Left ventricular systolic pressure-volume area (PVA) has been reported to be a reliable predictor of cardiac oxygen consumption rate per beat (VO2) in a given heart with a stable inotropic background. PVA is the specific area in the pressure-volume (PV) diagram, consisting of the area (EW) within the PV loop and the area (PE) bound by the end-systolic and end-diastolic PV lines and the relaxation segment of the PV loop. EW and PE correspond to the external mechanical work and the end-systolic elastic potential energy in the ventricular wall, respectively. We determined the optimal combination of EW and PE for the best prediction of VO2, using the linear multiple regression analysis. From EW, PE, and VO2, data of many isovolumic and ejecting contractions, the optimal coefficients of EW and PE were 1.67 +/- 0.43 (SD; 7 hearts) and 1.74 +/- 0.49 (10(-5) ml O2/mmHg . ml), virtually identical to each other, corroborating that PVA, i.e., a simple sum of EW and PE, can reliably predict VO2 of a given heart in a stable contractile state.

SUMMARY Left ventricular systolic pressure-volume area (PVA) has been found to be highly linearly correlated with cardiac oxygen consumption rate per beat (Voi) in a given canine heart with a stable inotropic background. PVA is a specific area in the pressure-volume (P-V) diagram that is bounded by the end-systolic and end-diastolic P-V relationship lines and the systolic segment of the P-V loop, consisting of the sum of external mechanical work and what Is considered the end-systolic elastic potential energy in the ventricular wall. In this study, we compared VOi's of steady state entirely isovolumic and variously ejecting contractions that were made to have equal PVA's in the canine left ventricle. We found that Voj's of these Isovolumic and ejecting contractions with equal PVA's (isovolumic vs. ejecting -1008 ± 64 (SB) vs. 1022 ± 62 mm Hg ml/beat, n = 32 pairs in 10 hearts) were equal to each other (0.0376 ± 0.0021 vs. 0.0368 ± 0.0021 ml Oi/beat) regardless of the marked differences in stroke volume (0 vs. 9.8 ± 0.6 ml), end-diastolic volume (20.3 ± 0.8 vs. 23.7 ± 0.9 ml), end-systolic volume (20.3 ± 0.8 vs. 13.9 ± 0.7 ml), peak pressure (123 ± 5 vs. 88 ± 5 mm Hg), stroke work (0 vs. 636 ± 36 mm Hg ml/beat), and calculated peak total wall force (1688 ± 77 vs. 1077 ± 72 g). Therefore, we conclude that PVA can serve as a reliable predictor of Vo» in a given canine left ventricle with a stable inotropic background whether the contraction mode is isovolumic or ejecting. Circ Res 49:1082-1091, 1981 MANY cardiodynamic variables and indices have been proposed as primary determinants of cardiac oxygen consumption (Braunwald et aL, 1976;Gibbs, 1978; Gibbs and Chapman, 1979). However, none of them alone or appropriately combined so far can consistently serve as a reliable predictor of cardiac oxygen consumption rate per beat (V02) under a variety of cardiac loading conditions. Even peak wall force of the ventricle, which has been widely accepted as the most important determinant of Vo 2 in a constant inotropic state, cannot uniquely predict V02 of a given contraction because its Vo 2 varies with ventricular ejection at a constant peak wall force (Coleman et al., 1969;Burns and Covell, 1972;Weber and Janicki, 1977).In search of a more reliable predictor of V02, our recent experiments on canine excised cross-circulated hearts have shown that Vo 2 is highly linearly correlated with the left ventricular systolic pressure volume area (PVA) (Suga, 1979;Khalafbeigui et al., 1979;Suga et al., 1981). PVA is a specific area in the pressure-volume (P-V) diagram that is bounded by the end-systolic and end-diastolic P-V relationship lines and the systolic segment of the P-V loop trajectory, as shown in Figure 1. PVA is therefore the sum of two areas; one for the external mechanical work and the other for what is considered the end-systolic elastic potential energy in the ventricular wall (Suga, 1979(Suga, ,1980. PVA can be considered total mechanical energy required for one contraction of the ventricle (Suga, 1979). However, the...

Objective: To determine the clinical features of 272 patients who were diagnosed with optic neuritis at an ophthalmological clinic in Japan. Methods: We reviewed the records of patients examined between January 1977 and late June 1999. Results: The ratio of women to men was 1.7 : 1. The mean age at onset was 35 years and 80.5% were unilateral. The most frequent complaint was a vision decrease in 82.4%. The disc appeared normal in 38.5%. The median visual acuity at onset was 0.1; it was 1.0 at the recovered stage. The mean time required for visual recovery was 92.3 days from the onset. The most common known cause of optic neuritis was multiple sclerosis (MS)(22.8%). The recurrence rate was 22.0% and the mean number of recurrences was 2.9. The time for the development of disc pallor was 124.8 days. Conclusions: We found no racial difference in the incidence of MS as has been reported between Caucasians and Japanese.

A 64-year-old man was transferred to our hospital because of acute heart failure associated with myocardial infarction. Echocardiography revealed severe mitral regurgitation due to total rupture of the posterior papillary muscle. Following the diagnosis of papillary muscle rupture, intraaortic balloon pumping support was started, and surgery was performed without coronary angiography because of cardiogenic shock and renal dysfunction. The posterior papillary muscle was completely ruptured, and the anterior leaflet of the mitral valve was severely prolapsed. Without resecting the posterior leaflet, mitral valve replacement was successfully performed using a St. Jude Medical® prosthetic valve. The postoperative course was uneventful except for ventricular tachyarrhythmia which occurred during the acute phase postoperatively. Postoperative coronary angiography demonstrated no significant coronary arterial stenosis. In a patient with cardiogenic shock due to papillary muscle rupture, immediate surgical intervention is recommended as soon as the diagnosis has been established by echocardiography.

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