Prognostic Significance of Bundle Branch Blocks in Acute Coronary Syndrome

Moorthy, P (2010) Prognostic Significance of Bundle Branch Blocks in Acute Coronary Syndrome. Masters thesis, Madras Medical College, Chennai.


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INTRODUCTION: Presence of new onset bundle branch block is associated with increased mortality in patients with acute coronary syndrome (ACS). Development of new bundle branch block despite prompt fibrinolytic therapy may signify an extensive and ongoing AMI. It is associated with overall poor prognosis, and high risk for short term mortality. Presence of complete Bundle Branch Block (BBB) Left or Right in AMI patients represents an independent and very important predictor of in-hospital complication and poor survival on long term.8 Earlier studies suggested that patients with BBB have move co-morbid conditions and are less likely to receive therapies such as thrombolytics, aspirin, β blockers and have an increased in hospital mortality rates.5 In our study we evaluated the prognostic significance of different types of BBB present during the course of AMI in the hospitalized patients and we followed up the patient at the end of one month. AIM OF STUDY: 1. To estimate the prevalence of BBB in patients with Acute coronary Syndrome. 2. To compare the clinical characteristics in patients with ACS with or without BBB. 3. To assess the prognostic significance of BBB in patients with ACS depending on its form of presentation. 4. Presence of BBB in ACS could be used for risk stratification and selection of treatment according to the risk pattern. MATERIALS AND METHODS: Study Design: This study is a single centre prospective analytical study carried out in the coronary care unit, Department of Cardiology, Madras Medial College during the period of January 2009 to December 2009. Total number of patients were 150. All the patients in the study were hospitalized. No out patients were included. A detailed informed concent was obtained from the patients Our Institutional ethical committee clearance was obtained. Standard approved protocol were used for treating all the patients. The results were tabulated and analysed using chi-square test. Inclusion and Exclusion Criteria: Patients presented with ACS in the coronary care unit were included and observed. Serial ECGs of all the patients admitted with ACS in CCU were studied. CK-MB was measured in some of the cases. Since facilities for measuring. Troponin was not available we were not able to measure it. Patients demographics, clinical variables like prior MI, angina, CHF, Cardiac risk factors like DM, SHT, smoking dylipidemia chest pain on admission, Killip class, use of thrombolytic therapy, reasons for not using thrombolytic therapy were recorded. Patients were followed until discharge from the hospital and at the end of one month. During the period of follow up, events like ventricular dysfunction, arrhythmias, recurrent angina, CHF, 2°, 3° heart block, mechanical complications, cardiac arrest and death were recorded. These variables are compared between ACS patients with BBB and without BBB. Patients were excluded if presented with 1. Pre existing BBB, 2. Non Specific Intraventricular conduction defects. SUMMARY: Prognostic significance of BBB in ACS was studied in coronary care unit, Department, of cardiology. Madras Medical College, following observations were made. • Of 150 patients studied 34 (22.66%) patients had new onset BBB. • BBB patients had higher killip class (II, III, IV)/. • BBB patients had increased incidence of arrhythmias. • Higher incidence of complete heart block. • Higher incidence of death due to complete heart block was observed. • Higher incidence of systolic and diastolic LV dysfunction. • BBB was associated with higher incidence of hypotension, heart failure. • Higher percentage of in hospital death (17.6%). • Among BBB group higher incidence of Mortality was seen in bifasicular block. No difference was observed in mortality at the end of 1 month between the two groups. CONCLUSION: When physicians are called to see a patient with ACS with BBB, major diagnostic and prognostic issues should be addressed. Many studies have dealt with the aspects of this problem. Patients having new onset BBB accompanying ACS early after fibrinolytic therapy independently have higher in-hospital mortality than patient without these conducting abnormalities. Patients with RBBB are more prone to arrhythmias and heart failure. Patients with LBBB are more prone to systolic LV dysfunction. Patients with bifasicular block are more prone to complete heart block, heart failure and cardiogenic shock. Among BBB, bifasicular block is associated with higher incidence of mortality. Bunde Branch block with ACS patients had worse clinical pattern such as • Higher Killip class, • Arrhythmias, • Complete heart block, • Systolic, diastolic LV dysfunction, • Hypotension, • Heart failure. Emergency physicians and cardiologists should be familiar with the mechanisms related to BBBs and with prognostic implication of BBBs in the setting of ACS. Such knowledge constitutes an immediate available clinical tool for the management of patients with ACS, especially nowadays when the pathways to the optimal reperfusion strategy are available.

Item Type: Thesis (Masters)
Uncontrolled Keywords: Prognostic Significance ; Bundle Branch Blocks ; Acute Coronary Syndrome.
Subjects: MEDICAL > General Medicine
Depositing User: Subramani R
Date Deposited: 29 Mar 2018 03:29
Last Modified: 29 Mar 2018 03:29

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