- Email: [email protected]
Safety of capsule endoscopy in patients with pacemakers
Safety of capsule endoscopy in patients with pacemakers
10.
11.
12.
13.
thoracic duct lymph in multiple organ dysfunction syndrome. Arch Surg 1997;132:13-8. Lemaire LC, van Deventer SJ, van Lanschot JJ, Meenan J, Gouma DJ. Phenotypical characterization of cells in the thoracic duct of patients with and without systemic inflammatory response syndrome and multiple organ failure. Scand J Immunol 1998;47:69-75. Vaughan JH, Fox RI, Abresch RJ, Rsoukas CD, Curd DJ, Carson DA. Thoracic duct drainage in rheumatoid arthritis. Clin Exp Immunol 1984;59:645-53. Duger Nier T, Reynaert MS, Deby-Dupont G, Roeseler JJ, Carlier M, Squifflet JP, et al. Prospective evaluation of thoracic duct drainage in the treatment of respiratory failure complicating severe acute pancreatitis. Intensive Care Med 1989; 15:372-8. Franksson C, Lundgren G, Magnusson G, Ringden O. Drainage of thoracic duct lymph in renal transplant patients. Transplantation 1976;212:133-40.
CASE STUDIES Safety of capsule endoscopy in patients with pacemakers Jonathan A. Leighton, MD, Virender K. Sharma, MD, Komandoor Srivathsan, MD, Russell I. Heigh, MD, Tony L. McWane, MA, Janice K. Post, RN, Sara R. Robinson, LPN, Jane L. Bazzell, RN, David E. Fleischer, MD Background: Capsule endoscopy, a new technology, allows visualization of the entire small intestinal mucosa. The main indication for capsule endoscopy at present is the evaluation of GI bleeding of obscure origin. Studies to date suggest that capsule endoscopy is safe and is associated with few adverse events. One concern, which has not been studied, is the potential effect of the capsule on cardiac pacemakers and other electromedical devices. The primary aims of this study were to evaluate the safety of capsule endoscopy in patients with cardiac pacemakers who are being evaluated for GI bleeding of obscure origin and to determine whether pacemakers have any effect on the images captured by the capsule endoscope. Methods: Patients with cardiac pacemakers referred for evaluation of GI bleeding of obscure origin were entered into the study. Before the procedure, an electrocarReceived August 26, 2003. For revision October 22, 2003. Accepted November 25, 2003. Current affiliations: Division of Gastroenterology and Hepatology and Division of Cardiology, Mayo Clinic Arizona, Scottsdale, Arizona. Reprint requests: Jonathan A. Leighton, MD, Division of Gastroenterology, Mayo Clinic Arizona, 13400 E. Shea Blvd., Scottsdale, AZ 85259. Copyright Ó 2004 by the American Society for Gastrointestinal Endoscopy 0016-5107/$30.00 PII: S0016-5107(03)02879-7 VOLUME 59, NO. 4, 2004
J Leighton, V Sharma, K Srivathsan, et al.
14. Guy-Grand D, Azogui O, Celli S, Darche S, Nussenzweig MC, Khourilsky P, et al. Extrathymic T cell lymphopoiesis: ontogeny and contribution to intraepithelial lymphocytes in athymic and euthymic mice. J Exp Med 2003; 197:333-41. 15. Klein RL, Rudel LL. Cholesterol absorption and transport in thoracic duct lymph lipoproteins of non-human primates: effect of dietary cholesterol. J Lipid Res 1983;24:343-56. 16. Gashev AA. Physiologic aspects of lymphatic contractile function: current perspectives. Ann N Y Acad Sci 2002;979: 178-87. 17. Reddy NP. Lymph circulation: physiology, pharmacology, and biomechanics. Crit Rev Biomed Eng 1986;14:45-91. 18. Swartz AM. The physiology of the lymphatic system. Adv Drug Deliv Rev 2001;50:3-20. 19. Nishimaki T, Tanaka O, Suzuki T, Aizawa K, Hatakeyma K, Muto T. Pattern of lymphatic spread in thoracic esophageal cancer. Cancer 1994;74:4-11.
