Broch Kaspar, de Marchi Stefano F, Massey Richard, Hisdal Jonny, Aakhus Svend, Gullestad Lars, Urheim Stig
Department of Cardiology, Oslo University Hospital, Oslo, Norway; Center for Heart Failure Research, Faculty of Medicine, University of Oslo, Norway.
Department of Cardiology, Bern University Hospital, Bern, Switzerland.
J Am Soc Echocardiogr. 2017 Apr;30(4):422-430.e2. doi: 10.1016/j.echo.2016.11.012. Epub 2017 Jan 5.
The role of speckle-tracking echocardiography in the assessment of chronic aortic regurgitation (AR) is not established. Load dependency may encumber the interpretation of strain measurements in the chronically overloaded left ventricle. The aim of this study was to investigate the mechanisms of left ventricular (LV) contraction patterns in asymptomatic patients with moderate to severe AR and preserved ejection fractions.
In this prospective, cross-sectional study, 31 patients with moderate to severe AR, 15 elite endurance athletes, and 17 healthy control subjects were examined using three-dimensional speckle-tracking echocardiography. Global circumferential strain (GCS), global longitudinal strain (GLS), end-systolic circumferential wall stress (ESSc), end-systolic meridional wall stress (ESSm), and the wall stress ratio (ESSc/ESSm) were measured.
LV end-diastolic volumes were similar in athletes and patients with AR and significantly larger than in healthy control subjects. Values of GLS in control subjects, athletes, and patients with AR were -18.8 ± 1.9%, -17.3 ± 2.0%, and -16.4± 2.0%, respectively (control subjects vs athletes and patients, P < .05), whereas values of GCS were -16.9 ± 2.0%, -15.5 ± 1.9%, and -17.9 ± 2.6%, respectively (athletes vs control subjects and patients, P < .01). The ESSc/ESSm ratio was lower in patients with AR (P < .01). When adjusted for ESSm, GLS remained impaired in patients compared with control subjects and athletes (P = .015). On the other hand, GCS was better in patients with AR when adjusted for ESSc (P = .003).
In compensated AR, relatively high GCS compensates for reduced GLS in a manner consistent with the preserved ejection fractions observed in these patients.
斑点追踪超声心动图在慢性主动脉瓣反流(AR)评估中的作用尚未明确。负荷依赖性可能会妨碍对长期超负荷左心室应变测量值的解读。本研究的目的是探讨中度至重度AR且射血分数保留的无症状患者左心室(LV)收缩模式的机制。
在这项前瞻性横断面研究中,使用三维斑点追踪超声心动图对31例中度至重度AR患者、15名精英耐力运动员和17名健康对照者进行了检查。测量了整体圆周应变(GCS)、整体纵向应变(GLS)、收缩末期圆周壁应力(ESSc)、收缩末期经线壁应力(ESSm)和壁应力比(ESSc/ESSm)。
运动员和AR患者的左心室舒张末期容积相似,且显著大于健康对照者。对照者、运动员和AR患者的GLS值分别为-18.8±1.9%、-17.3±2.0%和-16.4±2.0%(对照者与运动员及患者相比,P<.05),而GCS值分别为-16.9±2.0%、-15.5±1.9%和-17.9±2.6%(运动员与对照者及患者相比,P<.01)。AR患者的ESSc/ESSm比值较低(P<.01)。校正ESSm后,患者的GLS与对照者和运动员相比仍受损(P=.015)。另一方面,校正ESSc后,AR患者的GCS较好(P=.003)。
在代偿性AR中,相对较高的GCS以与这些患者保留的射血分数一致的方式补偿了降低的GLS。