Long-term course and cardiac sympathetic nerve activity in patients with hypertrophic cardiomyopathy.
OBJECTIVE
To investigate the relation between regional myocardial sympathetic nerve activity and the electrocardiographic and cardiac functional changes in hypertrophic cardiomyopathy.


METHODS
A retrospective study to compare the findings of myocardial scintigraphy with iodine-123 metaiodobenzylguanidine (MIBG) and the serial electrocardiographic changes.


METHODS
Myocardial scintigraphy was performed with iodine-123 MIBG and thallium-201 and single photon emission computed tomography (SPECT) in the division of nuclear medicine of Kanazawa University Hospital. Both SPECT studies were performed within a week.


METHODS
22 patients with hypertrophic cardiomyopathy classified according to their serial electrocardiographic changes--namely, 15 patients with an increase in or the appearance of a negative T wave (group A) and seven patients with a conduction disturbance or a decrease in or disappearance of the negative T wave (group B). The mean follow up period was 45 (range 12-143) months.


RESULTS
Group B showed a high rate of decreased activity or defects in MIBG uptake compared with group A (p less than 0.005). The areas of decreased activity or defects corresponded with the hypertrophied portion of the left ventricular wall. Although the early myocardial uptake (MIBG: thallium ratio) was similar in both groups, the mean (SD) MIBG clearance rate was significantly higher (p less than 0.05) in group B (0.25 (0.17)) than in group A (0.10 (0.15)).


CONCLUSIONS
Abnormalities of regional myocardial sympathetic nerve activity may be important in patients with hypertrophic cardiomyopathy and suspected progression of myocardial damage.
Shimizu
M
M
Second Department of Internal Medicine, School of Medicine, Kanazawa University, Kanazawa, Japan.
Sugihara
N
N
Kita
Y
Y
Shimizu
K
K
Horita
Y
Y
Nakajima
K
K
Taki
J
J
Takeda
R
R
D019797:3-Iodobenzylguanidine; D000328:Adult; D000368:Aged; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging / Q000503:physiopathology*; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000294:innervation* / Q000503:physiopathology; D006801:Humans; D007462:Iodobenzenes; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013564:Sympathetic Nervous System / Q000503:physiopathology*; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon
D007462:Iodobenzenes; D019797:3-Iodobenzylguanidine