COMPARING THE FREQUENCY OF LEFT MAIN STEM DISEASE AMONG PATIENTS WITH ST ELEVATION IN aVR LEAD

Background: Coronary artery disease (CAD) is one of the leading causes of mortality worldwide with similar prevalence in Pakistan. The main objective of the study is to compare the frequency of left main stem disease among patients with ST elevation in aVR. Methods: This cross-sectional study was conducted in Department of cardiology, Punjab institute of cardiology, Lahore. Sample size of 151 cases is calculated with 95% confidence level,7%margin of error and taking expected percentage of LMS is 74.2%. The data was collected through non probability consecutive sampling technique. Results: Mean age of the study population was 55.54±10.1 years. Majority of the cases were male 117(77.5%) and 34(22.5%) were female which were less in quantity. Mean body mass index was 28.61±2.58. Conclusion: Majority of the cases developed left mainstem disease who have been diagnosed with ST elevation in aVR. A significant difference of the diabetic versus non diabetic was observed who have been noted for LMS disease.


important.
The left main coronary artery (LMCA) supplies the largest area of myocardium, so patients with the disease of this artery are at very high risk for myocardial (6) infarction and its related complications.ECG rapidly interprets the manifestations of ACS in emergency department; however, ECG findings in lead aVR are mostly neglected.These findings are related to LMCA stenosis in ACS.The most common ECG findings related to LMCA stenosis are ST segment elevation 7 in lead aVR.The ST segment elevation of 0.1 mV or more in lead aVR on ECG suggests high probability of left main coronary artery disease or severe CAD with 8 associated worse prognosis.An acute obstruction of left main coronary artery (LMCA) is encountered approximately in only 0.5% of acute myocardial infarc-9 tion (AMI) cases.The ECG predicting an acute obstruction of the LMCA, thus the simple non-invasive, inexpensive, easily available ECG can help us earlier prediction of the deadly lesion in LMCA, so that we can proceed further to confirm the diagnosis and can take prompt, appropriate treatment strategy to reduce disease was observed in 50% diabetics and 50% non diabetics.This study concluded that prevalence of (11) LMS is equal in both diabetics and non diabetics.In a study by Ashraf M et al, out of 693 patients with acute coronary syndrome, 54.83% patient had diabetes (12) and 45.16 % patient were non diabetics.In another study by Parvin T et al, left main stem disease was more prevalent in diabetic patients than in non diabetics.

OBJECTIVES
The main objective of the study is to compare the frequency of left main stem disease among patients with ST elevation in aVR.

METHODS
This cross-sectional study was conducted in Department of cardiology, Punjab institute of cardiology, Lahore.Sample size of 151 cases is calculated with 95% confidence level,7%margin of error and taking expected percentage of LMS is 74.2%.The data was collected through non probability consecutive sampling technique.

DATA COLLECTION
After approval from the hospital ethical committee, all patients who will present in the department of medical emergency and fulfil the selection criteria, was included in the study.A valid informed consent was taken after counselling the patients regarding the procedure & objective of the study.The demographic information (age, sex etc.) was recorded.Demographic characteristics of all patients was obtained.Detailed medical history including past history was taken.A detailed physical examination with special emphasis on CVS was performed.ECG of all patients was evaluated followed by angiography for detection of patients with left main stem disease.The patients was labelled as yes if they are found to have left main stem disease.

DATA ANALYSIS
All the collected data was entered into SPSS version 22 and analyzed.Quantitative data like age (in years) was presented as means and standard deviations.The qualitative data like demographics (sex; male or female) and number of patients was presented as frequency and percentage.

RESULTS
Mean age of the study population was 55.54±10.1 years.Majority of the cases were male 117(77.5%)and 34(22.5%)were female which were less in quantity.Mean body mass index was 28.61±2.58.
It was noted that left main stem disease was in 96(63.6%) of cases while 55(36.4%)werewithout this disease.Diabetes mellitus was present in 33(21.9%)cases while 118(78.1%)were not diagnosed with the diabetes.
When data was stratified, it was noted that left main stem disease wasin 42(77.8%)cases with age 30-50 years and in 54(55.7% in age group of >50 years with a significant difference (P-value<0.05).

DISCUSSION
The left main coronary artery (LMCA) supplies up to 75-100% of left ventricular mass depending on the dominance type.For that reason acute non-STsegment elevation (NSTEMI) or ST-segment elevation (STEMI) myocardial infarction due to critical stenosis or abrupt occlusion of the LMCA is a catastrophic situation with a very high in-hospital and long-term mor-13 tality.Many cases are never reported because of prehospital death.Although coronary artery bypass grafting (CABG) remains a class I recommendation for LM revascularization in European and American guidelines, percutaneous coronary intervention(PCI) is becoming an attractive option in patients with acute myocardia linfarction and LMCA as an infarct-related artery, especially when in cardiogenic shock.Advances in devices and adjunctive pharmacotherapy make PCI of the LMCA feasible and with at least non-inferior 14 results to CABG.
Although electrocardiography is not a highly specific method for the diagnosis of myocardial infarction due to ULMCA disease, the primary results of our registry suggest that STEMI (vs.NSTEMI) remains an independent predictor of in-hospital and 12-month mortality.Several lines of evidence indicate that not all patients with severe ULMCA disease develop ECG 15 changes before a hemodynamic collapse.In those who present with ST-segment abnormalities an aVR lead is one of high specificity and sensitivity for ULMCA disease, especially when ST-elevation is higher than in the V1 lead, which correlates with mortality and hemodynamic deterioration.Mahajan et al. reported that differences in ST-segment deviations in the V1 and V6 leads are even more specific for pre-16 dicting ULMCA disease than the aVR lead itself.
Despite well-documented female sex-related discrepancies in the presentation, management, clinical course and outcomes in patients with STEMI in the general population, in the elderly and in the young, in the present study we did not find any significant malefavoring difference.This is a surprising finding, leading to the conclusion that the deleterious impact of the LMCA-related myocardial infarction on mortality is 17 the greatest of all known risk factors.

CONCLUSION
Majority of the cases developed left main stem disease who have been diagnosed with ST elevation in aVR.A significant difference of the dia-betic versus non diabetic was observed who have been noted for LMS disease.

Table 1 :
Distribution of the Mean Age and BMI of the Study Population

Table 2 :
Distribution of the Gender in the Study Population

Table 3 :
Vol. 21 No. 2 April -June 2023 Distribution of the Left Main Stem Disease in the Study Population

Table 4 :
Comparison of the Left Main Stem Disease in Diabetes versus non-Diabetes Cases