Geometric changes allow normal ejection fraction despite depressed myocardial shortening in hypertensive left ventricular hypertrophy.

OBJECTIVES: This study of hypertensive left ventricular hypertrophy 1) assessed myocardial shortening in both the circumferential and long-axis planes, and 2) investigated the relation between geometry and systolic function. BACKGROUND: In hypertensive left ventricular hypertrophy, whole-heart studies have suggested normal systolic function on the basis of ejection fraction-systolic stress relations. By contrast, isolated muscle data show that contractility is depressed. It occurred to use that this discrepancy could be related to geometric factors (relative wall thickness). METHODS: We studied 43 patients with hypertensive left ventricular hypertrophy and normal ejection fraction (mean +/- SD 69 +/- 13%) and 50 clinically normal subjects. By echocardiography, percent myocardial shortening was measured in two orthogonal planes; circumferential shortening was measured at the endocardium and at the midwall, and long-axis shortening was derived from mitral annular motion (apical four-chamber view). Circumferential shortening was related to end-systolic circumferential stress and long-axis shortening to meridional stress. RESULTS: Endocardial circumferential shortening was higher than normal (42 +/- 10% vs. 37 +/- 5%, p < 0.01) and midwall circumferential shortening lower than normal in the left ventricular hypertrophy group (18 +/- 3% vs. 21 +/- 3%, p < 0.01). Differences between endocardial and midwall circumferential shortening are directly related to differences in relative wall thickness. Long-axis shortening was also depressed in the left ventricular hypertrophy group (18 +/- 6% in the left ventricular hypertrophy group, 21 +/- 5% in control subjects, p < 0.05). Midwall circumferential shortening and end-systolic circumferential stress relations in the normal group showed the expected inverse relation; those for approximately 33% of the left ventricular hypertrophy group were > 2 SD of normal relations, indicating depressed myocardial function. There was no significant relation between long-axis shortening and meridional stress, indicating that factors other than afterload influence shortening in this plane. CONCLUSIONS: High relative wall thickness allows preserved ejection fraction and normal circumferential shortening at the endocardium despite depressed myocardial shortening in two orthogonal planes.

Cyclopentenylcytosine. A carbocyclic nucleoside with antitumor and antiviral properties.

Cyclopentenylcytosine (CPE-C, 2), a pyrimidine analogue of the fermentation derived carbocyclic nucleoside neplanocin A, has been synthesized from the optically active cyclopentenylamine 3b by two synthetic routes. CPE-C demonstrates significant antitumor activity against both the sensitive and ara-C resistant lines of L1210 leukemia in vivo. Multiple long term survivors are produced in both tumor models. The compound also gives 100% growth inhibition of the solid human A549 lung and MX-1 mammary tumor xenografts grown in athymic mice. Good activity is also observed against a third human tumor xenograft model, metastatic LOX melanoma. CPE-C has significant activity against both DNA and RNA viruses in vitro. Potent activity is observed against HSV-1 (TK+ and TK-), HSV-2, vaccinia, cytomegalovirus, and varicella-zoster virus. Good activity is also found against a strain of influenza virus (Hong Kong flu), vesicular stomatitis virus, Japanese encephalitis virus, and Punta Toro virus.