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Table of Contents
Year : 2018  |  Volume : 7  |  Issue : 1  |  Page : 43-45

Pseudo-Premature Ventricular Complex Can Herald Device Malfunction

1 Cardiac Electrophysiology Research Center, University of Medical Sciences, Tehran, Iran
2 Rajaie Cardiovascular Medical and Research Center, University of Medical Sciences, Tehran, Iran

Date of Web Publication26-Feb-2018

Correspondence Address:
Dr. Amir Farjam Fazelifar
Cardiac Electrophysiology Research Center, Iran University of Medical Sciences; Rajaie Cardiovascular Medical and Research Center; University of Medical Sciences, Tehran
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/rcm.rcm_11_17

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The increasing number of complex functions in implantable devices demands for an increased ability to recognize these features during patient monitoring and assessment. New device algorithm and lead structures are embryonic concerning device implantation; hence, we should familiarize ourselves and become alert of different types of device malfunction. Although it is unreasonable to expect to know the exact details of all algorithms, the numerous most often encountered should be discussed. This case highlights a novel device malfunction and its management in a 76-year-old male after coronary artery bypass grafts.

Keywords: Cardiac resynchronization, device malfunction, sensing abnormality

How to cite this article:
Fazelifar AF, Heidarali M, Haghjoo M. Pseudo-Premature Ventricular Complex Can Herald Device Malfunction. Res Cardiovasc Med 2018;7:43-5

How to cite this URL:
Fazelifar AF, Heidarali M, Haghjoo M. Pseudo-Premature Ventricular Complex Can Herald Device Malfunction. Res Cardiovasc Med [serial online] 2018 [cited 2023 Feb 6];7:43-5. Available from: https://www.rcvmonline.com/text.asp?2018/7/1/43/226157

  Introduction Top

New device algorithm and lead structures are evolving regarding device implantation; therefore, we should be alert of different types of device malfunction. Device registries based on the US Food and Drug Administration (FDA) showed 1.3 malfunctions per 1000 person-years (1). In the present case report, a novel device malfunction and its management are discussed.

  Case Report Top

A 76-year-old male, 8 years after coronary artery bypass grafts, presented with the episodes of dyspnea referred to our tertiary care center. His electrocardiography (ECG) showed right bundle branch block, left anterior hemiblock (QRS duration 160 ms), and first-degree atrioventricular nudal block. His left ventricular (LV) ejection fraction was about 25% with mild-to-moderate mitral regurgitation and severe LV enlargement. A three-chamber pacemaker plus defibrillator (Unify™ 3231-40Q CRT-D) was implanted for him in another center according to the American College of Cardiology-American Heart Association device guidelines.[1],[2] Two years device analysis and medical follow-up were normal. In 2012, his symptoms were presented with light-headedness, dizziness, and palpitation. ECG showed infrequent premature ventricular complexes (PVCs), sinus rhythm with markers of biventricular pacing. Device analysis reported total pace dependency with normal pacing thresholds and impedance monitoring for right atrium, right ventricle (RV), and LV leads. He referred to our center because of no response to drug therapy and PVC management. During device analysis, we could capture device sensing malfunction which was presented with pseudo-PVC [Figure 1] and should be differentiated from real PVC [Figure 2]. Real PVC could be detected in surface ECG by repolarization after depolarization and intracardiac signals are presented in both RV and LV tip channel markers [Figure 2]. In other circumstances, abnormal sensing was detected on the intracardiac RV channel, but it was not confirmed by surface ECG or intracardiac LV channel; therefore, this abnormal sensing inhibits ventricular pacing and makes symptoms such as lightheadedness or dizziness. First, we changed the pacing mode from dual-chamber (DDD) pacing mode to single-chamber ventricular pacemaker (VVI) to evaluate crosstalk phenomenon, but symptoms were not resolved. This malfunction was related either to the abnormal sensing-pacing defibrillator lead function (Durata 7120 Q) or lead-generator connector block malfunction. We programmed DDT mode instead of DDD according to the patients' pace dependency. He did not experience dizziness after new programmed mode but felt more palpitation. We decided to implant a new shock lead. Left subclavian venography showed total subclavian vein occlusion. Different approaches were available (a) Left subclavian venoplasty and insertion of a new IS4 defibrillator lead, (b) Insertion of a new IS4 defibrillator leads from the right side and tunneling into the left-sided pocket, and (c) Using an adaptor to convert IS4 model to IS1. We can implant a new sense and pace lead in the RV and connect it to the new cardiac resynchronization therapy defibrillator (CRT-D) generator, compatible with the IS1 system. Occasionally, in this situations, we can connect bipolar coronary sinus lead to the sense and pace defibrillator connector block and vice versa. The last two ways are not regularly accepted. The sensing, pacing, and lead impedances in bipolar, unipolar tip, and unipolar ring configurations, especially for RV defibrillator lead were all in normal limit. Gentle traction on Implantable cardioverter defibrillator lead did not reveal any abnormality. A new CRT-D DF4 generator (Maximo II D264 TRM) was implanted. New device analysis was absolutely normal. The pocket was closed in two layers, and DDD mode was programmed. PVC response option was turned on to avoid any problem. Next day, the CRT-D analysis was normal. He was asymptomatic, and 3 days Holter monitoring showed <2% PVC count and no pacing abnormality. He was followed for more than 2 years, and no new symptoms were reported.
Figure 1: Pseudo-premature ventricular complex. Please notice to the abnormal signals on line 4 (right ventricle sense and pace). No depolarization or repolarization on line 1 (electrocardiography lead) or line 5 (left ventricular unipolar tip marker)

