Which is an abnormal response to a stress echocardiogram?

Comprehensive and Detailed Explanation From Exact Extract:

During a normal stress echocardiogram, the left ventricle demonstrates hyperdynamic wall motion with increased contractility, leading to an increased ejection fraction and typically decreased end-systolic volume due to more complete emptying.

An increase in end-systolic volume during stress is abnormal and suggests ischemia or impaired contractile reserve. This indicates that the ventricle is not contracting effectively, possibly due to coronary artery disease or myocardial dysfunction.

This interpretation is thoroughly explained in the "Textbook of Clinical Echocardiography, 6e", Chapter on Stress Echocardiography and Ischemia Detection【20:400-410†Textbook of Clinical Echocardiography】.