Gated single-photon emission computed tomography detects subendocardial ischemia in hypertrophic cardiomyopathy.
BACKGROUND
Patients with hypertrophic cardiomyopathy (HCM) sometimes develop subendocardial ischemia (SEI) in the left ventricle (LV). In the present study it was examined whether volumetric variables obtained by gated single-photon emission computed tomography (SPECT) are useful in detecting exercise-induced SEI in patients with HCM.


RESULTS
Exercise 99mTc-tetrofosmin myocardial scintigraphy was performed in 26 HCM patients having non-obstruction and mild hypertrophy with a ventricular septal thickness < or = 20 mm. SEI was quantified using software developed previously, and the results were correlated with volumetric variables obtained using Quantitative Gated SPECT software. Exercise-induced percentage change in LV end-systolic volume was higher in 9 HCM patients with SEI (25.8+/-3.1%) than in 17 patients without (10.0+/-2.5%, p=0.009), although the percentage change in LV end-diastolic volume was similar in the 2 groups. The receiver-operator characteristics curve of the percentage changes in LV end-systolic volume for the detection of SEI showed that the optimal cutoff was 17%. This cutoff point yielded a good diagnostic value for the presence of SEI with a sensitivity of 89%, specificity 82%, and likelihood ratio 5.04.


CONCLUSIONS
Gated SPECT technique is useful in detecting SEI during exercise in a select population of HCM patients.
Kawasaki
Tatsuya
T
Department of Cardiology, Matsushita Memorial Hospital, Moriguchi, Osaka, Japan. js-k@wf6.so-net.ne.jp
Akakabe
Yoshiki
Y
Yamano
Michiyo
M
Miki
Shigeyuki
S
Kamitani
Tadaaki
T
Kuribayashi
Toshiro
T
Sugihara
Hiroki
H
D000368:Aged; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications* / Q000503:physiopathology; D004452:Echocardiography; D004562:Electrocardiography; D015444:Exercise; D005260:Female; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000209:etiology*; D012680:Sensitivity and Specificity; D012984:Software; D015899:Tomography, Emission-Computed, Single-Photon