Left ventricular functional reserve in nonobstructive hypertrophic cardiomyopathy: evaluation by continuous left ventricular function monitoring.
The cardiac functional response to exercise in patients with nonobstructive hypertrophic cardiomyopathy (HCM) was evaluated using a continuous ventricular function monitor with a cadmium telluride detector (CdTe-VEST).


METHODS
Supine ergometric exercise was performed under CdTe-VEST monitoring in 41 patients with nonobstructive HCM (34 men and 7 women, age 18-72 yr, mean 51 yr) and 15 patients without cardiac disease (9 men and 6 women, age 36-56 yr, mean 49 yr).


RESULTS
Although 20 of 41 patients with HCM maintained a LVEF above baseline at peak exercise (Group A), 21 did not show an EF increase at peak exercise (Group B). Exercise duration and work load in Group A were longer and higher, respectively, than in Group B. Resting EF in Group B (72 +/- 7.7%) was significantly higher than that in Group A (65 +/- 8.2%) and the control group (62 +/- 5.9%). The EF increase from baseline to EF overshoot during recovery and the time to EF overshoot were lower and longer, respectively, in Group B than in Group A and the control group. Septal wall thickness and the septum-to-posterior-wall-thickness ratio between Groups A and B were not different. ST-segment depression was observed in all 21 Group B patients and in 8 of the Group A patients.


CONCLUSIONS
In patients with nonobstructive HCM, left ventricular dysfunction during exercise and during recovery was frequently observed but was not related to the degree of septal wall hypertrophy. The CdTe-VEST is a useful means to evaluate left ventricular functional reserve to exercise in patients with HCM.
Taki
J
J
Department of Nuclear Medicine, Kanazawa University School of Medicine, Japan.
Nakajima
K
K
Shimizu
M
M
Tonami
N
N
Hisada
K
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure; D006328:Cardiac Catheterization; D002312:Cardiomyopathy, Hypertrophic / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D017023:Coronary Angiography; D003971:Diastole; D004452:Echocardiography; D005080:Exercise Test; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D011877:Radionuclide Imaging; D012016:Reference Values; D013599:Systole; D013667:Technetium; D016277:Ventricular Function, Left
D013667:Technetium