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Neuromuscular electric stimulation in heart transplantation candidates with cardiac pacemakers
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BRIEF REPORT
Neuromuscular Electric Stimulation in Heart Transplantation Candidates With Cardiac Pacemakers Guenther F. Wiesinger, MD, Richard Crevenna, MD, Martin J. Nuhr, MD, Martin Huelsmann, MD, Veronika Fialka-Moser, MD, PhD, Michael Quittan, MD ABSTRACT. Wiesinger GF, Crevenna R, Nuhr MJ, Huelsmann M, Fialka-Moser V, Quittan M. Neuromuscular electric stimulation in heart transplantation candidates with cardiac pacemakers. Arch Phys Med Rehabil 2001;82:1476-7. Twenty percent of heart transplantation candidates have cardiac pacemakers. Application of neuromuscular electric stimulation (NMES) in patients with pacemakers is controversial because of potential electromagnetic field interference and subsequent failure of the pacemaker. We present a safety protocol as a procedure before applying NMES in pacemaker patients. In 4 patients with chronic heart failure, NMES was applied under supervised conditions for 20 minutes to evaluate the individual risk. No changes in the clinical state and no complications secondary to electromagnetic field interference were observed. A check of pacemaker function after this 20minute stimulation revealed no changes in the pacemaker parameters. After a thorough safety protocol, NMES of knee extensor muscles in patients with pacemakers appears to be safe. Key Words: Electric stimulation; Heart transplantation; Pacemaker, artificial; Rehabilitation. © 2001 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation ARDIAC TRANSPLANTATION is currently the state of the art in the treatment of severe chronic heart failure. C Heart transplantation candidates suffer from marked weakness of skeletal muscles and sometimes from cardiac cachexia.1 Neuromuscular electric stimulation (NMES) of skeletal muscles is an effective modality of strength training in patients with severe chronic heart failure who are waiting for a donor heart.2,3 NMES improves strength in the knee extensor muscles of patients with chronic heart failure who are unable to exercise; it is also an alternative to active strength training.2,3 However, all of these studies excluded persons with cardiac pacemakers. Twenty percent of heart transplantation candidates have pacemakers. The application of low-frequency electric current such as NMES in these patients is controversial because of potential electromagnetic field interference and subsequent failure of the
From the Departments of Physical Medicine and Rehabilitation (Wiesinger, Crevenna, Nuhr, Fialka-Moser, Quittan) and of Internal Medicine II/Cardiology (Huelsmann), General Hospital Vienna, University of Vienna, Vienna, Austria. Accepted in revised form December 4, 2000. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated. Reprint requests to Guenther F. Wiesinger, MD, Department of Physical Medicine and Rehabilitation, University of Vienna, Waehringer Gu¨rtel 18-20, A-1090 Vienna, Austria, e-mail: [email protected]. 0003-9993/01/8210-6400$35.00/0 doi:10.1053/apmr.2001.25908
Arch Phys Med Rehabil Vol 82, October 2001
pacemaker. Pacemaker dysfunction, such as atrial triggering or ventricular inhibition from electromagnetic interference is widely discussed, especially in connection with the use of mobile telephones.4,5 Our aim was to determine whether NMES caused pacemaker dysfunction in patients with chronic heart failure who were waiting for a donor heart. METHODS Four men (average age, 58yr) with severe chronic heart failure (New York Heart Association6 stage IV) awaiting a donor heart gave their informed-consent to undergo NMES. They had implanted bipolar dual-chamber pacemakers because of bradyarrhythmia. In a protocol to assess treatment safety, NMES was applied under intensive care conditions to 1 patient and under supervision of a physiatrist and a cardiologist to the other 3 patients to evaluate the individual risk. NMES of the knee extensor muscles was applied for 20 minutes under continuous electrocardiogram monitoring. The NMES protocol consisted of biphasic, symmetric, constant voltage impulses of 0.7-ms pulse width at a frequency of 50Hz, 2 seconds on and 6 seconds off. The impulses were applied to both knee extensor muscles, with the electric current being applied through surface electrodes. The distance between the pacemaker electrode vector and the nearest skin electrode was a minimum of 50cm in each patient. After this procedure, the pacemakers were checked by a cardiologist to detect potential changes in their programmed parameters. RESULTS During the 20-minute stimulation period, all patients received 150 on-and-off phases and 428,571 electric stimuli. No