This study assessed a new method of estimating the slope (Ees) of the end-systolic pressure-volume relation (ESPVR) from a single beat of the human heart. Left ventricular pressure was recorded with a high-fidelity micromanometer in patients with heart disease during left ventriculography. Peak isovolumic pressure at the end-disastolic volume was estimated by a curve-fitting technique from an isovolumic left ventricular pressure curve. The ESPVR line was drawn from the estimated peak isovolumic pressure-volume point tangential to the left upper corner of the pressure-volume loop. The slope of this estimated ESPVR line from single-beat analysis was compared with the slope of the ESPVR line obtained from three pressure-volume loops in 16 patients given angiotensin II or nitroglycerin infusion. The estimated Ees was 5.0 +/- 2.2 mm Hg/ml/m2, and the conventional Ees was 4.9 +/- 2.7 mm Hg/ml/m2. The estimated Ees showed a positive correlation with the conventional Ees (r = 0.91, p less than 0.001, SEE = 1.2 mm Hg/ml/m2). In the other 13 patients, after dobutamine infusion (5 micrograms/kg/min i.v.) the estimated Ees increased significantly from 5.6 +/- 1.4 to 7.4 +/- 2.0 mm Hg/ml/m2 (p less than 0.01). Thus, the estimated Ees approximated the conventional Ees and was sensitive to a positive inotropic intervention. We conclude that this single-beat analysis method facilitates assessment of the beat-by-beat ESPVR of the human heart.
Our data suggest that asymptomatic occlusive lesions in the carotid and intracranial arteries are fairly common in Japanese patients with IHD, although the degree of stenosis is relatively mild. Coexistence of carotid atherosclerosis should be suspected in IHD patients with severe coronary atherosclerosis, and the possibility of atherosclerosis in the intracranial arteries should be considered in aged IHD patients.
Ab initio calculations were performed for eight Claisen rearrangements, eqs 1-8. Transition-state (TS) structures of [3,3] sigmatropic rearrangements of reactions 1-4 are similar, but their activation energies (E(a)'s) are different, E(a)(1) < E(a)(2) and E(a)(3) < E(a)(4). From the intermediate of reaction 3, a hydrogen is moved intermolecularly to form the product, o-allyl phenol. The lower reactivities of reactions 2 and 4 relative to reactions 1 and 3 are ascribed to large endothermicities in the sigmatropic rearrangements, respectively. Chair-type transition states are more favorable than boat-type transition states in reactions 1-4. The allyl group is released from the in-plane C-X (X = O or N) sigma bond and is captured by the pi-type lone-pair electrons. The sulfur- and phosphorus-containing rearrangements, reactions 5-8, are computed to have smaller activation energies but are to be less exothermic than those of oxgyen- and nitrogen-containing rearrangements.
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