Final answer:
The most appropriate name for idiopathic hypertrophic subaortic stenosis (IHSS) is Hypertrophic Cardiomyopathy (HCM), which is a pathological enlargement of the heart generally for no known reason, leading to obstructed blood flow.
Step-by-step explanation:
A more appropriate name for idiopathic hypertrophic subaortic stenosis (IHSS) is Hypertrophic Cardiomyopathy (HCM). Hypertrophic cardiomyopathy is a condition where there is a pathological enlargement of the heart, usually without a known cause. This differs from conditions such as stenosis of the heart valves, which may lead to the heart working harder to propel blood through a narrowed valve, possibly due to rigid, calcified valves over time. HCM is characterized by a thickening of the heart muscle, particularly the ventricular septum, which can obstruct blood flow out of the ventricle, leading to reduced cardiac output and sometimes symptomatic heart disease.
Other terms such as Aortic tunnel disease (ATD), Discrete subaortic valve stenosis (DSS), and Subaortic hourglass deformity (SHD) refer to different structural heart defects and conditions that are not related to the generalized muscle enlargement seen in HCM.