Myocardial contrast echocardiography guided alcohol septal ablation (PTSMA) is an established treatment for symptomatic hypertrophic obstructive cardiomyopathy (HOCM). Most important properties of the optimal echocardiographic contrast agent are good contrast imaging and sufficient stability without fast washing out. HOCM was diagnosed in a 49-year-old female patient 4 years before first admission. Despite optimal medical treatment the patient was highly symptomatic with angina pectoris and dyspnoea NYHA II-III.Investigations, treatment and course: ECG showed signs of left ventricular hypertrophy. Echocardiography revealed asymmetric septal hypertrophy, dynamic LVOT obstruction with pronounced SAM and associated moderate mitral valve regurgitation. Coronary angiography performed in the catheterization laboratory showed coronary atherosclerosis and haemodynamic measurements verified a significant LVOT obstruction. An atypical septal branch, originating from the intermediate artery, was regarded as target branch and was occluded with a balloon catheter. For the contrast echocardiography guided septal ablation cold, agitated Gelafundin® was used. This led to a good subaortic septal contrast demarcation with confirmation of the correct choice of target branch. No arrhythmias were recorded during the administration of contrast medium. Injection of Levovist® in the same septal branch for comparison resulted in opacification of the same myocardial area without any sign of misplacement. After alcohol injection in the balloon-occluded septal branch, an effective elimination of the LVOT gradient could be haemodynamically documented. For contrast echocardiography guided PTSMA a good myocardial opacification with an appropriate contrast agent is essential, not only to recognize the obstruction dependent region but also to identify any possible misplacement. Gelafundin® seems to offer similarly sufficient contrast potential as Levovist®, so that Gelafundin® could be a possible alternative.