Electrocardiographic Artifact Research Articles

Electrocardiographic Artifacts Caused by Defective Marker Circuitry

To the Editor.— Interpretation of ECG is complicated by a variety of artifacts caused by disturbances such as broken lead wires (1972;220:1130; 1973;223:439) and transposed lead wires (1979;242:617), muscle tremors, seizures and hiccups, 1,2 arteriovenous fistula (1979;241:2380), intravenous infusion devices, 3,4 malfunction of an electric watch (1974;228:26), and a pacemaker pulse-width controller. 5 Reported here is an artifact resembling an intermittent atrial flutter caused by defective marker circuitry of an ECG machine. Report of a Case.— A 48-year-old man experienced the onset of chest pain while playing tennis and was brought to the emergency room of the Maui Memorial Hospital. An ECG was obtained, and the physician on duty reviewed the strip before mounting the lead samples onto an ECG form. Although there was no evidence of ischemia or infarction, the physician observed what appeared to be P waves in rapid irregular bursts (Figure) and arranged admission to the coronary care

Electrocardiographic Artifact Caused by an Arteriovenous Fistula

To the Editor.— A variety of artifacts may produce ECG findings simulating cardiac arrhythmias. Alternating current may produce regular fibrillary deflections in the tracing baseline; muscular tremor in patients with Parkinson's disease, diaphragmatic flutter, or hiccoughs may produce findings simulating atrial flutter. 1 We have seen an ECG artifact produced by a subcutaneous arteriovenous fistula (AVF) in a patient receiving hemodialysis. Report of a Case.— A 68-year-old man with end-stage renal disease from chronic interstitial nephropathy had been receiving hemodialysis therapy for five years. Hemodialysis access was an AVF in his right arm. A previously constructed AVF in his left arm was patent but unused because of excessive tortuosity. At the end of a dialysis treatment, he complained of chest pain and palpitations. A standard ECG was performed. A rhythm strip in lead I showed an idioventricular rhythm (Fig 1). The left arm electrode had been placed over the unused

Electrocardiographic artifact caused by an arteriovenous fistula

Electrocardiographic artifact caused by an arteriovenous fistula

Pseudoarrhythmia Due to Defective Infusion Pump and ECG Monitor

<h3>To the Editor.—</h3> Electrocardiographic artifacts mimicking cardiac arrhythmias have been reported^1-3with increasing frequency since the wide-spread application of ECG monitoring in the care of critically ill patients. We are reporting an artifact that mimicked atrial flutter and resulted in the detection and correction of equipment malfunction that might otherwise have escaped attention. <h3>Report of a Case.—</h3> A 53-year-old man with coronary heart disease was admitted for palpitations and an irregular pulse. The initial rhythm strip showed sinus rhythm, premature atrial contractions and pairs of premature ventricular contractions. An intravenous lidocaine infusion was begun at a rate of 2 mg/min, with the use of a peristalic pump (model 530, I VAC Corp, San Diego, Calif). Shortly thereafter, the rhythm strip shown in panel A (Figure) was recorded. Normal P waves accompanied the "flutter" waves, suggesting artifact. Acceleration of the pump resulted in acceleration of the "atrial activity" (strip B),

T-Wave Inversions

To the Editor. —Leier and associates in the October issue of theArchives(134:766, 1974) observed that, in their patient with alcoholic cardiomyopathy and heart block, deep precordial T-wave inversions occurred following the institution of artificial cardiac pacing. They ascribed these changes to intracranial disease, apparently without considering the possibility that they may have been caused by the pacing per se. Chatterjee and associates, 1 Gould and associates, 2 and Nevins 3 have called attention to the frequent occurrence of repolarization abnormalities in patients who have pacemakers. The T-wave inversion may be striking and may mimic changes due to subendocardial ischemia or infarction. Physicians treating patients who have pacemakers should be aware of this electrocardiographic artifact and not be led to a false diagnosis of myocar dial or other disease. The accompanying illustrations give a particularly dramatic example of this phenomenon. Figure 1 shows the admission electrocardiogram from a 70-year-old woman who had complete heart block with Stokes-Adams

Electrocardiographic Artifact Due to Malfunction of An Electric Watch

To the Editor.— Artifacts of the electrocardiogram may appear as abnormalities of QRS complex or S-T segment configuration, as cardiac arrhythmias, or as apparent pacemaker malfunction. The latter two are of particular interest since misdiagnosis of rhythm or pacemaker function may result in the acute administration or use of inappropriate therapeutic agents. Artifacts that simulate rhythm disorders include myotonic muscle contractions due to hypothermia (223:439, 1973), benign familial tremor and the tremor of Parkinson disease (224: 1534, 1973). Apparent pacemaker malfunction may be caused by a broken wire in an extremity lead (220:1130, 1972). This communication describes another potential source of electrocardiographic artifact. Caused by an electric watch, it may appear as either a rhythm or a pacemaker artifact. Example.— A 73-year-old man was being studied because of vertigo. His initial ECG revealed 1- to 3-mm amplitude spikes that were independent of the basic cardiac rhythm and occurred at a rate

Letter: Electrocardiographic artifact due to malfunction of an electric watch

Letter: Electrocardiographic artifact due to malfunction of an electric watch

False Electrocardiographic Diagnosis of Atrial Flutter

To the Editor.— The simulation of atrial by electrocardiographic artefacts may be of varied origin, including a broken wire in an extremity electrode, 1 myoclonic contractions of the pectoralis major muscle secondary to cold, 2 and the muscle tremor of Parkinson disease. 3-5 While the electrical artefact produced by the tremor of Parkinson disease is usually easily recognized, a well-defined flutter may occasionally be produced. This simulated may appear only in the standard leads with bilateral tremor, or may be confined to certain of the standard leads when unilateral. 3 However, the spurious pattern may also be seen in the chest leads in some cases, increasing the difficulty of diagnosis. 4 Various methods have been proposed to eliminate these false patterns such as warming the patient in the case of cold-induced tremor, 2 and holding the affected extremity in parkinsonism. 3 Saint-Pierre 5 has suggested placing

