Echocardiographic assessment of LV hypertrophy and function in aortic-banded mice: necropsy validation

Abstract

.-We characterized the time course of the left ventricular (LV) geometric and functional changes after aortic banding, validated them by necropsy, and investigated the sensitivity of echocardiographic findings on LV hypertrophy. C57BL/6 mice were subjected to transverse aortic constriction (TAC) or sham operation; echocardiographic assessments were performed before or at 2, 4, 6, and 11 wk after surgery; and some of the mice were euthanized at the corresponding time points. There was a progressive increase in diastolic posterior wall thickness and LV systolic dimension; the percentage of LV fractional shortening (LV%FS) decreased progressively at 4 wk, whereas these parameters remained stable in sham-operated mice. Echo LV mass and LV%FS correlated well with actual whole heart mass and ratio of lung weight to body weight, respectively (r ϭ 0.765 and Ϫ0.749, respectively; P Ͻ 0.0001). These results suggest that the development of myocardial hypertrophy and systolic dysfunction is a time-dependent process. Echocardiographic assessment of myocardial hypertrophy and functional changes correlate well with the actual heart mass and lung mass. Echocardiography is sensitive enough to assess myocardial hypertrophy and heart functional changes induced by pressure overload in mice. myocardial; heart failure; left ventricular hypertrophy WITH THE ADVENT OF TRANSGENIC TECHNOLOGY, genetically altered mice with remarkable cardiovascular phenotypes have been commonly used in cardiovascular research, and it is an important approach to integrate a genetically engineered mouse with a pressure overload intervention to study the interplay of genes and pathophysiology of cardiac hypertrophy in vivo. However, the murine model of pressure overload by transverse aortic constriction (TAC) is not widely used because it is difficult to prepare the model in such a small animal; microsurgical techniques are thus required (3, 9, 11). Furthermore, it is critically important to develop approaches for accurate and reproducible measurements of cardiac morphology and function in the intact mice with pressure overload.Transthoracic echocardiography has been reported (5, 8, 14) as a reliable tool for monitoring the changes of cardiac geometry and function in vivo, but serial echocardiographic evaluation of myocardial hypertrophy in mice with TAC has not been extensively performed. Therefore, it is important to confirm the ability of echocardiography to distinguish between differences in severity of cardiac hypertrophy and myocardial function in TAC murine models.In the present study, we hypothesized that echocardiography is able to monitor the changes of left ventricular (LV) hypertrophy and has the sensitivity to distinguish between differences in severity of disease in TAC mice. To test this hypothesis, we established a murine model of TAC and assessed morphometric and functional characteristics with the use of echocardiography. Furthermore, we validated the results of echocardiographic heart mass by necropsy over a time course and checked the cor...

Lymphocytes Are Not Required for the Rapid Onset of Coronary Heart Disease in Scavenger Receptor Class B Type I/Apolipoprotein E Double Knockout Mice

“…Figure 4 shows representative M-mode and 2D echocardiographic images of control, dKO, and tKO mice. The mean FS for control mice was 50.1%Ϯ5.0%, corresponding to data reported by several groups for conscious 38 and anesthetized 33,35,37 mice. There were clear defects in LV wall motion in dKO and tKO mice compared with controls (Table; Figure 4).…”

“…Echocardiography was used to assess cardiac function and hypertrophy [33][34][35][36][37] in lightly anesthetized (pentobarbital; 25 mg/kg IP) dKO and tKO mice and their SR-BI-positive littermate controls (Table). No significant differences between RAG2(Ϫ/Ϫ) and RAG2(ϩ/ϩ) control mice were observed; therefore, all controls were pooled.…”

Pre-emptive gene therapy using recombinant adeno-associated virus delivery of extracellular superoxide dismutase protects heart against ischemic reperfusion injury, improves ventricular function and prolongs survival

“…Short axis echocardiography images were obtained by Sonos 5500 (Agilent Technologies, Palo Alto, CA, USA) workstation and 12-MHz transducer. Left ventricular end-diastolic (EDD) and endsystolic dimension (ESD) measurements were manually digitized, using parasternal short axis view 33 and were in millimeter units. Percentage FS was calculated as % FS ¼ (EDD-ESD)/ (EDD) Â 100.…”

Atorvastatin Slows the Progression of Cardiac Remodeling in Mice with Pressure Overload and Inhibits Epidermal Growth Factor Receptor Activation

“…We have previously demonstrated that pulmonary edema is a reliable index of cardiac function in this model (10,18,19). Compared with that in sham mice, the lung/body weight ratio (LW/BW) was increased by 93% in TAC mice, whereas there was only a 17% increase of the LW/BW in the TAC +atorvas-tatin group (Fig.…”

“…Male C57BL/6J mice (7-8 weeks old and weighing 20-24 g) were anesthetized with a mixture of intraperitoneal xylazine (5 mg/kg) and ketamine (100 mg/kg). Transverse aortic constriction (TAC) was performed to induce cardiac hypertrophy and heart failure, as described previously (9,10).…”