Journal of the American College of Cardiology
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J. Am. Coll. Cardiol. · Jan 2003
Randomized Controlled Trial Clinical TrialAcute systemic inflammation enhances endothelium-dependent tissue plasminogen activator release in men.
The purpose of this study was to investigate in vivo the effects of acute systemic inflammation on the endogenous fibrinolytic capacity in men. ⋯ Our results showed that acute systemic inflammation augmented local forearm t-PA release in men, which suggests that acute inflammation may invoke a protective response by enhancing the acute endogenous fibrinolytic capacity in healthy men. Further studies are needed to clarify whether this response is impaired in patients with cardiovascular disease.
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J. Am. Coll. Cardiol. · Jan 2003
Clinical TrialAblation of electrograms with an isolated, delayed component as treatment of unmappable monomorphic ventricular tachycardias in patients with structural heart disease.
We sought to evaluate the feasibility of identifying and ablating the substrate of unmappable ventricular tachycardia (VT). ⋯ Electrograms with IDCs related to clinical VT can be identified in the majority of patients during RVA pacing. Radiofrequency ablation of E-IDC seems effective in controlling unmappable VT.
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J. Am. Coll. Cardiol. · Jan 2003
Upper and lower limits of vulnerability to sudden arrhythmic death with chest-wall impact (commotio cordis).
In an animal model of commotio cordis, sudden death with chest-wall impact, we sought to systematically evaluate the importance of impact velocity in the generation of ventricular fibrillation (VF) with baseball chest-wall impact. ⋯ The energy of impact is an important variable in the generation of VF with chest-wall impacts. Impacts at 40 mph were more likely to produce VF than impacts with greater or lesser velocities, suggesting that the predilection for commotio cordis is related in a complex manner to the precise velocity of chest-wall impact.
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J. Am. Coll. Cardiol. · Jan 2003
Mechanism of syncope in patients with positive adenosine triphosphate tests.
We prospectively evaluated the mechanism of syncope in patients with positive adenosine triphosphate (ATP) tests (defined as the induction of atrioventricular [AV] block with a ventricular pause >/=6 s after an intravenous bolus of 20 mg ATP). ⋯ In patients with adenosine-sensitive syncope, the mechanism of syncope is heterogeneous, although bradycardia is the most frequent finding. Adenosine triphosphate-induced AV block predicts AV block as the mechanism of spontaneous syncope in only a few tilt-negative patients.
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J. Am. Coll. Cardiol. · Dec 2002
ReviewCardiac troponins in renal insufficiency: review and clinical implications.
Patients with renal insufficiency may have increased serum troponins even in the absence of clinically suspected acute myocardial ischemia. While cardiovascular disease is the most common cause of death in patients with renal failure, we are just beginning to understand the clinical meaning of serum troponin elevations. Serum troponin T is increased more frequently than troponin I in patients with renal failure, leading clinicians to question its specificity for the diagnosis of myocardial infarction. ⋯ Despite persistent uncertainty about the mechanism of elevated serum troponins in patients with reduced renal function, data from smaller groups of renal failure patients have suggested that troponin elevations are associated with added risk, including an increase in mortality. It is possible that increases in serum troponin from baseline in patients with renal insufficiency admitted to hospital with acute coronary syndrome may signify myocardial necrosis. Further studies are needed to clarify this hypothesis.