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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 31, No 3, May/June 2020
154
AFRICA
Rhythm-control therapy in AF
Maintenance of sinus rhythm is the primary goal, especially
for patients younger than 65 years with severe symptoms or
first-diagnosed AF.
17,18
For these individuals, restoration and
maintenance of sinus rhythm may alleviate symptoms and
improve the quality of life. Selection of the anti-arrhythmic drug
for maintenance of sinus rhythm is based on the drug’s safety
and efficacy. Generally, class Ic and IIIc anti-arrhythmic drugs
are mainly used for maintenance of sinus rhythm (Table 1).
Class Ic treatment with flecainide or propafenone is often
preferred, which exerts its effects by blocking sodium channels
to reduce the rate of rise of the action potential and reduce
excitation of the cardiac tissue. Class Ic drugs are recommended
for paroxysmal AF, but their use is contra-indicated for AF
patients with underlying structural heart diseases due to increased
risk of ventricular arrhythmias and atrial flutter.
19
Class IIIc treatment with sotalol, amiodarone, ibutilide or
dofetilide is often preferred, which exerts its effects by potassium
channel blockade and prolonging action potential duration to
delay conduction. Class IIIc drugs are recommended for persistent
AF, and also benefit AF patients with structural heart diseases.
19,20
For patients with infrequent episodes of AF (less than one per
month), oral flecainide or propafenone can be self-administered
by the patient at home (‘pill in the pocket’ therapy). In those
patients with frequent episodes of AF, daily maintenance anti-
arrhythmic drug therapy with propafenone, flecainide or sotalol
is preferred as first line. Amiodarone is used for those patients
with low left ventricular ejection fraction (LVEF) ischaemic heart
disease. Interventional therapies or surgical treatments should be
taken into consideration when anti-arrhythmic drugs are contra-
indicated, have been ineffective, or cannot be tolerated.
18
Rate-control therapy in AF
Rate-control therapy has been demonstrated to improve
symptoms and reduce hospital admissions, which benefit patients
older than 65 years with minimal symptoms.
17,19
According to the
latest European Society of Cardiology (ESC) guidelines for the
management of AF,
21
AF patients should target a resting heart
rate of
<
110 beats per minute (bpm); it can be reduced to 80 to
100 bpm if symptoms call for stricter rate control. Commonly
used drugs to control ventricular rate are
β
-adrenergic receptor
Table 1. Anti-arrhythmic drugs for the maintenance of sinus rhythm
Drug
Route Typical dose
Contra-indications
References
Flecainide
Oral 50–150 mg, BID
Ischaemic or structural heart disease; sinus node dysfunction, second- or third-
degree atrioventricular block or bundle branch disease without a pacemaker
20, 21
IV 1.5–2.0 mg/ kg, over 10 min
Propafenone Oral 150–300 mg, TID
Ischaemic or structural heart disease; asthma; sinus node dysfunction, second-
or third-degree atrioventricular block or bundle branch disease without a
pacemaker
20, 21
IV 1.5–2.0 mg/ kg, over 10 min
Sotalol
Oral 80–160 mg, BID
Asthma; creatinine clearance
<
40 ml/min; left ventricular dysfunction; QTc >
450 ms; sinus bradycardia
<
50 bpm, second- or third-degree atrioventricular
block without a pacemaker
20
Amiodarone Oral 200 mg, TID for 1 week; 200 mg, BID for 1
week; then maintenance dose of 200 mg QD
Avoid in those with advanced lung disease, severe hepatic impairment, thyroid
dysfunction
21
IV 5.0–7.0 mg/kg
Ibutilide
IV 1.0 mg over 10 min, the same dose after waiting
for 10 min
Avoid in patients with QT prolongation, hypokalaemia, severe left ventricular
hypertrophy or low ejection fraction
21
Dronedarone Oral 400 mg, BID
Permanent atrial fibrillation; severe heart failure (NYHA class III–IV); QTc >
500 ms; severe hepatic impairment
17, 20
QD, once daily; BID, twice daily; TID, three times a day; IV, intravenous.
Table 2. Drugs for rate control
Drug
Route Typical dose
Contra-indications
References
β
-blockers
Metoprolol (tartrate)
Oral 25–100 mg, BID
Acute pulmonary oedema, heart failure, asthma, severe atrioven-
tricular block and severely depressed patients
17, 28
Metoprolol (succinate) Oral 50–400 mg, QD
Bisoprolol
Oral 2.5–10 mg, QD
Atenolol
Oral 25–100 mg, QD
ND-CCBs
Diltiazem
Oral 120–360 mg QD
Severe hypotension, cardiogenic shock, second- or third-degree
atrioventricular block or sick sinus syndrome without a pacemaker,
patients with left ventricular systolic dysfunction and decompen-
sated heart failure owing to their negative inotropic effects
17, 21, 28
IV 0.25 mg/kg IV bolus over 2 min, then 5–15 mg/h
Verapamil
Oral 120–480 mg QD
IV (0.075–0.15 mg/kg) IV bolus over 2 min, then
0.005 mg/kg/min infusion
Digitalis glycosides
Digoxin
Oral 0.125–0.25 mg QD
Ventricular tachycardia, hypertrophic obstructive cardiomyopathy
and pre-excitation syndrome combined with AF
17, 21, 28
IV 0.25 mg IV with repeat dosing to a maximum of
1.5 mg over 24 h
Specific indications
Amiodarone
Oral 100–200 mg QD
Severe sinus node dysfunction, second- or third-degree atrioventricu-
lar block or bundle branch disease, syncope caused by bradycardia
and diffuse interstitial pulmonary fibrosis
21, 28
IV 300 mg IV over 1 h, then 10–50 mg/h over 24 h
QD, once daily; BID, twice daily; IV, intravenous.