ECG loop recorders have a retrospective (loop) memory which continuously records and deletes the patient's ECG. They include a patient-activation function that allows the patient to activate ECG storage as a result of symptoms and an auto-activation feature that allows the capture of arrhythmic events without relying on patient compliance or perception of symptoms. Loop recorder devices can be both implantable (ILR) and external (ELR). Table 1 summarizes the characteristics of the most common diagnostic loop recorders. The retrospective memory differentiates loop recorders from prospective-only event recorders. While event recorders have some usefulness in patients with intermittent palpitations, they have no indication to detect syncope.\n\nView this table:\n\nTable 1 \nMost common implantable and external loop recorders\n\n\n\nKnowledge of what occurs during a spontaneous event is the ideal gold standard for evaluation. Patients with infrequent short-duration transient symptoms, recurring over weeks or months, are unlikely to be diagnosed by conventional Holter monitoring, since the likelihood of symptom-ECG correlation is very low. Consideration should be given to patient-activated event recording in such patients, but this technique has important limitations that might prevent a successful ECG recording of the event, especially for those with syncope, as it implies the activation of recording by the patients once the patient has already recovered consciousness. In such circumstances, consideration should be given to implantable and external ECG loop recorders. It is likely that loop recorders will become increasingly important, and their use will increasingly be appropriate instead of, or before, many current conventional investigations. This early loop recorder approach implies, on the one hand, the need for careful initial risk stratification in order to exclude from such a strategy patients with potential life-threatening conditions that require immediate hospitalization or intensive evaluation and treatment. On the other hand, as a general rule ECG loop recorders are indicated only when there is …

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Indications for the use of diagnostic implantable and external ECG loop recorders (vol 11, pg 671, 2009)

https://www.medpagetoday.com/upload/2013/12/16/11009-1.pdf

ACCF/AHA/ASE/ASNC/HFSA/HRS/SCAI/SCCT/SCMR/STS 2013 Multimodality Appropriate Use Criteria for the Detection and Risk Assessment of Stable Ischemic Heart Disease

Background: Syncope, or fainting, affects approximately 6.2% of the population, and is associated with significant comorbidity. Many syncopal events occur secondary to excessive venous pooling and capillary filtration in the lower limbs when upright. As such, a common approach to the management of syncope is the use of compression stockings. However, research confirming their efficacy is lacking. We aimed to investigate the effect of graded calf compression stockings on orthostatic tolerance. Methodology/Principal Findings: We evaluated orthostatic tolerance (OT) and haemodynamic control in 15 healthy volunteers wearing graded calf compression stockings compared to two placebo stockings in a randomized, cross-over, double-blind fashion. OT (time to presyncope, min) was determined using combined head-upright tilting and lower body negative pressure applied until presyncope. Throughout testing we continuously monitored beat-to-beat blood pressures, heart rate, stroke volume and cardiac output (finger plethysmography), cerebral and forearm blood flow velocities (Doppler ultrasound) and breath-by-breath end tidal gases. There were no significant differences in OT between compression stocking (26.062.3 min) and calf (29.362.4 min) or ankle (27.663.1 min) placebo conditions. Cardiovascular, cerebral and respiratory responses were similar in all conditions. The efficacy of compression stockings was related to anthropometric parameters, and could be predicted by a model based on the subject’s calf circumference and shoe size (r=0.780, p=0.004). Conclusions/Significance: These data question the use of calf compression stockings for orthostatic intolerance and highlight the need for individualised therapy accounting for anthropometric variables when considering treatment with compression stockings.

