“…It is also pertinent to differentiate electronic events from pacemaker syndrome. Also by the long iPR, the closer the atrial systole to the ventricular systole of the previous beat ("P over T fusion", Fig 6), would produce the same clinical consequences as retrograde ventricular-atrial conduction, and similar manifestations to the classic pacemaker syndrome 32,33 . In the latter, however, AV dyssynchrony is purely systolic because the atrium and ventricle contract simultaneously, a situation commonly associated with the VVI mode in the presence of sinus rhythm 33 .…”