Transvenous Cardiac Pacing
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This article describes transvenous cardiac pacing. In a healthy heart, electrical impulses are generated in the sinoatrial (SA) node (sinus node), which is near the junction of the superior vena cava (SVC) and the right atrium (RA). The specialized cells of the SA node generate electrical impulses faster than other parts of the conduction system and with automaticity; therefore, these cells are usually the dominant natural pacemakers of the heart. The impulse is then conducted through the RA and left atrium (LA) and reaches the atrioventricular (AV) node.
The AV junction, which is at the base of the interatrial septum and extends into the interventricular septum, has two main parts: the AV node in the upper part, and the bundle of His in the lower part. In a healthy heart, the AV node is the only electrical connection between the atria and the ventricles. The inherent delay in transmitting the electrical impulse from the atria to the ventricles provides the appropriate diastolic duration to enable ventricular filling.
The His bundle divides into the left and right bundle branches and then into the Purkinje fibers, which conduct the impulse rapidly through the ventricles to produce rapid and simultaneous ventricular contractions. In general, symptomatic abnormalities of the conduction system are the main indications for cardiac pacing, a method by which a small pulsed electrical current is artificially delivered to the heart.
Of the several methods for temporary pacing of the heart (transcutaneous, transvenous, transesophageal, transthoracic, and epicardial), transvenous and transcutaneous cardiac pacing are the most commonly used. The main factor that dictates the use of one approach instead of another is the urgency of the need for pacing.
In an emergency where a patient is experiencing cardiac symptoms or asystole, transcutaneous pacing is the method of choice. Nevertheless, transvenous pacing has the following advantages over the transcutaneous method:
However, because transvenous pacing requires central venous access, it cannot be initiated as fast as transcutaneous pacing can, and it is associated with several complications that result from obtaining venous access.
A common scenario is one in which transcutaneous pacing is employed first in an emergency, followed by transvenous placement of a lead that will enable a longer period of pacing and evaluation in patients who may require permanent pacing later during their hospitalization.
Transvenous cardiac pacing can be used as a bridge to permanent pacing when permanent pacing is not available, when the pacing need is only temporary, or when further evaluation is required. [1] Therefore, all indications for permanent cardiac pacing are indications for transvenous pacing as well. Temporary pacing is appropriate when a permanent pacemaker must be replaced, repaired, or changed or when permanent pacing fails. In emergencies (eg, asystole), transcutaneous pacing may be the most appropriate type of temporary pacing.
Recommended indications for cardiac pacing can be complex and depend on a combination of presenting symptoms and electrocardiographic (ECG) findings. These recommendations, along with their level of supporting evidence, are well summarized by the American College of Cardiology (ACC) and the American Heart Association (AHA). [2, 3]
Because transvenous pacing is a temporary method, it may be indicated for treating a reversible condition for which permanent pacing is contraindicated. For example, Ho et al reported using transcutaneous pacing in patients with bradycardia due to hypothermia. [4]
Temporary cardiac pacing is occasionally used to determine whether a patient requires permanent pacing. However, patients treated with cardiac pacing may become pacemaker-dependent and exhibit asystole when pacing is terminated, even though they may not have experienced asystole in the absence of pacing.
Although temporary transvenous cardiac pacing is indicated primarily for the treatment of bradycardia and various types of heart block, intermittent overdrive pacing can also be used as an antitachycardic treatment for a variety of atrial and ventricular tachycardias, such as postoperative atrial flutter or monomorphic ventricular tachycardia (VT). Pacing is also used to prevent bradycardia-dependent tachycardias, such as torsades de pointes.
Reversible causes of heart block that may call for temporary cardiac pacing include the following:
In general, temporary cardiac pacing should not be considered for asymptomatic patients who have a fairly stable rhythm (eg, a first-degree AV block or a Mobitz I or stable escape rhythm). For example, pacing an asymptomatic patient with a stable escape rhythm may render that individual dependent on pacing, and withholding pacing may then cause asystole.
Although the aforementioned rhythms are stable for the most part, there are exceptions (eg, a Mobitz I rhythm with a wide QRS may originate from an infra-AV nodal area and therefore may progress to complete heart block). When in doubt, having transcutaneous pacing ready for use in emergencies may be reasonable.