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Figure 2: Real premature ventricular complex, depolarization, repolarization, and intracardiac signals can be detected on lines 1 (surface electrocardiography), 4 (intracardiac right ventricle sense and pace), and 5 (intracardiac left ventricular tip)

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  Discussion Top

New device algorithm and lead structures are evolving regarding device implantation; thus, we should be alert of different types of device malfunction. Device registries based on the US FDA showed 1.3 malfunctions per 1000 person-years.[3] In the present case report, a novel device malfunction and its management in a 76-year-old male after coronary artery bypass grafts were discussed. Several etiologies can result in nonphysiologic over-sensing, such as diaphragmatic myopotentials, movement of the fixation screw in an integrated bipolar lead system,[4] lead insulation break, cross-talk, electromagnetic interference, and loose set-screw. In the present case, nonphysiologic oversensing was differentiated from physiologic PVC sensing. All oversensing sources were checked, the devices were analyzed several times, and the programmed parameters were changed to detect the main problem. Oversensing was related to the loose set screw. Even though the problem was occurred about 2 years after device implantation and pseudo-PVCs were not seen frequently during follow-up, the patient became symptomatic according to the pace dependency. This case presentation shows connector block malfunction can be detected in a short or late period after device implantation. To the best of our knowledge, this is the first case presented with single beats pseudo-PVC and connector block abnormality was its etiology. Connector block abnormality is not time-dependent after device implantation. We should be aware of new abnormal nonphysiologic oversensing features in new device and generator series (for example, DF4 configuration). Improved recognition of these potential sources of confusion will simplify and improve patient care.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

This case report was supported by the funds of Iran University of Medical Sciences.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Maisel WH, Moynahan M, Zuckerman BD, Gross TP, Tovar OH, Tillman DB, et al. Pacemaker and ICD generator malfunctions: Analysis of food and drug administration annual reports. JAMA 2006;295:1901-6.  Back to cited text no. 1
Epstein AE, DiMarco JP, Ellenbogen KA, Estes NA 3rd, Freedman RA, Gettes LS, et al. ACC/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities: Executive Summary a Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices) Developed in Collaboration With the American Association for Thoracic Surgery and Society of Thoracic Surgeons. J Am Coll Cardiol 2008;51:e1-62.  Back to cited text no. 2
Dickstein K, Vardas PE, Auricchio A, Daubert JC, Linde C, McMurray J, et al. 2010 focused update of ESC guidelines on device therapy in heart failure: An update of the 2008 ESC guidelines for the diagnosis and treatment of acute and chronic heart failure and the 2007 ESC guidelines for cardiac and resynchronization therapy. Developed with the special contribution of the Heart Failure Association and the European Heart Rhythm Association. Eur Heart J 2010;31:2677-87.  Back to cited text no. 3
Doshi RN, Goodman J, Naik AM, Shivkumar K, Chen PS, Peter CT, et al. Initial experience with an active-fixation defibrillation electrode and the presence of nonphysiological sensing. Pacing Clin Electrophysiol 2001;24:1713-20.  Back to cited text no. 4


  [Figure 1], [Figure 2]


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