Pfeffer M A, Pfeffer J M, Frohlich E D
Circ Res. 1976 May;38(5):423-9. doi: 10.1161/01.res.38.5.423.
Cardiac pumping ability was assessed during the natural development of left ventricular hypertrophy by elevating venous pressure by infusing Tyrode's solution intravenously to produce peak cardiac output. This experiment was performed on spontaneously hypertensive rats (SHR) of three age groups (11, 24, and 83 weeks). From 11 to 24 weeks, peak cardiac output of SHR increased in direct proportion to the abnormally increased ventricular mass; Thus peak cardiac output per gram of left ventricle (LV) remained stable. Similar results were obtained for two strains of normotensive rats at each of the same three age groups. Thus, in the normotensive animal peak cardiac output per gram of LV remained stable over a wide range of ages and varying left ventricular weights. However, with progressive elevation of arterial pressure in aging SHR (83 weeks), we observed severe ventricular hypertrophy (100% increases in left ventricular to body weight ratio). In this oldest SHR group, unlike age-matched normotensive rats, there was a marked reduction in the pumping ability per gram of LV. Thus, during the natural development of left ventricular hypertrophy SHR demonstrated both a stable stage of hypertrophy in which the increased left ventricular mass maintained its pumping ability, and a later stage of deterioration in which there was a loss of the normal relationship between ventricular mass and pumping ability.
通过静脉输注台氏液升高静脉压以产生心输出量峰值，从而在左心室肥厚的自然发展过程中评估心脏泵血能力。该实验在三个年龄组（11周、24周和83周）的自发性高血压大鼠（SHR）上进行。从11周到24周，SHR的心输出量峰值与异常增加的心室质量成正比增加；因此，每克左心室（LV）的心输出量峰值保持稳定。在相同的三个年龄组中的每一组，两种正常血压大鼠品系也得到了类似结果。因此，在正常血压动物中，每克LV的心输出量峰值在很宽的年龄范围和不同的左心室重量情况下都保持稳定。然而，在衰老的SHR（83周）中，随着动脉压的逐渐升高，我们观察到严重的心室肥厚（左心室与体重比增加100%）。在这个最老的SHR组中，与年龄匹配的正常血压大鼠不同，每克LV的泵血能力明显降低。因此，在左心室肥厚的自然发展过程中，SHR既表现出一个肥厚的稳定阶段，即增加的左心室质量维持其泵血能力，也表现出一个后期的恶化阶段，即心室质量与泵血能力之间的正常关系丧失。
