Myocardial infarction after percutaneous transluminal septal myocardial ablation in hypertrophic obstructive cardiomyopathy: evaluation by contrast-enhanced magnetic resonance imaging.
OBJECTIVE
The aim of this study was to evaluate myocardial infarction induced by percutaneous transluminal septal myocardial ablation (PTSMA) in symptomatic patients with hypertrophic obstructive cardiomyopathy using contrast-enhanced (CE) magnetic resonance imaging (MRI).


BACKGROUND
Contrast-enhanced MRI delineates the extent of myocardial infarction in coronary artery disease, but its role in ethanol-induced infarction has not been established.


METHODS
Cine and CE MRI were performed before and one month after PTSMA in 24 patients. Size and location of the induced infarction were related to left ventricular (LV) mass reduction, enzyme release, volume of ethanol administered, LV outflow tract gradient reduction, and coronary ablation site.


RESULTS
One month after PTSMA, regional hyperenhancement was visualized in the basal interventricular septum in all patients. Mean infarction size was 20 +/- 9 g, corresponding to 10 +/- 5% and 31 +/- 16% of total LV and septal mass, respectively. Total LV mass decreased from 219 +/- 64 to 205 +/- 64 g (p < 0.01), and septal mass from 76 +/- 25 to 68 +/- 22 g (p < 0.01). Total LV mass reduction exceeded septal mass reduction (p < 0.01). Infarction size correlated with peak creatine phosphokinase-MB (beta = 0.67, p < 0.01), volume of ethanol administered (beta = 0.47, p = 0.02), total LV and septal mass reduction (beta = 0.50, p = 0.02; beta = 0.73, p < 0.01), and gradient reduction (beta = 0.63, p < 0.01). Seven patients with exclusively right-sided septal infarction had smaller infarction size and less gradient reduction than remaining patients with left-sided or transmural infarction (p < 0.01). In five of these, PTSMA was performed distal in the target artery.


CONCLUSIONS
Contrast-enhanced MRI allowed detailed evaluation of size and location of septal myocardial infarction induced by PTSMA. Infarction size correlated well with clinical indexes of infarct size.
van Dockum
Willem G
WG
Department of Cardiology, VU University Medical Center, Amsterdam, The Netherlands. wg.vandockum@vumc.nl
ten Cate
Folkert J
FJ
ten Berg
Jurrien M
JM
Beek
Aernout M
AM
Twisk
Jos W R
JW
Vos
Jeroen
J
Hofman
Mark B M
MB
Visser
Cees A
CA
van Rossum
Albert C
AC
D006328:Cardiac Catheterization / Q000009:adverse effects*; D002312:Cardiomyopathy, Hypertrophic / Q000473:pathology* / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects*; D003287:Contrast Media; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology* / Q000473:pathology
D003287:Contrast Media