Final answer:
A MUGA scan with LBBB will show a characteristic pattern of asynchrony in the heart's ventricles, with delayed contraction of the septal wall compared to the lateral wall.
Step-by-step explanation:
Phase analysis on a Multigated Acquisition (MUGA) scan with a Left Bundle Branch Block (LBBB) will show asynchronous contraction of the ventricles. Typically, in a patient with LBBB, the septal wall of the heart is activated later than the lateral wall due to delayed electrical conduction. This results in a characteristic pattern on phase analysis. The MUGA scan creates images that depict the motion of the heart's walls and calculates the ejection fraction, which is a measure of the heart's pumping efficiency. In the presence of LBBB, the phase histogram may show an abnormal septal motion and delayed activation compared to the lateral wall, exhibiting an overall delay in the time to peak contraction of the ventricles.