Journal of the American College of Cardiology
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J. Am. Coll. Cardiol. · Mar 1993
Response of the interatrial septum to transatrial pressure gradients and its potential for predicting pulmonary capillary wedge pressure: an intraoperative study using transesophageal echocardiography in patients during mechanical ventilation.
We hypothesized that the directional movement of the interatrial septum and its curvature may reflect the pressure relations between the left and right atria. ⋯ These findings suggest that overall interatrial septum shape depends on the pressure gradient between the left and right atria. Midsystolic reversal of the interatrial septum, which probably reflects the increased venous return in the right relative to the left atrium during mechanical expiration, may be a useful indicator of the pulmonary capillary wedge pressure.
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J. Am. Coll. Cardiol. · Mar 1993
Comparative StudyMeasurements of cardiac output by impedance cardiography in pacemaker patients at rest: effects of various atrioventricular delays.
The purpose of this study was to evaluate the ability of impedance cardiography to determine the change in cardiac output caused by modifications in the atrioventricular (AV) delay in DDD (dual-chamber) pacing mode while pacing the atrium and ventricle at different programmed rates. ⋯ 1) Impedance cardiography allows highly reproducible noninvasive assessments of cardiac output in pacemaker patients; 2) inappropriate programming of the AV interval in patients with atrial and ventricular pacing can decrease cardiac output significantly, and the extent of the decrease is similar to or less than that observed in ventricular pacing; 3) hemodynamic measurements obtained with impedance cardiography can facilitate optimal programming of pacemaker variables.
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J. Am. Coll. Cardiol. · Mar 1993
Pulmonary and peripheral vascular factors are important determinants of peak exercise oxygen uptake in patients with heart failure.
This study was conducted to determine the relations among exercise capacity and pulmonary, peripheral vascular, cardiac and neurohormonal factors in patients with chronic heart failure. ⋯ In comparison with rest indexes of cardiac performance, measures of pulmonary function and peripheral vasodilator capacity were more closely associated with peak exercise oxygen uptake in patients with heart failure. Furthermore, the associations were independent of each other and together accounted for 50% of the variance in peak oxygen uptake. These data suggest that pulmonary and peripheral vascular adaptations may be important determinants of exercise intolerance in heart failure.
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J. Am. Coll. Cardiol. · Mar 1993
Which subgroup of patients with dilated cardiomyopathy would benefit from long-term beta-blocker therapy? A histologic viewpoint.
The purpose of this study was to elucidate whether the effectiveness of long-term beta-blocker therapy could be predicted before this therapy is started. ⋯ The extent and type of fibrosis may be important factors in the prediction of the effectiveness of long-term beta-blocker therapy for dilated cardiomyopathy.