肥厚型心肌病(hypertrophic cardiomyopathy，HCM)是最常见的遗传性心血管疾病，发病率为1∶500～1∶200，患者自然病程差异大、临床表现多样，部分无明显症状或症状轻微，也有相当数量的患者出现不明原因的晕厥，给日常生活带来潜在危险，若未予重视或抢救不及时可能导致严重的临床后果[1-3]。目前对HCM的研究多集中于心功能的评估，而患者颈部和颅脑血流动力学情况以及是否与其症状相关尚不清楚。本研究通过比较HCM患者和正常人心脏、颈部和颅脑血管超声相关参数，重点探讨HCM患者颈脑血流动力学变化，旨在为HCM患者全面临床评估、早期治疗和预后判断提供影像学依据，报告如下。

1 资料与方法

1.1 一般资料 选取2017年10月—2019年1月我院肥厚型心肌病诊疗中心就诊的成人HCM患者40例，出现胸痛19例，胸闷22例，心悸10例，气短15例，晕厥14例，家庭猝死史2例，服用血管紧张素转换酶抑制剂/血管紧张素受体拮抗剂8例、β受体阻滞剂15例、钙拮抗剂8例。所有患者进行病史采集、体格检查、心脏超声、颈部血管和颅脑血管彩色多普勒检查。纳入标准：①符合HCM诊断标准[4]，临床不能解释的左心室某一节段或多个节段室壁厚度≥15 mm；②年龄≥16岁。排除标准：①严重高血压，血压≥160/100 mmHg(1 mmHg=0.133 kPa)、瓣膜性心脏病、先天性心脏病、代谢性疾病等引起心室肥厚、运动员心室肥厚；②合并严重颈脑血管疾病(颈脑血管畸形与狭窄)及焦虑患者。另外纳入我院体检正常的受检者25例作为对照组。2组性别、年龄、体表面积、体重指数、收缩压、舒张压、心率差异均无统计学意义(P>0.05)，具有可比性，见表1。

表1 2组一般资料比较
Table 1 Comparison of clinical data between two groups

1.2 数据收集

1.2.1 心脏超声与数据测量 应用Philips IE33超声诊断仪，S5-1探头(1～5 MHz)行心脏超声检查。根据指南[5]测量左心室最大室壁厚度(maximal left ventricular wall thickness，MLVWT)、左心室舒张末期内径(left ventricular end-diastolic diameter，LVEDD)、左心室舒张末期容积(left ventricular end-diastolic volume，LVEDV)、左心室收缩末期容积(left ventricular end-systolic volume，LVESV)、左心室射血分数(left ventricular ejection fraction，LVEF)、左心室流出道峰值压力阶差(left ventricular outflow tract pressure gradients，LVOT-PG)、左心房前后径(left atrial diameter，LAD)、二尖瓣口和瓣环舒张早期血流峰速(E峰和e′)，计算E/e′比值。

1.2.2 颈部和颅脑血管彩色多普勒超声与数据测量 应用Philips IU Elite超声诊断仪，L9-3探头(3～9 MHz)和S5-1探头(1～5 MHz)。沿胸锁乳头肌水平检查双侧颈总动脉(common carotid artery，CCA)、颈内动脉(internal carotid artery，ICA)和椎动脉(vertebral artery，VA)；经颞窗检查双侧大脑中动脉(middle cerebral artery，MCA)、大脑前动脉(anterior cerebral artery，ACA)和大脑后动脉(posterior cerebral artery，PCA)；经枕窗检查双侧椎动脉颅内段(vertebral artery-intracranial，VA-IC)和基底动脉(basilar artery，BA)。根据指南[6]测量收缩期最大血流速度(peak systolic velocity，PSV)、舒张末期最大血流速度(maximum end-diastolic velocity，EDV)、舒张末期平均血流速度(average end-diastolic velocity，MDV)、搏动指数(pulsative index，PI)、阻力指数(resistance index，RI)、血流速度时间积分(velocity-time integrals，VTI)、收缩期和舒张期流速比(S/D)和平均血流速度(mean velocity，Mean)。

