AM. High-frequency speckle tracking echocardiography in the assessment of left ventricular function and remodeling after murine myocardial infarction. Am J Physiol Heart Circ Physiol 306: H1371-H1383, 2014. First published February 15, 2014 doi:10.1152/ajpheart.00553.2013.-The objectives of this study were to assess the feasibility and accuracy of high-frequency speckle tracking echocardiography (STE) in a murine model of myocardial infarction (MI). STE is used clinically to quantify global and regional cardiac function, but its application in mice is challenging because of the small cardiac size and rapid heart rates. A high-frequency microultrasound system with STE (Visualsonics Vevo 2100) was compared against magnetic resonance imaging (MRI) for the assessment of global left ventricular (LV) size and function after murine MI. Animals subjected to coronary ligation (n ϭ 46) or sham ligation (n ϭ 27) were studied 4 wk postoperatively. Regional and global deformation were also assessed. STE-derived LV ejection fraction (EF) and mass correlated well with MRI indexes (r ϭ 0.93, 0.77, respectively; P Ͻ 0.001), as did STE-derived mass with postmortem values (r ϭ 0.80, P Ͻ 0.001). Higher STE-derived volumes correlated positively with MRI-derived infarct size (P Ͻ 0.01). Global strain parameters were significantly reduced after MI (all P Ͻ 0.001) and strongly correlated with LV mass and MRI-derived infarct size as promising surrogates for the extent of remodeling and infarction, respectively (both P Ͻ 0.05). Regional strain analyses showed that radial strain and strain rate were relatively preserved in anterior basal segments after MI compared with more apical segments (P Ͻ 0.001); however, longitudinal strain and strain rate were significantly impaired both basally and distally (P Ͻ 0.001). Strain-derived parameters of dyssynchrony were significantly increased in the MI group (P Ͻ 0.01). Analysis time for STE was 210 Ϯ 45 s with acceptable inter-and intraobserver variability. In conclusion, high-frequency STE enables quantitative assessment of regional and global function in the remodeling murine LV after MI. mouse; myocardial infarction; strain; echocardiography; left ventricular function COMPARED WITH CLINICAL IMAGING, echocardiography in mouse models remains relatively challenging, primarily because of the exceptional spatial and temporal resolution required to image such a small, rapidly beating heart. Research studies involving gene-modified mouse models commonly use clinical echocardiography systems (with transducer frequencies of up to 15 MHz) and tend to rely on rather simple measures of LV size and function, for example from M-mode tracings. These measures provide relatively crude estimates of global LV size and function, especially in remodeled hearts (e.g., after MI) where the geometric assumptions of symmetry are likely to be inaccurate. In clinical practice, such measures have largely been superseded, and the last decade has seen the introduction of several advanced echocardiography techniques to improve...

Aims To consolidate evidence to determine (i) the association between cardiovascular risk factors and health outcomes with coronavirus 2019 (COVID-19); and (ii) the impact of COVID-19 on cardiovascular health. Methods and results An umbrella review of systematic reviews was conducted. Fourteen medical databases and pre-print servers were searched from 1 January 2020 to 5 November 2020. The review focused on reviews rated as moderate or high-quality using the AMSTAR 2 tool. Eighty-four reviews were identified; 31 reviews were assessed as moderate quality and one was high-quality. The following risk factors were associated with higher mortality and severe COVID-19: renal disease [odds ratio (OR) (95% confidence interval) for mortality 3.07 (2.43–3.88)], diabetes mellitus [OR 2.09 (1.80–2.42)], hypertension [OR 2.50 (2.02–3.11)], smoking history [risk ratio (RR) 1.26 (1.20–1.32)], cerebrovascular disease [RR 2.75 (1.54–4.89)], and cardiovascular disease [OR 2.65 (1.86–3.78)]. Liver disease was associated with higher odds of mortality [OR 2.81 (1.31–6.01)], but not severe COVID-19. Current smoking was associated with a higher risk of severe COVID-19 [RR 1.80 (1.14–2.85)], but not mortality. Obesity associated with higher odds of mortality [OR 2.18 (1.10–4.34)], but there was an absence of evidence for severe COVID-19. In patients hospitalized with COVID-19, the following incident cardiovascular complications were identified: acute heart failure (2%), myocardial infarction (4%), deep vein thrombosis (7%), myocardial injury (10%), angina (10%), arrhythmias (18%), pulmonary embolism (19%), and venous thromboembolism (25%). Conclusion Many of the risk factors identified as associated with adverse outcomes with COVID-19 are potentially modifiable. Primary and secondary prevention strategies that target cardiovascular risk factors may improve outcomes for people following COVID-19.

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