Ambulatory ECG monitoring in primary care

Objective: Investigating symptoms suggestive of cardiac arrhythmia in primary care requires a strategy beyond the resting 12-lead electrocardiogram (ECG), as the test is generally only of use while the patient is experiencing discomfort during the recording. This study assessed the use of automated ambulatory ECG monitors in diagnosing cardiac arrhythmias. Design: A retrospective review of patients at one general practice. Participants: 52 consecutive patients (73% female; age 52+18 years, range 22 to 93 years) with symptoms suggestive of cardiac arrhythmia. Method: Automated ECG was recorded for 24 hours. Patients were also given a diary to record symptoms. The ECG reports were examined at the end of the test and correlated with symptoms, patient notes, and history before a decision to refer to secondary care was made. Results: Episodes (> 30 s) of tachycardia (> 120 bpm) were present in 52% of patients and bradycardia (< 50 bpm) in 19%. The most common supraventricular arrhythmia was atrial ectopics, detected in 52% of patients. Three patients (6%) were found to have atrial fibrillation (AF) during the 24-hour test. Ventricular arrhythmia was detected in 71% of patients, with an average ectopic rate of 28+88 per hour (range < 1 to 397 per hour). Overall, 73% of patients were symptomatic during the 24-hour test, with 10% experiencing symptoms on at least 10 occasions. Conclusions: Use of ambulatory ECG in patients with symptoms of cardiac arrhythmia proved feasible and useful in primary care. Results were used as the basis of referrals for 50% of patients tested, and to inform initiation or changes of medication in a further 24% of patients.