Aims Right ventricular (RV) strain is a known predictor of outcomes in various heart and lung pathologies but has been considered too technically challenging for routine use in critical care. We examined whether RV strain acquired from the subcostal view, frequently more accessible in the critically ill, is an alternative to conventionally derived RV strain in intensive care. Methods and results RV strain data were acquired from apical and subcostal views on transthoracic echocardiography (TTE) in 94 patients (35% female), mean age 50.5 +/- 15.2 years, venovenous extracorporeal membrane oxygenation (VVECMO) (44%). RV strain values from the apical (mean +/- standard deviation; -20.4 +/- 6.7) and subcostal views (-21.1 +/- 7) were highly correlated (Pearson's r -0.89, P < 0.001). RV subcostal strain correlated moderately well with other echocardiography parameters including tricuspid annular plane systolic excursion (r -0.44, P < 0.001), RV systolic velocity (rho = -0.51, P < 0.001), fractional area change (r -0.66, P < 0.01), and RV outflow tract velocity time integral (r -0.49, P < 0.001). VVECMO was associated with higher RV subcostal strain (non-VVECMO -19.6 +/- 6.7 vs. VVECMO -23.2 +/- 7, P = 0.01) but not apical RV strain. On univariate analysis, RV subcostal strain was weakly associated with survival at 30 days (R-2 = 0.04, P = 0.05, odds ratio =1.08) while apical RV was not (P = 0.16). Conclusion RV subcostal deformation imaging is a reliable surrogate for conventionally derived strain in critical care and may in time prove to be a useful diagnostic marker in this cohort.

Recent data suggest targeting higher mean arterial pressure (MAP) using norepinephrine reduces myocardial injury in cardiogenic shock. 1 Ameloot K. Jakkula P. Hästbacka J. Reinikainen M. Pettilä V. Loisa P. et al. Optimum blood pressure in patients with shock after acute myocardial infarction and cardiac arrest. J Am Coll Cardiol. 2020; 76: 812-824 Crossref PubMed Scopus (35) Google Scholar Despite being recommended in international guidelines, the impact of norepinephrine on coronary perfusion in critical illness has not been widely studied. Myocardial contrast echocardiography (MCE) is a well-validated method of qualitative and quantitative assessment of myocardial perfusion in the noncritically ill. 2 Wei K. Jayaweera A.R. Firoozan S. Linka A. Skyba D.M. Kaul S. Quantification of myocardial blood flow with ultrasound-induced destruction of microbubbles administered as a constant venous infusion. Circulation. 1998; 97: 473-483 Crossref PubMed Scopus (1418) Google Scholar We therefore examined coronary perfusion along with its clinical determinants in an unselected critical care cohort. Our aim was to investigate whether MCE can be used to assess norepinephrine-related perfusion abnormalities that could be responsible for reduced left ventricular function.