Limb Lead Interchange in Thorough QT/QTc Studies

The investigators analyzed 85 133 electrocardiograms (ECGs) recorded in 484 subjects from 5 thorough QT/QTc studies (3 using Holter devices, 2 using 12‐lead ECGs) for inadvertent limb lead interchanges using a dedicated quality control process in a central ECG laboratory. Limb lead interchanges were present in 2919 (3.4%) ECGs in 17.9% of subjects and were more frequent with Holter devices (7.5% vs 0.8%, P < .0001), where leads remain connected for prolonged periods, affecting data from several time points. Left arm—left leg interchange was seen in 54% of 12‐lead ECGs and right arm—left arm interchange in 38%. The ECG device itself could identify 21.7% of interchanges, whereas experienced readers blinded to subject and visit identified 79% of interchanges; 21% of interchanges were identified only during the quality control process. If correctly identified, QT measurement could be performed in a precordial lead. If undiagnosed, incorrect QT interval measurements and morphological diagnosis may confound results.

[1]  I. Hoffman.  Einthoven's left foot: a plea for disciplined electrode placement. , 2008, Journal of electrocardiology.

[2]  K. C. Ho,et al.  Use of the sinus P wave in diagnosing electrocardiographic limb lead misplacement not involving the right leg (ground) lead. , 2001, Journal of electrocardiology.

[3]  M. Malik,et al.  Measurement, interpretation and clinical potential of QT dispersion. , 2000, Journal of the American College of Cardiology.

[4]  O. Pahlm,et al.  Detection of frequently overlooked electrocardiographic lead reversals using artificial neural networks. , 1996, The American journal of cardiology.

[5]  J A Kors,et al.  Accurate automatic detection of electrode interchange in the electrocardiogram. , 2001, The American journal of cardiology.

[6]  Eugen Palma,et al.  Variable Patterns of Preexcitation: What is the Mechanism? , 2003, Journal of cardiovascular electrophysiology.

[7]  Derek J Rowlands.  Inadvertent interchange of electrocardiogram limb lead connections. Analysis of predicted consequences. , 2008, Journal of electrocardiology.

[8]  Ferenc Follath,et al.  Electrocardiographic artifacts due to electrode misplacement and their frequency in different clinical settings. , 2007, The American journal of emergency medicine.

[9]  C. Tracy,et al.  ACC/AHA clinical competence statement on electrocardiography and ambulatory electrocardiography: A report of the ACC/AHA/ACP-ASIM task force on clinical competence (ACC/AHA Committee to develop a clinical competence statement on electrocardiography and ambulatory electrocardiography) endorsed by the , 2001, Circulation.

[10]  Galen S Wagner,et al.  The influence of cardiograph design and automated algorithms on the incidence and detection of electrode cable reversals in an academic electrocardiogram laboratory. , 2008, Journal of electrocardiology.

[11]  Elsayed Z Soliman.  Recording electrocardiograms using 3-limb lead cables instead of the standard 4: a modification to minimize incorrect electrode placements. , 2008, Journal of electrocardiology.

[12]  Mary E Coleman.  A technicians' perspective: tips and techniques for using disposable tab electrocardiogram electrodes; an easy to remember method for preventing electrocardiogram lead interchange. , 2006, Journal of electrocardiology.

[13]  J. Seward,et al.  American College of Cardiology/American Heart Association clinical competence statement on echocardiography: a report of the American College of Cardiology/American Heart Association/American College of Physicians--American Society of Internal Medicine Task Force on Clinical Competence. , 2003, Circulation.

[14]  Ferenc Follath,et al.  Influence of electrode misplacement on the electrocardiographic signs of inferior myocardial ischemia. , 2003, The American journal of emergency medicine.

[15]  I. Hoffman,et al.  A flatline electrocardiogram in lead II is a marker for right arm/right leg electrode switch. , 2007, Journal of electrocardiology.

[16]  Robert J Myerburg,et al.  Images in cardiovascular medicine: Left bundle-branch block with technical right-axis deviation. , 2002, Circulation.

[17]  An Evaluation of ECG Leads Used to Assess QT Prolongation , 2006, Cardiology.

[18]  J A Milliken,et al.  Recognition of electrocardiographic left arm/left leg lead reversal. , 1997, The American journal of cardiology.

[19]  S. Horwitz,et al.  Left anterior hemiblock or inadvertent lead misplacement? , 1976, Chest.

[20]  Marek Malik,et al.  Incorrect electrode cable connection during electrocardiographic recording. , 2007, Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology.

[21]  I. Hoffman.  A flatline lead I results from bilateral arm-to-leg electrode exchange. , 2008, Journal of electrocardiology.

[22]  D. Karnad,et al.  Update on the evaluation of a new drug for effects on cardiac repolarization in humans: issues in early drug development , 2010, British journal of pharmacology.

[23]  J. Ornato,et al.  Recognition of electrocardiographic lead misplacements. , 1993, The American journal of emergency medicine.

[24]  N. Saoudi,et al.  Electrocardiographic Patterns Resulting From Improper Connections of the Right Leg (Ground) Cable , 1985, Pacing and clinical electrophysiology : PACE.

[25]  David L Ware,et al.  Unusual Evolution of ST Elevation Acute Myocardial Infarction , 2004, Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc.

[26]  L. Edenbrandt,et al.  Recognition of lead reversals in pediatric electrocardiograms. , 1998, The American journal of cardiology.

[27]  A Guijarro-Morales,et al.  ECG diagnostic errors due to improper connection of the right arm and leg cables. , 1991, International journal of cardiology.

[28]  Reginald T Ho,et al.  Simple Diagnosis of Limb‐Lead Reversals by Predictable Changes in QRS Axis , 2006, Pacing and clinical electrophysiology : PACE.

[29]  Vincenzo Marafioti,et al.  Pseudoinfarction pattern by misplacement of electrocardiographic precordial leads. , 2004, The American journal of emergency medicine.

[30]  K. R. Bennett,et al.  Observations on the use of the aVR-V6 relationship to recognize limb lead error. , 2009, The Journal of emergency medicine.

[31]  Freeman T Bennett,et al.  Einthoven's triangle: lead errors and an algorithm for solution. , 2005, The American journal of the medical sciences.