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Table of Contents
Year : 2012  |  Volume : 15  |  Issue : 1  |  Page : 47-49
Earthing defect: A cause for unstable hemodynamics

Department of Anaesthesiology and Critical Care, Pondicherry Institute of Medical Sciences, Kanagachettikulam, Pondicherry, India

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Date of Submission18-Jun-2011
Date of Acceptance31-Aug-2011
Date of Web Publication5-Jan-2012


Interference of monitored electrocardiogram (ECG) is a common event in intensive care units and operation theaters. Artifacts in the ECG tracing can resemble serious arrhythmia, thus leading to unnecessary usage of antiarrhythmics or electrical defibrillation. In addition, ECG artifacts may lead to serious hemodynamic consequences secondary to intra-aortic balloon pump (IABP) trigger failure. We report a rare event of IABP failure due to ECG artifact, which appeared on placement of the transthoracic echocardiography probe over the chest. Subsequent evaluation revealed potential current leakage from echocardiography machine secondary to earthing defect in the machine.

Keywords: Earthing defect, electrocardiogram artifact, echocardiography, intra-aortic balloon pump failure

How to cite this article:
Selvan R B, Rao PB, Ramachandran T R, Veliath DG. Earthing defect: A cause for unstable hemodynamics. Ann Card Anaesth 2012;15:47-9

How to cite this URL:
Selvan R B, Rao PB, Ramachandran T R, Veliath DG. Earthing defect: A cause for unstable hemodynamics. Ann Card Anaesth [serial online] 2012 [cited 2022 Nov 28];15:47-9. Available from:

   Introduction Top

Intra-aortic balloon pump (IABP) therapy is considered to be a class I indication (american college of cardiology/american heart association guidelines) for the management of cardiogenic shock not rapidly reversed by pharmacological therapy. [1] This is a clinical scenario where one needs echocardiography as well for the evaluation of left ventricular function. We report here, an uncommon but significant observation based on electrocardiogram (ECG) artifact secondary to interaction between two very common and essential machineries, echocardiography and the intra-aortic counter pulsation system.

   Case Report Top

A 55-year-old male presented to the casualty with history of chest pain and breathlessness for last 6 h. He was diagnosed to have anterolateral wall myocardial infarction with left ventricular dysfunction (left ventricular ejection fraction=40%). Coronary angiography revealed triple vessel disease with 90% occlusion of the left main coronary artery for which he underwent emergency coronary artery bypass graft surgery. Intraoperative period was uneventful. After weaning from cardiopulmonary bypass, he was shifted to cardiac ICU on nor-adrenalin 0.05 mg/kg/min, dobutamine 5 mg/kg/min, and IABP (Datascope System 97e, Datascope Corporation, Paramus, NJ, USA) on ECG trigger in lead 2 with a 1:1 augmentation ratio. ECG input to the IABP machine was provided through a cable attached to the main monitor (Agilent V24, Philips Corporation, Boeblingen, Germany). The following day, transthoracic echocardiography (Just Vision 200, Toshiba Corporation, Tuchigi, Japan) was planned to evaluate postoperative myocardial contractility. On placement of the echocardiography probe in the left fourth intercostal space to get the parasternal short axis view, ECG trace on the monitor went isoelectic mimicking cardiac arrest. IABP ceased to function instantaneously and mean arterial pressure dropped from 70 to 40 mm Hg. But, to our relief, arterial blood pressure and plethysmography tracings were normal during the event. When echocardiography probe was taken off the chest, ECG trace resumed and IABP started to function with immediate improvement in the hemodynamics. Placing the probe again onto the chest led to a similar event. Immediate diagnosis of ECG interference was made. IABP trigger changed to pressure mode and echocardiography was performed.

Evaluation of the interference started with the power source, optimum positioning and skin contact of the electrodes (3M Monitoring electrode, 3M Health Care, MN, USA) and ECG cable, for any contact with electrical sources. Echocardiography probe was placed again after changing the ECG leads, which produced similar ECG interference. Thus, the probe along with machine was sent to the biomedical department for evaluation. They reported a current leakage and earth continuity test confirmed the earthing fault.

   Discussion Top

Artifacts, which are not uncommon during ECG monitoring, can mimic the entire range of pathologic electrocardiographic findings, ranging from arrhythmia to ischemic changes. [2] However, accurate differentiation of ECG artifacts from true pathologies is generally poor among physicians, [3] resulting in unnecessary and potentially dangerous therapeutic interventions. [4] In addition, this may lead to potentially dangerous hemodynamic alterations when the patient is on IABP with ECG trigger mode. Sakiewicz et al. reported an abnormal ECG artifact from concomitant use of hemodialysis machine and IABP. [5] Literature evidence speaks about many possible reasons behind an ECG artifact as follows:

