Journal Article

Palpitations and dizziness in a 64-year-old man

Moayedi, Yasbanoo, Angaran, Paul, Kumareswaran, Ramanan

2015

Overview

[...]a gradual decrease in amplitude in the QRS complexes is non-physiological and implies undersensing of ventricular activity by the ILR electrodes due to movement of the ILR in the pocket. [...]the patient should not undergo further device implantation (answers A and D). An ILR is a device that stores events either automatically by set programmable criteria or manually by the patient for symptoms. 1 It is particularly useful when non-invasive testing has not yielded a diagnosis. 2 It is a system that does not require an intravascular lead and therefore a chest X-ray would not be useful (answer C). Since an ILR to date can only record one lead, it is important to achieve a good signal at the time of implant. 3 4 Undersensing episodes have been attributed to an abrupt decrease in the recorded QRS amplitude or to a transient loss of signal. 3 This case illustrates that although ILRs remain highly sensitive for detecting arrhythmias and the gold standard for recurrent syncope of unknown aetiology, clinicians should be cautious of device-triggered 'asystole' episodes due to undersensing and correlate these findings to the clinical presentation before any treatment or intervention is decided.

• Publisher: BMJ Publishing Group LTD
• Subject: Cardiac arrhythmia / Electrocardiography