page111
only be used as monotherapy in predominantly seden-
tary patients.
When a single drug fails to adequately
control
the ventricular
rate,
patients
should receive
digoxin with either a beta-blocker,
diltiazem,
or verap-
amil. If ventricular function is diminished, the combina-
tion of
a beta-blocker (that is licensed for use in heart
failure) and digoxin is preferred (see section 2.5.5,
and
interactions: Appendix 1 (cardiac glycosides)). Digoxin
is also used when atrial
fibrillation is accompanied by
congestive heart failure.
Sinus
rhythm can be restored by electrical
cardio-
version,
or pharmacological
cardioversion with an oral
or intravenous anti-arrhythmic drug e.g.
flecainide or
amiodarone. If necessary, sotalol or amiodarone can be
started
4
weeks
before
electrical
cardioversion
to
increase success of
the procedure.
If
atrial
fibrillation
has been present for more than 48 hours, cardioversion
should not be attempted until the patient has been fully
anticoagulated (see section 2.8.2) for at least 3 weeks; if
this is not possible,
parenteral
anticoagulation (section
2.8.1) should be commenced and a left atrial thrombus
ruled out
immediately before cardioversion;
oral
anti-
coagulation should be given after
cardioversion and
continued for at least 4 weeks.
For atrial
fibrillation of
over 48 hours duration,
electrical
cardioversion is pre-
ferred to pharmacological methods. If drug treatment is
required to maintain sinus rhythm,
a beta-blocker
is
used.
If
a standard beta-blocker is not
appropriate or
is ineffective, an oral anti-arrhythmic drug such as sota-
lol (section 2.4), flecainide, propafenone, or amiodarone,
is required.
In symptomatic paroxysmal
atrial
fibrillation,
ventri-
cular rhythm is controlled with a beta-blocker.
Alterna-
tively,
if
symptoms
persist
or
a beta-blocker
is
not
appropriate, an oral anti-arrhythmic drug such as sota-
lol, flecainide, propafenone, or amiodarone can be given
(see
also
Paroxysmal
Supraventricular
Tachycardia
below,
and Supraventricular Arrhythmias).
In selected
patients with infrequent episodes of
symptomatic par-
oxysmal atrial fibrillation, sinus rhythm can be restored
using the ‘pill-in-the-pocket’ approach; this involves the
patient
taking oral
flecainide or
propafenone to self-
treat an episode of atrial fibrillation when it occurs.
All patients with atrial fibrillation should be assessed for
their risk of stroke and the need for thromboprophylaxis.
Anticoagulants (section 2.8) are indicated for those with
a
history
of
ischaemic
stroke,
transient
ischaemic
attacks,
or
thromboembolic
events,
and those with
valve disease,
heart failure,
or impaired left ventricular
function; anticoagulants should be considered for those
with cardiovascular disease,
diabetes,
hypertension,
or
thyrotoxicosis,
and in the elderly.
Anticoagulants are
also indicated during cardioversion procedures
(see
above).
Aspirin (section 2.9) is less effective than warf-
arin at
preventing emboli,
but
may be appropriate if
there are no other risk factors for stroke, or if warfarin is
contra-indicated.
Atrial flutter
Like atrial fibrillation, treatment options
for atrial flutter involve either controlling the ventricular
rate or attempting to restore and maintain sinus rhythm.
However,
atrial
flutter generally responds less well
to
drug treatment than atrial fibrillation.
Control
of
the ventricular
rate is usually an interim
measure pending restoration of
sinus rhythm.
Ventri-
cular rate can be controlled by administration of a beta-
blocker (section 2.4),
diltiazem [unlicensed indication],
or verapamil (section 2.6.2); an intravenous beta-block-
er or verapamil
is preferred for rapid control.
Digoxin
(section 2.1.1)
can be added if
rate control
remains
inadequate,
and may be particularly useful
in those
with heart failure.
Conversion to sinus rhythm can be achieved by elec-
trical cardioversion (by cardiac pacing or direct current),
pharmacological
cardioversion,
or catheter ablation.
If
the duration of atrial flutter is unknown, or it has lasted
for
over
48
hours,
cardioversion
should
not
be
attempted until the patient has been fully anticoagulated
(see section 2.8.2)
for at
least
3 weeks;
if
this is not
possible,
parenteral
anticoagulation
(section
2.8.1)
should be commenced and a left atrial
thrombus ruled
out
immediately
before
cardioversion;
oral
anti-
coagulation should be given after
cardioversion and
continued for at least 4 weeks.
Direct current cardioversion is usually the treatment of
choice when rapid conversion to sinus rhythm is neces-
sary (e.g.
when atrial
flutter is associated with haemo-
dynamic compromise); catheter ablation is preferred for
the treatment
of
recurrent
atrial
flutter.
There is
a
limited role for
anti-arrhythmic drugs as their
use is
not
always successful.
Flecainide or
propafenone can
slow atrial
flutter,
resulting in 1:1 conduction to the
ventricles,
and should therefore be prescribed in con-
junction with a ventricular rate controlling drug such as
a
beta-blocker,
diltiazem [unlicensed indication],
or
verapamil.
Amiodarone can be used when other drug
treatments are contra-indicated or ineffective.
All
patients should be assessed for their risk of
stroke
and the need for
thromboprophylaxis;
the choice of
anticoagulant is based on the same criteria as for atrial
fibrillation (see notes above).
Paroxysmal
supraventricular
tachycardia
This
will often terminate spontaneously or with reflex vagal
stimulation such as a Valsalva manoeuvre,
immersing
the face in ice-cold water, or carotid sinus massage; such
manoeuvres should be performed with ECG monitoring.
If the effects of reflex vagal stimulation are transient or
ineffective, or if the arrhythmia is causing severe symp-
toms,
intravenous adenosine (section 2.3.2)
should be
given.
If
adenosine is ineffective or
contra-indicated,
intravenous verapamil
(section 2.6.2) is an alternative,
but it should be avoided in patients recently treated with
beta-blockers (see p.
133).
Failure to terminate paroxysmal supraventricular tachy-
cardia with reflex vagal
stimulation or drug treatment
may suggest an arrhythmia of atrial origin, such as focal
atrial tachycardia or atrial flutter.
Treatment with direct current cardioversion is needed
in haemodynamically unstable patients
or
when the
above measures have failed to restore sinus rhythm
(and an alternative diagnosis has not been found).
Recurrent
episodes
of
paroxysmal
supraventricular
tachycardia can be treated by catheter
ablation,
or
prevented with drugs
such as
diltiazem,
verapamil,
beta-blockers including sotalol
(section 2.4),
flecainide,
or propafenone (section 2.3.2).
Arrhythmias
after
myocardial
infarction
In
patients with a paroxysmal tachycardia or rapid irregu-
larity of
the pulse it is best not to administer an anti-
arrhythmic until
an ECG record has
been obtained.
Bradycardia, particularly if complicated by hypotension,
BNF 61
2.3.1 Management of arrhythmias
91
2
Cardiovascular system