A 83-year-old woman presented with a 25-year history of hypertension which was long-standing, uncontrolled, severe hypertension because of irregular oral administration of antihypertensive drug underwent an echocardiographic examination as part of an evaluation of hypertension. She described chest distress associated with activity, syncope for three times in the past one year. On physical examination, she was in no acute distress, with a regular pulse rate and blood pressure of 185/115 mmHg. On auscultation, her lung fields were clear. There was a III/VI late peaking crescendo/decrescendo systolic murmur along the left sternal border radiating to the apex, which increased with standing and Valsalva's maneuver and decreased with squatting. There was no report of provocative maneuvers performed during auscultation. There was no edema. Transthoracic echocardiography showed a hyperdynamic left ventricle with markedly increased left ventricular wall thicknesses and asymmetrical septal hypertrophy. M-mode echocardiography showed systolic anterior motion of the mitral valve apparatus and midsystolic closure of the aortic valve. A dynamic left ventricular outflow tract obstruction was present, with a resting maximal instantaneous gradient of 55 mmHg. With the Valsalva maneuver, the gradient increased to 114 mmHg. No any factors that could cause hypertension were found at kidney, adrenal gland and renal artery etc. by ultrasound and multislice compute tomography.