diogram was obtained, and pacemaker functions were checked. Capsule endoscopy was performed in a hospital setting to allow closer monitoring, instead of the outpatient clinic, which is our routine. Cardiac rhythm was assessed simultaneously during capsule endoscopy with a Holter monitor. Post-procedure pacemaker function was again checked for any disturbance. When the capsule endoscopy studies were reviewed, observations were made with particular reference to technical difficulty or interference with imaging. Observations: Five consecutive patients (4 men, 1 woman; mean age, 73 years, range 56-92 years) with cardiac pacemakers were studied. In all patients, the indication for capsule endoscopy was GI bleeding of obscure origin. A cardiologist and pacemaker nurse specialist reviewed the Holter monitor recordings and evaluated pacemaker function after the procedure for each patient. No arrhythmia or other adverse cardiac event was noted during capsule transmission. No pacemaker-induced interference on the capsule endoscopy images was observed. Conclusions: Capsule endoscopy appears to be safe in patients with cardiac pacemakers and does not appear to be associated with any significant adverse cardiac event. Pacemakers do not interfere with capsule imaging.
Capsule endoscopy (CE), a new advanced technology, enables endoscopic evaluation of the entire small intestinal mucosa.1,2 The capsule endoscope is ingested after an 8-hour fast and is propelled through the small intestine by peristalsis. It is composed of a lens, a light source, a complementary metal-oxide semiconductor (CMOS) imaging sensor, a battery, and a transmitter. The development of this CMOS imaging sensor has made CE possible because it requires less energy to operate and is more light sensitive compared with previously developed integrated imaging sensors. The capsule endoscope transmits the acquired images via a digital radiofrequency communication channel to the data GASTROINTESTINAL ENDOSCOPY
567
J Leighton, V Sharma, K Srivathsan, et al.
recorder unit located outside the body. The data recorder is an external receiving/recording unit that receives the data transmitted by the capsule. The portable data recorder consists of a sensor array (antenna), carried in proximity to the body; a receiver; and memory for accumulation of the data acquired during the examination. There is a theoretical potential for interference between the digital radiofrequency communication of the capsule (434.09 MHz) and a cardiac pacemaker. This concern led the Food and Drug Administration in the United States and the manufacturer (Given Imaging, Yoqneam, Israel) to list the presence of a cardiac pacemaker as a relative contraindication to the use of CE. Electromagnetic interference can be defined as electrical signals of non-physiologic origin that may affect pacemaker or implantable cardioverter defibrillator (ICD) function. The potential for radiofrequency electrosurgery to interfere with pacemaker function is well known.3 Because elderly patients comprise the population most at risk for GI bleeding of obscure origin and constitute the same population that also may have pacemakers, it is important to clarify whether there is any interaction between the components of the capsule endoscope and pacemakers. The aims of this study were to determine if the capsule endoscope interferes with normal pacemaker functions and whether pacemakers interfere with CE imaging. PATIENTS AND METHODS All consecutive patients with cardiac pacemakers who were referred for CE were included in this observational study. An endoscopy assistant (a registered nurse) and a technician identified the patients, together with a cardiology registered nurse trained in pacemaker management. For each patient, a standard electrocardiogram was obtained, and pacemaker functions were checked at baseline evaluation. Cardiac rhythm was monitored during CE by means of a Holter monitor. After the procedure, pacemaker functions again were checked. All patients were studied in a hospital setting for the purpose of closer monitoring. Our institutional review board reviewed and approved this study. The Given Diagnostic Imaging System (Given Imaging, Norcross, Ga.) was used for CE. This system has 3 main subsystems: a capsule endoscope, a recorder, and a workstation. The disposable and ingestible 11 3 26-mm capsule (M2A; Given Imaging) consists of 4 light-emitting diodes, a lens, a CMOS sensor, two batteries, a transmitter, and an antenna. The capsule endoscope acquires images during natural peristaltic propulsion through the digestive tract. The hemispheric lens has a 1408 field of view and magnifies images 8:1. Images are acquired at a rate of 2 per second with approximately 50,000 recorded over the 8 hours of 568
