Prolongation of the descending branch of the T-wave in electrocardiograms with no apparent data consistent with risk for sudden death. / Retraso de la rama descendente de la onda T en electrocardiogramas sin datos de riesgo aparente de muerte súbita.

Introduction: Prolongation of the descending branch of the T-wave in the electrocardiogram (ECG) has been identified to be able to determine the risk for sudden death of cardiac origin, but its importance in the general population is not known. Objective: To provide a tool for easy acquisition and effective application to identify the risk of sudden death in the general population. Method: We measured the dbT/jT index (descending branch of the T wave/space between the j point and the end of T), and it was found to be completely normal in 400 ECGs, 656 had alterations that don't affect ventricular repolarization, and 82 had branch block. We carried out the Z transformation of the nonparametric distribution curves and calculated the Z ratio to data far from the mean value. Results: The distribution was asymmetric, with no difference in the three groups. The Z transformation showed a mean value of 30 ± 7, which suggests that 95% of the population has a dbT/jT index < 0.45. Conclusion: dbT/jT index results > 0.44 are beyond two standard deviations and are therefore abnormal, which should prompt specialized assessment in order to determine if there is risk for death in the carrier.

Introducción: Se ha identificado que la prolongación de la rama descendente de la onda T del electrocardiograma (ECG) puede determinar riesgo de muerte súbita de origen cardiaco, pero se desconoce su importancia en población general. Objetivo: Proporcionar una herramienta de fácil adquisición y aplicación efectiva para identificar riesgo de muerte súbita en población general. Método: Medimos el índice rdT/jT (la rama descendente de la onda T/el espacio entre el punto j y el fin de la T) en 400 electrocardiogramas (ECG) totalmente normales, 656 con alteraciones que no afectan la repolarización ventricular y 82 con bloqueo de rama. Hicimos transformación Z de las curvas de distribución no paramétrica y calculamos razón Z a datos alejados del valor medio. Resultados: La distribución fue asimétrica, sin diferencia en los tres grupos. La transformación Z mostró valor medio de 30 ± 7, lo que sugiere que 95 % de la población debe tener índice rdT/jT < 0.45. Conclusión: Resultados del índice rdt/jT > 0.44 se sitúan más allá de dos desviaciones estándar, por lo tanto, son anormales y deben ser motivo de estudio especializado del portador en busca de riesgo de muerte.

[Myocardial ischemia mimicking the Brugada syndrome]. / Isquemia miocárdica que semeja síndrome de Brugada.

We describe a patient with a syncopal event who displayed an electrocardiographic tracing highly suggestive of Brugada syndrome. The coronary angiogram, however, showed unequivocal non-atheromatous coronary lesions.

[Diminished vascular density in the aortic wall. Morphological and functional characteristics of atherosclerosis]. / Densidad vascular disminuida en la pared de la aorta. Característica morfológica y funcional de la aterosclerosis.

PURPOSE: To determine disproportion in thicknesses of the vascular wall and vasa vasorum in eight fragments of human aorta because of the irregular distribution of atherosclerosis in arterial walls. METHOD: The length and thickness of the wall and its layers were measured and the vasa vasorum were conted. Vascular density, considered as the number of vessels per square millimeter in healthy and diseased areas, was calculated along with mean value, variance, standard deviation and the confidence interval for values and null hypotesis. Variances were analyzed, and the comparative and paired "t" test was applied. RESULTS: There were differences in thicknesses of the healthy (27 :m) and diseased (120.5 :m) intima (p < 0.001) and between the healthy (125.2 :m) and diseased (102.3 :m) media (P < 0.001). Vascular density was higher in healthy fragments (mean +/- Cl 99% = 4.40 +/- 1.4 vs 2.20 +/- 0.8, = < 0.001 for Ha; 0 +/- 1.0775 for Ho; paired "t" 2.1 +/- 1.1, P < 0.01), and higher compared to the healthy intima area (31.6 vs 5.1, P < 0.01). There were no differences compared to the media layer area. The relation between the number of vessels and the length of the vascular segments was greater in the healthy fragments (mean +/- Cl 95% = 4.9 +/- 1.02 vs 3.5 +/- 0.68; 1.4 difference, P < 0.05). CONCLUSION: Vascular density is lower in the atherosclerotic aortic wall than in the healthy aorta and this could initiate the pathologic process.

