Gated SPECT in patients with hypertrophic obstructive cardiomyopathy undergoing transcoronary ethanol septal ablation.
BACKGROUND
Transcoronary ethanol septal ablation (TESA) is a novel treatment for obstructive hypertrophic cardiomyopathy (HOCM). Our objective was to evaluate the use of gated single photon emission computed tomography (SPECT) in patients with HOCM and the effects of TESA on myocardial perfusion.


RESULTS
We performed gated SPECT and Doppler echocardiography before and 6 weeks after TESA in 30 patients with severe HOCM. The lung-to-heart and septal-to-lateral wall count-activity ratios were calculated. Before ablation, SPECT showed perfusion abnormalities in only 6 patients. Asymmetric septal hypertrophy was noted in 21 patients (70%). In patients with a lung-to-heart ratio greater than 0.50 before ablation, the ratio decreased from 0.56 +/- 0.04 to 0.45 +/- 0.08 after ablation (P <.01). The septal-to-lateral wall ratio also decreased significantly after ablation. Mean Doppler pressure gradient across the left ventricular outflow tract decreased from 52 +/- 39 mm Hg to 13 +/- 13 mm Hg (P <.01) immediately after ablation and to 10 +/- 21 mm Hg 6 weeks later (P <.01). There were no significant changes in left ventricular ejection fraction by gated SPECT after the procedure. SPECT studies done after ablation showed fixed septal defects in 29 of 30 patients (96.7%). The defects involved the basal and mid septum in 100% and 38% of patients, respectively, and ranged in size from 2% to 30% of the left ventricle (mean, 8.8% +/- 7.0%).


CONCLUSIONS
TESA is an effective technique for relieving left ventricular outflow obstruction in patients with HOCM. Myocardial gated SPECT can identify the presence and location of infarction after TESA.
Keng
Felix Y j
FY
Section of Cardiology, Baylor College of Medicine and The Methodist Hospital, Houston, TX 77030, USA. sherifn@bcm.tmc.edu
Chang
Su Min
SM
Cwajg
Eduardo
E
He
Zuo-Xiang
ZX
Lakkis
Nasser M
NM
Nagueh
Sherif F
SF
Spencer
William H
WH
Verani
Mario S
MS
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006328:Cardiac Catheterization / Q000009:adverse effects; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D015331:Cohort Studies; D016503:Drug Delivery Systems / Q000379:methods; D000431:Ethanol / Q000008:administration & dosage* / Q000009:adverse effects; D005260:Female; D015637:Gated Blood-Pool Imaging / Q000379:methods*; D006346:Heart Septum / Q000000981:diagnostic imaging* / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology
D000431:Ethanol