Does silent myocardial infarction add prognostic value in ST-elevation myocardial infarction patients without a history of prior myocardial infarction? Insights from the Assessment of Pexelizumab in Acute Myocardial Infarction (APEX-AMI) Trial

Electrocardiographic identification of prior myocardial infarction during right ventricular pacing--effect of septal versus apical pacing

BACKGROUND

Electrocardiographic (ECG) identification of prior myocardial infarction (MI) during right ventricular (RV) pacing is of clinical importance. Proposed ECG criteria have been evaluated only during apical pacing. We evaluated the effect of pacing site on the predictive performance of ECG signs of prior MI.

METHODS

The present study is a secondary analysis of a prospective, multicenter study which randomized recipients of an implantable cardioverter defibrillator to an apical versus septal RV lead positioning. ECGs of patients with or without prior MI were analyzed for the presence of the following criteria: Cabrera sign, Chapman sign, QR pattern in leads I, aVL, V5 or V6, QR in inferior leads and notching in the descending slope of the QRS complex in inferior leads.

RESULTS

The MI group included 89 patients (55.1% apically paced), while 99 patients had no prior MI (50.5% apically paced). In the total population, the Cabrera sign presented the highest specificity (97%) and diagnostic accuracy (62.2%), with a sensitivity of 23.6%. The Cabrera sign was the only significant predictor of a prior MI [OR=9.9, (95%CI:2.8-34.5), p<0.001], among all ECG markers. Pacing site did not significantly influence the sensitivity and specificity of the Cabrera sign for detection of prior MI.

CONCLUSIONS

In our study, the Cabrera sign was the only ECG marker that predicted the presence of prior MI during ventricular paced rhythm. Septal RV lead positioning did not affect the predictive performance of the Cabrera sign.

Anticoagulation in patients with dilated cardiomyopathy, low ejection fraction, and sinus rhythm: back to the drawing board

Heart failure patients present an important thrombo-embolic risk, including symptomatic or silent peripheral arterial embolism, pulmonary embolism, and stroke. Patients in sinus rhythm who have concomitant depressed (< 35%) left ventricular ejection fraction have a 4% rate of embolic events. Several prospective randomized trials of anticoagulation in this group of patients were either underpowered or had a short period of follow-up. Even though in two studies warfarin had a slight advantage over aspirin (in the WATCH and WARCEF trials), it was at the cost of an increased risk in major hemorrhage. To decrease bleeding rates and to improve anticoagulant effect, new treatment strategies have to be tested. Novel anticoagulants (dabigatran, rivaroxaban, and apixaban) seem to be a promising alternative.