[Exercise-induced ST-segment depression and myocardial ischemia in patients with hypertrophic cardiomyopathy: myocardial scintigraphic study].
OBJECTIVE
Patients with hypertrophic cardiomyopathy (HCM) sometimes develop myocardial ischemia during exercise in the absence of coronary lesions. The relationship between myocardial ischemia and ST-segment depression was investigated during exercise testing in patients with HCM.


METHODS
Regional hypoperfusion and/or transient left ventricular cavity dilation, a parameter of subendocardial hypoperfusion, were assessed on exercise 99mTc-tetrofosmin myocardial scintigraphy in 42 patients with non-obstructive HCM. The scintigraphic results were further correlated with the ST-segment responses to exercise.


RESULTS
Regional hypoperfusion or transient left ventricular cavity dilation were observed in 19 (45%) or 16(38%)patients with HCM, respectively. The incidence of ST-segment depression > or = 0.1 mV during exercise testing was similar in HCM patients with regional hypoperfusion, with transient left ventricular cavity dilation, and without hypoperfusion (42%, 38%, 38%, p = 0.95). Furthermore, exercise-induced ST-segment depression > or = 0.1 mV occurred similarly irrespective of symptoms, exercise tolerance, the degree or the site of hypertrophy, or the presence or absence of resting ST-segment depression.


CONCLUSIONS
ST-segment depression during exercise testing was common in patients with HCM, but seems to be an unreliable marker of myocardial ischemia as assessed by exercise scintigraphy.
Miyai
Nobuyuki
N
Department of Cardiology, Matsushita Memorial Hospital, Osaka. nobu-m0525@s4.dion.ne.jp
Kawasaki
Tatsuya
T
Taniguchi
Takuya
T
Kamitani
Tadaaki
T
Kawasaki
Shingo
S
Sugihara
Hiroki
H
D000368:Aged; D002312:Cardiomyopathy, Hypertrophic / Q000503:physiopathology*; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000503:physiopathology*; D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals
D009943:Organophosphorus Compounds; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C078700:technetium tc-99m tetrofosmin