Okay, let's tackle this question. The patient is a 60-year-old marathon runner with dizziness and an ejection systolic murmur on auscultation. The ECG is done, but the options aren't given, which is a bit tricky. But based on the information provided, I need to figure out the most likely diagnosis.

First, the key points here are age, physical activity (marathon runner), dizziness, and a systolic ejection murmur. Ejection murmurs are typically heard in conditions where there's increased pressure in the left ventricle or obstruction to outflow. Common causes include aortic stenosis, hypertrophic cardiomyopathy (HCM), and maybe even aortic regurgitation, though that's more diastolic. Since it's a systolic ejection murmur, the main differentials would be aortic stenosis and HCM.

Marathon runners are often young and fit, but the patient here is 60. Aortic stenosis is more common in older adults, often due to calcification. However, HCM is a genetic condition that can present in younger individuals but can also affect older adults. HCM is also associated with sudden cardiac death, especially in athletes, which might explain the dizziness episodes. The ejection murmur in HCM is typically dynamic and can increase with maneuvers that reduce preload, like standing up. An ECG in HCM might show left ventricular hypertrophy with ST-T changes, which could be relevant here.

But wait, the patient is a marathon runner. HCM can be asymptomatic in some cases, but the presence of dizziness and a murmur points towards some form of obstruction. Another consideration could be aortic stenosis, but given the patient's age and activity level, maybe HCM is more likely. Also, HCM is a known cause of sudden cardiac death in athletes, which is a high-yield point for exams.

The incorrect options would likely include conditions that don't fit. For example, mitral regurgitation might present with a holosystolic murmur. Atrial septal defect usually has a systolic ejection murmur but is more common in younger patients and might not explain the dizziness. Hypertension could lead to left ventricular hypertrophy but isn't a direct cause of a systolic ejection murmur unless there's underlying HCM.

So, putting it all together, the most probable diagnosis is hypertrophic cardiomyopathy. The clinical pearl here is that HCM is a leading cause of sudden cardiac death in athletes and should be considered in any athlete with syncope or dizziness and a family history of sudden death. The ECG findings would support this diagnosis, showing LVH and other abnormalities.

**Core Concept**
The clinical scenario involves a 60-year-old marathon runner with dizziness and an ejection systolic murmur, pointing to a cardiac outflow obstruction. Key differentials include **hypertrophic cardiomyopathy (HCM)** and **aortic stenosis**, with HCM being more relevant in athletes due to its association with sudden cardiac death.

**Why the Correct Answer is Right**
Hypertrophic cardiomyopathy (HCM) is characterized by asymmetric left ventricular hypertrophy, dynamic outflow obstruction, and a systolic ejection murmur that intensifies with maneuvers reducing preload (

✓ Correct Answer: B. LVH with Valvular Aoic stenosis