Abdominal Implantation of Loop Recorders in Infants and Children Narayanswami Sreeram, MD, Francois Hitchcock, MD, and Gerardus Bennink, MD University Hospital of Cologne, Cologne, Germany, and University Medical Center, Utrecht, the Netherlands
FEATURE ARTICLES
Implantable loop recorders have an important role in establishing symptom–rhythm correlation in adults with recurrent syncope or palpitations. The standard location of these devices is in a subcutaneous prepectoral pocket. As the device is bulky, this is not an ideal location in young patients. We report a technique of abdominal
implantation of this device in 10 consecutive infants and children, achieving an excellent cosmetic result and diagnostic-quality electrograms at follow-up.
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been approved by the Institutional Ethics Committee (January 1999). Under general anesthesia a small, 2-cm-long transverse incision is made in the midline, adjacent to the subxiphoid area. A pocket is created behind the rectus abdominis, while staying in front of the peritoneal cavity. The device is positioned longitudinally in this pocket (Fig 1), and the wound is closed in layers using 4.0 Vicryl sutures. No preimplant surface ECGs were recorded to determine ideal device orientation. There were no procedure-related complications. Patients were discharged from hospital the next day. Over a median follow-up of 8 months (range, 2 to 14 months or until device explantation) there were no infectious or other complications associated with using the abdominal location. Excellent quality electrograms were obtained in all patients during follow-up (Fig 2). Symptom–rhythm correlation was obtained for all patients. Established diagnoses included the following: recurrent supraventricular tachycardia (n ⫽ 3), recurrent ventricular tachycardia (n ⫽ 2), sinus arrest and asystole requiring pacemaker implantation (n ⫽ 2), Munchausen’s syndrome by proxy (suffocation resulting in hypoxemia, with junctional escape rhythm and ST-segment changes; n ⫽ 1) [4], or sinus tachycardia (n ⫽ 2). There were no false positive or negative events related to undersensing or oversensing of cardiac electrical events.
yncope, near-syncope, and palpitations are common symptoms in childhood. While the majority of such symptoms are benign, they may occasionally be a marker for a malignant and potentially lethal arrhythmia. When conventional testing is negative, a recently developed diagnostic option has been the use of an implantable loop recorder (ILR Reveal; Medtronic, Minneapolis, MN) to allow continuous monitoring of cardiac rhythm for prolonged periods of as long as several months. This device has two surface electrodes and can continuously record the electrocardiogram (ECG) for as long as 42 minutes [1]. The standard implantation technique, for both adults and children, has been to choose a prepectoral subcutaneous location for the device [2]. Preimplant surface mapping with standard ECG electrodes is recommended to determine the optimal implant location and orientation of the device [3]. As the device is rather bulky (61 mm ⫻ 19 mm ⫻ 8 mm), it is often not possible to implant it prepectorally in young patients and achieve a cosmetically satisfactory result. We report a technique of abdominal submuscular implantation in 10 children.
Technique Ten consecutive infants and children (age range, 0.8 to 6 years), weighing between 9.0 and 26.5 kg, underwent abdominal ILR implantation for long-term assessment of cardiac rhythm. Indications for implant included acute life-threatening event (n ⫽ 2), recurrent syncope, with a positive family history of sudden cardiac death (n ⫽ 3), or recurrent syncope without any apparent provocation (n ⫽ 5). Four of the 10 patients had undergone prior surgical repair of a congenital heart defect. Informed consent was obtained before all procedures. The use of the device had Accepted for publication Nov 21, 2003. Address reprint requests to Dr Sreeram, Department of Pediatric Cardiology, University Hospital of Cologne, Jozef Stelzmann Str 9, 50924 Cologne, Germany; e-mail:
[email protected].
© 2005 by The Society of Thoracic Surgeons Published by Elsevier Inc
(Ann Thorac Surg 2005;79:726 –7) © 2005 by The Society of Thoracic Surgeons
Comment In adults with undiagnosed syncope, the use of the ILR has enabled symptom-to-rhythm correlation to be established for the majority of patients [5]. The use of the device in pediatric practice has been limited [2]. This limitation is partly related to cost issues. An important additional consideration has been the relative bulk of the device in relation to patient size. Unlike standard pacemakers—for example, the St. Jude Microny device, which is to date the smallest single-chamber system, measuring approximately 35 mm ⫻ 33 mm ⫻ 6 mm and which can be implanted prepectorally or retropectorally—the ILR is 0003-4975/05/$30.00 doi:10.1016/j.athoracsur.2003.11.019
Ann Thorac Surg 2005;79:726 –7
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subcutaneous implant. As the distance to the heart is short, abdominal implant does not affect the quality of the recorded electrograms. Prior testing with standard ECG leads to guide optimal device location also appears to be unnecessary for these patients.
References
Fig 1. Abdominal plain x-ray film showing device location 24 hours after implant in a 6-year-old boy. Despite the apparent distance between the device and the heart, excellent electrograms could be obtained.
61 mm long and produces a cosmetically unsatisfactory result when implanted in the chest wall in young patients. Implantation in the abdomen obviates several of the potential problems (skin necrosis, unacceptable cosmetic result, twiddling) associated with a superficial
1. Krahn AD, Klein GJ, Yee R, Norris C. The etiology of syncope in patients negative non-invasive and invasive testing: final results from a pilot study with an implantable loop recorder. Am J Cardiol 1998;82:117–9. 2. Rossano J, Bloemers B, Sreeram N, Balaji S, Shah MJ. Efficacy of implantable loop recorders in establishing symptomrhythm correlation in young patients with syncope and palpitations. Pediatrics 2003;112:e228 –33. 3. Krahn AD, Klein GJ, Yee R, Takle-Newhouse T, Norris C. Use of an extended monitoring strategy in patients with problematic syncope. Circulation 1999;99:406 –10. 4. Hoorntje TM, Langerak W, Sreeram N. Munchausen’s syndrome by proxy identified with an implantable electrocardiographic recorder. N Engl J Med 1999;341:1478 –9. 5. Krahn AD, Klein GJ, Skanes AC, Yee R. Use of implantable loop recorder in evaluation of patients with unexplained syncope. J Cardiovasc Electrophysiol 2003;14(Suppl 9):70 –3.
FEATURE ARTICLES
Fig 2. Automatically recorded electrogram 6 weeks after loop recorder implant, demonstrating nocturnal sinus bradycardia.