The American journal of cardiology
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Multicenter Study Comparative Study
Trends in hospitalization for the implantation of cardioverter-defibrillators in the United States, 1990-2005.
Implantable cardioverter-defibrillators were first approved for use in the United States in 1985. Their efficacy in improving the survival of patients at risk for sudden cardiac death has been shown, and the number of patients eligible for ICDs has increased. ⋯ The rate of ICD procedures was substantially greater in men than women, and the rate increased significantly with age, although there was no increase in ICD use in patients aged >or=75 years. In conclusion, as the list of clinical indications and insurance coverage for ICD use expand, continued surveillance to monitor trends in the use of ICDs is warranted.
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Variations in candidate genes participating in oxidative stress, inflammation, and their interactions are potentially associated with diseases of atherosclerotic origin. We investigated independent and joint associations of variations in cholesterol ester transfer protein (CETP), interleukin-8 (IL8), peroxisome proliferator activator receptor-alpha (PPARA), and Toll-like receptor 4 (TLR4) genes with incident nonfatal myocardial infarction (MI) or ischemic stroke. In a population-based case-control study, patients (848 with MI and 368 with ischemic stroke) and controls (2,682) were recruited from postmenopausal women and hypertensive men/women who were members of Group Health in western Washington State. ⋯ The minor allele of the PPARA SNP, rs4253623, was associated with a higher risk of MI (odds ratio 1.25, 95% confidence interval 1.08 to 1.46), whereas the minor allele of the TLR4 SNP, rs1927911, was associated with a lower risk of MI (odds ratio 0.88, 95% confidence interval 0.77 to 0.99). No within-gene or gene-gene interaction was associated with MI or ischemic stroke risk. In conclusion, potential SNP-disease associations identified in the present study are novel and need further investigation.
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Stress (takotsubo) cardiomyopathy (SC) is a recently recognized syndrome with clinical and electrocardiographic (ECG) presentation resembling ST elevation anterior myocardial infarction. As experience with this condition has evolved, a more diverse spectrum of 12-lead ECG patterns has emerged that may affect differential diagnosis. Fifty-nine consecutive patients with SC were prospectively identified at a large community-based cardiology practice. ⋯ During recovery, diffuse T-wave inversion evolved in 49 patients with SC (83%). In conclusion, patients with SC present with diverse ECG findings, and no single pattern alone can reliably distinguish this condition from acute coronary syndromes. The diagnosis of SC requires heightened awareness of its unique clinical profile as well as coronary arteriography and left ventriculography.
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Comparative Study
Impact of individual and cumulative coronary risk factors on coronary flow reserve assessed by dobutamine stress echocardiography.
Traditional cardiovascular risk factors have been shown to cause microvascular dysfunction. Most studies that have evaluated microcirculation rely on invasive measurement tools. We used dobutamine stress echocardiography, a validated method to measure coronary flow velocity (CFV) and coronary flow reserve (CFR), in a previously unstudied population without known significant coronary artery disease to determine the impact of traditional risk factors on CFR. ⋯ In conclusion, CFR was abnormal in patients with DM, hypertension, and obesity. CFR impairment is exaggerated as the number of risk factors increases. Despite a negative dobutamine stress echocardiographic result, aggressive risk factor assessment and control should be implemented in patients with coronary risk factors due to an underlying abnormal CFR.
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Multicenter Study Comparative Study
Usefulness of cardiac magnetic resonance imaging combined with low-dose dobutamine stress to detect an abnormal ventricular stress response in children and young adults after fontan operation at young age.
After Fontan operation, patients are limited in increasing cardiac output and in exercise capacity. This has been related to impaired preload or other factors leading to decreased global ventricular performance with stress. To study these factors, the stress responses of functionally univentricular hearts were assessed at rest and during low-dose dobutamine stress using cardiovascular magnetic resonance imaging. ⋯ At rest, dominant left ventricles had higher ejection fractions than dominant right ventricles (p = 0.01), but this difference disappeared with stress testing. In conclusion, a functionally univentricular heart after Fontan completion at young age has an adequate increase in ejection fraction with beta-adrenergic stimulation. However, as a result of impaired preload with stress, cardiac output can be increased only by increasing heart rate.