The American journal of cardiology
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Reduced heart rate variability (HRV) and increased C-reactive protein (CRP) levels are both predictors of coronary artery disease and correlate with each other. We examined whether these 2 phenotypes share a common genetic substrate and investigated the relations of the CRP gene polymorphisms with both CRP levels and HRV indexes. We examined 236 male twins free of symptomatic coronary artery disease, with a mean age +/- SD of 54 +/- 2.9 years. ⋯ One CRP single nucleotide polymorphism (rs1205) was significantly associated with both CRP (p = 0.003) and ultra-low-frequency power (p = 0.005) and explained 11% of the genetic covariance between them. In conclusion, reduced HRV correlates significantly with increased CRP plasma levels and this correlation is due, in large part, to common genetic influences. A polymorphism in the CRP gene contributes to both CRP levels and HRV.
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Comparative Study
Usefulness of fragmented QRS on a 12-lead electrocardiogram in acute coronary syndrome for predicting mortality.
Electrocardiographic signs of a non-ST elevation myocardial infarction (NSTEMI) are nonspecific, and therefore the diagnosis of NSTEMI during acute coronary syndromes (ACS) depends mainly on cardiac biomarker levels. Fragmented QRS (fQRS) represents myocardial conduction abnormalities due to myocardial infarction (MI) scars in patients with coronary artery disease. However, the time of appearance of fQRS during ACS has not been investigated. ⋯ Fragmented QRS, T-wave inversion, and ST depression were independent predictors of mortality during a mean follow-up period of 34 +/- 16 months. In conclusion, fQRS on 12-lead electrocardiography is a moderately sensitive but highly specific sign for ST elevation MI and NSTEMI. Fragmented QRS is an independent predictor of mortality in patients with ACS.
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Accelerated idioventricular rhythm (AIVR) has been considered a marker of successful reperfusion in fibrinolytic-treated patients. Evidence is limited regarding its significance in patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention (PPCI). The purpose of the present study was to determine the prevalence and associated outcomes of arrhythmias and conduction disturbances occurring during PPCI. ⋯ Patients with AIVR less often achieved spontaneous ST resolution before PPCI (13% vs 36%, p <0.001), less often had Thrombolysis In Myocardial Infarction flow 3 on admission (3% vs 33%, p <0.001), had a larger area at risk (35% vs 23% of the left ventricle, p <0.001), had a longer time to complete ST resolution (39 vs 21 minutes, p <0.001), had a larger FIS (13% vs 5% of the left ventricle, p <0.001) but had similar mortality (8.6% and 6.5%, p = 0.39) compared to patients without AIVR. In conclusion, AIVR is the most frequent arrhythmia occurring during PPCI in patients with ST-elevation myocardial infarction. However, it is not a marker of successful reperfusion but is associated with extensive myocardial damage and delayed microvascular reperfusion.
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Comparative Study
Comparison of the value of coronary calcium detection to computed tomographic angiography and exercise testing in patients with chest pain.
The aim of this study was to investigate the value of coronary calcium detection by computed tomography compared to computed tomographic angiography (CTA) and exercise testing to detect obstructive coronary artery disease (CAD) in patients with stable chest pain. A total of 471 consecutive patients with new stable chest complaints were scheduled to undergo dual-source multislice computed tomography (Siemens, Germany; coronary calcium score [CCS] and coronary CTA) and exercise electrocardiography (XECG). Clinically driven invasive quantitative angiography was performed in 98 patients. ⋯ In patients with diagnostic results for all tests, the sensitivity and specificity to detect >50% quantitative angiographic diameter stenosis were 100% and 15% for CCS >0, 82% and 64% for CCS >100, 97% and 36% for CTA, and 70% and 76% for XECG, respectively. In conclusion, nonenhanced computed tomography for calcium detection is a reliable means to exclude obstructive CAD in stable, symptomatic patients. Contrast-enhanced CTA can exclude significant CAD in patients with a low-intermediate CCS but is of limited value in patients with a high CCS.