American heart journal
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American heart journal · Aug 2001
Randomized Controlled Trial Clinical TrialSafety and feasibility of a novel rate-smoothed ventricular pacing algorithm for atrial fibrillation.
This study was conducted to establish the safety and performance of a new rate-smoothing pacing algorithm for patients with atrial fibrillation (AF). ⋯ Long-term rate-smoothed pacing is feasible. Because of concerns about pacing-induced heart failure in some patients with rapid ventricular rates, rate-smoothed pacing should be reserved for those who remain symptomatic despite adequate control of the ventricular rate. The RSA may help to reduce symptoms in patients with medically refractory AF; more study is required to define its efficacy in reducing symptoms and morbidity in this population.
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American heart journal · Aug 2001
Randomized Controlled Trial Clinical TrialThe dual endothelin receptor antagonist tezosentan acutely improves hemodynamic parameters in patients with advanced heart failure.
Endothelin-1, a potent vasoconstrictor, is elevated in congestive heart failure and is postulated to play a major role in the pathogenesis of the disease. Endothelin receptor antagonism may be a specific therapeutic approach. This study was designed to determine the effective dosage range, hemodynamic effects, and tolerability of tezosentan, an intravenous dual endothelin receptor antagonist, in patients with advanced heart failure. ⋯ Tezosentan rapidly and dose dependently improved hemodynamics. The favorable effects on cardiac index and pulmonary and systemic vascular resistances without changes in heart rate may be beneficial in the treatment of acute heart failure.
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American heart journal · Aug 2001
Comparative efficacy of fibrinogen and platelet supplementation on the in vitro reversibility of competitive glycoprotein IIb/IIIa (alphaIIb/beta3) receptor-directed platelet inhibition.
Platelet surface glycoprotein (GP) IIb/IIIa (alphaIIb/beta(3)) receptor inhibition, by preventing fibrinogen binding and platelet aggregation, concomitantly attenuates arterial thrombotic capacity and impairs protective hemostasis, 2 divergent platelet-dependent processes. Because the currently available Food and Drug Administration-approved small molecule GP IIb/IIIa receptor antagonists are considered "competitive" inhibitors and because there is limited information on the reversibility of platelet inhibition by fibrinogen or platelet supplementation, the following series of in vitro experiments were performed. ⋯ The reversibility of GP IIb/IIIa-directed platelet inhibition is influenced by cell surface receptor availability and the intrinsic pharmacodynamic mechanism of action. Fibrinogen supplementation with fresh frozen plasma or cryoprecipitate either alone or in combination with platelet transfusion, represents an important and readily available treatment consideration for restoring hemostatic potential and managing major hemorrhagic complications associated with the administration of small molecule competitive GP IIb/IIIa receptor antagonists.
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American heart journal · Jul 2001
Comparative StudyExperimental pain and psychologic status of patients with chest pain with normal coronary arteries or ischemic heart disease.
The cause of chest pain in patients with a normal coronary angiogram (NCA) remains an enigma. Also, it is unclear whether psychosocial factors play a role in the etiology of chest pain in these patients. The objective of the current study was to compare psychosocial factors, clinical pain, and responses to experimental pain in NCA patients, patients with ischemic heart disease (IHD), and healthy control subjects. ⋯ The results suggest that higher scores on various psychosocial measures in both chest pain groups are related to their pain, rather than being the cause of pain, and do not support a psychogenic explanation for chest pain in the presence of normal coronary arteries.
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American heart journal · Jul 2001
Randomized Controlled Trial Clinical TrialMyoglobin levels at 12 hours identify patients at low risk for 30-day mortality after thrombolysis in acute myocardial infarction: a Thrombolysis in Myocardial Infarction 10B substudy.
We sought to identify, by use of serum cardiac markers, patients at low risk for 30-day mortality after ST-segment elevation myocardial infarction. ⋯ Serum cardiac markers can identify greater than two thirds of patients at low risk for 30-day mortality. A low 12-hour myoglobin level (< or = 239 ng/mL in this substudy) identifies such patients at low risk and could potentially assist in early risk stratification and triage after ST-segment elevation myocardial infarction.