Yu Li, Zeng Shi, Zhou Qichang, Yang Zurong, Huang Yiyuan
Department of Ultrasound Diagnosis, Second Xiangya Hospital, Central South University, Changsha 410011.
Department of Cardiovascular Medicine, Second Xiangya Hospital, Central South University, Changsha 410011, China.
Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2024 Dec 28;49(12):1934-1940. doi: 10.11817/j.issn.1672-7347.2024.240171.
Hypertrophic cardiomyopathy (HCM) frequently leads to myocardial ischemia and cardiac dysfunction. Even genotype-positive/phenotype-negative (G/P) individuals, carriers of pathogenic sarcomere gene mutations without left ventricular hypertrophy, remain at risk of progression to clinical HCM. This study aims to evaluate myocardial perfusion and contractile function in familial HCM patients and their first-degree relatives using myocardial contrast echocardiography (MCE) and velocity vector imaging (VVI), in order to identify early myocardial dysfunction and at-risk individuals within families.
Thirty-five genetically confirmed HCM patients with left ventricular hypertrophy were assigned to a G/P group. A total of 30 first-degree relatives carrying sarcomere mutations but without echocardiographic evidence of left ventricular hypertrophy were assigned to a G/P group. A total of 38 age- and sex-matched gene-negative healthy family members served as controls. All participants underwent MCE and VVI assessments. Myocardial perfusion parameters, including peak intensity (PI), time to peak concentration (TP), and the ratio of declining intensity and declining time (dI/dT), as well as strain parameters including global longitudinal strain (GLS), global radial strain (GRS), and global circumferential strain (GCS) were recorded and analyzed for differences and correlations.
Compared to both the G/P and normal control groups, the G/P group had significantly lower PI, dI/dT, GLS, and GRS, along with significantly increased TP (all <0.05). GLS and GRS were positively correlated with PI (=0.629 and =0.613, respectively; both <0.01) and negatively correlated with TP (=-0.597 and =-0.571, respectively; both <0.01). Compared to the normal control group, the G/P group showed a significant reduction in GLS (<0.05), but no significant differences in GRS, GCS, PI, TP, or dI/dT (all >0.05).
Myocardial contractile dysfunction in HCM patients is closely related to impaired perfusion. Even in the absence of wall hypertrophy, sarcomere mutation carriers show early signs of subclinical left ventricular dysfunction. MCE and VVI can quantitatively assess myocardial perfusion and function, offering valuable tools for early detection and risk stratification in HCM patients and their relatives.
肥厚型心肌病（HCM）常导致心肌缺血和心脏功能障碍。即使是基因型阳性/表型阴性（G/P）个体，即携带致病性肌节基因突变但无左心室肥厚的携带者，仍有进展为临床HCM的风险。本研究旨在使用心肌对比超声心动图（MCE）和速度向量成像（VVI）评估家族性HCM患者及其一级亲属的心肌灌注和收缩功能，以识别家族内早期心肌功能障碍和高危个体。
35例经基因确诊且有左心室肥厚的HCM患者被分配到G/P组。共有30例携带肌节突变但无超声心动图左心室肥厚证据的一级亲属被分配到G/P组。共有38例年龄和性别匹配的基因阴性健康家庭成员作为对照。所有参与者均接受MCE和VVI评估。记录并分析心肌灌注参数，包括峰值强度（PI）、达峰时间（TP）以及强度下降率和下降时间比（dI/dT），以及应变参数，包括整体纵向应变（GLS）、整体径向应变（GRS）和整体周向应变（GCS），以比较差异并分析相关性。
与G/P组和正常对照组相比，G/P组的PI、dI/dT、GLS和GRS显著降低，而TP显著升高（均P<0.05）。GLS和GRS与PI呈正相关（分别为r=0.629和r=0.613；均P<0.01），与TP呈负相关（分别为r=-0.597和r=-0.571；均P<0.01）。与正常对照组相比，G/P组的GLS显著降低（P<0.05），但GRS.GCS.PI.TP或dI/dT无显著差异（均P>0.05）。
HCM患者的心肌收缩功能障碍与灌注受损密切相关。即使在无室壁肥厚的情况下，肌节突变携带者也表现出亚临床左心室功能障碍早期迹象。MCE和VVI可定量评估心肌灌注和功能，为HCM患者及其亲属的早期检测和风险分层提供有价值的工具。
