Journal of the American College of Cardiology
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J. Am. Coll. Cardiol. · Jun 1994
Comparative StudyRelation between QT intervals and heart rates from 40 to 120 beats/min in rest electrocardiograms of men and a simple method to adjust QT interval values.
The aim of this study was to establish the relation between QT intervals and a wide range of rest heart rates in men. These data provided the basis of a simple method for adjusting the QT interval for heart rate. ⋯ The QT-RR relation over a wide range of heart rates does not permit the use of one simple adjustment equation. A nomogram providing, for every heart rate, the number of milliseconds that the QT interval must be corrected gives excellent adjustment.
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J. Am. Coll. Cardiol. · Jun 1994
Intermediate follow-up of pediatric heart transplant recipients with elevated pulmonary vascular resistance index.
This study examined perioperative and intermediate outcomes in pediatric cardiac transplant recipients who had elevated pulmonary vascular resistance indexes preoperatively. ⋯ Group I patients did not require significantly oversized donors, restricted donor locations or longer intensive care unit stays or have higher infection rates; however, arrhythmias were more frequent. Pulmonary resistance index normalized early after transplantation. Pulmonary vascular reactivity may be more important for survival than absolute resistance index.
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J. Am. Coll. Cardiol. · Jun 1994
Randomized Controlled Trial Clinical TrialEfficacy of spinal cord stimulation as adjuvant therapy for intractable angina pectoris: a prospective, randomized clinical study. Working Group on Neurocardiology.
In a prospective, randomized study with an 8-week follow-up period, we evaluated the efficacy of spinal cord stimulation on exercise capacity and quality of life in patients with intractable angina. ⋯ Spinal cord stimulation significantly improves exercise capacity and quality of life. On the basis of an increase in exercise capacity and rate-pressure product, the mechanism by which spinal cord stimulation acts may be related to improved oxygen supply to the heart combined with an analgesic effect.
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J. Am. Coll. Cardiol. · Jun 1994
Aminophylline fails to improve the outcome of cardiopulmonary resuscitation from prolonged ventricular fibrillation: a placebo-controlled, randomized, blinded experimental study.
The purpose of this study was to evaluate systematically the effects of the adenosine antagonist aminophylline on resuscitation outcome in a canine model of postcardioversion nonperfusing rhythm. ⋯ The results of this study suggest that aminophylline fails to improve the outcome of resuscitation from prolonged ventricular fibrillation. It does not reverse established electromechanical dissociation and may in fact increase the number of cardioversion applications required to terminate ventricular fibrillation. The rationale for conducting clinical trials with aminophylline during cardiopulmonary resuscitation is questionable.
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J. Am. Coll. Cardiol. · Jun 1994
Comparative StudyImproved hemodynamic function and mechanical efficiency in congestive heart failure with sodium dichloroacetate.
The purpose of this study was to determine whether sodium dichloroacetate improves hemodynamic performance and mechanical efficiency in congestive heart failure. ⋯ Dichloroacetate administration stimulates myocardial lactate consumption and improves left ventricular mechanical efficiency. Forward stroke volume and left ventricular minute work increase significantly, with a simultaneous reduction in myocardial oxygen consumption. Dobutamine administration results in similar hemodynamic improvements but with no change in left ventricular mechanical efficiency and with opposite effects on lactate metabolism. The opposing metabolic actions, yet similar hemodynamic responses, of dichloroacetate and dobutamine suggest that these agents may be complementary in the treatment of congestive heart failure.