Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Seta, Otsu 520-2192, Japan.
Ann Nucl Med. 2010 Jul;24(6):469-76. doi: 10.1007/s12149-010-0382-x. Epub 2010 May 11.
Echocardiographic studies have suggested an association between diastolic dysfunction and exercise intolerance. The aim of this study was to examine the relationship between exercise capacity and left ventricular (LV) function during stress myocardial scintigraphy, and to investigate whether or not this relationship is caused by ischemia during exercise.
The studied patients underwent technetium-99m sestamibi quantitative gated SPECT, including treadmill exercise. Myocardial stress images were acquired 30 min after the first tracer injection (370 MBq) during maximal exercise. Three hours later, the second tracer (740 MBq) was injected, and resting images were acquired 30 min after this injection. The presence of ischemia was determined by tracer accumulation. From the same data source, LV diastolic parameters [first third filling fraction (1/3FF), first third filling rate (1/3FR), peak filling rate (PFR) and time to PFR (TPF)], and systolic parameters [ejection fraction (EF), peak ejection rate (PER), time to PER (TPE) and first third ejection fraction (1/3EF)] were analyzed.
Subjects with exercise inability (<6 METs) were excluded. In 45 patients, diastolic parameters 1/3FF, 1/3FR, PFR and TPF correlated significantly with exercise duration (r = 0.32*, 0.37*, 0.37* and -0.40(#), respectively; p < 0.05, (#) p < 0.01), but systolic parameters EF, PER, TPE and 1/3EF did not. At rest, 1/3FF, PFR and PER were significantly increased, suggesting functional deterioration during exercise. Even after 3 h, 1/3FR, PFR and TPF still correlated significantly with exercise duration (r = 0.29, 0.36* and -0.30*, respectively; p < 0.05). Such findings were observed even when the 10 patients who exhibited ischemia during exercise were excluded (1/3FR: r = 0.34; PFR: r = 0.37*; TPF: r = -0.36*; *p < 0.05, n = 35).
Our findings suggested that LV diastolic dysfunction, not systolic dysfunction, is associated with limited exercise capacity independent of the occurrence of ischemia.
超声心动图研究表明舒张功能障碍与运动耐量降低有关。本研究旨在探讨应激心肌闪烁显像时运动能力与左心室（LV）功能之间的关系，并探讨这种关系是否是由运动时的缺血引起的。
研究对象接受了 99mTc-甲氧基异丁基异腈（99mTc-sestamibi）定量门控单光子发射计算机断层扫描（SPECT），包括踏车运动。在最大运动时第一次示踪剂（370MBq）注射后 30 分钟采集心肌应激图像。3 小时后，注射第二次示踪剂（740MBq），并在注射后 30 分钟采集静息图像。通过示踪剂积聚来确定是否存在缺血。从同一数据来源中，分析了 LV 舒张参数[前 1/3 充盈分数（1/3FF）、前 1/3 充盈率（1/3FR）、峰值充盈率（PFR）和充盈率达峰时间（TPF）]和收缩参数[射血分数（EF）、峰值射血率（PER）、达峰时间（TPE）和前 1/3 射血分数（1/3EF）]。
排除运动能力不足（<6METs）的患者。在 45 例患者中，舒张参数 1/3FF、1/3FR、PFR 和 TPF 与运动时间显著相关（r=0.32*、0.37*、0.37和-0.40（#），分别；p<0.05，（#）p<0.01），但收缩参数 EF、PER、TPE 和 1/3EF 则不然。在休息时，1/3FF、PFR 和 PER 显著增加，提示运动时功能恶化。即使在 3 小时后，1/3FR、PFR 和 TPF 仍与运动时间显著相关（r=0.29、0.36和-0.30*，分别；p<0.05）。即使排除了 10 例在运动时出现缺血的患者（1/3FR：r=0.34；PFR：r=0.37*；TPF：r=-0.36*；*p<0.05，n=35），仍观察到了这些发现。
我们的研究结果表明，LV 舒张功能障碍与运动能力受限有关，与缺血的发生无关。