1.3 统计学方法 应用SPSS 22.0统计软件分析数据。计量资料比较采用两独立样本t检验；计数资料比较采用χ2检验。P<0.05为差异有统计学意义。

2 结 果

2.1 心脏超声比较 HCM组MLVWT、LVOT-PG、LAD、E/e′比值均明显高于对照组(P<0.05)；2组其余指标差异均无统计学意义(P>0.05)。见表2。

2.2 颈部血管超声比较 HCM组双侧CCA的EDV、MDV和VTI均低于对照组，PI和RI均高于对照组(P<0.05)；右侧ICA的PSV、EDV、MDV均低于对照组，PI和RI均高于对照组(P<0.05)；左侧ICA的EDV低于对照组，PI和RI均高于对照组(P<0.05)；右侧VA的PI和RI均高于对照组(P<0.05)；左侧VA的EDV低于常对照组，PI和RI均高于对照组(P<0.05)；2组其余指标差异均无统计学意义(P>0.05)。见表3。

2.3 颅内血管超声比较 HCM组左侧MCA的RI和Mean均高于对照组(P<0.05)；双侧PCA和左侧ACA的VTI均高于对照组(P<0.05)；右侧VA-IC的PSV、PI、RI和SD均高于对照组(P<0.05)；2组其余颅内血管血流动力学参数差异均无统计学意义(P>0.05)。见表4。

表3 2组颈部血管超声指标比较
Table 3 Comparison of carotid arteries ultrasound between two groups

表4 2组颅内血管超声指标比较
Table 4 Comparison of cerebral arteries ultrasound between two groups

3 讨 论

HCM作为最常见的遗传性心血管疾病，临床表现多样，除常见的心悸、胸闷、胸痛、心律失常等症状，还存在诸多心脏以外的表现，如头晕、黑矇、晕厥、运动过程中血压异常等。因此，对HCM的全面评估还应考虑外周血管，特别是脑供血动脉(颈动脉和椎动脉)和颅脑动脉的血流特征，以及外周血管对心脏的影响。近年来，颈脑血流动力学特征在冠心病[7-8]、扩张性心肌病[9]、心力衰竭[10-12]等均进行相关研究，但在HCM患者中鲜有报道。故本研究采用彩色多普勒超声技术对HCM患者和正常人的心脏、颈部和颅脑血管超声参数进行测量并比较，重点探讨HCM患者颈脑血流动力学变化。

本研究结果显示，HCM组双侧CCA和右侧ICA的EDV、MDV和VTI均低于对照组，表明舒张末期流速降低、血流量减少；PI和RI均高于对照组，表明血管的弹性和顺应性降低。考虑为HCM患者左心室壁增厚、左心室顺应性降低、左心室流出道梗阻所致高阻力血流动力学改变，造成心排血量降低、体循环血量减低、颈部血管血流量不足。文献报道，HCM患者颈动脉搏动的典型双峰脉，也称为重搏，向上的颈动脉搏动波和紧跟其后的第二个峰，

系左心室过度收缩所致[8]。而HCM双侧BA的血流量在无明显降低的情况下，PI和RI高于对照组，提示远心端血管的弹性和顺应性降低。关于颅脑动脉，本研究发现大多数血流动力学参数在HCM和对照组差异均无统计学意义。脑血流灌注的调节受较多因素影响[13-14]，可以通过机体神经调节、血流代谢耦联调节及自身调节等多种模式，即在心排血量和颈部血管供血量减低的情况下，仍保持脑血流灌注相对稳定[15-16]。此外，受颅内血管特殊解剖关系的影响，颅内大脑动脉环对前后循环的脑血流具有代偿功能，故导致HCM患者颅脑动脉血流参数与正常对照组差异无统计学意义。

