RWMA is short for regional wall motion abnormality, a terminology used in echocardiography. This is usually applied with regards to abnormalities of motion of the left ventricular (lower muscular chamber of the heart) walls. No RWMA means that all segments of the left ventricle are contracting normally. At rest means that no stress test like exercise test or stress test with medications (e.g. dobutamine, adenosine) has been done to check for wall motion abnormalities with exercise or other forms of stress. If the blood vessels supplying the heart are narrowed or blocked, the region of the heart wall supplied by that vessel can show wall motion abnormalities either at rest or with exercise /other stress. Abnormalities could be a diminished contraction (hypokinesia), absence of contraction (akinesia) or abnormal motion (bulging out as the rest of the heart contract: dyskinesia). These findings are usually reported on echocardiography (ultrasound imaging of the heart).
The same terminology of RWMA can be used in any modality of real time imaging of the heart like cine cardiac magnetic resonance imaging, cine computed tomography and radionuclide imaging.