GASTROINTESTINAL ENDOSCOPY
Safety of capsule endoscopy in patients with pacemakers
a CE study. The capsule endoscope transmits the acquired images via a digital radiofrequency communication channel to the data recorder unit located outside the body. The portable data recorder consists of a sensor array (antenna) carried in proximity to the body, a receiver, and memory for accumulation of the data acquired during the examination. Upon completion of the examination, the nurse/technician transfers the accumulated data in the data recorder via high-capacity digital link to a computer workstation for interpretation. The workstation is a modified standard personal computer that is intended for off-line storage, interpretation, and analysis of the acquired data and for generating reports. Patients undergoing CE were instructed to consume a regular diet during the day before the examination. They also were advised to eat nothing after midnight the evening before CE, i.e., to fast for 8 hours before the procedure. Patients were permitted to take essential medication 2 hours before the procedure and to resume taking medication 2 hours after capsule ingestion. Patients reported to the Endoscopy Suite at 7:00 am and were met by the study nurse. Men had the abdomen shaved. The sensor array was then applied in a standard manner to the abdomen by using adhesive pads, and then connected to the data recorder and battery pack, which fit in a belt worn around the waist. The capsule endoscope was activated and then swallowed by the patient with a glass of water. The patients were permitted to drink fluid at 2 hours and to eat solid food at 4 hours after swallowing the capsule. They were instructed to avoid any strenuous activity during the next 8 hours and to contact the nurse or physician if they experienced nausea, vomiting, or abdominal pain. Patients also were provided with a diary to record activity, including consumption of food and drink. The sensor array and data recorder were removed after 8 hours. All CE studies were reviewed for evidence of technical difficulties or interference with imaging.
OBSERVATIONS Five consecutive patients with cardiac pacemakers implanted for symptomatic bradyarrhythmias undergoing CE were studied. The indication for CE was GI bleeding of obscure origin in all cases. The primary end point was any identified disturbance in pacemaker function during or immediately after CE. A cardiologist and pacemaker nurse specialist reviewed the Holter monitor recordings and checked pacemaker functions for each patient. Results of the pre- and post-procedure pacemaker checks and Holter monitor recordings are shown in Table 1. Occasional premature atrial contractions and premature ventricular contractions were observed in 3 patients. One patient had a 3-beat run of non-sustained ventricular tachycardia. A hemodynamically significant arrhythmia was not recorded for any patient. Normal pacemaker functions were not altered. No other complication was noted. No patient complained of any problem or symptom. VOLUME 59, NO. 4, 2004
Safety of capsule endoscopy in patients with pacemakers
J Leighton, V Sharma, K Srivathsan, et al.
Table 1. Pacemaker data Pat 1 pre Mode Device Tachyarrhythmia Failure to capture Threshold change Bradyarrhythmia Symptoms Magnetic mode Holter
Medtronic None None No None None No 3 beat VT
Pat 1 pos Pat 2 pre Pat 2 pos DDDR Medtronic None None No None None No
DDDR CPI None None No None None No PVC/PAC
DDDR CPI None None No None None No
Pat 3 pre
Pat 3 pos
DDDR CPI None None No None None No Upper rate behavior
DDDR CPI None None No None None No
Pat 4 pre DDDR St Jude None None No No None No Occ PVC/APC
Pat 4 pos Pat 5 pre DDDR St Jude None None No No None No
VVIR Medtronic None None No No None No Occ PVC
Pat 5 pos VVIR Medtronic None None No No None No
DDDR, Dual chamber rate responsive; VVIR, single chamber rate responsive; NC, no change.