本研究的局限性为纳入病例数较少，颈脑血流量是通过评估相应动脉血流速度、血流速度时间积分以及动脉弹性等间接获得的，故本研究是对HCM患者颈脑血流动力学变化的初步探讨，现有结果需在未来多中心和大样本研究中进一步验证。

综上所述，HCM除心脏功能改变之外，患者颈部血管血流动力学参数也会出现异常。因此，HCM患者应常规进行颈部血管超声筛查，这对全面临床评估和早期干预具有重要意义。

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Assessment of the hemodynamic changes of carotid and cerebral arteries in hypertrophic cardiomyopathy with color Doppler ultrasound

ZHAO Yong-feng, WANG Jing, ZUO Lei, KANG Nan, YANG Fan, LIU Li-wen*

(Department of Ultrasound， Xijing Hospital， Air Force Medical University, Shaanxi Province, Xi′an 710032, China)

[Abstract] Objective To investigate the hemodynamic changes of carotid and cerebral arteries in hypertrophic cardiomyopathy(HCM). Methods Totally 40 HCM patients and 25 normal controls were enrolled. All of them received echocardiography, carotid and cerebral arteries color Doppler ultrasound. Echocardiographic parameters included maximal left ventricular wall thickness(MLVWT), left ventricular end-diastolic diameter(LVEDD), left ventricular end-diastolic and systolic volume(LVEDV and LVESV), left ventricular ejection fraction(LVEF), left ventricular outflow tract pressure gradients(LVOT-PG), left atrial diameter(LAD), and mitral valve inflow and annular early diastolic velocity(E and e′). Besides, the carotid and cerebral arteries were involved including bilateral common carotid artery(CCA), internal carotid artery(ICA), middle cerebral artery(MCA), vertebral artery(VA), anterior cerebral artery(ACA), posterior cerebral artery(PCA), vertebral artery-intracranial(VA-IC) and basilar artery(BA). The ultrasound parameters of these arteries, such as peak systolic velocity(PSV), maximum end-diastolic velocity(EDV), average end-diastolic velocity(MDV), pulsative index(PI), resistance index(RI), velocity-time integrals(VTI), S/D, mean velocity(Mean) were all measured and compared. Results The ratios of MLVWT, LVOT-PG, LAD, and E/e′ in the HCM group were significantly higher than those in the control group; EDV, MDV, and VTI of bilateral CCA were lower than those in the control group, and PI and RI were higher. PSV, EDV and MDV in right ICA were lower than those in the control group, PI and RI were higher. EDV in left ICA was lower than that in the control group, PI and RI were higher. PI and RI of the right VA were higher than the control group. EDV in left VA was lower than that in normal control group, PI and RI were higher. RI and Mean in left MCA were higher than that of the control group. VTI of bilateral PCA and left ACA were higher than that of the control group; PSV, PI, RI and SD of right va-ic were higher than that of the control group, the differences were statistically significant(P<0.05). Conclusion In addition to cardiac dysfunction, abnormal hemodynamic changes of carotid and cerebral arteries may also occurr in HCM. Therefore, carotid and cerebral vascular ultrasound should be performed routinely in HCM, which is of great significance for comprehensive clinical evaluation and early intervention.

[Key words] cardiomyopathy, hypertrophic; hemodynamics; ultrasonography, Doppler, color

[收稿日期]2019-11-01；[修回日期]2019-12-18

[基金项目]国家国际科技合作专项(2014DFA31980)；国家自

然科学基金青年科学基金(81601498)；国家自然科学基金面上项目(81671693)；陕西省重点研发项目(2017ZDXM-SF-058)

[作者简介]赵永锋(1980-)，男，陕西长武人，空军军医大学西京医院主治医师，医学学士，从事医学超声诊断研究。

*通信作者。E-mail:liuliwen@fmmu.edu.cn

[中图分类号] R542.2

[文献标志码]A

[文章编号]1007-3205(2020)01-0061-06

(本文编辑：赵丽洁)