Methods
We carried out a retrospective analysis of all acute admissions of
patients on donepezil treatment to our institution between March 2019 –
March 2020. An admission resting 12-lead ECG was obtained and compared
to their ECG prior to commencement of donepezil therapy. All data were
collected from our local hospital electronic care record and memory
clinic database. Patient characteristics and demographics were recorded,
including indications for donepezil, comorbidities and left ventricular
function (assessed using the Simpson’s biplane method on images obtained
from a recent transthoracic echocardiogram). Baseline serum electrolytes
(magnesium, adjusted calcium and potassium) and thyroid status were
noted. Medications with potential side-effects on cardiac conduction or
known to cause electrolyte disturbances, including beta-blockers,
levothyroxine, rate-limiting calcium-channel blockers, diuretics,
digoxin, tricyclic antidepressants, antipsychotics and selective
serotonin reuptake inhibitor (SSRI)/selective serotonin noradrenaline
reuptake inhibitor (SNRI) antidepressants were all recorded. In
addition, the duration of donepezil therapy was established and rounded
off to the nearest year.
Exclusion criteria included recent initiation of donepezil therapy
(<6 months), patients with electrolyte disturbances or
deranged thyroid function on admission, patients with a paced rhythm on
ECG and those patients in whom an ECG prior to commencement of therapy
could not be obtained.