changes in the subjective or clinical state of the 4 patients were registered during or after the application of NMES. Neither atrial triggering nor ventricular inhibition secondary to electromagnetic field interference was observed during NMES treatment of the thigh muscles. The check of pacemakers revealed no changes in the programmed parameters. DISCUSSION It is well known that electromagnetic fields may interfere with normal pacemaker function.4 The development of bipolar sensing leads and modern noise filtering techniques has reduced this problem. Technical advancements have led to the production of pacemakers that are well protected against dysfunction resulting from electromagnetic field interference.4 It has been shown statistically that risk analyses to detect harmful events require an extremely large sample size to arrive at valid predictions for the community. However, large safety studies are not feasible. Conditions such as different modes of stimulation, different pacemaker types, different pacemaker models, and the location of the pacemaker electrode after implantation may also influence the potential risk for the individual patient. We included only patients with DDDR pacemakers because that type has less electromagnetic interference.4
NMES AND PACEMAKERS, Wiesinger
The amount and duration of the applied electric current is also important.5 Pacemaker dysfunction can only occur when electric current is applied. In our protocol, the single bursts of electric current lasted only 2 seconds—a period too brief for potential pacemaker dysfunction that could lead to critical cardiovascular situations. In accordance with the guidelines of the American College of Cardiology, there is no evidence that RR interval on electrocardiogram of less then 3 seconds have any harmful effects on the patients.7 The distance between the pacemaker electrode vector and an electrical source is the most important factor in electromagnetic interference and resultant pacemaker dysfunction.8 When NMES is applied to the knee extensor muscles, the electrodes closest to the pacemaker are placed on the proximal thigh, at a distance of approximately 50cm from the pacemaker.8,9 This distance is considered sufficient to permit safe NMES application without electromagnetic interference.8,9 Nevertheless, we provide a careful safety protocol in every pacemaker patient for evaluation of the risk to individuals during NMES. The pacemakers of our 4 patients showed no dysfunction or disturbances from electromagnetic interference during the 20minute stimulation period. A check of the pacemaker after NMES revealed no abnormalities. CONCLUSION From this observation, NMES of knee extensor muscles appears to be safe in pacemaker patients with bipolar DDDR pacemakers. Nevertheless, a safety protocol before NMES treatment of these patients is recommended. Further studies are needed to determine the long-term safety of NMES treatment in patients with pacemakers.
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References 1. Mancini DM, Walter G, Reichek N, Lenkinski R, McCully KK, Mullen JL, et al. Contribution of skeletal muscle atrophy to exercise intolerance and altered muscle metabolism in heart failure. Circulation 1992;85:1364-73. 2. Quittan M, Sochor A, Wiesinger GF, Kollmitzer J, Sturm B, Pacher R, et al. Strength improvement of knee extensor muscles in patients with chronic heart failure by neuromuscular electrical stimulation. Artif Organs 1999;23:432-5. 3. Quittan M, Wiesinger GF, Sturm B, Puig S, Mayr W, Sochor A, et al. Improvement of thigh muscles by neuromuscular electrical stimulation in patients with refractory heart failure. A single-blind, randomized, controlled trial. Am J Phys Med Rehabil 2001;80: 206-14. 4. Imich W, Batz L, Muller R, Tobisch R. Electromagnetic interference of pacemakers by mobile phones. Pacing Clin Electrophysiol 1996;19:1431-46. 5. Naegeli B, Oswald S, Deola M, Burkart F. Intermittent pacemaker dysfunction caused by digital mobile telephones. J Am Coll Cardiol 1996;27:1471-7. 6. Fisher JD. New York Heart Association Classification. Arch Intern Med 1972;129:836. 7. Gregoratos G, Cheitlin MD, Conill A, Epstein AE, Fellows C, Ferguson TB Jr, et al. ACC/AHA guidelines for implantation of cardiac pacemakers and antiarrhythmia devices: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Pacemaker Implantation). J Am Coll Cardiol 1998;31:1175-209. 8. Jacob C, Volkmann H, Ziegenhahn C, Uhlemann C. Sto¨rbeeinflussung von implantierten Herzschrittmachern durch apparative Physiotherapie. Z Arztl Fortbild (Berl) 1990;84:443-7. 9. Burck G, Hentschel R, Wiedemann D, Henßge R. Beeinflussung von Herzschrittmachern der MCP- und LCP-Serie durch Elektrodiagnostik- und Elektrotherapieverfahren. Z Gesamte Inn Med 1988;43:572-7.
