The American journal of cardiology
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The incorporation of antitachycardia pacing (ATP) into implantable cardioverter defibrillators (ICDs) has provided a better tolerated alternative to shocks. ATP has been shown to be effective in terminating approximately 80% to 90% of spontaneous ventricular tachycardia (VT) episodes. Although ATP is routinely used, little is known about predictors of ATP failure. ⋯ A faster heart rate immediately preceding the onset of VT (103 +/- 19 vs 78 +/- 14 beats/min, respectively, hazard ratio 4.08, 95% confidence interval 2.11 to 7.89, p <0.001), and absence of beta-blocker therapy (82% vs 93%, respectively, hazard ratio 2.71, 95% confidence interval 1.72 to 4.29, p = 0.02) were found, by Cox proportional-hazard analysis, to be the sole independent predictors of ATP ineffectiveness in ICD recipients. Thus, the present study identified both preceding sinus tachycardia (reflecting an increased sympathetic tone) and lack of beta-blocker use as independent risk factors for reduced success of ATP therapy in terminating VT. Therefore, modification of sympathetic tone may be beneficial for patients with ICDs.
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Comparative Study
Value of definitive diagnostic testing in the evaluation of patients presenting to the emergency department with chest pain.
The optimal diagnostic evaluation of patients presenting to the emergency department (ED) with chest pain but without myocardial infarction or unstable angina is controversial. We performed a prospective, nonrandomized, observational study of 1,195 consecutive patients presenting to the ED with chest pain but who had normal or nondiagnostic electrocardiograms and negative cardiac biomarkers. Patients (mean +/- SD age 61 +/- 15 years; 55% women) were admitted to the hospital and a standard protocol for evaluation and treatment was suggested. ⋯ During the 3-month follow-up period, patients with a normal stress perfusion study during their index hospitalization had fewer return visits (4%) compared with patients with abnormal perfusion studies (19%), those who underwent catheterization directly (16%), or patients with no initial diagnostic evaluation (15%) (p <0.001). In addition, patients who had a diagnostic evaluation during their index hospitalization had a lower incidence of either acute myocardial infarction (0.9% vs 2.1%) or death (0.4% vs 3.0%, p <0.001) in the 3-month follow-up period. Accordingly, we strongly advocate provocative stress MPI early after presentation for chest pain in all patients with risk factors for coronary artery disease.
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Comparative Study
Relation of mortality of primary angioplasty during acute myocardial infarction to door-to-Thrombolysis In Myocardial Infarction (TIMI) time.
For primary angioplasty of acute myocardial infarction (AMI), the relation of treatment benefit and time has been debated. The present study aimed to evaluate, in a single-center cohort of patients with ST-segment elevation AMI, which time intervals were carefully and consistently measured, and the relations among ischemic time, in-hospital delays, and in-hospital survival. We included 499 patients (mean age 59 years; 80% men) who underwent successful primary percutaneous transluminal coronary angioplasty (PTCA) for AMI admitted < or =6 hours after symptom onset. ⋯ The in-hospital mortality rate was 3.2%. There was no significant relation between the various tertiles of time intervals and in-hospital mortality. After linear logistic regression, only age (odds ratio [OR] 1.79 per 10 years), female gender (OR 3.56), and door-to-TIMI 3 time (OR 1.27 per 15 minutes) were independently correlated with in-hospital mortality.