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Are Compression Stockings an Effective Treatment for Orthostatic Presyncope

A B S T R A C T Introduction and objectives: Implantable loop recorders have proven efficacy in the study of patients with syncope and palpitations. Remote monitoring of patients with pacemakers and implantable cardioverter-defibrillators has been shown to be safe and effective. The purpose of this study was to analyze the safety and effectiveness of remote monitoring in patients with an implantable loop recorder. Methods: Retrospective observational study in which 109 patients with an implantable loop recorder were analyzed and 2 population groups were compared: 1 receiving conventional follow-up consisting of 3-monthly office visits (41 patients) and 1 with remote monitoring via monthly telephone transmissions and yearly visits (68 patients). The mean follow-up was 64 weeks (range, 0.57-164.57 weeks). The study analyzed diagnosis of a significant event, defined as any event that led to a therapeutic approach and explained the symptoms leading to the implant, as well as the mean time from implant to diagnosis and the specific treatment. Results: A significant event was diagnosed in 82.6% of patients; of these, 54.4% had a normal electrocardiogram; 26.7%, asystole; 15.6%, tachycardia, and 3.3%, bradycardia. The mean time from implant to diagnosis was 260 days (range, 5-947 days) in conventional follow-up, compared with 56 days (range, 0-650 days) in patients with remote monitoring (P<.01), which led to targeted treatment in this group 187 days earlier, on average, with no secondary complications. Conclusions: Remote monitoring of patients with an implantable loop recorder can significantly shorten the time to diagnosis and targeted treatment, without adversely affecting patient safety.

Effectiveness and Safety of Remote Monitoring of Patients With an Implantable Loop Recorder

Implantable loop recorders (ILRs) are increasingly being used for ambulatory electrocardiography. We sought to evaluate ILR indications, diagnostic yield, ILR-guided interventions, and complications in two Canadian centers. This was a retrospective study using electronic medical records to identify ILR implants at Queen’s University and the University of Manitoba. Information was collected on patient characteristics, medications, indication for implant, results of prior investigations, diagnostic outcome, and subsequent management. A total of 540 patients were identified; 386 had completed monitoring at time of analysis. Forty patients were lost to follow-up. Indications were unexplained syncope 84.8%, palpitations 12.8%, and suspected atrial fibrillation 11.7%. For syncope, ILRs documented arrhythmia or conduction disorder in 46%. Most common conditions were asystole/sinus pause (22%), complete heart block (10.4%), and atrial fibrillation (AF) (6.9%). After ILR diagnosis, 39.9% of implanted patients received pacemaker/ICD and 2.7% underwent catheter ablation. For palpitations, ILRs documented arrhythmia or conduction disorder in 60.4%. Most common conditions were AVNRT, AF, complete heart block, and ventricular tachycardia. After diagnosis, 25% underwent catheter ablation and 22.9% received pacemaker/ICD. For suspected AF, AF was diagnosed in 40%. Complications were observed in 3.3% of implanted patients: implant site infection 1.5%, non-infectious implant site pain requiring device removal or pocket revision 1.5%, 0.2% hypertrophic scar, and 0.2% device malfunction. An ILR has excellent diagnostic yield for syncope, palpitations, and suspected AF, and a considerable proportion of patients undergo ILR-directed interventions following monitoring. ILR implantation is a low-risk procedure.

Implantable loop recorders in the real world: a study of two Canadian centers

Responsabilidad Las Guias de Practica Clinica recogen la opinion de la ESC y se han elaborado tras una consideracion minuciosa de las evidencias disponibles en el momento en que fueron escritas. Se anima a los profesionales de la sanidad a que las tengan en plena consideracion cuando ejerzan su juicio clinico. No obstante, las Guias de Practica Clinica no deben invalidar la responsabilidad individual de los profesionales de la salud a la hora de tomar decisiones adecuadas a las circunstancias individuales de cada paciente, consultando con el propio paciente y, cuando sea necesario y pertinente, con su tutor o representante legal. Tambien es responsabilidad del profesional de la salud verificar las normas y los reglamentos que se aplican a los farmacos o dispositivos en el momento de la prescripcion.

Steve W. Parry

Papers

Guía de práctica clínica para el diagnóstico y manejo del síncope (versión 2009)