الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 164 |  |  |
| | | from | 164 | | |
Abstract
Coronary heart disease is a major cause of mortality and this health problem is reaching pandemic in both developed, and developing countries. ACS carries significant morbidity and mortality and the prompt diagnosis, and appropriate treatment is essential. Every effort is done to risk stratify coronary artery disease patients and various risk stratification scores have been developed. Moreover, the assessment of severity of coronary artery lesion has gained major concern. HR was identified as a risk predictor of ACS. Both continuous increase in high baseline heart rate and decrease in low baseline heart rate are associated with higher risk of CVD. Decreased heart rate could also cause dispersion of atrial repolarization which, in turn, initiate cardiovascular events. During the acute phase of ischemia, structural myocardial damage, electrolytic imbalance and an ion channel dysfunction in combination with an increased sympathetic activity may lead to a prolongation of the QT interval. Therefore, when approaching a patient with ACS, the prognostic role of corrected QT (QTc) interval prolongation should be considered. The aim of this study was to assess the correlation between admission heart rate and corrected QT interval prolongations with severity of coronary artery disease in acute coronary syndrome patients The current study was conducted on 120 patients admitted with acute coronary syndrome& divided into two groups based on syntax score: 1. Low syntax score group (syntax score <22) 2. Intermediate to high syntax score group (syntax score >22). Both groups were compared to each other regarding different demographic laboratory, electrographic, echocardiographic &angiographic parameters The present study revealed that acute coronary syndrome patients with intermediate – high syntax score were older and had higher prevalence of DM, HTN, smoking,, Dyslipidemia, prior PAD, prolonged QTc, lower LV EF, left main disease, 3-vessel disease, proximal LAD lesion & incidence of MACE compared to low SS patients. This study showed that there was highly significant difference between both groups regarding admission heart rate & QTc interval The current study showed that both groups of low AHR< 60 bpm & high AHR >90bpm were significantly associated with severe CAD &.Mainly those patients with higher admission heart rate were more likely to have higher Syntax scores (severe coronary lesion ). Also, patients with prolonged QTc had severe coronary artery diseases, higher SS & high probability to suffer adverse cardiac events more than patients without prolonged QTc interval. This study revealed that admission heart rate >80 Bpm & QTC >450ms was identified as the optimal cutoff values to predict severe Coronary artery lesion represented by higher Syntax scores & determine patients at the highest risk of adverse cardiac events. This study highlights the potential role of admission heart rate & QTc interval as non –invasive tools to predict severity of CAD.