Septal stunning by dipyridamole stress shown on quantitative gated perfusion SPECT in a child with hypertrophic cardiomyopathy.
OBJECTIVE
Myocardial ischemia is an important problem in hypertrophic cardiomyopathy. Stunning is an important mechanism in progressive dysfunction of the ischemic myocardium. In this report, the authors found prolonged myocardial stunning in a child with hypertrophic cardiomyopathy that was induced by dipyridamole stress on quantitative gated SPECT.


METHODS
A 6-year-old boy with septal hypertrophy underwent rest and dipyridamole stress gated myocardial SPECT. Software was used to quantify automatically segmental perfusion and function at rest and after stress.


RESULTS
Perfusion imaging showed a reversible perfusion decrease in the hypertrophic septum. Cine-gated imaging of the septum showed dyskinesia and a severe abnormality of systolic thickening during the poststress period, whereas it showed nearly complete recovery at rest. Quantified regional perfusion and function indices also showed this perfusion decrease and myocardial dysfunction after dipyridamole stress.


CONCLUSIONS
In a child with hypertrophic cardiomyopathy, myocardial stunning was induced by dipyridamole stress, in accordance with decreased perfusion reserve.
Paeng
Jin Chul
JC
Department of Nuclear Medicine, Seoul National University College of Medicine, Chongno-gu, Seoul, Korea.
Lee
Dong Soo
DS
Yeo
Jeong Seok
JS
Noh
Chung Il
CI
Kim
Yu Kyeong
YK
Chung
June-Key
JK
Lee
Myung Chul
MC
D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging*; D002648:Child; D004176:Dipyridamole; D015637:Gated Blood-Pool Imaging; D006346:Heart Septum; D006801:Humans; D008297:Male; D017682:Myocardial Stunning / Q000000981:diagnostic imaging* / Q000209:etiology; D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon; D014665:Vasodilator Agents
D019275:Radiopharmaceuticals; D014665:Vasodilator Agents; D004176:Dipyridamole; D017256:Technetium Tc 99m Sestamibi