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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 32, No 2, March/April 2021
102
AFRICA
Review Article
Atrial high-rate episodes: a comprehensive review
Gelu Simu, Radu Rosu, Gabriel Cismaru, Mihai Puiu, Gabriel Gusetu, Ioan Minciuna,
Sabina Istratoaie, Raluca Tomoaia, Dumitru Zdrenghea, Dana Pop
Abstract
Cardiac electronic implantable devices (CIEDs) have the
ability to monitor, store and interpret complex arrhythmias,
which has generated a new arrhythmic entity: atrial high-rate
episodes (AHRE). AHRE are atrial tachyarrhythmias, detect-
ed only by CIEDs. They are widely considered a precursor to
atrial fibrillation (AF) but can also be represented by other
kinds of supraventricular arrhythmias such as atrial flutter or
atrial tachycardia. CIED-detected AHRE are associated with
an increased risk of stroke, but the risk is significantly lower
than the stroke risk of clinical AF. Moreover, there seems
to be no temporal correlation between AHRE and throm-
boembolic events. Because of the current gaps in evidence,
the appropriate management of this arrythmia can be chal-
lenging. In this review we take into account the epidemiol-
ogy behind AHRE, predictive factors, clinical impact and
management of this arrhythmia.
Keywords:
atrial high-rate episodes, anticoagulant agents, atrial
fibrillation, stroke, pacemaker
Submitted 23/12/19, accepted 11/11/20
Published online 15/1/21
Cardiovasc J Afr
2021;
32
: 102–107
www.cvja.co.zaDOI: 10.5830/CVJA-2020-052
Atrial fibrillation (AF) is the most common sustained
tachyarrhythmia encountered in clinical practice. Because of
its high impact on morbidity and mortality, it is also the most
studied tachyarrhythmia.
1
Despite the latest progress achieved
in managing AF, it still is one of the major causes of stroke,
heart failure, sudden death and cardiovascular morbidity.
1-4
Its incidence and prevalence are expected to rise steeply in the
following years because of population ageing and the progress
achieved in diagnosing asymptomatic episodes.
The recent development of devices capable of long-term
continuous monitoring of cardiac rhythm revealed that
asymptomatic AF is more frequent than symptomatic AF.
5-8
Despite the obvious difference in quality of life, there is currently
no evidence that these two entities have a different risk profile.
There are however several prospective ongoing trials that focus
on this subject.
9-11
Different options in long-term monitoring of the cardiac
rhythm are currently used: handheld electrocardiograph (ECG)
monitoring devices, long-term Holter ECG, subcutaneous
implantable cardiac monitors (ICM), cardiac implantable
electronic devices (CIEDs) and even smartphone ECG
applications. A significant advantage of CIEDs when compared
to other long-term rhythm-monitoring devices is their ability
to continuously monitor cardiac rhythm. Due to their complex
algorithms, modern CIEDs are able to store and interpret
complex arrythmias, which has resulted in a new arrhythmic
entity: atrial high-rate episodes (AHRE).
Definitions
The European Heart Rhythm Association (EHRA) consensus
for device-detected subclinical atrial tachyarrhythmias defines
AHRE as follows: atrial tachyarrhythmia episodes with an atrial
rate of > 190 beats/min (bpm) detected only by CIEDs.
12
The various definitions used in the literature have generated
confusionbetweenAHREand subclinical atrial tachyarrhythmias
(AT). Subclinical (asymptomatic) AT can be detected by a variety
of different methods, including external surface-monitoring
methods (standard ECGs, Holter monitors or event monitors)
and CIEDs [pacemakers, implantable cardioverter defibrillators
(ICDs)], while AHRE are detected only by CIEDs. Furthermore,
AHRE are widely considered a precursor to AF but can also be
represented by other kinds of supraventricular arrythmias such
as atrial flutter or atrial tachycardia.
12
While the impact of AHRE on morbidity and mortality has
been proven, there are certain differences when compared to AF.
CIED-detected AHRE are associated with a two-fold increase
in stroke risk when compared to patients with no AHRE, but
the risk is significantly lower than the stroke risk of clinical
AF.
13,14
This is the main reason why AHRE must be distinguished
from asymptomatic paroxysmal AF diagnosed by surface ECG
Department of Internal Medicine, Cardiology-Rehabilitation,
‘Iuliu Ha
ţ
ieganu’ University of Medicine and Pharmacy,
Cluj-Napoca, Romania
Gelu Simu, MD
Radu Rosu, MD, PhD,
rosu.radu1053@gmail.comGabriel Cismaru, MD, PhD
Mihai Puiu, MD
Gabriel Gusetu, MD, PhD
Ioan Minciuna, MD
Raluca Tomoaia, MD
Dumitru Zdrenghea, MD, PhD
Dana Pop, MD, PhD
Department of Pharmacology, Toxicology and Clinical
Pharmacology, ‘Iuliu Ha
ţ
ieganu’ University of Medicine and
Pharmacy, Cluj-Napoca, Romania
Sabina Istratoaie, MD