False Atrial Flutter From Nasogastric Suction Pump

To the Editor.— Parkinsonian tremor and hiccups,1a roller pump used in hemodialysis,2myoclonic movement (211:829, 1970), and broken electrocardiographic electrode wires (220:1130, 1972) have caused false atrial arrhythmias. Recently we observed electrocardiographic artifacts that mimicked atrial flutter during nasogastric suction with a roller pump. When seen by us, a patient with intestinal obstruction had no muscle tremor or hiccups, had been given digitalis for a short term for what was thought to be atrial flutter, and was connected to an Air-Shields Drainage Pump (model DP-45-1) via nasogastric tubing. False atrial flutter occurred only during suction and completely disappeared whenever the pump was turned off or suction tubing disconnected, thus ruling out atrial dissociation (Fig). Further testing of the drainage pump, electrocardiographic recorder and electrodes, and alternating current wall receptacle showed that this artifact was not electrically induced, but rather mechanically caused by the roller pump as it regularly

Electrocardiographic Artifacts Simulating Atrial Flutter

To the Editor.— Rubenfire recently observed an unusual electrocardiographic artifact simulating atrial flutter. The artifact was only evident in leads II, III, and aV F . The artifact was proven to be due to a broken wire on the left leg electrode. According to Rubenfire, had this artifact occurred in a monitoring situation, auricular flutter would have inappropriately been diagnosed. We have recently observed an unusual ECG in which involuntary muscle contractions caused simulation of atrial flutter. The ECG showed typical F waves in leads to V 1 to V 2 (Fig 1). Involuntary muscle contractions of the muscle pectoralis major were observed in the anterior chest wall. These myoclonics were probably caused by the cold temperature of the room, because they disappeared immediately after a warm cover was put on the patient (Fig 2). The frequency and size of these muscle contraction waves were quite unusual and might be almost considered

Electrocardiographic artifacts simulating atrial flutter

Electrocardiographic artifacts simulating atrial flutter

Electrocardiographic artifacts simulating atrial flutter.

To the Editor.— Proper interpretation of an electrocardiogram (ECG) depends upon the competence of the equipment, the technician, and the electrocardiographer. We have recently observed an unusual electrocardiogram in which a broken wire caused simulation of atrial flutter. The ECG (Figure) performed on a 10-year-old Cambridge ECG recorder, was initially interpreted as demonstrating an unusual flutter mechanism. However, this was only evident in leads II, III, and aV F . The remaining leads, although demonstrating 60 cycles interference, showed sinus rhythm and were otherwise normal. The technician alertly switched the channel selector from lead V 1 to standard lead II and the flutter mechanism was again seen. At this point an artifact was suspected and verified to be a broken wire in the left leg electrode. Although the artifact in this particular case was rather easy to detect because the arrhythmia seemed to occur only in the inferior leads, had this

The artifactual electrocardiogram recorded during closed-chest massage

By studying compression and by analyzing instantaneous vectors of electrocardiographic artifacts produced by closed-chest cardiac massage in 12 patients, a primary mechanical etiology for the complexes was apparent. The recognition of the artifactual electrocardiogram proved useful in the differentiation of intrinsic from extrinsic electrical cardiac activity. Since the configuration of the electrocardiographic artifact is directly related to the method of sternal compression, it is of value in the instruction of proper technique for closed-chest cardiac massage.

The Artifactual Electrocardiogram Recorded During Closed-Chest Massage

By studying compression and by analyzing instantaneous vectors of electrocardiographic artifacts produced by closed-chest cardiac massage in 12 patients, a primary mechanical etiology for the complexes was apparent. The recognition of the artifactual electrocardiogram proved useful in the differentiation of intrinsic from extrinsic electrical cardiac activity. Since the configuration of the electrocardiographic artifact is directly related to the method of sternal compression, it is of value in the instruction of proper technique for closed-chest cardiac massage.

Atrial dissociation: An electrocardiographic artifact produced by the accessory muscles of respiration

The electrocardiographic features of so-called atrial dissociation are defined. Tracings obtained from 10 patients are presented wherein the relation of the phenomenon to respiration is illustrated. The origin of this respiratory artifact is discussed with reference to the action of the accessory muscles of respiration. It is concluded that of the tracings reported recently purporting to illustrate the phenomenon of atrial dissociation there are a few which must be regarded as at best doubtful documentation of such an arrhythmia. The majority are considered to be examples of the respiratory artifact as described herein.

Electrocardiographic Artefacts

Electrocardiographic Artefacts

Interrelations between hiccup and the electrocardiogram

1. 1. In five cases of recurrent hiccup the hiccup sounds were recorded synchronously with three leads of the electrocardiogram. 2. 2. In three cases the hiccup movements caused electrocardiographic artifacts which could be confused with U waves or with auricular and ventricular premature beats. 3. 3. The hiccup sounds as well as the artifacts always occurred 0.17 to 0.40 seconds after the beginning of the QRS complex of the electrocardiogram, and in some cases two successive heart beats were followed by hiccup movements. It is postulated that in the reported cases the hiccup was caused by stimulation of one of the phrenic nerves by the electric currents registering as the QRS complex of the electrocardiogram. 4. 4. The hyperirritability of the phrenic nerves in the reported cases was probably due to a decrease in the ionized serum calcium or to alkalosis.