Compared with other studies: Ersbll M (2012), NT - proBNP has a positive correlation with GLS (r = 0.62, p <0.0001); De Vecchis (2015), correlation between log (NT-proBNP) and GLS (r = 0.8; p <0.01) - GLS has a positive, moderate correlation with serum lactate level (r = 0.3; p <0.05).