الفهرس 
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Abstract
Objectives: Right ventricular(RV), adaptive mechanisms in hypertrophic
cardiomyopathy (HCM) is poorly understood. We attempted to assess RV
deformation response to exercise in HCM and its relationship to LV
function, using vector velocity imaging (VVI).
Methods: resting and exercise echocardiography was performed in 40
consecutive HCM patients (41±19 years; 58% male) and 33 age and sex
matched healthy control. Longitudinal peak systolic strain(εsys), strain
rate[SRsys, SRe, SRa] of RV segments from apical four-chamber view were
used to evaluate RV functional reserve (stress-rest/rest). Similar
parameters were quantified in LV wall segments. Intra-V dyssynchrony
was defined as SD of TTP (measured from regional strain curves for each
segment, as time from beginning of Q wave to time to peak εsys).
Results: In HCM and immediately postexertion, RV εsys (-18.5±10 versus
-28.2±5 P<0.001) and SRsys (-1.7±1.2versus -2.7±0.6s-1 P<0.0001) was
significantly lower and RV dyssynchrony (73.9±33versus 28.4±12 ms,
P<0.0001) was greater compared with control subjects. A significant
correlation was evident between exercise capacity and RV TTP-SD, r=-
.32, P<.04 and RV SR sys (r=.34 , P<.03). RV functional systolic reserve
showed direct relationship to LV systolic functional reserve, r=.32, P<.04.
However, using multivariate regression analysis, LV SRsys and LV TTPSD
is the only predictor of exercise capacity. While RV functional reserve
did not change the outcome. Exercise stress induced RV dysfunction in
HCM is associated with exercise intolerance and strongly related to LV
deformation abnormalities as evaluated by VVI. Conversely, LV systolic
parameters remain the most important indicators linked to exercise
capacity in this population.