Myocardial Work Measurement With Functional Capacity Evaluation in Primary Systemic Hypertension Patients: Comparison Between Left Ventricle With and Without Hypertrophy.

OBJECTIVE
Noninvasive measurement of myocardial work (MW) incorporates left ventricular (LV) pressure, and, therefore, allows correction of global longitudinal strain for changing afterload conditions. We sought to investigate MW as a tool to detect early signs of LV dysfunction in primary systemic hypertension patients, particularly with different predictive indices.


METHODS AND RESULTS
None left ventricular hypertrophy (NLVH) and left ventricular hypertrophy (LVH) patients established were all primary systemic hypertension with preserved ejection fraction. Forty in NLVH and forty in LVH according to left ventricular end-diastolic mass index (LVEDmassI) were prospectively enrolled. The following indices of MW were assessed: global work index, global constructive work, global wasted work (GWW), and global work efficiency (GWE). Both global work index (P=0.348) and global constructive work (P=0.225) were increased in NLVH and decreased in LVH, and GWW (P<0.001) was increased significantly in NLVH and increased more in LVH, while GWE (P<0.001) was decreased significantly in NLVH and decreased more in LVH. The clinical utility of GWW (95% CI: 0.802-0.951) and GWE (95% CI: 0.811-0.950) were verified by receiver-operating characteristic curve analysis showing larger net benefits as evaluated with LVH and control comparisons. In multivariate linear regression analysis, 4-dimenaional LVEDmassI was independently associated with GWE (P=0.018) in systemic hypertension patients. Assessment of intraobserver and interobserver variability in the MW echocardiographic data documented good interclass correlation coefficients (all >0.85).


CONCLUSION
GWW and GWE derived from MW are more accurate, sensitive, and reproducible predictors to detect early LV dysfunction in primary systemic hypertension patients, especially in distinguishing the potential functional abnormality of NLVH and LVH, even though the ejection fraction is preserved.