title: Magnetic resonance imaging of microvascular obstruction in hypertrophic obstructive cardiomyopathy after percutaneous transluminal septal myocardial ablation.
abstract: BACKGROUND
  The clinical significance of microvascular obstruction (MO) in hypertrophic cardiomyopathy (HOCM) after percutaneous transluminal septal myocardial ablation (PTSMA) remains unknown.
  
  
  OBJECTIVE
  To assess the relationship between the location of MO and the improvement in symptoms and pressure gradient after PTSMA in patients with HOCM.
  
  
  METHODS
  Twenty-three patients with HOCM underwent MRI within 24 weeks after PTSMA. The MO was defined visually as the hypointense region adjacent to the left or right ventricular cavity, which was surrounded by myocardial infarction. The location of MO and improvement in clinical symptoms and pressure gradient at 3-6 months follow-up were assessed.
  
  
  RESULTS
  MO was observed in 16 patients who underwent MRI within 7 weeks after PTSMA. Left-sided MO was observed in 12 patients, and right-sided MO was observed in four patients. Improvement in clinical symptoms and reduction in the pressure gradient were not sufficient in the patients with right-sided MO, while PTSMA was effective in the patients with the left-sided MO.
  
  
  CONCLUSIONS
  The location of MO identified by MRI may be related to the effectiveness of PTSMA at the short-term follow-up. The left-sided MO is related to complete improvement in clinical symptoms and pressure gradients.
authors.affiliation: Department of Radiology, Nippon Medical School, Tokyo, Japan yas-amano@nifty.com.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Amano
authors.affiliation: Intensive Coronary Care Unit, Nippon Medical School, Tokyo, Japan.
authors.forename: Mitsunobu
authors.initials: M
authors.lastname: Kitamura
authors.affiliation: Department of Radiology, Nippon Medical School, Tokyo, Japan.
authors.forename: Fumi
authors.initials: F
authors.lastname: Yamada
authors.affiliation: Department of Radiology, Nippon Medical School, Tokyo, Japan.
authors.forename: Kumiko
authors.initials: K
authors.lastname: Aita
authors.affiliation: Department of Cardiology, Sakakibara Heart Institute, Tokyo, Japan.
authors.forename: Morimasa
authors.initials: M
authors.lastname: Takayama
authors.affiliation: Department of Radiology, Nippon Medical School, Tokyo, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Tachi
authors.affiliation: Department of Radiology, Nippon Medical School, Tokyo, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Kumita
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002312:Cardiomyopathy, Hypertrophic / Q000473:pathology / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods*; D003251:Constriction, Pathologic; D003287:Contrast Media; D004452:Echocardiography; D005260:Female; D019786:Gadolinium DTPA; D006346:Heart Septum / Q000601:surgery*; D006571:Heterocyclic Compounds; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009942:Organometallic Compounds; D011183:Postoperative Complications / Q000175:diagnosis*
chemical_list: D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C050823:gadolinium 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetate; D019786:Gadolinium DTPA
keywords: Magnetic resonance imaging (MRI); hypertrophic obstructive cardiomyopathy; microvascular obstruction; percutaneous transmural septal myocardial ablation