P wave locations and get the PP time series. Eight Holter records from patients with congenital type III AVB were used to verify the proposed algorithm. Although further improvements should be made to improve the algorithm's performance, the results obtained show high average values of sensitivity (90.52%) and positive prediction (90.98%).

Análisis del grado de captación de los pacientes hipercolesterolémicos por los servicios de atención primaria extremeños / No disponible

La dislipemia está considerada como uno de los factores de riesgo principales de la cardiopatía coronaria,pero es un factor de riesgo modificable a través del tratamiento higiénico-dietético o farmacológico.La cartera de servicios establece una serie de parámetros que debe cumplir cada equipo de atención primaria para la atención de sus pacientes. Uno de dichos parámetros es la captación de pacientes con hipercolesterolemia, en función de los criterios de inclusión especificados.El objeto principal de este estudio es determinar el grado de captación de los pacientes hipercolesterlo-lémicos por parte de los equipos de atención primaria de la Comunidad Autónoma de Extremadura a lo largo delperiodo que comprende la cartera de servicios (octubre de 2002 a septiembre de 2003).Para ello se partirá de la siguiente hipótesis: los pacientes que toman fármacos hipolipemiantes deberíanestar diagnosticados como dislipémicos, por lo cual deberían estar incluidos en ese servicio de la Cartera deAtención Primaria.En la realización de este estudio se han recogido los datos de todos los centros de salud de la ComunidadAutónoma de Extremadura referentes a los pacientes captados en este servicio, y a su vez, se han analizadolos datos de prescripción de fármacos hipolipemiantes en esta Comunidad.Como resultado general del análisis del grado de captación de los pacientes hipercolesterolémicos por losEquipos de Atención Primaria extremeños se aprecian diferencias importantes en los valores obtenidos enla dosis habitante día por pacientes captados y por población total

Dyslipidemia is considered one of the major risk factors for coronary heart disease, but is modifiable throughthe application of hygienic and dietetic measures or by drug therapy. The service portfolio establishes a series of parameters that should be met by each primary care team in the attention to their patients. One of these parameters is the identification of patients with hypercholesterolemia on the basis of specific inclusion criteria.The main objective of this study was to determine the degree of success in identifying hypercholesterolemicpatients by primary care teams of the Autonomous Community of Extremadura over the period of the application of the service portfolio (October 2002 to September 2003).For this purpose, the study was based on the following hypothesis: the patients taking hypolipidemic agents mustbe diagnosed as having dyslipidemia and, thus, should be included in this primary care service portfolio.Data concerning the users of this service was collected from all the health care centers in the AutonomicCommunity of Extremadura, while the data on the prescription of hypolipidemic agents in this communitywere analyzed.The overall result of the analysis of the degree of success in identifying hypercholesterolemic patients by the primary care teams of Extremadura reveals considerable differences in the daily dose per identified patient and per inhabitant of the total population

Valsalva sinus pseudoaneurysm causes acute myocardial infarction and stroke simultaneously.

Spontaneous Valsalva sinus pseudoaneurysm is a rare and highly lethal condition. Below we present a clinical case of a young woman with spontaneous Valsalva sinus pseudoaneurysm diagnosed presenting with acute myocardial infarction (AMI) and ischemic stroke.

[Heart rate-ventricular extrasystole relations and their dependence on circadian rhythms]. / Estudio de las relaciones frecuencia-extrasistolia ventricular y su dependencia de ritmos circadianos.

The linear correlation of the circadian rhythms (CR) of heart rate (HR) with those of ventricular extrasystole (VE) is analyzed by electrocardiographic ambulatory monitoring in 32 patients: 22 with ischemic post-infarction cardiopathy (group A) and ten free of structural cardiopathy (group B). Variability expressed as the coefficient of ventricular extrasystole variation (100 x standard deviation/mean) presented an inverse correlation with the number of recording extrasystoles. Linear correlation between HR and VE was statistically significant in 72% of recordings in group A, and in 60% in group B. The percentage of cases with significant linear correlation was greater on analyzing the three-minute periods than with the longer periods. When the cases analyzed presented over 200 extrasystoles, the percentage with significant linear correlation between HR and extrasystole was greater in group A than in group B. The circadian rhythm of the ventricular extrasystoles using interpolation of a cosinor function was significant in 50% of group A cases, and in 60% of group B. The achrophases were diurnal in group B, but only in 45% of cases in group A, two correspondence models being found between the CR achrophases and the inverse linear correlation between HR and VE.

Transvenous ablation with high frequency energy for atrioventricular junctional (AV nodal) reentrant tachycardia.

We performed transcatheter AV junction ablation with high frequency energy in four patients with AV nodal reentrant tachycardia where extensive trials of several antiarrhythmic drugs failed to prevent further recurrences of tachycardia. Initially high frequency catheter ablation induced complete AV block in all patients. A recuperation of AV 1:1 conduction followed some time later, persisting in follow-up. No complications have been encountered in either the acute phase or the follow-up (from 6 to 8 months; mean +/- SD: 8.7 +/- 2.5 months). The electrophysiological study was carried out 6 weeks following ablation, and all patients showed AV 1:1 conduction. No dual nodal pathway was encountered and no tachycardia could be triggered. With refinement of the method, the potential application of high frequency energy to interrupt intranodal or perinodal connections responsible for reentrant supraventricular tachycardia or to retard AV nodal conduction appears promising.

Function of atrioventricular node conduction: hyperbolic model.

Twenty four patients were subjected to an electrophysiologic clinical procedure. The conventional extrastimulus test was applied to verify the relation between conduction time increase through the atrioventricular node of the extrastimulus beat (delta AH), and its preceding interval (A1A2). Following the least square root method the parameters of the hyperbolic model delta AH.A1A2 = m . delta AH + n were adjusted. The correlation coefficients obtained and tested in all cases were very high and significant. From this hyperbolic equation it was possible to determine the equations for the effective refractory period (ERPe = m) and functional refractory period (FRPe = ERPe + n). The theoretical values for refractoriness approached very closely those of the actually measured ERP and FRP, in all cases. This model proved to be, in respect to adjustments and especially in calculating refractory periods, at least as good as the exponential model proposed previously by other authors.