MSFinals-0240

A 51-year-old man passed away from a massive middle cerebral artery stroke. He had no previous medical issues. Upon autopsy, it was discovered that his heart weighed 400 g and had normal valves and coronary arteries. The atria and ventricles were not enlarged. The right ventricular walls were normal, while the left ventricular wall was uniformly hypertrophied to 20-mm thickness. What is the probable reason for these autopsy results?