HEART IMAGING WITH SINGLE PHOTON AGENTS

严重高血压Dahl品系大鼠，在充血性 心力衰竭，表现出脂肪酸摄取减少的焦点区， 左心室内膜和游离壁。 脂肪减少 酸摄取伴随着葡萄糖摄取的互补增加， 尽管灌注保持均匀。 这些观察表明，在 慢性压力超负荷、肥厚、心室、代谢 并且功能变化在时间上接近发生。 的观察结果 “功能失调”心肌在灌注时脂肪酸摄取减少 是统一的，表明测量区域脂肪酸摄取将是 可用作心肌收缩完整性的指标。 到 为了验证这一假设，我们建议对脂肪酸进行连续测量， 酸摄取、灌注、心室功能和心肌超微结构 在Dahl紧张大鼠中，由于严重的 高血压 当脂肪酸摄取变化的关系， 功能和形态的定义，两个药物干预研究将 在另外的大鼠组中进行。 第一项研究将测试 钙通道阻滞剂和β受体阻滞剂早期治疗的能力， 防止脂肪酸摄取和功能的下降。 第二项研究 将确定是否使用地高辛、钙通道阻滞剂或β-羟考酮治疗 在静息左心室射血分数达到 减少可以防止脂肪酸摄取的进一步恶化， 功能 在动物研究的同时，左心室患者 将通过平面和SPECT成像评价心室肥大， 脂肪酸分布、左室功能和灌注。

Severely hypertensive Dahl strain rats, in the early stages of congestive heart failure, demonstrated focal zones of reduced fatty acid uptake in their left ventricular endocardium and free wall. The decrease in fatty acid uptake was accompanied by a complimentary increase in glucose uptake, although perfusion remained uniform. These observations suggest that in the chronically pressure overloaded, hypertrophied, ventricle, metabolic and functional changes occur in temporal proximity. The observation that 'dysfunctional' myocardium has decreased fatty acid uptake while perfusion is uniform suggests that measurement of regional fatty acid uptake will be useful as an indicator of the contractile integrity of the myocardium. To test this hypothesis we propose to perform serial measurements of fatty acid uptake, perfusion, ventricular function and myocardial ultrastructure in Dahl strain rats with evolving myocardial hypertrophy due to severe hypertension. When the relationship of changes in fatty acid uptake, function and morphometry are defined, two drug intervention studies will be performed in additional groups of rats. The first study will test the ability of early therapy with calcium channel blockers and beta blockade to prevent the decrease of fatty acid uptake and function. The second study will determine if therapy with digoxin, calcium channel blockade, or beta blockade started after rest left ventricular ejection fraction has decreased can prevent further deterioration of fatty acid uptake and function. In parallel with the animal studies, patients with left ventricular hypertrophy will be evaluated by planar and SPECT imaging of the distribution of fatty acid, left ventricular function and perfusion.