Mechanism of decreased sensitivity of XXXX associated left ventricular wall motion analyses for appreciating inducible @entity63 in older adults.

@entity1 @entity154 @entity939 @entity452 @entity101 @entity6 @entity63 @entity26 @entity741 @entity453 @entity2287 @entity122
BACKGROUND: @entity452 associated left ventricular (LV) wall motion analyses exhibit reduced sensitivity for detecting inducible @entity63 in individuals with increased LV wall thickness. This study was performed to better understand the mechanism of this reduced sensitivity in the elderly who often manifest increased LV wall thickness and risk factors for @entity453 . METHODS: During @entity452 cardiovascular magnetic resonance (DCMR) stress testing, we assessed rate pressure product (RPP), aortic pulse wave velocity ( @entity122 ), LV myocardial @entity26 demand (pressure volume area, @entity939 , mass, volumes, concentricity, and the presence of wall motion abnormalities (WMA) and first pass @entity2287 enhanced @entity154 ( @entity154 ) indicative of @entity63 in 278 consecutively recruited individuals aged 69        8  years with pre-existing or known risk factors for @entity453 . Each variable was assessed independently by personnel blinded to @entity1 identifiers and analyses of other DCMR or hemodynamic variables. RESULTS: @entity1 were 80% white, 90% @entity101 , 43% @entity6 and 55% @entity1 . With @entity452 , 60% of the @entity1 who exhibited @entity154 had no inducible WMA. Among these @entity1 , myocardial @entity26 demand was lower than that observed in those who had both wall motion and perfusion abnormalities suggestive of @entity63 (p   =   0.03). Relative to those with @entity154 and inducible WMAs, myocardial @entity26 demand remained different in these individuals with @entity154 without an inducible WMA after accounting for LV afterload and contractility (p   =   0.02 and 0.03 respectively), but not after accounting for either LV stress related end diastolic volume index (LV preload) or resting concentricity (p   =   0.31-0.71). CONCLUSIONS: During @entity452 stress testing, elderly @entity1 experience increased LV concentricity and declines in LV preload and myocardial @entity26 demand, all of which are associated with an absence of inducible LV WMAs indicative of @entity741 . These findings provide insight as to why @entity452 associated wall motion analyses exhibit reduced sensitivity for identifying inducible @entity63 in elderly. TRIAL REGISTRATION: This study was registered with Clinicaltrials.gov (NCT00542503) .
