Introduction: Mitral regurgitation in obstructive hypertrophic cardiomyopathy (HOCM) is not related only to Venturi effect in LVOT, the anatomical changes of valvular and subvalvular apparatus playing an essen-tial role. Understanding of this changes is essential for transaortic mitral valvuloplasty. In patients with mild hypertrophy with SAM and obstruction, the mitral val-ve plasty is more important than miectomy.

Objective: Preoperatory describing of mitral valve anatomy using multimodal imaging (ecocardiography transthoracic and transesopageal, cardiac MR, ventri-culography, cardiac CT).

Methods: 64 consecutive patients went operated between May 2015 and April 2019.21 (32.81%) of those had moderate to severe mitral regurgitation. The mitral valve anatomy was studied by multimodal imaging. We looked for the length of anterior mitral valve, the ante-rioization of the coptation point, papillary muscles ro-tation, the anterior comisure fixation, the adherence of the papillary muscles to the free walls of the left ventri-cle with the tethering of the anterior valve, presence of the secondary chordae and of the mitro-aortic discon-tinuity. Using the informations offered by preoperatory imaging, transaortic miectomy was accompanied by mitral valve plastyin all patients with significant mitral valve regurgitation. 7 patients (30%) had a maximum septal thikness of 18 mm, the miectomy being shallow, mitral pasty having the main role in obstruction elimi-nation. The plasty procedure were secondary cordae cutting, the release of papillary muscles, splitting of the papillary, anterior valve palicaturing.

Results: T her were not mitral valve replacement or postoperative death.There were not interventricular septum defects. Moderate postoperaor mitral regur-gitation was present in 2 patient (9%). The maximum dynamic gradient decreased from 76.66 ± 14.34 mmHg to 12.09 ± 4.4 mmHg.

Conclusions: Multimodal imaging plays an important role in understanding of anatomy and physiology of the mitral valve in HOCM, positively influencing the results of surgery.