Department of Physiology, Université Rennes 1, Rennes, France; INSERM UMR 1099, Rennes, France; CIC-IT 804, Université Rennes 1, CHU Rennes, Rennes, France.
INSERM UMR 1099, Rennes, France; Department of Cardiology, Pontchaillou Hospital, Rennes, France; CIC-IT 804, Université Rennes 1, CHU Rennes, Rennes, France.
J Am Soc Echocardiogr. 2013 Oct;26(10):1163-1169. doi: 10.1016/j.echo.2013.06.002. Epub 2013 Jul 13.
Hypertrophic cardiomyopathy (HCM) and aortic stenosis (AS) may influence left ventricular (LV) systolic function, despite preservation of LV ejection fraction. The aim of this study was to determine the relative importance of cardiac afterload and myocardial hypertrophy in the potential dysfunction of myocardial deformation, at rest and during standardized exercise.
Patients with moderate to severe (≤ 1.5 cm(2)) asymptomatic AS and patients with HCM in sinus rhythm were prospectively studied using resting and exercise echocardiography during submaximal exercise. Myocardial deformations were assessed using two-dimensional strain. Exclusion criteria were altered LV ejection fraction (<50%), coronary artery disease, intra-LV obstruction > 30 mm Hg at rest, diastolic LV thickness ≥ 30 mm, and New York Heart Association class > II. Thus, 50 patients (25 with AS, 25 with HCM) were selected and matched for age, sex, rest and exercise blood pressure, degree of LV hypertrophy (defined by maximal wall thickness), and LV ejection fraction.
Mean resting global longitudinal strain (GLS) was -14.9 ± 4.7% in patients with AS and -16.1 ± 3.9% in those with HCM (P = .30). During exercise (mean heart rate, 110 ± 10 beats/min), mean GLS was -13.9 ± 4.2% in patients with AS and -18.1 ± 5.4% in those with HCM (P = .004). GLS decreased in patients with AS but increased in those with HCM (ΔGLS, 0.9 ± 3.1% and -1.9 ± 3.2%, respectively, P = .003). The same results were observed for global circumferential strain. Mean resting global circumferential strain was -16.4 ± 5.8% in patients with AS and -17.9 ± 4.5% in those with HCM (P = .36). During exercise, mean global circumferential strain was -13.8 ± 4.1% in patients with AS and -18.6 ± 5.3% in those with HCM (P = .011). Afterload was higher, particularly during exercise, in patients with AS than in those with HCM.
Longitudinal and circumferential LV deformation during exercise was lower in patients with AS compared with those with HCM, despite similar resting characteristics. The greater afterload observed in patients with AS led to reduced contractile reserve.
尽管左心室射血分数正常，但肥厚型心肌病（HCM）和主动脉瓣狭窄（AS）可能会影响左心室（LV）的收缩功能。本研究旨在确定心脏后负荷和心肌肥厚在心肌变形潜在功能障碍中的相对重要性，包括静息和标准运动期间。
采用二维应变技术，前瞻性研究了 50 例中重度（≤1.5cm2）无症状 AS 患者和窦性心律的 HCM 患者在亚极量运动期间的静息和运动超声心动图。排除标准为：左心室射血分数降低（<50%）、冠状动脉疾病、静息时室间隔内梗阻>30mmHg、舒张期左室厚度≥30mm 和纽约心脏协会（NYHA）心功能分级>II 级。因此，选择了 50 例患者（25 例 AS，25 例 HCM），并根据年龄、性别、静息和运动血压、左室肥厚程度（定义为最大壁厚度）和左心室射血分数进行匹配。
AS 患者的静息整体纵向应变（GLS）为-14.9±4.7%，HCM 患者为-16.1±3.9%（P=0.30）。在运动时（平均心率 110±10 次/分），AS 患者的 GLS 为-13.9±4.2%，HCM 患者为-18.1±5.4%（P=0.004）。AS 患者的 GLS 降低，而 HCM 患者的 GLS 增加（ΔGLS 分别为 0.9±3.1%和-1.9±3.2%，P=0.003）。整体圆周应变也有同样的结果。AS 患者的静息整体圆周应变（GLS）为-16.4±5.8%，HCM 患者为-17.9±4.5%（P=0.36）。在运动时，AS 患者的整体圆周应变（GLS）为-13.8±4.1%，HCM 患者为-18.6±5.3%（P=0.011）。与 HCM 患者相比，AS 患者的后负荷较高，尤其是在运动时。
尽管静息特征相似，但与 HCM 患者相比，AS 患者在运动时 LV 的纵向和圆周应变较低。AS 患者的后负荷较大导致收缩储备减少。
