A STUDY OF ECG PATTERNS IN PATIENTS WITH PROXIMAL LEFT ANTERIOR DESCENDING ARTERY STENOSIS
Keywords:ECG (Electrocardiography), LBBB (Left Bundle Branch Block), deWinter’s Twaves, LAD(Left Anterior Descending Artery)
BACKGROUND:Anterior wall Myocardial Infarction is ST segment elevation myocardial infarction and involves left anterior descending artery which may be proximal or distal depending upon the site of stenosis. There is a diversity in Electrocardiographic patterns of anterior wall myocardial infarction including ST elevations in different limb leads and anterior leads applied on chest. Acute Left Bundle Branch Block with chest pain is also an important ECG presentation of anterior wall myocardial infarction. Similarly De Winter’s syndrome or de Winter’s T waves is also an important sign of proximal Left Anterior Descending Artery (LAD) occlusion and can be used in clinical practice to diagnose hidden acute myocardial infarction. 1, 2
OBJECTIVE: To study the ECG patterns in patients presenting with Anterior Wall Myocardial Infarction and proximal LAD occlusion.
MATERIAL AND METHODS: It was a cross sectional observational study carried out in the Department of Cardiology, Government Khawaja Muhammad Safdar Medical College, Sialkot and Wazirabad Institute of Cardiology Wazirabad over a duration from 01-12-2019 to 29-02-2020. A total number of 200 patients with electrocardiographic (ECG) evidence Acute Anterior St segment elevation Myocardial infarction, Acute Left Bundle Brach Block with chest pain and de winters T waves were enrolled. Patients with Inferior, Infero Posterior and Right Ventricular infarct were excluded from the study. Coronary Angiography was performed over all the study cohort in the Cardiac Catheterization lab of Wazirabad Institute of Cardiology on presentation after ruling out contraindications and only those with Proximal LAD stenosis were included in the study while patients with the involvement of Right Coronary Artery and Left Circumflex were excluded. The study cohort was subdivided in to four groups depending upon the electrocardiographic patterns. Group one comprised of patients with ST-Elevations in leads I-aVL, V1-V6 while the second group included those with ST Elevations in leads V1-V6 and a third group comprised of patients presenting with Acute LBBB with Chest pain and the last group consisted of patients with de winters T waves. The classical electrocardiographic findings of de Winters syndrome are tall and upright significant T waves in precordial leads and these T waves are symmetrical. There is ST segment depression with up sloping of more than 1mm at the J point in the precordial leads without ST elevation. There is absence of ST segment elevation i.e. 0-5 mm -1mm in aVR. All the collected data was subjected to statistical analysis in SPSS for windows version 21 and results were analyzed.
RESULTS: Electrocardiographic analysis of the cases under study revealed a diversity of patterns. 100(50%) patients had ST elevations in leads I-aVL and Precordial leads V1-V6. 29(14.5%) patients revealed ST elevations in V1-V6. De Winter’s T wave pattern was seen in 30(15%) patients. Acute LBBB with chest seen was observed in 18(09%) of the patients while Wallen’s Snydrome was present in 23(11.5%).
CONCLUSION: Proximal LAD artery stenosis reveals significant diversity in ECG patterns.
KEY WORDS: ECG (Electrocardiography), LBBB (Left Bundle Branch Block), deWinter’s Twaves, LAD(Left Anterior Descending Artery)