Epidemiology and pattern of fascicular block following ST-Elevated acute myocardial infarction

Abstract

Aim: The aim of the study was to observe the epidemiology and pattern of fascicular block following ST elevated acute myocardial infarction (AMI).

Background: Fascicular block following S-T elevated acute myocardial infarction is often seen in CCU. It predicts poorer in-hospital outcome and signifies underlying extensive myocardial damage with jeopardized conducting system.

Materials and Method: This one year prospective observational study was carried out among the S-T elevated AMI patients in the CCU of NICVD during the period of January 2004 to December 2004. Hundred consecutive patients of first attack of AMI with or without fascicular block were included in this study. The patients suffering from congenital heart disease, cardiomyopathy, valvular heart disease and the patients having permanent pacemaker or preexisting syndrome were excluded from the study. Case selection was done with the help of history, physical examination, twelve leads surface ECG and echocardiography.

Results: The mean age of the studied patients was 54.2±10.0 years. Highest percentage (38%) was in the age group 51-60 years. The mean age of male Patients was 51.0±9.9 years. Analysis reveals that the mean age of the female patients was significantly higher than the male patients. Among the studied patients, highest percentage had history of smoking 67% followed by hypertension (39%), diabetes mellitus (39%) etc. Among the studied patients 66% had anterior MI and 34% had inferior MI. Highest percentage of patients presented with isolated RBBB (54.0%), followed by LBBB (18%), bi-fascicular (16.0%), tri-fascicular block (8.0%) and isolated LAHB (4.0%). Among the patients with anterior MI, highest percentage presented with RBBB (42.4%) followed by bi-fascicular block (24.2%), LBBB (15.2%) and LAHB (6%) whereas with inferior MI, 76.5 percentage had RBBB followed by LBBB (23.5%).

Conclusion: In this study majority of the patients were male. Most of the patients were in the age group 50-60 years. Number of anterior MI was higher (66%) than inferior MI (34%). Anterior MI showed highest incidence of fascicular block than inferior MI which is statistically significant. Among the fascicular blocks, RBBB was the highest (54.0%) and next common fascicular block was LBBB, least common was LAHB. Left posterior hemi-block was not found in this study. Statistical variation among the different types of fascicular blocks observed in this study was significant. Smoking was the most important risk factor. So, fascicular blocks following acute MI are more prone to develop complications than acute MI without fascicular block. Message is that patient with fascicular blocks following acute MI needs special care and treatment.

Bangladesh Journal of Medical Science Vol.14(2) 2015 p.186-189