Circulation
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Randomized Controlled Trial Comparative Study Clinical Trial
Significance of arrhythmias during the first 24 hours of acute myocardial infarction treated with alteplase and effect of early administration of a beta-blocker or a bradycardiac agent on their incidence.
Although early intravenous beta-blocker therapy during acute myocardial infarction (AMI) reduces the incidence of fatal arrhythmias in patients not treated with thrombolytic agents, its antiarrhythmic effect in thrombolysed patients remains controversial. We investigated prospectively the arrhythmia incidence in 244 patients with AMI receiving alteplase and a double-blind randomized adjunctive therapy with intravenous atenolol, alinidine, or placebo. Moreover, the characteristics and prognostic significance of early arrhythmias and their relation with infarct size and coronary patency were evaluated. ⋯ (1) Our data do not support the hypothesis that beta-blockers or bradycardiac agents might reduce the incidence of major arrhythmias when used in conjunction with thrombolytic therapy. (2) The pathogeneses of VT and VF early during AMI are clearly distinct. (3) VT or VF during the first 2 weeks is a marker for a larger infarct. (4) We could not detect a relation between malignant arrhythmias on day 1 and recurrences within the following 2 weeks.
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Randomized Controlled Trial Comparative Study Clinical Trial
Diagnostic and prognostic value of dipyridamole echocardiography in patients with suspected coronary artery disease. Comparison with exercise electrocardiography.
Before any new diagnostic test is accepted in clinical practice, such a test should be compared with established diagnostic tools in an appropriately large series of patients encompassing the complete spectrum of challenges to which the test is exposed. The aim of the present study was to assess the relative diagnostic and prognostic accuracies of high-dose dipyridamole echocardiography (two-dimensional echocardiographic monitoring during dipyridamole infusion up to 0.84 mg/kg over 10 hours) versus maximal symptom-limited bicycle exercise ECG test in patients with angina. ⋯ In patients with no previous myocardial infarction and good resting left ventricular function, compared with exercise ECG, dipyridamole echocardiography has a similar sensitivity and a higher specificity for the noninvasive detection of angiographically assessed coronary artery disease. Dipyridamole echocardiography also provides information in addition to that provided by exercise ECG for predicting death, infarction, and all events when the presence as well as the timing, severity, and extension of dipyridamole-induced wall motion abnormalities are considered.
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Recurrent sustained ventricular tachycardia (VT) is not responsive to antiarrhythmic drugs in the majority of patients, who therefore need therapy with nonpharmacological methods. We evaluated prospectively the feasibility, safety, and efficacy of transcatheter radiofrequency (RF) ablation of VT in 21 selected patients with ischemic heart disease and VT. ⋯ Transcatheter RF ablation is feasible but has only moderately high efficacy in a small, selected group of patients with ischemic heart disease and drug-refractory, highly frequent, hemodynamically tolerated, sustained VT. In the majority of the patients, this treatment technique is palliative rather than definitive, and many of the patients continue to require other methods of antiarrhythmic therapy.
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The outcome of the Fontan operation largely depends on the selection of patients because this procedure is a physiological correction. Among the several selection criteria for the Fontan operation, the importance of adequate size of the pulmonary artery remains controversial. In this series, in order to clarify whether the pulmonary artery size is indispensable or not as one of the selection criteria for the Fontan operation, we considered the physiological meaning of pulmonary artery size and investigated how it influenced postoperative hemodynamics of the Fontan operation. ⋯ The smaller pulmonary artery size causes more disadvantageous hemodynamics after the Fontan operation, with resultant effects of the rise in pCVP and the increase in afterload to the single ventricle.