Relaxation in hypertrophic cardiomyopathy and hypertensive heart disease: relations between hypertrophy and diastolic function

Aim-To determine the relation between the extent and distribution of left v entricular hypertrophy and the degree of disturbance of regional relaxation and global left ventricular filling. Methods-Regional wall thickness (rWT) was measured in eight myocardial regi ons in 17 patients with hypertrophic cardiomyopathy, 12 patients with hyper tensive heart disease, and 10 age matched normal subjects, and an asymmetry index calculated. Regional relaxation was assessed in these eight regions using regional isovolumetric relaxation time (rIVRT) and early to late peak filling velocity ratio (rE/A) derived from Doppler tissue imaging. Asynchr ony of rIVRT was calculated. Doppler left ventricular filling indices were assessed using the isovolumetric relaxation time, the deceleration time of early diastolic filling (E-DT), and the E/A ratio. Results-There was a correlation between rWT and both rIVRT and rE/A in the two types of heart disease (hypertrophic cardiomyopathy: r = 0.47, p < 0.00 01 for rIVRT; r -0.20, p < 0.05 for rE/A; hypertensive heart disease: r = 0 .21, p < 0.05 for rIVRT; r = -0.30, p = 0.003 for rE/A). The degree of left ventricular asymmetry was related to prolonged E-DT (r = 0.50, p = 0.001) and increased asynchrony (r = 0.42, p = 0.002) in all patients combined, bu t not within individual groups. Asynchrony itself was associated with decre ased EIA (r = -0.39, p = 0.01) and protracted E-DT (r = 0.69, p < 0.0001) a nd isovolumetric relaxation time (r = 0.51, p = 0.001) in all patients. The se correlations were still significant for E-DT in hypertrophic cardiomyopa thy (r = 0.56, p = 0.02) and hypertensive heart disease (r = 0.59, p < 0.05 ) and for isovolumetric relaxation time in non-obstructive hypertrophic car diomyopathy (n = 8, r = 0.87, p = 0.005). Conclusions-Non-invasive ultrasonographic examination of the left ventricle shows that in both hypertrophic cardiomyopathy and hypertensive heart dise ase, the local extent of left ventricular hypertrophy is associated with re gional left ventricular relaxation abnormalities. Asymmetrical distribution of left ventricular hypertrophy is indirectly related to global left ventr icular early filling abnormalities through regional asynchrony of left vent ricular relaxation.