All are true about hypertrophic obstructive cardiomypathy except –
**Core Concept**
Hypertrophic obstructive cardiomyopathy (HOCM) is a genetic disorder characterized by abnormal thickening of the heart muscle, which can lead to obstruction of blood flow out of the heart. This condition is often inherited in an autosomal dominant pattern and can cause symptoms such as chest pain, shortness of breath, and fainting.
**Why the Correct Answer is Right**
HOCM is caused by mutations in genes that encode proteins involved in the contraction of heart muscle cells. These mutations lead to an increase in the contractile force of the heart muscle, resulting in thickening of the heart wall. The obstruction of blood flow occurs when the thickened heart muscle compresses the left ventricular outflow tract, leading to symptoms such as chest pain and shortness of breath. The obstruction can be exacerbated by conditions such as dehydration, high blood pressure, and certain medications that increase heart rate.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because HOCM is not a result of high blood pressure. While high blood pressure can exacerbate the symptoms of HOCM, it is not a cause of the condition.
* **Option B:** This option is incorrect because HOCM is not typically associated with a dilated left ventricle. In fact, the left ventricle is often small and hyperdynamic in patients with HOCM.
* **Option C:** This option is incorrect because while HOCM can cause syncope (fainting), it is not a result of a patent foramen ovale. A patent foramen ovale is a congenital heart defect that allows blood to flow between the left and right atria, but it is not directly related to HOCM.
**Clinical Pearl / High-Yield Fact**
A key feature of HOCM is the presence of a "hypertrophied" left ventricle, which can be identified on echocardiography. This hypertrophy can lead to a characteristic "scooped out" appearance of the left ventricle, which is often seen in patients with HOCM.
**Correct Answer: A, B, C. The statements are false about hypertrophic obstructive cardiomyopathy.