An insertable loop recorder (ILR) in patients with infrequent syncope or palpitations may be useful to decide management strategies, including clinical observation, medical therapy, pacemaker, or implantable cardioverter defibrillator (ICD). We sought to determine the diagnostic utility of the Reveal ILR (Medtronic, Inc., Minneapolis, MN, USA) in pediatric patients.
Retrospective review of clinical data, indications, findings, and therapeutic decision in 27 consecutive patients who underwent ILR implantation from 1998-2007.
The median age was 14.8 years (2-25 years). Indications were syncope in 24 patients and recurrent palpitations in three. Overall, eight patients had structural heart disease (six congenital heart disease, one hypertrophic cardiomyopathy, one Kawasaki), five had previous documented ventricular arrhythmias with negative evaluation including electrophysiology study, and three patients had QT prolongation. Tilt testing was performed in 10 patients, of which five had neurocardiogenic syncope but recurrent episodes despite medical therapy. After median three months (1-20 months), 17 patients presented with symptoms and the ILR memory was analyzed in 16 (no episode stored in one due to full device memory), showing asystole or transient atrioventricular (AV) block (2), sinus bradycardia (6), or normal sinus rhythm (8). Among asymptomatic patients, 3/10 had intermittent AV block or long pauses, automatically detected and stored by the ILR. In 19 of 20 patients, ILR was diagnostic (95%) and five subsequently underwent pacemaker implantation, while seven patients remained asymptomatic without ILR events. Notably, no life-threatening events were detected. The ILR was explanted in 22 patients after a median of 22 months, two due to pocket infection, 12 for battery depletion and eight after clear documentation of nonmalignant arrhythmia.
The ILR in pediatrics is a useful adjunct to other diagnostic studies. Patient selection is critical as the ILR should not be utilized for malignant arrhythmias. A diagnosis is attained in the majority of symptomatic patients, predominantly bradyarrhythmias including pauses and intermittent AV block.
[Show abstract][Hide abstract] ABSTRACT: Knowledge of what occurs during spontaneous syncope is the gold standard for evaluation. Initially, implantable loop recorders (ILRs) were used in patients with unexplained syncope at the end of unsuccessful full, conventional work-up. In pooled data regarding 247 patients, a correlation between syncope and electrocardiographic findings was found in 84 patients (34%); of these, 52% had a bradycardia or asystole at the time of the recorded event, 11% had tachycardia, and 37% had no arrhythmia. Presyncope-electrocardiography correlation was observed in another third of the patients; presyncope was much less likely to be associated with an arrhythmia than was syncope. The diagnostic yield was similar in patients with and without structural heart diseases and was higher in older than in younger patients. Recent studies showed that ILR implantation can be safely performed in an early phase of the diagnostic evaluation--provided that patients at risk for life-threatening events are carefully excluded--in the patients who have a severe presentation of syncope (because of high risk of trauma or high frequency of episodes) which can be a benefit of a mechanism-specific therapy.
[Show abstract][Hide abstract] ABSTRACT: Event or loop recorders monitor heart rhythm using discontinuous ECG storage which enables them to obtain a correlation between symptoms and the underlying heart rhythm in patients with infrequent, short-lasting episodes. External event recorders with intermittent monitoring, i.e., with electrodes within the device, are suitable for patients with palpitations or tachycardia who remain conscious. External event recorders with continuous monitoring are tolerated by patients for a few weeks and have a limited diagnostic impact in patients with recurrent syncope. The implantable loop recorder (ILR) monitors heart rhythm for one year and after patient-triggered or automatic activation stores a one-lead ECG up to 42 minutes prior to device activation. The diagnostic benefit of ILR in comparison to conventional approaches has been demonstrated in randomised studies. Furthermore, an ILR identifies patients with recurrent syncope of unknown origin in whom a pacemaker implantation can avoid further episodes. Additional possible indications are the monitoring of atrial fibrillation, the diagnostics of infrequent palpitations and patients with seizures.
[Show abstract][Hide abstract] ABSTRACT: Implantable loop recorders (ILR) have been found to be useful in the diagnosis and management of syncope of unclear etiology. The clinical symptoms of abnormalities seen during ILR monitoring have not been adequately studied.
The aim of this retrospective study was to determine the clinical symptoms which were the best predictors of asystolic or bradycardic responses during ILR monitoring.
Patients with either asystole or bradycardia recorded during ILR monitoring were analyzed from our database. The clinical characteristics of these patients were compared to the patients with ILR's who did not have recorded bradycardic episodes. The episodes were characterized as being convulsive or nonconvulsive, brief (<5 minutes) or prolonged (> 5 minutes), and having had a prodrome or no prodrome.
Eleven patients (4 males and 7 females; age 39 +/-11 years) had asystole or bradycardia on ILR monitoring. Eleven patients (2 males and 9 females; age 46+/-23) had no bradycardiac events. Palpitations, convulsive syncope, prolonged episode, and prodrome were present in 37% vs. 74% (P = 0.125), 62% vs. 0% (P = 0.002), 87% vs. 0% (P=0), and 73% vs. 13% (P=0.009) patients, respectively, in the asystole/bradycardia and non-bradycardia groups. In the asystole/bradycardia group eight patients had bradycardia (HR < 20) for > 10 seconds and three patients had asystole >10 seconds.
Convulsive syncope, prolonged loss of consciousness during syncopal episode, and absence of prodrome or aura are clinical predictors of asystole or bradycardia on ILR monitoring.
International journal of medical sciences 02/2009; 6(2):106-10. · 2.00 Impact Factor
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