To compare the results of transthoracic contrast echocardiography (TTCE) adding a grading scale with the results of thoracic computed tomography (CT) in order to optimise the use of both techniques.95 patients with hereditary haemorrhagic telangiectasia (HHT) were examined with TTCE and thoracic CT to detect pulmonary arteriovenous malformations (PAVMs). According to previous studies, TTCE was divided into a four grade scale depending on the degree of opacification of the left ventricle after the administration of a contrast agent.Of the 95 patients (50.5% female; mean age 46 yrs), none with normal or grade 1 TTCE had detectable PAVMs on thoracic CT. Shunts of grades 2, 3 and 4 were associated with PAVMs according to thoracic CT in 25, 80, and 100% of the cases. There was a statistically significant association between the TTCE grade and the detection of a PAVM by thoracic CT. There were also statistically significant associations between TTCE grade and the cardiac cycle when the contrast was first visible in the left atrium, and size of the feeding artery.Graded TTCE and timing of left atrium opacification may be useful techniques in selecting HHT patients for PAVM screening with thoracic CT scans.
Background
Aging is accompanied by an alteration in myocardial contractility. However, its noninvasive detection is difficult. The effect of chronic exercise on this decrease is unknown. Murine models of senescence are increasingly used to test therapies in aging. We tested whether strain rate imaging detected left ventricular (LV) systolic dysfunction in aging mice and was able to assess a potential improvement after exercise.
Methods and Results
Young (3 weeks), adult (2 to 3 months), and old (6 to 18 months) C57BL6 male mice underwent echocardiograms with strain rate imaging, either in sedentary conditions or before, 2 weeks and 4 weeks after chronic swimming. Hemodynamic parameters of LV function including maximal and end-systolic elastance were obtained before euthanizing. LV fibrosis was measured using Sirius red staining. Conventional echocardiography was unable to detect LV systolic dysfunction in old mice, whereas both systolic strain rate and load-independent hemodynamic parameters such as preload recruitable stroke work and end-systolic elastance were significantly decreased. Both strain rate and load-independent hemodynamic parameters normalized after 4 weeks of exercise. Both endocardial and epicardial fibrosis were increased in the LV of aging mice. Endocardial fibrosis decreased in exercised aged mice.
Conclusions
Strain rate noninvasively detects LV systolic dysfunction associated with aging in mice, whereas conventional echocardiography does not. Chronic exercise normalizes LV systolic function and decreases fibrosis in old mice. Strain rate imaging in mice may be a useful tool to monitor the effect of new therapeutic strategies preventing the myocardial dysfunction associated with aging.
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