Capsule endoscopy images from the 5 patients were reviewed. No technical difficulty was encountered. There was no interference noted in the images. DISCUSSION Capsule endoscopy clearly has a place in the armamentarium for evaluation of certain GI disorders, especially GI bleeding of obscure origin.4 Many of the patients with these disorders are elderly, and some have underlying cardiac disease that requires pacemaker implantation. Therefore, it is of critical importance to know whether this new technology can be used safely in this group of patients. Electromagnetic devices may interfere with the function of pacemakers.5,6 Interference with ICDs may have even more serious cardiac consequences.7 In the present study, patients with pacemakers alone were studied. Pre- and post-procedure assessment did not reveal any clinically significant alteration in the functions of the pacemakers. The pacemakers in all patients had leads with a bipolar configuration, the type least susceptible to external interference.7 Radiofrequency treatment of hepatic neoplasms in patients with permanent pacemakers has been reported to be safe.8 The vector of radiofrequency transmission is mostly within the abdomen and, therefore, away from the pacemaker location, which also is helpful in reducing interference. The present small study suggests that CE is safe in patients with cardiac pacemakers. Although there is the theoretical potential for interference with the pacemaker from the digital radiofrequency communication between the capsule and the data recorder, no significant effect was observed in any of the 5 patients studied. In addition, there was no instance in which the pacemaker interfered with the images acquired with the capsule endoscope. As a result of this study, patients with pacemakers are no longer hospitalized by us for CE, but this sub-population VOLUME 59, NO. 4, 2004
of patients is continuing to be followed prospectively by us. Capsule endoscopy is likely to be used more frequently in the elderly, many of whom also have pacemakers. The small number of patients is a limitation of the present study, but the results suggest that CE is safe in patients with pacemakers. Larger studies, however, will be required to confirm these observations and to formulate guidelines for the use of CE in patients with pacemakers. Capsule endoscopy in patients with an ICD was not evaluated by the present study. Further study is needed of the safety of CE in patients with an ICD, including the potential for technical problems with the interpretation of CE in patients with this type of implanted device. REFERENCES 1. Iddan G, Meron G, Glukhovsky A, Swain P. Wireless capsule endoscopy. Nature 2000;405:417. 2. Appleyard M, Glukhovsky A, Swain P. Wireless-capsule diagnostic endoscopy for recurrent small-bowel bleeding. N Engl J Med 2001;344:232-3. 3. Vanerio G, Maloney J, Rashidi R, McCowan R, Castle L, Morant V, et al. The effects of percutaneous catheter ablation on preexisting permanent pacemakers. Pacing Clin Electrophysiol 1990;13:1637-45. 4. Yousfi M, Sharma VK, Leighton JA, Musil D, WcWane T, Fleischer D. Video capsule endoscopy (VCE) for obscure gastrointestinal bleeding (OGIB) and iron deficiency anemia (IDA). Gastroenterology 2002;122:A-18. 5. Hayes DL, Wang PJ, Reynolds DW, Estes M 3rd, Griffith JL, Steffens RA, et al. Interference with cardiac pacemakers by cellular telephones. N Engl J Med 1997;336:1473-9. 6. Dodinot B, Godenir JP, Costa AB. Electronic article surveillance: a possible danger for pacemaker patients. Pacing Clin Electrophysiol 1993;16:46-53. 7. Santucci PA, Haw J, Trohman RG, Pinski SL. Interference with an implantable defibrillator by an electronic antitheftsurveillance device. N Engl J Med 1998;339:1371-4. 8. Hayes DL, Charboneau JW, Lewis B, Asirvatham SJ, Dupuy DE, Lexvold NY. Radiofrequency treatment of hepatic neoplasms in patients with permanent pacemakers. Mayo Clin Proc 2001;76:950-2. GASTROINTESTINAL ENDOSCOPY
569
10.
