In a patient with atrial flutter and 2:1 AV block, which diagnostic study is most appropriate next to evaluate for valvular disease?

• A. Transthoracic echocardiogram
• B. Cardiac catheterization
• C. Nuclear stress test
• D. Holter monitor

Answer: (A)

Evaluating valve structure and function with noninvasive imaging is the best next step when valvular disease is a concern in someone with atrial flutter. Transthoracic echocardiography uses ultrasound to visualize all heart valves, quantify stenosis or regurgitation, and assess chamber sizes and left ventricular function. This information helps determine the presence and severity of valvular disease and guides management, including whether valve surgery or percutaneous intervention might be needed. Cardiac catheterization is more invasive and not the initial test for valvular assessment, and nuclear stress testing or Holter monitoring do not evaluate valve anatomy or function. So, the most appropriate next study is transthoracic echocardiography.