Submit Manuscript | http://medcraveonline.com 8]. The concept of shock index, defined as the ratio of heart rate and systolic blood pressure, first introduced by Allgower et al, in 1967 as a simple and effective means for gauging the degree of hypovolemia in hemorrhagic and infectious shock states [9]. Subsequently, experimental and clinical studies demonstrated that SI was inversely related to physiologic parameters, such as cardiac index, stroke volume, left ventricular stroke work, and mean arterial pressure [10].A new index, modified shock index (MSI), is created by as the ratio of HR and mean arterial pressure (MAP). He noticed that SI uses only systolic blood pressure, but diastolic blood pressure (DBP) is also of undeniable importance when determining patient's clinical severity. Hence he incorporated diastolic blood pressure and developed the modified shock index (MSI) [16].
Subjects and MethodsThis study was carried prospectively and included 216 patients who presented to CCU of Cardiology department, Zagazig university hospitals with acute STEMI who were treated with PPCI (from 1/2014 until 8/2016), with A time window for doing PPCI of 12 hours from onset of maximum chest pain. Extended time window to 18 hours from onset of maximum chest pain was used for patients presented with cardiogenic shock. We excluded the patients who, received fibrinolytic therapy, presented more than 12 hours from the onset of chest pain except for whom presented with cardiogenic shock, died at ER or before doing PPCI and presented by acute hemorrhage, acute hypovolemia, severe sepsis, severe trauma, or suspicion of pulmonary embolism.Patients who met the inclusion criteria were subjected to thorough history taking, Physical examination with special emphasis on both Blood pressure and pulse that were measured accurately in the supine position with >2 readings were taken with 1 min interval, and averaged. Admission SI was calculated for every patient that equals (admission HR/ admission SBP). Modified Admission SI was calculated for every patient that equals (admission HR/ mean admission BP, here MBP= [(DBPx2) +SBP]/3). The optimal cut-off values of SI, and MSI were based on optimizing the sum of sensitivity and specificity by receiver operating characteristic curve analysis, which predicted inhospital major adverse cardiovascular events.The patients were divided into 4 groups: The TIMI risk score was calculated for each patient using the variables obtained at admission according to the published criteria [5]. Killip's classification, Chest examination: with emphasis on detecting pulmonary edema or presence of pulmonary congestion, Cardiac examination: with emphasis on detecting murmurs Volume 7 Issue 4 -2016