Background: A diagnosis of an old Inferior Wall Myocardial Infarction (IMI), on a routinely performed Electrocardiogram (ECG) often leads to further consultations and imaging studies.The aim of this study was to assess the predictive value of Q waves in inferior leads, alone or in combination with repolarization abnormalities, for the diagnosis of inferior wall myocardial infarction confirmed by imaging studies.Methods: Fifty-six patients, in whom computerized interpretation of the electrocardiogram resulted in the diagnosis of inferior wall myocardial infarction, and in whom imaging studies were also available, were included in this study. Electrocardiograms were performed using the GE MAC-HD 5500. Electrocardiograms were interpreted using the MUSE GE system. Echocardiograms and nuclear medicine cardiac imaging were performed and interpreted using standard equipment and techniques. S AS 9.3 software (SAS Institute, Inc., Cary, North Carolina) was used to calculate 95% exact binomial confidence intervals (CI) for the population PPVs.Results: Computerized interpretation of the ECGs leading to the diagnosis of old inferior wall myocardial infarction when compared with inferior wall myocardial infarction confirmed by imaging studies, had a positive predictive value of 52.78%. Adding the criteria of Q waves wider than 0.04 ms, using manual interpretation of ECG, increased the positive predictive value of the test to 80%. However, the presence of ST changes and/or negative or isoelectric T waves, in the presence of diagnostic Q waves in the inferior leads, increased the positive predictive value to 92%.Conclusions: These results suggest that the computerized interpretation of ECG results in a high rate of false positive readings of old inferior myocardial infarction. This may result in overutilization of imaging modalities. Presence of diagnostic Q waves in inferior leads, if accompanied by repolarization abnormalities, improves the accuracy of the electrocardiogram for the diagnosis of inferior wall myocardial infarction..

Background: Anticoagulation strategies used in peripheral percutaneous intervention (PPI) are based primarily on percutaneous coronary intervention. In these studies, relatively higher doses of heparin were used, usually in combination with a GP IIb/IIIa agent. There are no studies comparing PPIs done with low-dose heparin alone versus bivalirudin in PPI. We compared the efficacy and safety (i.e. bleeding complications) of low-dose heparin versus bivalirudin in PPI. Methods: We assessed prospectively 160 consecutive patients who underwent PPI from January through April 2008 during their index hospitalization for bleeding and thrombotic complications. Inclusion criteria included patients age >18 undergoing PPI for subclavian, renal or lower extremity arterial stenosis. Exclusion criteria included acute limb ischemia, use of fibrinolytic agents or GP IIb/IIIa antagonists, recent MI or CVA, and contraindication to heparin or bivalirudin. Out of 160 patients, 79 patients were dosed with heparin at 50 u/kg (goal ACT of 180 –225) and 81 patients were dosed with bivalirudin at 0.75 mcg/kg bolus followed by 1.75-mcg/kg infusion. Bivalirudin infusions were discontinued at the end of the procedure. Procedural success was defined as less than 30% post procedure residual stenosis. Major bleeding was defined as intracranial or retroperitoneal hemorrhage, or fall in Hgb ≥3 g/dl. All other bleeding was considered a minor bleed. In addition, anticoagulation cost analysis was conducted. Results: Procedural success in 100% and 96.2% patients (p=NS) (no patient suffered acute vessel occlusion or any intraprocedural thrombotic complications), major bleeding occurred in 0% and 3.7% patients (p=NS), minor bleeding occurred in 5.1% and 11% patients (p=NS), who received heparin and bivalirudin, respectively. There was no statistical difference in time to sheath removal, time-to-ambulation, and length of hospital stay. The average charge to patients for heparin was $66, whereas the charge for bivalirudin was $2727. Conclusion: Low-dose heparin is equally as safe and effective as bivalirudin in PPI. PPI with heparin is considerably more cost-effective than PPI with bivalirudin. Larger randomized studies are required to further evaluate this issue.