11.
12.
13.
thoracic duct lymph in multiple organ dysfunction syndrome. Arch Surg 1997;132:13-8. Lemaire LC, van Deventer SJ, van Lanschot JJ, Meenan J, Gouma DJ. Phenotypical characterization of cells in the thoracic duct of patients with and without systemic inflammatory response syndrome and multiple organ failure. Scand J Immunol 1998;47:69-75. Vaughan JH, Fox RI, Abresch RJ, Rsoukas CD, Curd DJ, Carson DA. Thoracic duct drainage in rheumatoid arthritis. Clin Exp Immunol 1984;59:645-53. Duger Nier T, Reynaert MS, Deby-Dupont G, Roeseler JJ, Carlier M, Squifflet JP, et al. Prospective evaluation of thoracic duct drainage in the treatment of respiratory failure complicating severe acute pancreatitis. Intensive Care Med 1989; 15:372-8. Franksson C, Lundgren G, Magnusson G, Ringden O. Drainage of thoracic duct lymph in renal transplant patients. Transplantation 1976;212:133-40.
CASE STUDIES Safety of capsule endoscopy in patients with pacemakers Jonathan A. Leighton, MD, Virender K. Sharma, MD, Komandoor Srivathsan, MD, Russell I. Heigh, MD, Tony L. McWane, MA, Janice K. Post, RN, Sara R. Robinson, LPN, Jane L. Bazzell, RN, David E. Fleischer, MD Background: Capsule endoscopy, a new technology, allows visualization of the entire small intestinal mucosa. The main indication for capsule endoscopy at present is the evaluation of GI bleeding of obscure origin. Studies to date suggest that capsule endoscopy is safe and is associated with few adverse events. One concern, which has not been studied, is the potential effect of the capsule on cardiac pacemakers and other electromedical devices. The primary aims of this study were to evaluate the safety of capsule endoscopy in patients with cardiac pacemakers who are being evaluated for GI bleeding of obscure origin and to determine whether pacemakers have any effect on the images captured by the capsule endoscope. Methods: Patients with cardiac pacemakers referred for evaluation of GI bleeding of obscure origin were entered into the study. Before the procedure, an electrocarReceived August 26, 2003. For revision October 22, 2003. Accepted November 25, 2003. Current affiliations: Division of Gastroenterology and Hepatology and Division of Cardiology, Mayo Clinic Arizona, Scottsdale, Arizona. Reprint requests: Jonathan A. Leighton, MD, Division of Gastroenterology, Mayo Clinic Arizona, 13400 E. Shea Blvd., Scottsdale, AZ 85259. Copyright Ó 2004 by the American Society for Gastrointestinal Endoscopy 0016-5107/$30.00 PII: S0016-5107(03)02879-7 VOLUME 59, NO. 4, 2004
J Leighton, V Sharma, K Srivathsan, et al.
14. Guy-Grand D, Azogui O, Celli S, Darche S, Nussenzweig MC, Khourilsky P, et al. Extrathymic T cell lymphopoiesis: ontogeny and contribution to intraepithelial lymphocytes in athymic and euthymic mice. J Exp Med 2003; 197:333-41. 15. Klein RL, Rudel LL. Cholesterol absorption and transport in thoracic duct lymph lipoproteins of non-human primates: effect of dietary cholesterol. J Lipid Res 1983;24:343-56. 16. Gashev AA. Physiologic aspects of lymphatic contractile function: current perspectives. Ann N Y Acad Sci 2002;979: 178-87. 17. Reddy NP. Lymph circulation: physiology, pharmacology, and biomechanics. Crit Rev Biomed Eng 1986;14:45-91. 18. Swartz AM. The physiology of the lymphatic system. Adv Drug Deliv Rev 2001;50:3-20. 19. Nishimaki T, Tanaka O, Suzuki T, Aizawa K, Hatakeyma K, Muto T. Pattern of lymphatic spread in thoracic esophageal cancer. Cancer 1994;74:4-11.
