Relation between left ventricular outflow tract obstruction and left ventricular shape in patients with hypertrophic cardiomyopathy: a cardiac magnetic resonance imaging study.
BACKGROUND
Hypertrophic cardiomyopathies (HCM) are often associated with left ventricular (LV) outflow tract obstruction, which can explain symptoms and impact prognosis.


AIMS
To better understand the mechanisms that link obstruction and LV shape in HCM.


METHODS
Patients with HCM who underwent cardiac magnetic resonance (CMR) imaging were included retrospectively. Obstructive HCM was defined as LV outflow gradient more than 30 mm Hg at rest by transthoracic echocardiography. The LV shape and mitral angle were assessed by CMR. Results were compared with control subjects.


RESULTS
Mean LV-mitral angle was smaller in patients with obstructive HCM (n=29) than in patients with non-obstructive HCM (n=15) or control subjects (n=15) (80 ± 5° vs 87 ± 7° [P=0.0002] and 89 ± 2° [P<0.0001]). Mean mitral papillary muscles angle was greater in patients with non-obstructive HCM than in patients with obstructive HCM or control subjects (136 ± 17° vs 123 ± 16° [P=0.007] and 118 ± 10° [P=0.002]). Patients with non-obstructive HCM had a greater mean LV-aortic root angle than patients with obstructive HCM or control subjects (139 ± 6° vs 135 ± 7° [P=0.04] and 133 ± 7° [P=0.03]).


CONCLUSION
There is a relation between morphological and functional parameters in HCM within which the mitral valve is probably part of pathophysiogenesis.
['Martin|Romain|R|', 'Lairez|Olivier|O|', 'Boudou|Nicolas|N|', 'Méjean|Simon|S|', 'Lhermusier|Thibault|T|', 'Dumonteil|Nicolas|N|', 'Berry|Matthieu|M|', 'Cognet|Thomas|T|', 'Massabuau|Pierre|P|', 'Elbaz|Meyer|M|', 'Rousseau|Hervé|H|', 'Galinier|Michel|M|', 'Carrié|Didier|D|']
D000328:Adult D000368:Aged D002312:Cardiomyopathy, Hypertrophic D015150:Echocardiography, Doppler D005260:Female D006352:Heart Ventricles D006801:Humans D019028:Magnetic Resonance Imaging, Cine D008297:Male D008875:Middle Aged D008943:Mitral Valve D011237:Predictive Value of Tests D012189:Retrospective Studies D014694:Ventricular Outflow Obstruction
Left ventricular outflow tract obstruction left ventricular Left ventricular shape Hypertrophic cardiomyopathy Hypertrophic cardiomyopathy Cardiac magnetic resonance imaging cardiac magnetic resonance magnetic resonance imaging HCM LV CMR mitral papillary muscles angle Cardiomyopathie hypertrophique Géométrie ventriculaire gauche Imagerie par résonance magnétique cardiaque LVARa LVMa MPMa MRI Obstruction intraventriculaire gauche SD hypertrophic cardiomyopathy left ventricular–aortic root angle left ventricular–mitral angle standard deviation