Arch Phys Med Rehabil Vol 82, October 2001
BRIEF REPORT
Neuromuscular Electric Stimulation in Heart Transplantation Candidates With Cardiac Pacemakers Guenther F. Wiesinger, MD, Richard Crevenna, MD, Martin J. Nuhr, MD, Martin Huelsmann, MD, Veronika Fialka-Moser, MD, PhD, Michael Quittan, MD ABSTRACT. Wiesinger GF, Crevenna R, Nuhr MJ, Huelsmann M, Fialka-Moser V, Quittan M. Neuromuscular electric stimulation in heart transplantation candidates with cardiac pacemakers. Arch Phys Med Rehabil 2001;82:1476-7. Twenty percent of heart transplantation candidates have cardiac pacemakers. Application of neuromuscular electric stimulation (NMES) in patients with pacemakers is controversial because of potential electromagnetic field interference and subsequent failure of the pacemaker. We present a safety protocol as a procedure before applying NMES in pacemaker patients. In 4 patients with chronic heart failure, NMES was applied under supervised conditions for 20 minutes to evaluate the individual risk. No changes in the clinical state and no complications secondary to electromagnetic field interference were observed. A check of pacemaker function after this 20minute stimulation revealed no changes in the pacemaker parameters. After a thorough safety protocol, NMES of knee extensor muscles in patients with pacemakers appears to be safe. Key Words: Electric stimulation; Heart transplantation; Pacemaker, artificial; Rehabilitation. © 2001 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation ARDIAC TRANSPLANTATION is currently the state of the art in the treatment of severe chronic heart failure. C Heart transplantation candidates suffer from marked weakness of skeletal muscles and sometimes from cardiac cachexia.1 Neuromuscular electric stimulation (NMES) of skeletal muscles is an effective modality of strength training in patients with severe chronic heart failure who are waiting for a donor heart.2,3 NMES improves strength in the knee extensor muscles of patients with chronic heart failure who are unable to exercise; it is also an alternative to active strength training.2,3 However, all of these studies excluded persons with cardiac pacemakers. Twenty percent of heart transplantation candidates have pacemakers. The application of low-frequency electric current such as NMES in these patients is controversial because of potential electromagnetic field interference and subsequent failure of the
From the Departments of Physical Medicine and Rehabilitation (Wiesinger, Crevenna, Nuhr, Fialka-Moser, Quittan) and of Internal Medicine II/Cardiology (Huelsmann), General Hospital Vienna, University of Vienna, Vienna, Austria. Accepted in revised form December 4, 2000. No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated. Reprint requests to Guenther F. Wiesinger, MD, Department of Physical Medicine and Rehabilitation, University of Vienna, Waehringer Gu¨rtel 18-20, A-1090 Vienna, Austria, e-mail: [email protected]. 0003-9993/01/8210-6400$35.00/0 doi:10.1053/apmr.2001.25908
Arch Phys Med Rehabil Vol 82, October 2001
pacemaker. Pacemaker dysfunction, such as atrial triggering or ventricular inhibition from electromagnetic interference is widely discussed, especially in connection with the use of mobile telephones.4,5 Our aim was to determine whether NMES caused pacemaker dysfunction in patients with chronic heart failure who were waiting for a donor heart. METHODS Four men (average age, 58yr) with severe chronic heart failure (New York Heart Association6 stage IV) awaiting a donor heart gave their informed-consent to undergo NMES. They had implanted bipolar dual-chamber pacemakers because of bradyarrhythmia. In a protocol to assess treatment safety, NMES was applied under intensive care conditions to 1 patient and under supervision of a physiatrist and a cardiologist to the other 3 patients to evaluate the individual risk. NMES of the knee extensor muscles was applied for 20 minutes under continuous electrocardiogram monitoring. The NMES protocol consisted of biphasic, symmetric, constant voltage impulses of 0.7-ms pulse width at a frequency of 50Hz, 2 seconds on and 6 seconds off. The impulses were applied to both knee extensor muscles, with the electric current being applied through surface electrodes. The distance between the pacemaker electrode vector and the nearest skin electrode was a minimum of 50cm in each patient. After this procedure, the pacemakers were checked by a cardiologist to detect potential changes in their programmed parameters. RESULTS During the 20-minute stimulation period, all patients received 150 on-and-off phases and 428,571 electric stimuli. No changes in the subjective or clinical state of the 4 patients were registered