A 29 year-old female with IV drug use history presents with symptoms consistent with possible infective endocarditis. What is the diagnostic study of choice?

In cases of suspected infective endocarditis, especially in patients with risk factors like a history of intravenous drug use, a transesophageal echocardiogram (TEE) is considered the diagnostic study of choice. The TEE provides excellent visualization of the heart's structures, including the valves and potential vegetations, which are critical for diagnosing endocarditis.

The TEE is particularly advantageous over a transthoracic echocardiogram (TTE) in cases where the patient may have prosthetic valves or when the structures of the heart are difficult to assess, as is often the case in patients with significant risk factors. It allows for more sensitive detection of infective endocarditis-related changes and complications such as abscesses.

While other studies like an electrocardiogram, CT angiogram, or cardiac catheterization may provide useful information in various cardiovascular conditions, they do not directly visualize the heart valves and associated structures in the same manner as the TEE, making them less preferred for the specific diagnosis of infective endocarditis.