diogram was obtained, and pacemaker functions were checked. Capsule endoscopy was performed in a hospital setting to allow closer monitoring, instead of the outpatient clinic, which is our routine. Cardiac rhythm was assessed simultaneously during capsule endoscopy with a Holter monitor. Post-procedure pacemaker function was again checked for any disturbance. When the capsule endoscopy studies were reviewed, observations were made with particular reference to technical difficulty or interference with imaging. Observations: Five consecutive patients (4 men, 1 woman; mean age, 73 years, range 56-92 years) with cardiac pacemakers were studied. In all patients, the indication for capsule endoscopy was GI bleeding of obscure origin. A cardiologist and pacemaker nurse specialist reviewed the Holter monitor recordings and evaluated pacemaker function after the procedure for each patient. No arrhythmia or other adverse cardiac event was noted during capsule transmission. No pacemaker-induced interference on the capsule endoscopy images was observed. Conclusions: Capsule endoscopy appears to be safe in patients with cardiac pacemakers and does not appear to be associated with any significant adverse cardiac event. Pacemakers do not interfere with capsule imaging.
Capsule endoscopy (CE), a new advanced technology, enables endoscopic evaluation of the entire small intestinal mucosa.1,2 The capsule endoscope is ingested after an 8-hour fast and is propelled through the small intestine by peristalsis. It is composed of a lens, a light source, a complementary metal-oxide semiconductor (CMOS) imaging sensor, a battery, and a transmitter. The development of this CMOS imaging sensor has made CE possible because it requires less energy to operate and is more light sensitive compared with previously developed integrated imaging sensors. The capsule endoscope transmits the acquired images via a digital radiofrequency communication channel to the data GASTROINTESTINAL ENDOSCOPY
567
J Leighton, V Sharma, K Srivathsan, et al.
recorder unit located outside the body. The data recorder is an external receiving/recording unit that receives the data transmitted by the capsule. The portable data recorder consists of a sensor array (antenna), carried in proximity to the body; a receiver; and memory for accumulation of the data acquired during the examination. There is a theoretical potential for interference between the digital radiofrequency communication of the capsule (434.09 MHz) and a cardiac pacemaker. This concern led the Food and Drug Administration in the United States and the manufacturer (Given Imaging, Yoqneam, Israel) to list the presence of a cardiac pacemaker as a relative contraindication to the use of CE. Electromagnetic interference can be defined as electrical signals of non-physiologic origin that may affect pacemaker or implantable cardioverter defibrillator (ICD) function. The potential for radiofrequency electrosurgery to interfere with pacemaker function is well known.3 Because elderly patients comprise the population most at risk for GI bleeding of obscure origin and constitute the same population that also may have pacemakers, it is important to clarify whether there is any interaction between the components of the capsule endoscope and pacemakers. The aims of this study were to determine if the capsule endoscope interferes with normal pacemaker functions and whether pacemakers interfere with CE imaging. PATIENTS AND METHODS All consecutive patients with cardiac pacemakers who were referred for CE were included in this observational study. An endoscopy assistant (a registered nurse) and a technician identified the patients, together with a cardiology registered nurse trained in pacemaker management. For each patient, a standard electrocardiogram was obtained, and pacemaker functions were checked at baseline evaluation. Cardiac rhythm was monitored during CE by means of a Holter monitor. After the procedure, pacemaker functions again were checked. All patients were studied in a hospital setting for the purpose of closer monitoring. Our institutional review board reviewed and approved this study. The Given Diagnostic Imaging System (Given Imaging, Norcross, Ga.) was used for CE. This system has 3 main subsystems: a capsule endoscope, a recorder, and a workstation. The disposable and ingestible 11 3 26-mm capsule (M2A; Given Imaging) consists of 4 light-emitting diodes, a lens, a CMOS sensor, two batteries, a transmitter, and an antenna. The capsule endoscope acquires images during natural peristaltic propulsion through the digestive tract. The hemispheric lens has a 1408 field of view and magnifies images 8:1. Images are acquired at a rate of 2 per second with approximately 50,000 recorded over the 8 hours of 568