during or after the application of NMES. Neither atrial triggering nor ventricular inhibition secondary to electromagnetic field interference was observed during NMES treatment of the thigh muscles. The check of pacemakers revealed no changes in the programmed parameters. DISCUSSION It is well known that electromagnetic fields may interfere with normal pacemaker function.4 The development of bipolar sensing leads and modern noise filtering techniques has reduced this problem. Technical advancements have led to the production of pacemakers that are well protected against dysfunction resulting from electromagnetic field interference.4 It has been shown statistically that risk analyses to detect harmful events require an extremely large sample size to arrive at valid predictions for the community. However, large safety studies are not feasible. Conditions such as different modes of stimulation, different pacemaker types, different pacemaker models, and the location of the pacemaker electrode after implantation may also influence the potential risk for the individual patient. We included only patients with DDDR pacemakers because that type has less electromagnetic interference.4
NMES AND PACEMAKERS, Wiesinger
The amount and duration of the applied electric current is also important.5 Pacemaker dysfunction can only occur when electric current is applied. In our protocol, the single bursts of electric current lasted only 2 seconds—a period too brief for potential pacemaker dysfunction that could lead to critical cardiovascular situations. In accordance with the guidelines of the American College of Cardiology, there is no evidence that RR interval on electrocardiogram of less then 3 seconds have any harmful effects on the patients.7 The distance between the pacemaker electrode vector and an electrical source is the most important factor in electromagnetic interference and resultant pacemaker dysfunction.8 When NMES is applied to the knee extensor muscles, the electrodes closest to the pacemaker are placed on the proximal thigh, at a distance of approximately 50cm from the pacemaker.8,9 This distance is considered sufficient to permit safe NMES application without electromagnetic interference.8,9 Nevertheless, we provide a careful safety protocol in every pacemaker patient for evaluation of the risk to individuals during NMES. The pacemakers of our 4 patients showed no dysfunction or disturbances from electromagnetic interference during the 20minute stimulation period. A check of the pacemaker after NMES revealed no abnormalities. CONCLUSION From this observation, NMES of knee extensor muscles appears to be safe in pacemaker patients with bipolar DDDR pacemakers. Nevertheless, a safety protocol before NMES treatment of these patients is recommended. Further studies are needed to determine the long-term safety of NMES treatment in patients with pacemakers.
1477
References 1. Mancini DM, Walter G, Reichek N, Lenkinski R, McCully KK, Mullen JL, et al. Contribution of skeletal muscle atrophy to exercise intolerance and altered muscle metabolism in heart failure. Circulation 1992;85:1364-73. 2. Quittan M, Sochor A, Wiesinger GF, Kollmitzer J, Sturm B, Pacher R, et al. Strength improvement of knee extensor muscles in patients with chronic heart failure by neuromuscular electrical stimulation. Artif Organs 1999;23:432-5. 3. Quittan M, Wiesinger GF, Sturm B, Puig S, Mayr W, Sochor A, et al. Improvement of thigh muscles by neuromuscular electrical stimulation in patients with refractory heart failure. A single-blind, randomized, controlled trial. Am J Phys Med Rehabil 2001;80: 206-14. 4. Imich W, Batz L, Muller R, Tobisch R. Electromagnetic interference of pacemakers by mobile phones. Pacing Clin Electrophysiol 1996;19:1431-46. 5. Naegeli B, Oswald S, Deola M, Burkart F. Intermittent pacemaker dysfunction caused by digital mobile telephones. J Am Coll Cardiol 1996;27:1471-7. 6. Fisher JD. New York Heart Association Classification. Arch Intern Med 1972;129:836. 7. Gregoratos G, Cheitlin MD, Conill A, Epstein AE, Fellows C, Ferguson TB Jr, et al. ACC/AHA guidelines for implantation of cardiac pacemakers and antiarrhythmia devices: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Pacemaker Implantation). J Am Coll Cardiol 1998;31:1175-209. 8. Jacob C, Volkmann H, Ziegenhahn C, Uhlemann C. Sto¨rbeeinflussung von implantierten Herzschrittmachern durch apparative Physiotherapie. Z Arztl Fortbild (Berl) 1990;84:443-7. 9. Burck G, Hentschel R, Wiedemann D, Henßge R. Beeinflussung von Herzschrittmachern der MCP- und LCP-Serie durch Elektrodiagnostik- und Elektrotherapieverfahren. Z Gesamte Inn Med 1988;43:572-7.
Arch Phys Med Rehabil Vol 82, October 2001