Complications of Atrial Fibrillation Ablation

When Prevention Is Better Than Cure

Antonio Sorgente; Gian-Battista Chierchia; Carlo de Asmundis; Andrea Sarkozy; Lucio Capulzini; Pedro Brugada

Disclosures

Europace. 2011;13(11):1526-1532. 

In This Article

Haemorrhagic Complications

Haemorrhagic complications include major and minor bleedings. Cardiac tamponade has to be considered a major bleeding and is by far the most common major complication of AF catheter ablation. Other major bleedings should be considered any haematoma which requires intervention, the need of transfusion, massive haemoptysis, haemothorax, and retroperitoneal bleeding. Minor bleedings has to be considered any kind of haematoma or bleeding which does not require intervention or which remains asymptomatic. Femoral pseudoaneurysms and femoral arterovenous fistula are included in haemorrhagic complications and could cause, accordingly to their extent, major or minor bleedings.

Cardiac Tamponade

Different physiopathologic mechanisms lead to cardiac tamponade during and after PVI. Among the others, main cofactors in this clinical context must be considered the transseptal puncture[37] and ablation-related damage to the left atrium.[1]

Transseptal puncture represents an inevitable vulnerability to the heart during AF ablation procedures. Current transseptal puncture technique is very similar to the first initial reports in late 50s.[38] Briefly, after being inserted into a long sheath and set against the fossa ovalis, a needle is used to puncture the septum to enter the left atrium. Safety of transseptal puncture lies in the recognition of the right atrial anatomy and in particular of the fossa ovalis. Very recently, Sy et al.[39] provided a very interesting overview on the technique of the transseptal puncture and at the same time proposed a very promising 'problem-based stepwise approach', helpful in troubleshooting difficult left atrial transseptalizations and hopefully also in reducing the incidence of cardiac perforation. The authors reinforced the utility of intracardiac echocardiography or transoesophageal echocardiography in those procedures in which right atrial anatomy is unusual or in which fossa ovalis is difficult to engage. Transoesophageal echocardiography is often poorly tolerated and requires deep sedation or general anaesthesia; intracardiac echocardiography is associated with increased costs and needs a precise expertise. A third possibility has been recently proposed by Mitchell-Heggs et al.[40] and consists in guiding transseptal puncture in patients not under general anaesthesia using an intracardiac echocardiography probe positioned intranasally into the oesophagus.

Left atrial linear ablations are also associated with a higher incidence of cardiac tamponade.[41] Hsu et al.[42] not only confirmed this finding but found also a significant correlation of cardiac tamponade with 'popping', a well-known physical phenomenon related to the sudden boiling and consequent rupture of the endocardial tissue exposed to high levels of radiofrequency energy. However, radiofrequency energy is not the only cause of cardiac rupture: contact force is another relevant cofactor and many studies conducted in preclinical field corroborated this finding.[7,8,43] Indeed, Yokoyama et al.[43] developed an open-irrigated ablation catheter able to measure contact force: interestingly, they found that not only radiofrequency energy lesion size but also steam pop and thrombus incidence are strictly depending on contact force exerted by the ablation catheter on the interface with cardiac tissue. Hopefully, the introduction on the market of these new catheters will allow a safer ablation of cardiac tissues and a reduction in the incidence of cardiac tamponade or rupture.

Some warning should be raised for late cardiac tamponade. Even if there's no clear-cut definition for it, delayed cardiac tamponade has been described.[3] Taking this into account, extreme attention should be given to signs and symptoms such as agitation, tachycardia, oligouria in patients undergone a recent AF ablation.

Speaking more generally about AF-ablation-related bleeding, an increasing amount of data has been produced in the last few years to clarify which should be adopted as optimal anticoagulation management before and after PVI. Most significant contributions in this field belong to the same group of investigators, who demonstrated that periprocedural administration of warfarin is safe and efficacious[44] and may reduce thromboembolic events without increasing the risk of haemorrhagic complications (including major and minor bleedings).[45] Future randomized international multicentre trials should confirm if the standard protocol of anticoagulation (which usually includes discontinuation of warfarin 3–5 days before the procedure and bridging with low-molecular weight heparins before and after the procedure along with restoration of warfarin) should be modified.

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