Normal reference of myocardial work during exercise stress echocardiography and the doubt about wasted work

Abstract Aims Myocardial work (MW) estimated based on pressure-strain loops is a noninvasive parameter for evaluating left ventricular function. The aims of this study were (1) to characterize the MW changes at rest and post-exercise in healthy adults and heart failure with preserved ejection fraction (HFpEF) patients, (2) to explore the related influencing factors for the increase of global wasted work (GWW) after exercise. Methods and results The study enrolled 167 healthy adults and 38 HFpEF patients. All subjects underwent comprehensive echocardiographic assessment at rest and immediately after a symptom-limited treadmill stress test. The MW changes and the impact of sex were analyzed. The related influencing factors for the increase of GWW after exercise were explored. Global work efficiency (GWE) was decreased and other global parameters were increased after exercise in normal adults. There was no significant difference of all global parameters between sexes at rest. GWE was higher in men after exercise (p<0.05).There was no significant difference in MW reserve parameters between sexes. Peak positive strain (PPS) significantly increased after exercise, while GWE reduced in normal adults and HFpEF patients (p<0.05). PPS was independently associated with GWW in normal adults and patients with HFpEF both at rest and after exercise (normal adults: r: 0.77, p<0.001 at rest, r: 0.72, p<0.001 after exercise; HFpEF patients: r: 0.74, p<0.001 at rest, r: 0.62, p<0.001 after exercise). Conclusion Global MW parameters were less affected by sex. PPS was independently associated with GWW in normal adults and patients with HFpEF and the work done due to myocardial elongation might not be calculated as wasted work during the isovolumic contraction phase.example of myocardial work and PPSThe relationship between PPS and GWW