HEART IMAGING WITH SINGLE PHOTON AGENTS

重度高血压Dahl品系大鼠，充血性早期 心力衰竭，表现为脂肪酸摄取减少的焦点区域 他们的左室内膜和游离壁。脂肪的减少 酸摄取伴随着葡萄糖摄取的增加， 尽管血流灌注率保持一致。这些观察表明，在 慢性压力超负荷、肥厚、心室、代谢 而功能变化发生在时间上的接近。观察到的是 功能障碍的心肌在灌流时脂肪酸摄取减少 是一致的，这表明对区域脂肪酸摄取的测量将是 可作为心肌收缩完整性的指标。至 测试这一假设，我们建议对脂肪进行连续测量 摄酸、血流、心功能和心肌超微结构 重度心肌肥厚的Dahl系大鼠模型 高血压。当脂肪酸摄取变化的关系， 定义了功能和形态测量，将进行两项药物干预研究 在其他大鼠组中进行。第一项研究将测试 早期应用钙通道阻滞剂和β-受体阻滞剂治疗的能力 防止脂肪酸摄取和功能下降。第二项研究 将确定地高辛、钙通道阻滞剂或β-受体阻滞剂治疗 静息状态下左心室射血分数 减少可以防止脂肪酸摄取的进一步恶化和 功能。在动物研究的同时，左撇子患者 将通过平面和SPECT成像来评估心室肥厚 脂肪酸分布、左心功能及血流灌注量。

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.