New directions for ambulatory monitoring following 2017 HRS-ISHNE expert consensus

Abstract

The main role of ambulatory electrocardiography (AECG) in clinical practice is to detect and characterize the behavior of cardiac electrical activity during ordinary daily life activities. Because certain rhythm abnormalities may be infrequent and paroxysmal, and may occur only during sleep or in association with mental, emotional, or exercise-induced perturbation in cardiac function, AECG needs to be recorded over a long period of time, originally lasting 24 h and now expanding up to several weeks and even to months.

New technologies for continuous prolonged AECG monitoring, and new algorithms for automatic arrhythmia detection and wireless data transmission in near real-time, have significantly improved the ECG signals quality for long-term recordings and the diagnostic yield for infrequent cardiac arrhythmias.

New wireless electrode systems, such as patches, vests or belts have greatly increased the tolerability, quality and feasibility of prolonged AECG, which is particularly useful for the diagnosis of infrequent symptoms, such as unexplained syncope, palpitations or cryptogenic stroke.

Introduction

Electrocardiographic Ambulatory Monitoring (AECG) usually referred as “Holter” monitoring, now represents an essential tool in the diagnostic evaluation of patients with cardiac arrhythmias. From the first introduction in 1957, long-term monitoring systems underwent major technologic evolution, both for the acquisition and for the analysis of the ECG signals [1], [2], [3]. Holter recording evolved from the original analogic recorder based on reel-to reel magnetic tapes, then moving to cassette tape recorders. In the last two decades, new digital recorders have been developed, with miniaturized, inexpensive, stable, durable, fast and high-capacity memories allowing very prolonged and multiple channel recordings.

According to the “ACC/AHA Practice Guideline for Ambulatory Electrocardiology”, released in 1999, AECG monitoring had a class 1 indication for the clinical evaluation of symptoms attributed to cardiac arrhythmias, such as syncope and palpitation [1]. AECG was soon recognized to have a major role in the diagnostic work-up of patients with ventricular arrhythmias at risk of sudden death and for the identification of silent atrial fibrillation [4], [5], [6].

Very recently, a new document entitled “ISHNE-HRS Expert Consensus Statement on Ambulatory ECG and External Cardiac Monitoring/Telemetry”, has been developed and endorsed jointly by the International Society for Holter and Noninvasive Electrocardiology (ISHNE) and by the Heart Rhythm Society (HRS), with the purpose to review how contemporary AECG devices acquire and process ECG signals, how these signals should be interpreted, what is the appropriate utilization of AECG devices in the management of cardiovascular diseases; and how to promote standards for an accurate and appropriate use of AECG in clinical practice [7].

Today prolonged AECG is typically used to evaluate symptoms such as syncope, dizziness, chest pain, palpitations, or shortness of breath, that may correlate with intermittent and paroxysmal cardiac arrhythmias [8], [9]. Additionally, AECG is used to evaluate patient response to initiation, revision, or discontinuation of arrhythmic drug therapy, and to assess prognosis and risk of arrhythmias in specific clinical conditions. These include patients at risk of ventricular arrhythmias and sudden death, in congenital and acquired conditions such as heart failure, ischemic heart disease or genetic cardiac disorders, or in the evaluation of permanent or paroxysmal atrial fibrillation, including patients with unexplained syncope or cryptogenic stroke [4], [5], [6], [7], [8], [9], [10].