What is the most likely diagnosis for a patient presenting with exertional syncope, dyspnea, and angina?

The most likely diagnosis in this scenario is aortic stenosis. Aortic stenosis is characterized by the narrowing of the aortic valve, which can lead to significant obstruction of blood flow from the left ventricle into the aorta. During exertion, the heart requires an increased cardiac output to meet the body's demands, but in aortic stenosis, this increased demand cannot be met due to the fixed outflow obstruction.

Patients often present with symptoms such as exertional syncope (passing out during physical activity), dyspnea (shortness of breath), and angina (chest pain), which are classic manifestations of this condition. These symptoms occur because the heart struggles to pump effectively, especially during times of increased physical stress. The combination of exertional symptoms points strongly towards aortic stenosis as it is typically seen in older patients or those with congenital heart defects involving the aortic valve.

While other conditions like aortic regurgitation, mitral stenosis, and mitral valve prolapse can also present with similar cardiovascular symptoms, they generally do not combine exertional syncope, dyspnea, and angina in the same way that aortic stenosis does. Aortic regurgitation often presents with different characteristics,