Cardiac Remodeling, Adaptations and Associated Myocardial Mechanics in Hypertensive Heart Diseases.

UNLABELLED: Hypertension is the leading cause of heart failure and cardiovascular comorbidities in developed countries. Left ventricular structural/functional alterations such as concentric remodeling or hypertrophy have been extensively studied in hypertensive heart diseases. Furthermore, it is also well-recognized that diastolic function actually deteriorates in hypertensive subjects prior to overt heart failure. Novel imaging modality techniques such as myocardial deformation have allowed for early detection of regional/global myocardial contractile dysfunction. Myocardial deformation, which can be quantified by measuring the systolic strain and strain rate in three different directions (longitudinal, circumferential and radial), has facilitated new insights into the understanding of cardiac systolic mechanics in subjects with early stage myocardial damage. Previous studies had shown that longitudinal function remains the most sensitive parameter in identifying hypertension-related myocardial dysfunction, particularly for those patients who had developed LV hypertrophy. Instead, preserved or enhanced short-axis function, when presented as circumferential or radial strains, may remain relatively preserved or enhanced in order to compensate for longitudinal functional decline. In this manner, global cardiac pumping in terms of ejection fraction may remain relatively unchanged. The early recognition of subclinical systolic dysfunction and associated mechanical compensation in the context of hypertension is crucial, which potentially helps to identify a disease stage that is still responsive to therapeutic intervention. KEY WORDS: Concentric remodeling; Hypertension; Myocardial mechanics; Strain; Subclinical systolic dysfunction.