Single photon emission computed tomography (SPECT) has been extensively used to evaluate left ventricular (LV) systolic function. However, there are few studies comparing diastolic parameters based on SPECT with established reference values for the assessment of LV diastolic function.

To evaluate the sensitivity of SPECT-estimated LV diastolic parameters in coronary heart disease with left ventricular end-diastolic pressure (LVEDP) examined by left cardiac catheterization as the gold standard for comparison.

Totally 97 patients with suspected or comfired coronary artery disease were prospectively selected from Department of Cardiology, the Affiliated Hospital of Xuzhou Medical University from September 2021 to January 2022. All of them performed echocardiography, coronary angiography with left cardiac catheterization〔estimating LVEDP, left ventricular end-systolic volume (LVESV) , left ventricular end-diastolic volume (LVEDV) and left ventricular ejection fraction (LVEF) 〕, SPECT〔estimating LVESV', LVEDV', LVEF', peak filling rate (PFR) , the first third filling fraction (1/3FF) , the first third filling rate (1/3FR) , mean filling rate (MFR) , and peak filling time (TPF) 〕within one to three days of admission. Based on coronary angiography data, all patients had at least one sub-epicardial coronary artery stenosed to over 50%. The general data, laboratory indices, and indices of left heart function were compared between patients with normal LV diastolic function (n=50, LVEDP<16 mm Hg) and those with LV diastolic dysfunction (n=47, LVEDP≥16 mm Hg) . The correlation of LVEDP with SPECT parameters was analyzed. The receiver operating characteristic (ROC) curve was applied to evaluate the predictive value of SPECT parameters for elevated LVEDP.

Patients with LV diastolic dysfunction had lower LVEF', PFR, 1/3FF, 1/3FR, MFR, and higher TPF (P<0.05) . The results of correlation analysis showed that there was a positive correlation between LVESV' and LVESV, and LVEDV' and LVEDV, LVEF' and LVEF (r_s=0.726, P<0.001; r_s=0.651, P<0.001; r=0.450, P<0.001) . PFR, 1/3FF, 1/3FR or MFR was negatively correlated with LVEDP (r_s=-0.481, r_s=-0.212, r=-0.354, r_s=-0.305, P<0.05) . TPF was positively correlated with LVEDP (r=0.442, P<0.001) . In predicting elevated LVEDP, the area under the ROC curve (AUC) of PFR was 0.778 with 60% sensitivity and 84% specificity, the AUC of 1/3FF was 0.662 with 75% sensitivity and 62% specificity, the AUC of 1/3FR was 0.653 with 57% sensitivity and 78% specificity, the AUC of MFR was 0.663 with 62% sensitivity and 68% specificity, and the AUC of TPF was 0.755 with 77% sensitivity and 70% specificity.

For patients with coronary heart disease and LVEF≥50%, diastolic function parameters obtained by SPECT can identify the increase of LVEDP, among which PFR and TPF indices have good feasibility and higher accuracy.

单光子发射计算机断层显像（SPECT）已被广泛用于准确评估左心室收缩功能，但是，很少有研究将SPECT左心室舒张功能参数与已建立的左心室舒张功能参考标准进行比较。

以左心导管检查的左心室舒张末压（LVEDP）为金标准，探讨SPECT评估冠心病患者左心室舒张功能的敏感指标。

前瞻性选择2021年9月至2022年1月于徐州医科大学附属医院心内科就诊，因可疑或已知冠心病行冠状动脉造影（CAG）检查并同时行左心导管检查的患者97例。患者均在入院后1~3 d完成超声心动图、SPECT检查，后行CAG检查及左心导管检查发现心外膜下冠状动脉直径狭窄超过50%确诊为冠心病。CAG检查及左心导管检查得到LVEDP、左心室收缩末期容积（LVESV）、左心室舒张末期容积（LVEDV）及左心室射血分数（LVEF）。SPECT检查得到心功能参数：LVESV'、LVEDV'、LVEF'、高峰充盈率（PFR）、前1/3充盈分数（1/3FF）、前1/3充盈率（1/3FR）、平均充盈率（MFR）、高峰充盈时间（TPF）。根据LVEDP测量结果，将患者分为左心室舒张功能正常组（LVEDP<16 mm Hg，50例）和左心室舒张功能不全组（LVEDP≥16 mm Hg，47例）。比较两组患者一般资料、实验室指标以及左心功能指标差异。分析SPECT参数与LVEDP间的相关性。应用受试者工作特征（ROC）曲线评价SPECT参数对LVEDP增高的预测价值。

左心室舒张功能不全组LVEF'、PFR、1/3FF、1/3FR、MFR低于左心室舒张功能正常组，TPF高于左心室舒张功能正常组（P<0.05）。相关性分析结果显示，LVESV'与LVESV、LVEDV'与LVEDV、LVEF'与LVEF之间均呈正相关（r_s=0.726，P<0.001；r_s=0.651，P<0.001；r=0.450，P<0.001）；PFR、1/3FF、1/3FR、MFR与LVEDP均呈负相关（r_s=-0.481、r_s=-0.212、r=-0.354、r_s=-0.305，P<0.05）；TPF与LVEDP呈正相关（r=0.442，P<0.001）。PFR、1/3FF、1/3FR、MFR、TPF评价LVEDP增高的ROC曲线下面积（AUC）分别为0.778、0.662、0.653、0.663和0.755，灵敏度分别为60%、75%、57%、62%、77%，特异度分别为84%、62%、78%、68%、70%。

对于LVEF≥50%的冠心病患者，SPECT左心室舒张功能参数可以识别LVEDP增高，在这些参数中，PFR和TPF有较好的可行性和更高的准确性。