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To evaluate differences in left ventricular structural changes related to different hemodynamic patterns. DESIGN: One-kidney, one clip (1K1C; volume-dependent hypertension) rats were two-kidney, one clip (2K1C; high-resistance hypertension) to determine whether these two types of Goldblatt rats showed different types of left ventricular adaptation. METHODS: M-mode echocardiography was used to study 28 2K1C and 19 1K1C Wistar rats 8 weeks after surgery and 55 age-matched control animals. RESULTS: Systolic blood pressure was equally high in the two models; the 1K1C rats had a larger left ventricular chamber and normal plasma renin activity (PRA), whereas in the 2K1C rats PRA was increased and the left ventricular chamber was normal. The atrial natriuretic factor was significantly increased only in the 2K1C rats and was related to PRA. The left ventricular mass index was increased in both models, but more in the 1K1C than the 2K1C rats. CONCLUSIONS: In both models the degree of left ventricular hypertrophy was associated with the interacting effects of the hemodynamic component superimposed on the primary hemodynamic pattern (i.e. blood pressure as an expression of pressure overload in the primarily volume-dependent 1K1C rats and the left ventricular chamber size as an expression of volume overload in the high-resistance 2K1C rats). The interaction between pressure and volume increased the left ventricular wall thickness in both models, with additional chamber enlargement in the 1K1C rats. In these rats, the increase in left ventricular mass was more pronounced due to the greater volume load on the heart.

A group of normotensive obese subjects (group A), a group of hypertensive obese subjects (group B) and a group of control subjects (group C) were submitted to radionuclide ventriculography using 99mTc to investigate cardiac function and haemodynamic situation in the presence of an increased preload (group A), preload and afterload (group B). Results show a significant reduction in ejection fraction and systolic blood pressure/end systolic volume in group A. Group B shows better cardiac function probably for the presence of cardiac concentric hypertrophy. Left ventricle work either in a minute and for each beat is greatest in patients of group B. Thus the simultaneous presence of obesity and hypertension can cause a worse prognosis in such patients for cardiac ischaemia and/or sudden death.