Investigations
12-lead ECG showed sinus rhythm with AV dissociation as a result of
RV-only pacing. Device interrogation confirmed 100% RV pacing with
underlying complete AV block with a broad escape rhythm (LBBB, QRS
duration 132ms). TTE revealed a non-dilated LV with moderately impaired
systolic function (LVEF 40-45%), with late septal activation consistent
with RV apical pacing. RV function and pulmonary pressures were normal,
with no significant valve abnormalities.