Relation of 99mTc-sestamibi washout with myocardial properties in patients with hypertrophic cardiomyopathy.
BACKGROUND
We sought to determine the relationship between (99m)Tc-sestamibi washout and myocardial properties in hypertrophic cardiomyopathy (HCM) patients.


RESULTS
Twenty-four HCM patients underwent biventricular cardiac catheterization, with a micromanometer-tipped catheter, both at rest and during atrial pacing, echocardiography and myocardial (99m)Tc-sestamibi scintigraphy at rest. The (99m)Tc-sestamibi washout rate (WR) was calculated using initial and delayed planar images. The HCM patients were divided into two groups as follows: Group A consisted of 13 patients showing (99m)Tc-sestamibi WR < 22.5%; group B of 11 patients showing (99m)Tc-sestamibi WR ≥ 22.5%. Significant correlations were observed between (99m)Tc-sestamibi WR and percentage changes in pressure half-time (T (1/2)), as well as those in the maximum first derivative LV pressure (LV dP/dt (max)) (r = .43, P = .033; r = -.63, P = .001). The percentage changes in LV dP/dt (max) and those in T (1/2) were significantly more reduced in group B than in group A (P < .05). The biphasic force-frequency relation was more frequently observed in group B than in group A (82% vs. 18%).


CONCLUSIONS
Increased (99m)Tc-sestamibi washout is associated with an impaired contractile reserve and prolonged relaxation, suggesting that myocardial (99m)Tc-sestamibi scintigraphy may be useful in noninvasively detecting the early impairment of myocardial function in HCM patients.
Isobe
Satoshi
S
Department of Cardiology, Kami-iida Dai-ichi General Hospital, Kita-ku, Nagoya, Japan. sisobe@med.nagoya-u.ac.jp
Ohshima
Satoru
S
Unno
Kazumasa
K
Izawa
Hideo
H
Kato
Katsuhiko
K
Noda
Akiko
A
Hirashiki
Akihiro
A
Murohara
Toyoaki
T
D000368:Aged; D002312:Cardiomyopathy, Hypertrophic / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000473:pathology; D004452:Echocardiography / Q000379:methods; D005260:Female; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D009206:Myocardium / Q000473:pathology*; D011312:Pressure; D011379:Prognosis; D011877:Radionuclide Imaging; D017256:Technetium Tc 99m Sestamibi
D017256:Technetium Tc 99m Sestamibi