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Figure 3 . Holter monitor .

PAGE 38

ventricular rate of less

than 110bpm both at rest and at

moderate exertion — assess this at

regular intervals . 12

In patients for whom these agents

are either ineffective or contraindicated

, atrioventricular ( AV ) node ablation

together with the implantation

of a permanent pacemaker provides

definitive rate control .

RHYTHM CONTROL – CONVERTING

TO SINUS RHYTHM

While haemodynamically unstable

AF requires urgent electrical cardioversion

to sinus rhythm , various

factors require consideration in cardioverting

the stable patient .

First , cardioversion of AF ,

whether electrical or pharmacological

, increases the risk of thromboembolism and stroke . 17 This risk is minimal in those with onset of AF

within the previous 48 hours . However

, in those with onset of AF more

than 48 hours earlier , or where the

time of onset is unknown , there is

an increased risk of left atrial thrombus

, and the potential for thromboembolism

and stroke in the event of

cardioversion . To mitigate this risk ,

these patients require therapeutic

anticoagulation at the time of cardioversion

( for example , warfarin with

a therapeutic INR , NOACs , or low

molecular weight heparin ). 12

Second , patients need to have

Figure 4 . Smart watch .

been on three weeks of uninterrupted

therapeutic anticoagulation

However , the former requires at least

administration of flecainide , it occurs ,

maintenance of sinus rhythm ( see

potential for both significant acute

before cardioversion or have undergone a transoesophageal echocardiogram documenting the absence of an

light sedation and the assistance of a medical practitioner with experience in sedation and advanced airway support .

on average , eight hours after initiation of IV amiodarone loading

19 , 20

.

table 1 ). Flecainide , a class 1c antiarrhythmic , is effective , but contraindicated in those with ischaemic or

and delayed pulmonary , thyroid and hepatic toxicity . 23 Sotalol is associated with fewer toxicities compared with

LAA thrombus .

Pharmacological cardioversion

RHYTHM CONTROL – MAINTAINING

structural heart disease because of

amiodarone , but frequently prolongs

Third , patients are required to con-

can be performed using IV or oral fle-

SINUS RHYTHM

the possible increased risk of sudden

the QT interval , with associated risk

tinue on four weeks of uninterrupted

cainide in those without contraindi-

Many highly effective measures to

cardiac death . Flecainide is used con-

of life-threatening polymorphic ven-

anticoagulation after their cardiover-

cations ( see table 1 ). In those with a

maintain sinus rhythm are non-phar-

currently with an AV nodal blocking

tricular tachycardia . 24

sion , regardless of long-term stroke

contraindication to flecainide , car-

macological , such as weight loss , ces-

agent ( for example , a beta blocker ),

AF catheter ablation by a cardiac

risk , because of the increased risk of stroke during this period . 18

Electrical cardioversion has higher success rates ( greater than 90 %) com-

dioversion can be performed using amiodarone , which is usually associated with a longer time to cardioversion . While cardioversion occurs ,

sation of alcohol , and treatment of underlying OSA . 14 , 21 However , several pharmacological therapies and invasive approaches , each with risks and

because of the risk of 1:1 ventricular conduction in the event of atrial flutter . 22 Amiodarone is not contraindicated in those with ischaemic or

electrophysiologist is an invasive but effective means of maintaining sinus rhythm . This procedure most commonly involves electrical isolation of

pared with pharmacological methods .

on average , about 2-3 hours after the

benefits , are available to assist in the

structural heart disease but it has the

the pulmonary veins that are often