valuation of the change in right ventricular function in rabbits with hyperthyroid cardiomyopathy with different left ventricular geometry by quantitative tissue velocity imaging

AIM:To evaluate the change of right ventricular function in rabbits with hyperthyroid cardiomyopathy with different left ventricular geometry by quantitative tissue velocity imaging (QTVI). METHODS: Thirty purebred New Zealand rabbits were randomly divided into experimental group (n=20) and control group (n=10). Hyperthyroidism animal model was established by intraperitoneal injection of levothyroxine (L-Thy) ［(45 μg/(kg·day)］ for 28 days in the experimental group and according to the Ganau Classification, ultrasound parameters were divided into two groups: concentric hypertrophy (CH subgroup, n=7) and eccentric hypertrophy (EH subgroup, n=11). Peak velocity during systole (Vs), systolic acceleration (a), peak velocity during diastole (Ve) and E/Ve at the anterior valve tricuspid annulus were measured by QTVI, and conventional echocardiographic parameters were also obtained. RESULTS: LVMI and RWT in CH group increased significantly (both P<0.01). LVMI in EH group increased obviously (P<0.01), but no significant difference in RWT was seen compared with that in control group. Ve in CH group was lower than that in control group (P<0.05). E/Ve in CH group was higher than that in control group (P<0.05), but no significant difference in Vs and a was found between CH group and control group (both P>0.05). Ve, Vs and a in EH group were significantly lower than those in CH group and control group (both P<0.01). E/Ve in EH groups was significantly higher than that in CH group and control group (P<0.05). CONCLUSIONS: QTVI can accurately assess the right ventricular systolic and diastolic functions in rabbits with hyperthyroid cardiomyopathy with different left ventricular geometry.