ABSTRACT
Congenital heart block is a fetal arrhythmia detected by routine prenatal ultrasound. Natural history and risk factors for this condition are known. Patients having Ro/La antibodies have 2 to 4 percent risk of affected child and recurrence of up to 25 percent. There are standarized protocols for measuring the PR interval by ultrasound, as well as reference curves for different gestational ages. The experience at Hospital Clínico de la Universidad Católica de Chile is reported, describing follow up of 37 patients over a period of more than 4 years. A protocol based on monthly monitoring of risk group was adopted.
El bloqueo aurículo ventricular congénito constituye una de las arritmias fetales detectables mediante ultrasonido prenatal de rutina. Se conoce su evolución natural y la población de riesgo de sufrir esta afección. En portadoras de anticuerpos Ro/La el riesgo de un hijo afectado es entre 2 y 4 por ciento, y la recurrencia de hasta un 25 por ciento. Existen protocolos estandarizados para medir el intervalo PR mediante ultrasonido, como también curvas de referencia para las distintas edades gestacionales. Reportamos la experiencia en el Hospital Clínico de la Universidad Católica de Chile, con un seguimiento de 37 pacientes en un periodo de más de 4 años. Se adoptó un protocolo de seguimiento mensual del grupo de riesgo.
Subject(s)
Female , Pregnancy , Atrioventricular Block/congenital , Atrioventricular Block , Fetal Diseases , Ultrasonography, Prenatal , Autoantibodies , Arrhythmias, Cardiac , Atrioventricular Block/immunology , Pregnancy Complications/immunology , Fetal Diseases/immunology , Follow-Up Studies , Heart Rate, Fetal , Ultrasonography, DopplerABSTRACT
PurposeEvaluation of the prolonged PR interval and its predictive value for trifascicular block in individuals with bifascicular His bundle branch block. Patients and Methods55 patients, 36 male and 19 female aged 57 + 15,8 years with bifascicular bundle branch block type have been studied. 11 cases had complete left bundle branch block and 44 cases had complete right bundle branch block with left anterior ana superior division block. His bundle electrogram and atrial stimulation were performed in all patients. The atrial stimulation rate originating the Wenckebach phenomenon (SP) of the A-V conduction, and the A-H and H-V intervals were compared with the PR interval of the surface electrocardiogram. Patients were divided into three groups according to the PR interval: group 1, Pr < 200 ms, group II, PR between 190-280 ms and group III,PR 280 ms. ResultsThere was not linear correlation between the PR interval and WP in the three groups. There was a weak linear ascending correlation between the PR and A-H intervals in groups I and II (r + 0.59 and + + 0.43, respectively) and there was a descending correlation in the group III (r. - 0.64, P < 0.05). In relation to the H-V interval there was not linear correlation with the PR interval in groups I and II, but there was a good ascending linear correlation in the group III (r 0.84, P < 0.01). The incidence of prolonged A-H and H-V intervals increased as the PR interval was larger. Conclusion The prolonged PR interval with bifascicular bundle branch block means, in the majority of cases, diffuse damage of the conduction system envolving the A-V node and the infranodal region; starting from 280 ms, the delayed PR interval suggests envolvement predominantly below the A-V node: to a higher PR interval corresponds a higher H-V interval and also, to a relatively shortest A-H interval
Subject(s)
Humans , Male , Female , Bundle-Branch Block/physiopathology , Bundle of His/physiopathology , Electrocardiography , Time Factors , Predictive Value of Tests , Heart Conduction System/physiopathology , Heart Block/physiopathologyABSTRACT
Avaliar a funçäo do nó A-V (NAV) pela determinaçäo do período de Wenckebach (PW) e pela resposta à atropina nos casos de intervalo PR normal, no limite máximo normal e prolongado, todos com WRS estreito. Cento e vinte e nove pacientes, 79 homens, idades de 59 ñ 20 anos, assintomáticos ou com queixas de palpitaçöes, tonturas, pré-síncope e síncope, com ECG de taquicardia supraventricular, bloqueio A-V de 1§ grau (BAV 1§), de 2§ grau tipo Mobitz I intermitente e doença de nó nsinusal. Excluídos síndrome de pré-excitaçäo e dissociaçäo longitudinal do nó A-V. Cardioestimulaçäo atrial transesofágica realizou-se em todos os casos para avaliaçäo de atropina. Segundo o PW obtido, os pacientes foram divididos em 3 grupos: I, PW >= 125 ppm (N = 88); II, PW entre 125 e 110 ppm (N = 16) e III, PW <= 110 ppm (N = 25). Houve correlaçäo linear decrescente entre o PR e PW somente no grupo II (5 = 0,76 e p < 0,01). Houve incidência significativamente maior de PR > 240 ms no grupo III em relaçäo aos outros grupos e a resposta à atropina foi melhor nos casos de PR <= 240 ms, onde houve maior número de normalizaçäo do PW. Há correlaçäo linear decrescente entre o PR do ECG e o PW para indivíduos com PW <= 110 ppm: PR maior de 240 ms correspondeu melhor a PW abaixo de 110 ppm (em torno de 90 ppm), a maioria näo se normalizou com a atropina, considerando-se adequada a denominaçäo para estes casos de "bloqueio" A-V de 1§ grau. Para os BAV 1§ com PR menores de 240 ms, que se normalizaram com a atropina ...