Journal of the American College of Cardiology
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J. Am. Coll. Cardiol. · Jan 1994
Effect of thrombolysis on heart rate variability and life-threatening ventricular arrhythmias in survivors of acute myocardial infarction.
The aim of the present study was to determine the influence of early thrombolysis on ventricular tachyarrhythmias (clinical and inducible) and heart rate variability in survivors of myocardial infarction at high risk for life-threatening ventricular arrhythmias. ⋯ After myocardial infarction, in high risk patients, thrombolysis significantly reduced the occurrence of arrhythmic events independently of left ventricular function. This effect may be related to both an improvement in electrical heart stability, as elucidated by electrophysiologic study, and a favorable action on the cardiac sympathovagal balance.
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J. Am. Coll. Cardiol. · Jan 1994
Assessment of left ventricular performance by on-line pressure-area relations using echocardiographic automated border detection.
The purpose of this study was to evaluate left ventricular performance by on-line pressure-area relations using echocardiographic automated border detection in the in situ canine heart in a manner similar to pressure-volume analyses. ⋯ On-line pressure-area relations are a potentially useful means to assess left ventricular performance in a manner that is quantitatively similar to the predicted responses of pressure-volume relations.
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J. Am. Coll. Cardiol. · Jan 1994
Short-term effects of naloxone on hemodynamics and baroreflex function in conscious dogs with pacing-induced congestive heart failure.
The purpose of this study was to determine the effects of naloxone on systemic hemodynamics and reflex function in dogs with congestive heart failure induced by rapid pacing. ⋯ The increase in basal plasma beta-endorphin suggests that the endogenous opiate system is activated in left-sided congestive heart failure. Because naloxone improves the systemic hemodynamics and myocardial contractile function under this condition, the endogenous opioids appear to play an important role in mediating the myocardial depression that occurs in heart failure. However, the endogenous opiate system has no apparent effect on the regulation of baroreflex control in heart failure induced by rapid pacing.
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J. Am. Coll. Cardiol. · Dec 1993
Randomized Controlled Trial Comparative Study Clinical TrialFemoral vein delivery of contrast medium enhances transthoracic echocardiographic detection of patent foramen ovale.
We postulated that femoral vein delivery of contrast medium because of streaming, might enhance precordial echocardiographic detection of patent foramen ovale. ⋯ Femoral vein contrast delivery significantly enhances the ability of precordial contrast echocardiography to diagnose patent foramen ovale. Physiologic patency of the foramen ovale is more common (prevalence 33%) than previously documented.
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J. Am. Coll. Cardiol. · Dec 1993
Echocardiographic predictors of left ventricular outflow tract obstruction after repair of interrupted aortic arch.
This study was designed to identify preoperative echocardiographic predictors of left ventricular outflow tract obstruction after repair of interrupted aortic arch and ventricular septal defect closure. ⋯ The preoperatively measured cross-sectional area of the left ventricular outflow tract is significantly smaller in patients with interrupted aortic arch who develop subaortic obstruction postoperatively, with a left ventricular outflow tract area < or = 0.7 cm2/m2 being a sensitive predictor. Aortic arch anatomy (i.e., type of interrupted aortic arch and presence of aberrant right subclavian artery) is also predictive of postoperative left ventricular outflow tract obstruction, possibly by influencing the volume of blood flow across the left ventricular outflow tract. These data should enable preoperative identification of infants who may require surgical relief of subaortic stenosis.