In a similar vein, we may notice that these artefactual changes are more prominent in limb leads than in precordial leads.( 1) This can be appreciated in the ECGs of both Cases 1 and 2. Thirdly, repositioning electrodes closer to the torso may help to minimise interference to the isoelectric baseline from limb movements. Having a keen eye is useful in recognising these normal complexes that march in and out throughout the event. Normal complexes may also be seen before and after these periods of artefactual changes on ECG. from shivering or seizure), with an abrupt onset during the tremor and termination when the tremor ceases.( 4) Secondly, p waves may have uncharacteristic p wave and QRS complex morphologies with sharp contours. Firstly, artefacts would be observed during periods of tremulousness (e.g. Various factors that can help to distinguish a pseudo-AFL from a true arrhythmia should be considered. Secondly, it can lead to unnecessary investigations such as echocardiography or overtreatment with anticoagulation for cardioembolic stroke prophylaxis.( 3) For patients with suspected VT, this may include unnecessary intravenous infusions, cardioversions, electrophysiological studies and implantation of devices.( 4) This highlights the importance of correct identification of a suspected arrhythmia. Firstly, this may result in undertreatment of the precipitating neurological movement disorder or severe metabolic disturbance. Misinterpretation of artefactual ECGs as AF or AFL may lead to serious medical omissions and errors. Hence, computer ECG interpretation may not be able to differentiate artefacts, with a tendency to misinterpret these artefacts as AFL. A Parkinsonian tremor has a high probability of causing artefacts, and tremors with sufficient amplitude can lead to a misinterpretation of AFL, atrial fibrillation (AF) or even ventricular tachycardia (VT), as compared to those without.( 1, 2) The tremor in PD is 5–6 Hz, which translates to 300–360 cycles per minute, similar to the frequency at which a pseudoflutter can appear on an ECG. Movement artefacts in movement disorders resulting in mimics of arrhythmia have been well described in Parkinson‘s disease (PD). What does the ECG show?Ĭase 2: Repeat ECG shows resolution of artefacts. 2) was obtained to screen for cardiac rhythm disorders that could have contributed to the fall. Physical examination revealed right-sided coarse resting tremors with bradykinesia. She had a six-month history of right-sided resting hand tremors. CASE 2 CLINICAL PRESENTATIONĪ 60-year-old Indian woman presented to the emergency department after a fall. A repeat ECG after replacement of potassium demonstrated normal sinus rhythm with fewer movement artefacts. CLINICAL COURSEĪs the ECG revealed a diagnosis of atrial flutter (AFL), the patient was referred to the cardiology department. The patient was not known to have essential tremor. Other causes for tremors such as hyperthyroidism were excluded. Despite the absence of classic hypokalaemia ECG features, this ECG appearance was related to artefacts from tremor that were probably related to the hypokalaemia. These spikes were not typical of atrial activity and were more likely related to muscle tremors, which have a typical frequency of 3–12 Hz. These were dissociated with QRS complexes. 1 shows regular narrow QRS complexes with irregular high-frequency sharp spikes of irregular amplitudes and morphologies at 500/min (8 Hz).
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