Acute proliferative glomerulonephritis. Acute proliferative glomerulonephritis is a disorder of the glomeruli (glomerulonephritis), or small blood vessels in the kidneys.
Syncopation is created when the accent is shifted to a weak beat or an offbeat. But this term applies to music...
If the sound occurs only during expiration, it is likely that airway narrowing is the cause. If the abnormal sounds are loudest during inspiration, they are from disease other than in the chest. If you have noticed a change in your cat's voice, the larynx is the likely abnormal site.