GASTROINTESTINAL ENDOSCOPY
Safety of capsule endoscopy in patients with pacemakers
a CE study. The capsule endoscope transmits the acquired images via a digital radiofrequency communication channel to the data recorder unit located outside the body. The portable data recorder consists of a sensor array (antenna) carried in proximity to the body, a receiver, and memory for accumulation of the data acquired during the examination. Upon completion of the examination, the nurse/technician transfers the accumulated data in the data recorder via high-capacity digital link to a computer workstation for interpretation. The workstation is a modified standard personal computer that is intended for off-line storage, interpretation, and analysis of the acquired data and for generating reports. Patients undergoing CE were instructed to consume a regular diet during the day before the examination. They also were advised to eat nothing after midnight the evening before CE, i.e., to fast for 8 hours before the procedure. Patients were permitted to take essential medication 2 hours before the procedure and to resume taking medication 2 hours after capsule ingestion. Patients reported to the Endoscopy Suite at 7:00 am and were met by the study nurse. Men had the abdomen shaved. The sensor array was then applied in a standard manner to the abdomen by using adhesive pads, and then connected to the data recorder and battery pack, which fit in a belt worn around the waist. The capsule endoscope was activated and then swallowed by the patient with a glass of water. The patients were permitted to drink fluid at 2 hours and to eat solid food at 4 hours after swallowing the capsule. They were instructed to avoid any strenuous activity during the next 8 hours and to contact the nurse or physician if they experienced nausea, vomiting, or abdominal pain. Patients also were provided with a diary to record activity, including consumption of food and drink. The sensor array and data recorder were removed after 8 hours. All CE studies were reviewed for evidence of technical difficulties or interference with imaging.
OBSERVATIONS Five consecutive patients with cardiac pacemakers implanted for symptomatic bradyarrhythmias undergoing CE were studied. The indication for CE was GI bleeding of obscure origin in all cases. The primary end point was any identified disturbance in pacemaker function during or immediately after CE. A cardiologist and pacemaker nurse specialist reviewed the Holter monitor recordings and checked pacemaker functions for each patient. Results of the pre- and post-procedure pacemaker checks and Holter monitor recordings are shown in Table 1. Occasional premature atrial contractions and premature ventricular contractions were observed in 3 patients. One patient had a 3-beat run of non-sustained ventricular tachycardia. A hemodynamically significant arrhythmia was not recorded for any patient. Normal pacemaker functions were not altered. No other complication was noted. No patient complained of any problem or symptom. VOLUME 59, NO. 4, 2004
Safety of capsule endoscopy in patients with pacemakers
J Leighton, V Sharma, K Srivathsan, et al.
Table 1. Pacemaker data Pat 1 pre Mode Device Tachyarrhythmia Failure to capture Threshold change Bradyarrhythmia Symptoms Magnetic mode Holter
Medtronic None None No None None No 3 beat VT
Pat 1 pos Pat 2 pre Pat 2 pos DDDR Medtronic None None No None None No
DDDR CPI None None No None None No PVC/PAC
DDDR CPI None None No None None No
Pat 3 pre
Pat 3 pos
DDDR CPI None None No None None No Upper rate behavior
DDDR CPI None None No None None No
Pat 4 pre DDDR St Jude None None No No None No Occ PVC/APC
Pat 4 pos Pat 5 pre DDDR St Jude None None No No None No
VVIR Medtronic None None No No None No Occ PVC
Pat 5 pos VVIR Medtronic None None No No None No
DDDR, Dual chamber rate responsive; VVIR, single chamber rate responsive; NC, no change.