In 1974, the ACC and the AHA proposed a three-digit code system for categorizing the basic functions of pacemakers. The North American Society of Pacing and Electrophysiology (NASPE) and the British Pacing and Electrophysiology Group (BPEG) continued to expand these codes, and the coding system was subsequently updated in 2002. Currently, pacemaker function is described by means of the following position codes, which are generic and are used for all brands of pacemakers:
These position codes are used to describe pacemaker modes, as follows:
Sullivan BL, Bartels K, Hamilton N. Insertion and Management of Temporary Pacemakers. Semin Cardiothorac Vasc Anesth. 2016 Mar. 20 (1):52-62. [Medline]. [Full Text].
[Guideline] 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: 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 May 27. 51(21):e1-62. [Medline]. [Full Text].
[Guideline] Epstein AE, DiMarco JP, Ellenbogen KA, et al, American College of Cardiology Foundation, American Heart Association Task Force on Practice Guidelines, et al. 2012 ACCF/AHA/HRS focused update incorporated into the ACCF/AHA/HRS 2008 guidelines for device-based therapy of cardiac rhythm abnormalities: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol. 2013 Jan 22. 61 (3):e6-75. [Medline]. [Full Text].
Ho JD, Heegaard WG, Brunette DD. Successful transcutaneous pacing in 2 severely hypothermic patients. Ann Emerg Med. 2007 May. 49 (5):678-81. [Medline].
Burger H, Schwarz T, Ehrlich W, Sperzel J, Kloevekorn WP, Ziegelhoeffer T. New generation of transvenous left ventricular leads – first experience with implantation of multipolar left ventricular leads. Exp Clin Cardiol. 2011 Spring. 16 (1):23-6. [Medline]. [Full Text].
Nag K, Nagella AB, Kumar VR, Singh DR, Ravishankar M. Role of temporary pacing at the right ventricular outflow tract in anesthetic management of a patient with asymptomatic sick sinus syndrome. Anesth Essays Res. 2015 Sep-Dec. 9 (3):423-6. [Medline]. [Full Text].
Ferri LA, Farina A, Lenatti L, Ruffa F, Tiberti G, Piatti L, et al. Emergent transvenous cardiac pacing using ultrasound guidance: a prospective study versus the standard fluoroscopy-guided procedure. Eur Heart J Acute Cardiovasc Care. 2016 Apr. 5 (2):125-9. [Medline].
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Nolewajka AJ, Goddard MD, Brown TC. Temporary transvenous pacing and femoral vein thrombosis. Circulation. 1980 Sep. 62 (3):646-50. [Medline].
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Ali A Sovari, MD, FACP, FACC Attending Physician, Cardiac Electrophysiologist, Cedars Sinai Medical Center and St John’s Regional Medical Center
Ali A Sovari, MD, FACP, FACC is a member of the following medical societies: American College of Cardiology, American College of Physicians, American Physician Scientists Association, American Physiological Society, Biophysical Society, Heart Rhythm Society, Society for Cardiovascular Magnetic Resonance
Disclosure: Nothing to disclose.
Abraham G Kocheril, MD, FACC, FACP, FHRS Professor of Medicine, University of Illinois College of Medicine
Abraham G Kocheril, MD, FACC, FACP, FHRS is a member of the following medical societies: American College of Cardiology, Central Society for Clinical and Translational Research, Heart Failure Society of America, Cardiac Electrophysiology Society, American College of Physicians, American Heart Association, American Medical Association, Illinois State Medical Society
Disclosure: Nothing to disclose.
Vincent Lopez Rowe, MD Professor of Surgery, Program Director, Vascular Surgery Residency, Department of Surgery, Division of Vascular Surgery, Keck School of Medicine of the University of Southern California
Vincent Lopez Rowe, MD is a member of the following medical societies: American College of Surgeons, American Surgical Association, Pacific Coast Surgical Association, Society for Clinical Vascular Surgery, Society for Vascular Surgery, Western Vascular Society
Disclosure: Nothing to disclose.
Luis M Lovato, MD Associate Clinical Professor, University of California, Los Angeles, David Geffen School of Medicine; Director of Critical Care, Department of Emergency Medicine, Olive View-UCLA Medical Center
Luis M Lovato, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Emergency Physicians, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.
Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Nothing to disclose.
Acknowledgments
The authors would like to thank Anne Krajacic, RN, from the Clinical Cardiac Electrophysiology Laboratory at the University of Illinois, Chicago, for her help in preparing figures for this article.
Transvenous Cardiac Pacing
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