Cardiac monitoring for cholinesterase inhibitors: a survey

There is no consensus on the monitoring for rare but potentially serious cardiac adverse events associated with cholinesterase inhibitor drugs in the treatment of dementia. Different protocols have been proposed, with and without ECG examination. We surveyed an urban old age psychiatry service to investigate the variables that may influence the implementation of such protocols.

Case notes of 45 consecutive patients assessed for dementia were scrutinized, to establish how many underwent an ECG or other cardiac examination prior to drug treatments. Data were collected on demographics, medical conditions and drug treatments. Patient files were searched for indications of investigations and any outcomes.

Half of all patients treated with a cholinesterase inhibitor (11/22) had an ECG before treatment. In five cases no pulse or cardiac symptoms were recorded in the absence of an ECG. Medical history, findings on examination, seniority of the clinician, and patient cooperation all may have influenced whether patients had an ECG. In three cases treatment was not prescribed due to concerns over cardiac effects, and with five ECGs new diagnoses were made. A protocol based on pulse monitoring would only have indicated ECGs in two out of 22 cases.

Several factors may influence decisions on cardiac monitoring. Fewer ECGs could be done if only pulse and cardiac symptoms were monitored before cholinesterase inhibitor prescription, but new cardiac diagnoses might then be missed. Protocols can be devised to incorporate both cardiac investigation and cholinesterase inhibitor monitoring.