lipomatous hypertrophy of the interventricular septum is extremely rare and it usually affects interatrial septum.1 ) there are limited reports of this entity in the literature2)3 ) however in our knowledge is the second case diagnosed by magnetic resonance imaging ( mri).4 ) lipomatous hypertrophy should be differentiated by lipomas in the context that the latter are usually encapsulated and round - shaped while they do not exhibit myocardial fiber infiltration.4 ) although lipomatous hypertrophy has been associated in the past with sudden death,5 ) there is no enough evidence to support any kind of medical treatment or action in the case of lipomatous hypertrophy of the interventricular septum . this condition has been associated in some reports with atrial or ventricular arrhythmias following variable degree of conduction system infiltration . additionally in cases of severe interventricular septal hypertrophy there might be left ventricular outflow obstruction and in this case surgical rejection might be a reasonable management . a 46-year - old asymptomatic male with no medical history , was referred for routine cardiology examination due to his frequent participation in competitive sports . on physical examination his blood pressure was normal , his heart rhythm was regular and no heart murmurs were detected . the patient 's electrocardiogram showed a mild sinus tachycardia of around 100 beats per minute , an incomplete right bundle branch block pattern and no evidence of left ventricular hypertrophy ( supplementary fig . 1 ) . his echocardiographic study revealed a hyperechogenic interventricular septum , with a measured thickness of 1.34 cm , suggestive of asymmetrical left ventricular hypertrophy ( fig . 1 ) . there was no left ventricular outflow obstruction in rest neither following moderate treadmill exercise and there were no evidence of mitral valve regurgitation . his 24 h holter monitoring documented rare monomorphic ventricular extrasystoles and the patient was further referred for cardiac mri , in order to evaluate possible myocardial fibrosis indicative of hypertrophic cardiomyopathy . this area of lipomatous hypetrophy was nonhomogenic , not well circumscribed and was clearly defined from the rest normal myocardium ( fig . we are presenting , there was no overt symptomatology , the 24 h holter monitoring showed only rare ventricular extrasystoles and the exercise treadmill test was uneventful . additionally since there was no echocardiographic evidence of left ventricular outflow obstruction no further management was discussed . avoidance of competitive sports and yearly routine follow - up was finally recommended for this specific patient . . typical echocardiographic features of ventricular septal lipomatous hypertrophy is the characteristic septal hyperechogenicity in the long axis and four chamber view which is not associated with mitral valve leak , systolic anterior motion of the valve or left ventricular outflow obstruction . cardiac mri is the preferred imaging modality for diagnosis of this specific situation , as it shares significant sensitivity for myocardial fat infiltration identification . in some rare cases endomyocardial biopsy
asymmetrical left ventricular hypertrophy secondary to interventricular septum hypertrophy is usually considered a typical phenotype of hypertrophic cardiomyopathy . in rare cases other conditions such as tumors or lipomatous hypertrophy of the interventricular septum may have a similar presentation . 
 we present a case of a male patient who presented for routine cardiology work up and was diagnosed of having ventricular septal hypertrophy secondary to localized lipomatous hypertrophy .