Abdominal Implantation of Loop Recorders in Infants and Children

The diagnostic yield from implantable loop recorders in children and young adults

BACKGROUND

Syncope and palpitations occur frequently in young patients. Noninvasive diagnostic testing may be inconclusive.

AIM

To assess the diagnostic yield of implantable loop recorders in young patients.

PATIENTS AND METHODS

Thirty-three young patients underwent implantation of a loop recorder for long-term monitoring of cardiac rhythm, to establish symptom-rhythm correlation. They belonged to one of three subgroups: those with structurally normal heart, normal electrocardiogram at rest, and negative family history (n = 16); patients with structural heart disease and previous surgical repair (n = 11), and patients with proven or suspected primary electrical disease (n = 6). A combination of automatic and patient-activated recordings was used to monitor cardiac rhythm during symptomatic episodes.

RESULTS

There were no procedural complications. Diagnostic electrograms could be obtained in all patients. A high degree of symptom-rhythm correlation was established. In 8/33 patients, no recurrence of symptoms was observed either until end of battery life of the device (n = 4) or until last follow-up (n = 2). Specific cardiac therapy was required, based on rhythms recorded by the device in 15 patients (until last follow-up). This consisted of catheter ablation of a tachyarrhythmia (n = 7), pacemaker implantation or upgrade (n = 5) or ICD implantation (n = 5). In the remaining patients (n = 10), recurrence of symptoms was associated with a normal electrocardiogram, and in two of these patients a non-cardiac diagnosis was made.

CONCLUSIONS

In selected patients, the implantable loop recorder provides valuable diagnostic information to guide further therapy.

Wireless Holter transmission in suspected dysrhythmias

BACKGROUND

In patients with a history of possible dysrhythmias, documentation of an episode is mandatory before any form of treatment is given. Holter recordings with wireless telemetry offer the possibility of continuously recording electrocardiograms for days or even weeks with instantaneous analysis of the data in the physician's office.

METHODS

Thirty-seven patients (20 male; median age, 8.4 years; range, 0.1-22 years), were investigated by using a telemetric Holter system (M120, Schiller, Switzerland), that is, intermittent transmission of the electrocardiographic data to a remote server using cell phone frequencies, with a median duration of the recordings of 6.5 days (range 1-42 days).

RESULTS

Recording quality was sufficient in all patients. Problems were related to electrode disconnections only, which were adjusted by contacting the patients. Twenty-eight of 37 recordings showed decisive findings. Of the 28 patients, no treatment was indicated in 16 patients, as subjective symptoms did not correlate with dysrhythmias; psychotherapy was indicated in 2 patients; antiarrhythmic medication was initiated or intensified in 5 patients; radiofrequency ablation was successfully performed in 5 patients; and 1 patient received an ICD. In 6 of 9 patients with negative Holter findings, a loop recorder implantation (Medtronic, Minneapolis, Minn) was indicated. In 1 patient, no dysrhythmias were recorded; however, when invasively investigated, ventricular tachycardia was detected and successfully treated by radiofrequency ablation. In 2 patients, no decision has been made to date.

CONCLUSIONS

Wireless Holter recordings are useful in detecting dysrhythmias with rare occurrence, are less expensive and less invasive compared with implantable loop recorders, and offer the patient rather wide geographic ranges with sufficient signal quality.