American heart journal
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American heart journal · Nov 2004
Randomized Controlled Trial Multicenter Study Clinical TrialElectrocardiographic findings in cardiogenic shock, risk prediction, and the effects of emergency revascularization: results from the SHOCK trial.
To evaluate electrocardiographic (ECG) parameters as predictors of 1-year mortality in patients developing cardiogenic shock after acute myocardial infarction (AMI), and to document associations between these ECG parameters and the survival benefit of emergency revascularization versus initial medical stabilization. ⋯ ECG parameters identified patients with cardiogenic shock who were at high risk. Emergency revascularization eliminated the incremental mortality risk associated with cardiogenic shock in patients with a prolonged QRS duration, or inferior AMI accompanied by precordial ST depression. Prospective assessments of the magnitude of the treatment effect based on ECG parameters are required.
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American heart journal · Nov 2004
Randomized Controlled Trial Clinical TrialAcute Catheterization and Urgent Intervention Triage strategY (ACUITY) trial: study design and rationale.
Patients with acute coronary syndromes (ACS; unstable angina and non-ST-segment elevation myocardial infarction) are at significant risk for death and myocardial infarction. Early angiography followed by revascularization is considered the treatment of choice for moderate- to high-risk patients with ACS. However, despite the integration of newer therapies including stents, glycoprotein IIb/IIIa inhibitors, and thienopyridines, the rate of adverse ischemic events still remains unacceptably high, and the intensive pharmacologic regimens used to stabilize the disrupted atherosclerotic plaque and support angioplasty and surgical revascularization procedures elicit a high rate of bleeding complications. Pilot trials suggest that the thrombin-specific anticoagulant bivalirudin may improve clinical outcomes in ACS. ⋯ The ACUITY trial is the largest study yet performed in patients with ACS undergoing an invasive strategy. In addition to evaluating the utility of bivalirudin in ACS, this study will also provide important guidance regarding the necessity for and timing of IIb/IIIa inhibitor administration.
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American heart journal · Nov 2004
Comparative Study Clinical TrialUtility of B-natriuretic peptide in the evaluation of left ventricular diastolic function: comparison with tissue Doppler imaging recordings.
Although Doppler echocardiography provides assessment of abnormal left ventricular (LV) diastolic filling dynamics, its inherent limitations suggest the need for additional measures of diastolic dysfunction. The ratio of mitral velocity to early diastolic velocity of the mitral annulus (E/E') derived from tissue Doppler imaging is associated with the mean LV end diastolic pressure (LVEDP). Because data suggest that B-natriuretic peptide (BNP) reflects ventricular pressure, we hypothesized that BNP levels correlate with indices of LV diastolic function by tissue Doppler imaging. ⋯ BNP levels correlate with the E/E' ratios from tissue Doppler imaging (r = 0.48) and can reliably provide estimation of LV filling pressures. Although BNP levels do not correlate well with E/E' ratios across the full spectrum of values, the combination of BNP levels along with E/E' ratios from tissue Doppler imaging may be a better predictor of elevated LV filling pressures in patients with suspected diastolic dysfunction.
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American heart journal · Nov 2004
Prognostic value of low-level cardiac troponin-I elevations in patients without definite acute coronary syndromes.
Low-level cardiac troponin-I (cTn-I) elevations predict adverse cardiovascular outcomes in patients with definite acute coronary syndromes (ACS), as defined by the presence of chest pain accompanied by ischemic electrocardiographic changes. However, their prognostic value in other clinical situations remains unclear. ⋯ Low-level cTn-I elevations identify a subset of patients at increased risk for future cardiovascular events, even when obtained outside the context of definite ACS or presentation with chest pain.
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American heart journal · Nov 2004
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialEffect of nesiritide (human b-type natriuretic peptide) and dobutamine on heart rate variability in decompensated heart failure.
Previous studies have suggested that natriuretic peptides may have direct sympathoinhibitory effects. Nesiritide (recombinant human B-type natriuretic peptide) has been recently approved for treatment of decompensated congestive heart failure (CHF). We sought to assess the effects of nesiritide compared with dobutamine on time-domain indices of heart rate variability (HRV) in patients with decompensated CHF. ⋯ Low-dose nesiritide therapy in patients with decompensated CHF improves indices of overall HRV and parasympathetic modulation, particularly if HRV is severely depressed at baseline. Dobutamine and possibly high-dose nesiritide can potentially lead to further deterioration of autonomic dysregulation.