Journal of the American College of Cardiology
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J. Am. Coll. Cardiol. · Jul 1995
Chiari's network: normal anatomic variant or risk factor for arterial embolic events?
This study was performed to assess the prevalence of Chiari's network in patients undergoing transesophageal echocardiography and to determine whether this anomaly is associated with other cardiac lesions or is characterized by typical clinical findings. ⋯ In patients undergoing transesophageal echocardiography, the prevalence of Chiari's network was 2%, which is consistent with autopsy studies. By maintaining an embryonic right atrial flow pattern into adult life and directing the blood from the inferior vena cava preferentially toward the interatrial septum, Chiari's network may favor persistence of a patent foramen ovale and formation of an atrial septal aneurysm and facilitate paradoxic embolism.
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Antithrombotic therapy is clearly beneficial in the treatment of acute myocardial infarction, but the optimal regimen is controversial. Treatment with aspirin leads to substantial and significant reductions in rates of mortality, reinfarction and stroke in patients with acute myocardial infarction, and the benefits are additive with those of thrombolytic therapy. It is unclear whether heparin confers additional net benefits over aspirin alone. ⋯ Existing data support the need for further large-scale trials of current and newer antithrombotic regimens in acute myocardial infarction to assess the balance of benefits and risks of these regimens compared with that for aspirin alone. In patients not receiving thrombolytic therapy, randomized trial data are currently insufficient to adequately compare the benefits and risks of adding heparin to aspirin alone. The First American Study of Infarct Survival (ASIS-1) will directly compare the balance of risks and benefits of aspirin alone, aspirin plus intravenous heparin and aspirin plus intravenous hirudin in patients with acute myocardial infarction not receiving thrombolytic therapy.
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J. Am. Coll. Cardiol. · Jun 1995
Comparative StudyIncidence and hemodynamic characteristics of near-fainting in healthy 6- to 16-year old subjects.
We studied the incidence and hemodynamic characteristics of near-fainting under orthostatic stress in healthy children and teenagers. ⋯ Inadequate vasoconstriction is the common underlying mechanism of near-fainting in young subjects. The remarkably high incidence of near-fainting during the tilt-up test after intravascular instrumentation raises serious doubts about the utility of this procedure in evaluating syncope of unknown origin in young subjects.
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J. Am. Coll. Cardiol. · May 1995
Transesophageal echocardiographically facilitated early cardioversion from atrial fibrillation using short-term anticoagulation: final results of a prospective 4.5-year study.
We sought to validate the safety of transesophageal echocardiographically guided early cardioversion in conjunction with short-term anticoagulation as a strategy for guiding early cardioversion in hospitalized patients with atrial fibrillation. ⋯ Compared with smaller series that have shown only feasibility, this large prospective and consecutive study of patients undergoing transesophageal echocardiographically facilitated early cardioversion in conjunction with short-term anticoagulation validates the safety of this strategy. This treatment algorithm has a safety profile similar to conventional therapy and minimizes both the period of anticoagulation and the overall duration of atrial fibrillation.
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J. Am. Coll. Cardiol. · May 1995
Randomized Controlled Trial Clinical TrialPhysical training in patients with stable chronic heart failure: effects on cardiorespiratory fitness and ultrastructural abnormalities of leg muscles.
The present study was designed to evaluate the effect of an ambulatory training program on ultrastructural morphology and the oxidative capacity of skeletal muscle and its relation to central and peripheral hemodynamic variables in patients with chronic heart failure. ⋯ Regular physical training increases maximal exercise tolerance and delays anaerobic metabolism during submaximal exercise in patients with stable chronic heart failure. Improved functional capacity is closely linked to an exercise-induced increase in the oxidative capacity of skeletal muscle.