  1. Equipment-induced motion artifact: They are due to epidermal stretch-induced voltage change, which can mimic atrial flutter/ventricular tachycardia, for example, IABP, high frequency oscillatory ventilation. [6]
  2. Current leakage, grounding failure, and interference by capacitance: ECG artifacts may be due to interference from alternating current in the power outlets, light fixtures, and other electrical apparatus, which are not grounded properly. Furthermore, equipments like fluid infusion controller, fiber-optic bronchoscope, microdebrider for sinus surgery, pressure-controlled irrigation pump for shoulder surgery, and others, have also been reported due to current leakage. [7]
  3. Static and piezoelectric effects: Piezoelectricity is an electrical charge generated by the mechanical deformation of polymeric materials. Common scenarios are patients on cardiopulmonary bypass [8] and in patients receiving dialysis [5] due to the generation of static and piezoelectric currents in pumps rotating between 50 and 600 rpm.
  4. Electrostimulators: Like transcutaneous electrical nerve stimulator, somatosensory-evoked potentials unit, peripheral nerve stimulator, and so on. [7]
  5. Electromagnetic and radiofrequency interference: Electrocautery-induced electrical interference on the electrocardiogram is mainly due to high-frequency currents (radiofrequency range) of 800,000 to 1 million Hz (800-1000 kHz). Other contributing factors are power line (50/60 Hz) and low-frequency noise (0.1-10 Hz) from intermittent contact of the electrosurgical unit with the patient tissue. [9] It has been also described with the use of cell phones, [10] and intraoperative magnetic resonance imaging. [11]
  6. Others: Isolated power supply line isolation monitors, power distribution system components, televisions, radio, elevator motors, fluorescent lights, light dimmers, and smoke detectors.

In our patient, ECG artifact was so unique that it resembled asystolic cardiac arrest, which resulted from earthing defect-induced alternating current leakage in the echocardiography machine.

   Conclusion Top

Concurrent use of IABP on ECG trigger mode and transthoracic echocardiography is not a rare scenario in cardiac ICUs. Additionally, ECG artifact arising out of many possible reasons, can lead to IABP malfunction and thus hemodynamic instability. Medical professionals should have a high index of suspicion of ECG interference while encountering bizarre ECG rhythm, especially earthing defect before deciding for any therapeutic intervention. Recent advancements, such as "smart ECG interpreting software," may be promising in this aspect.

   References Top

1.Ryan TJ, Antman EM, Brooks NH, Califf RM, Hillis LD, Hiratzka LF, et al. 1999 update: ACC/AHA Guidelines for the Management of Patients with Acute Myocardial Infarction: Executive Summary and Recommendations: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Acute Myocardial Infarction). Circulation 1999;100:1016-30.  Back to cited text no. 1
2.Chase C, Brady WJ. Artifactual electrocardiographic change mimicking clinical abnormality on the ECG. Am J Emerg Med 2000;18:312-6.  Back to cited text no. 2
3.Knight BP, Pelosi F, Michaud GF, Strickberger SA, Morady F. Physician interpretation of electrocardiographic artifact that mimics ventricular tachycardia. Am J Med 2001;110:335-8.  Back to cited text no. 3
4.Knight BP, Pelosi F, Michaud GF, Strickberger SA, Morady F. Clinical consequences of electrocardiographic artifact mimicking ventricular tachycardia. N Engl J Med 1999 21;341:1270-4.  Back to cited text no. 4
5.Sakiewicz PG, Wright E, Robinson O, Mercer R, Kickel K, Paganini EP. Abnormal electrical stimulus of an intra-aortic balloon pump with concurrent support with continuous veno-venous hemodialysis. ASAIO J 2000;46:142-5.  Back to cited text no. 5
6.Patel S. Electrocardiographic artifact mimicking ventricular tachycardia during high-frequency oscillatory ventilation: A case report. Am J Crit Care 2006;15:310-1.  Back to cited text no. 6
7.Patel SI, Souter MJ. Equipment-related electrocardiographic artifacts: Causes, characteristics, consequences, and correction. Anesthesiology 2008;108:138-48.  Back to cited text no. 7
8.Khambatta HJ, Stone JG, Wald A, Mongero LB. Electrocardiographic artifacts during cardiopulmonary bypass. Anesth Analg 1990;71:88-91.  Back to cited text no. 8
9.Jain A, Solanki SL, Bhagat H. Electrocautery interference with intraoperative electrocardiogram mimicking ST-segment elevation. J Electrocardiol 2011;44:67-8.  Back to cited text no. 9
10.van Lieshout EJ, van der Veer SN, Hensbroek R, Korevaar JC, Vroom MB, Schultz MJ. Interference by new-generation mobile phones on critical care medical equipment. Crit Care 2007;11:R98.  Back to cited text no. 10
11.Jekic M, Ding Y, Dzwonczyk R, Burns P, Raman SV, Simonetti OP. Magnetic field threshold for accurate electrocardiography in the MRI environment. Magn Reson Med 2010;64:1586-91.  Back to cited text no. 11

Correspondence Address:
R Barani Selvan
Department of Anaesthesiology and Critical Care, Pondicherry Institute of Medical Sciences, Kanagachettikulam, Pondicherry 605 014
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0971-9784.91482

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