Polypharmacy as Part of Comprehensive Geriatric Assessment: Disclosure of False Diagnosis of Atrial Fibrillation by Drug Revision

To the Editor: Misinterpretation of electrocardiogram (ECG) artifacts as pseudoarrhythmia is known to be a cause of unnecessary and occasionally harmful treatment. Pseudoarrhythmia is reported mainly in the acute care setting. Despite the high prevalence of diseases such as Parkinson's and the advanced age of patients, specialists other than geriatricians report most cases. The case of a post-acute care patient in whom review of polypharmacy led to the final correct diagnosis of pseudosupraventricular arrhythmia caused by tremor is reported. A 65-year-old woman was transferred to an inpatient post-acute intermediate care unit (convalescence unit) after a 40-day admission in an acute care hospital because of a severe episode of pneumonia. She had a history of obesity, high blood pressure, hypercholesterolemia, osteoarthritis, bipolar disorder, and hypothyroidism but no history of heart disease. During her 3-day intensive care unit admission, where she was constantly monitored, episodes of paroxysmal atrial fibrillation with no hemodynamic compromise were reported, and treatment with amiodarone and aspirin was started. Serum lithium level and thyroid function test were within normal range. An echocardiogram was normal. The patient was transferred to acute care unit, where her clinical course was also satisfactory. A routine ECG performed there was interpreted as paroxysmal atrial fibrillation (Figure 1A). No cardiac events occurred during admission. As a result of acute illness and recent hospitalization, the patient presented severe functional loss and was transferred to a geriatric post-acute intermediate care unit. On physical examination, all vital signs were normal. A low-amplitude resting symmetric tremor that increased with intention was more evident in the upper limbs. No rigidity was present. Her medications at that time were losartan, hydrochlorothiazide, pravastatin, acetaminophen, tramadol, lithium, imipramine, fluphenazine, biperiden, levothyroxine, aspirin, and amiodarone. Polypharmacy was included on the list of goals of care of the interdisciplinary team. Although the indication of aspirin and amiodarone seemed appropriate, administering them would add a 12th drug with potential secondary cardiovascular, thyroid, and drug-to-drug side effects. Repeated physical examinations revealed no abnormal cardiac rhythm. When the previous ECG (Figure 1) was reviewed, the possibility of prior ECG misinterpretation arose. During admission, the tremor had improved and was only evident on intentional movement. A new 12-lead ECG was recorded in presence of the physician, with the patient relaxed and not presenting tremor (Figure 1B). The patient was then asked to move both hands, which caused the onset of tremor and simultaneous changes on the ECG (Figure 1C). A 12-lead ECG recorded while intentional tremor was still being provoked (Figure 1D) showed ECG artifacts identical to those in the initial ECG (Figure 1A). A definitive diagnosis of pseudosupraventricular arrhythmia caused by tremor was made. Treatment with aspirin and amiodarone was then withdrawn. A. Prior electrocardiogram (ECG) taken on admission to conventional acute care unit. Twelve-lead ECG shows normal sinus rhythm with initial apparent period of supraventricular tachycardia. Arrows show the “sinus” sign in lead I. B. ECG performed in post-acute intermediate care unit showing normal sinus rhythm. The patient was not presenting tremor. C. Rhythm strip, performed simultaneously to the start of voluntary hand movement, showing the appearance of tremor-induced artifact. D. ECG, taken as the patient was presenting intentional tremor, showing changes similar to those in A. ECG artifacts are a well-described cause of misinterpretation of ECG in cardiology text books,1 with tremor and alternating-current interferences being the most common causes of the resulting pseudoarrhythmia. In the medical literature, the most reported artifact is tremor-induced ventricular pseudoarrhythmia, frequently Parkinson-related.2–5 The immediate consequences of misdiagnosis, including unnecessary aggressive diagnostic and therapeutic procedures,6 are usually emphasized. Simultaneous physical examination, absence of hemodynamic deterioration, temporal relation to body movement, and careful analysis of the ECG trace looking for clues suggesting the presence of artifacts are recommended to avoid misinterpretation.2,4,7 Although ventricular tachycardia is the most reported pseudoarrhythmia, in the experience of some authors, supraventricular arrhythmia (pseudoatrial fibrillation or flutter) is a more common misdiagnosis of tremor artifact,8 although few cases have been reported. The causes of tremor in these cases were clonic movement in an epileptic patient, intermittent shivering in a hypothermic patient,4 and fever in a urosepsis context.9 In all cases, artifact was easily recognized as “sinus sign” on ECG; this is the presence of sinus rhythm in leads I, II, or III (arrows in Figure 1A in the present case). Although it has not been reported that pseudosupraventicular arrhythmias lead to immediate harmful interventions, little is known of the consequences of not detecting them, because they may constitute the most frequent misdiagnosis of tremor artifact. One reported case seems interesting in this respect, because the misdiagnosis led to oral anticoagulation for 1 year until the pseudoatrial fibrillation was identified as being due to Parkinson tremor.10 The need for a heightened degree of suspicion of ECG artifacts in physicians who treat patients with arrhythmia has been acknowledged6 but should also apply to physicians such as geriatricians, who care for persons with tremor. Financial Disclosure: None. Author Contributions: All the authors were involved with the study concept and design, acquisition of data, analysis and interpretation of data, and preparation of the letter. Sponsor's Role: There was no sponsor for this letter.