Densidad vascular disminuida en la pared de la aorta: Característica morfológica y funcional de la aterosclerosis / Diminished vascular density in the aortic wall: Morphological and functional characteristics of atherosclerosis

Antecedente: Por distribución irregular de aterosclerosis en paredes arteriales se buscó desproporción entre grosor de la pared vascular y vasa vasorum en ocho fragmentos de aorta humana. Método: Se midió longitud y grosor de pared y de sus capas y se contó vasa vasorum, se calculó densidad vascular como número de vasos por milímetro cuadrado en áreas sanas y enfermas, valor medio, varianza, desviación estándar e intervalo de confianza para valores y para hipótesis nula, se analizaron varianzas y se aplicó prueba "t" comparativa y pareada. Resultado: Hay diferencias de grosor entre íntima sana (27 micras) y enferma (120.5 micras), P < 0.001; y entre media sana (125.2 micras) y enferma (102.3 micras), P < 0.001. La densidad vascular es mayor en fragmentos sanos (media ± IC 99% = 4.4 ± 1.4 vs 2.2 ± 0.8, P < 0.001 para Ha; 0 ± 1.0775 para Ho; "t" pareada 2.1 ± 1.1, P < 0.01). Mayor ante íntima sana (31.6 vs 5.1, P < 0.01). No varía ante capa media. La relación entre número de vasos y longitud del segmento vascular es mayor en el fragmento sano (media ± IC 95% = 4.9 ± 1.02 vs 3.5 ± 0.68, diferencia 1.4, P < 0.05). Conclusión: La densidad vascular es menor en la pared de aorta aterosclerosa que en aorta sana lo que pudiera iniciar el proceso patógeno.

Purpose: To determine disproportion in thicknesses of the vascular wall and vasa vasorum in eight fragments of human aorta because of the irregular distribution of atherosclerosis in arterial walls. Method: The length and thickness of the wall and its layers were measured and the vasa vasorum were conted. Vascular density, considered as the number of vessels per square millimeter in healthy and diseased areas, was calculated along with mean value, variance, standard deviation and the confidence interval for values and null hypotesis. Variances were analyzed, and the comparative and paired "t" test was applied. Results: There were differences in thicknesses of the healthy (27 :m) and diseased (120.5 :m) intima (p < 0.001) and between the healthy (125.2 :m) and diseased (102.3 :m) media (P < 0.001). Vascular density was higher in healthy fragments (mean ± CI 99% = 4.40 ± 1.4 vs 2.20 ± 0.8, = < 0.001 for Ha; 0 ± 1.0775 for Ho; paired "t" 2.1 ± 1.1, P < 0.01), and higher compared to the healthy intima area (31.6 vs 5.1, P < 0.01). There were no differences compared to the media layer area. The relation between the number of vessels and the length of the vascular segments was greater in the healthy fragments (mean ± CI 95% = 4.9 ± 1.02 vs 3.5 ± 0.68; 1.4 difference, P < 0.05). Conclusion: Vascular density is lower in the atherosclerotic aortic wall than in the healthy aorta and this could initiate the pathologic process.

Tratamiento del síncope mediante denervación del seno carotídeo / Treatment of syncope by means of carotid sinus denervation

Con el objetivo de resolver simultáneamente los aspectos cardioinhibidor y vasodepresor del síndrome de seno carotídeo, se ha realizado denervación de la bifurcación de la arteria carótida de enfermos que respondieron con pausa R-R mayor a tres segundos en el electrocardiograma o disminución de más de 10 mmHg en la tensión arterial. Los resultados se compararon con los de un grupo de enfermos tratados mediante implante de marcapaso cardiaco definitivo. Se incluyen 17 pacientes, sexo masculino, edad promedio 76.8 años, hipotensión arterial de 25 mmHg y pausa de 4.4 segundos en respuesta al estímulo carotídeo. Siete pacientes del grupo estudiado (85 por ciento) y diez del grupo control (70 por ciento) quedaron asintomáticos y con respuesta normal al estímulo carotídeo, lo que confirma la utilidad del procedimiento