What minimum number of poorly-visualized contiguous left ventricular (i_V) regional wall segments indicate the use...

Comprehensive and Detailed Explanation From Exact Extract:

Contrast echocardiography is recommended to enhance the visualization of left ventricular endocardial borders when the image quality is suboptimal. Specifically, contrast agents should be used when at least three contiguous left ventricular segments are poorly visualized on standard two-dimensional imaging. This approach improves the accuracy and reliability of assessing regional wall motion and global systolic function.

The use of contrast is particularly important during stress echocardiography to ensure detection of ischemic segments, which might otherwise be missed due to inadequate image quality. Studies suggest that contrast enhancement is required in approximately 30% to 50% of stress echocardiographic studies depending on patient factors and laboratory practices.

These recommendations are detailed in the echocardiography guidelines and in the "Textbook of Clinical Echocardiography, 6e" (Chapter 8: Coronary Artery Disease and Stress Echocardiography) which emphasize the utility of contrast agents for better endocardial border definition when at least three segments are not clearly seen .