Capsule endoscopy images from the 5 patients were reviewed. No technical difficulty was encountered. There was no interference noted in the images. DISCUSSION Capsule endoscopy clearly has a place in the armamentarium for evaluation of certain GI disorders, especially GI bleeding of obscure origin.4 Many of the patients with these disorders are elderly, and some have underlying cardiac disease that requires pacemaker implantation. Therefore, it is of critical importance to know whether this new technology can be used safely in this group of patients. Electromagnetic devices may interfere with the function of pacemakers.5,6 Interference with ICDs may have even more serious cardiac consequences.7 In the present study, patients with pacemakers alone were studied. Pre- and post-procedure assessment did not reveal any clinically significant alteration in the functions of the pacemakers. The pacemakers in all patients had leads with a bipolar configuration, the type least susceptible to external interference.7 Radiofrequency treatment of hepatic neoplasms in patients with permanent pacemakers has been reported to be safe.8 The vector of radiofrequency transmission is mostly within the abdomen and, therefore, away from the pacemaker location, which also is helpful in reducing interference. The present small study suggests that CE is safe in patients with cardiac pacemakers. Although there is the theoretical potential for interference with the pacemaker from the digital radiofrequency communication between the capsule and the data recorder, no significant effect was observed in any of the 5 patients studied. In addition, there was no instance in which the pacemaker interfered with the images acquired with the capsule endoscope. As a result of this study, patients with pacemakers are no longer hospitalized by us for CE, but this sub-population VOLUME 59, NO. 4, 2004
of patients is continuing to be followed prospectively by us. Capsule endoscopy is likely to be used more frequently in the elderly, many of whom also have pacemakers. The small number of patients is a limitation of the present study, but the results suggest that CE is safe in patients with pacemakers. Larger studies, however, will be required to confirm these observations and to formulate guidelines for the use of CE in patients with pacemakers. Capsule endoscopy in patients with an ICD was not evaluated by the present study. Further study is needed of the safety of CE in patients with an ICD, including the potential for technical problems with the interpretation of CE in patients with this type of implanted device. REFERENCES 1. Iddan G, Meron G, Glukhovsky A, Swain P. Wireless capsule endoscopy. Nature 2000;405:417. 2. Appleyard M, Glukhovsky A, Swain P. Wireless-capsule diagnostic endoscopy for recurrent small-bowel bleeding. N Engl J Med 2001;344:232-3. 3. Vanerio G, Maloney J, Rashidi R, McCowan R, Castle L, Morant V, et al. The effects of percutaneous catheter ablation on preexisting permanent pacemakers. Pacing Clin Electrophysiol 1990;13:1637-45. 4. Yousfi M, Sharma VK, Leighton JA, Musil D, WcWane T, Fleischer D. Video capsule endoscopy (VCE) for obscure gastrointestinal bleeding (OGIB) and iron deficiency anemia (IDA). Gastroenterology 2002;122:A-18. 5. Hayes DL, Wang PJ, Reynolds DW, Estes M 3rd, Griffith JL, Steffens RA, et al. Interference with cardiac pacemakers by cellular telephones. N Engl J Med 1997;336:1473-9. 6. Dodinot B, Godenir JP, Costa AB. Electronic article surveillance: a possible danger for pacemaker patients. Pacing Clin Electrophysiol 1993;16:46-53. 7. Santucci PA, Haw J, Trohman RG, Pinski SL. Interference with an implantable defibrillator by an electronic antitheftsurveillance device. N Engl J Med 1998;339:1371-4. 8. Hayes DL, Charboneau JW, Lewis B, Asirvatham SJ, Dupuy DE, Lexvold NY. Radiofrequency treatment of hepatic neoplasms in patients with permanent pacemakers. Mayo Clin Proc 2001;76:950-2. GASTROINTESTINAL ENDOSCOPY
569