Catheter Ablation Therapy for Supraventricular Arrhythmias

Twelve-lead electrocardiogram taken during an emergency department visit for an episode of severe palpitations showing atrial fibrillation with rapid ventricular response.

A, Common pattern of myocardial fibers of the posterior left atrium and pulmonary vein trunks. Anatomical studies have demonstrated that myocardial fibers on the posterior aspect of the left atrium extend to surround the trunks of the pulmonary veins as myocardial sleeves.⁵³ The pattern and thickness of myocardial fibers vary between individuals. The pulmonary venous myocardial sleeves extend from 6 mm to 14 mm from the left atrium and include a mixture of horizontal, vertical, and oblique fiber contributions.⁵⁴ The relationship of these anatomical features to the genesis of arrhythmias, however, is not known. B, Representative map of the left atrium (in a similar posterior view) of a patient receiving ablative treatment for atrial fibrillation. Creation of the 3-dimensional map is based on a preacquired computed tomography or magnetic resonance image. Ablation lesions surrounding the ostia of the pulmonary veins are shown as red dots; each point represents approximately 5 to 10 seconds of radiofrequency application. The procedural end point is electrical isolation of each pulmonary venous myocardial sleeve from the body of the left atrium. Image courtesy of Hugh Calkins, MD.

A, Relevant anatomical landmarks and catheter positions for achieving electrical isolation of the pulmonary veins are shown. A diagnostic multipolar electrode catheter is placed in the coronary sinus to allow for pacing and recording from the left atrium. After placement of 2 transseptal sheaths across the interatrial septum and initial circumferential ablation around the pulmonary veins, a circular mapping catheter is positioned at the ostium of the right superior pulmonary vein (RSPV) to provide detailed information on the location of residual electrical connections between the vein and the left atrium. An ablation catheter is then positioned at the site of earliest electrical activation along the circular mapping catheter and radiofrequency current is applied. This sequence (see Figure 2B) is repeated for all 4 PVs until PV electrical activity either disappears or becomes dissociated from left atrial activity (see Figure 4). B, Representative fluoroscopic image using contrast venography, an early procedural step in which a hollow injecting catheter is placed sequentially into each of the pulmonary veins (here, RSPV) and contrast injection is performed to outline the size and shapes of the veins. An additional diagnostic catheter is positioned at the right ventricular apex in this view. C, Representative fluoroscopic image demonstrating technique of electrical isolation of the RSPV guided by a circular mapping catheter.

Intracardiac electrograms demonstrate abrupt disappearance of pulmonary vein electrical potentials during radiofrequency current application (arrowheads). Paired numbers refer to electrical bipoles (eg, CMC 19,20) indicating a recording using the most proximal 2 electrodes of the 20-pole circular mapping catheter. Displaying the bipoles in this fashion gives a complete circular picture of the electrical activity in the tube of the pulmonary vein. CMC indicates circular mapping catheter; ABL p, proximal bipole of ablation catheter; ABL d, distal bipole of ablation catheter; CS, diagnostic multipolar electrode catheter in coronary sinus.

A general approach to consideration of catheter ablation for supraventricular arrhythmias is outlined. Recommendation class (I, IIa, IIb, or III) and level of evidence (A, B, or C) are based on published ACC/AHA/ESC Clinical Practice Guidelines.^15,40 Class I recommendation indicates procedure/treatment should be performed; class IIa, it is reasonable to perform procedure/administer treatment; class IIb, procedure/treatment may be considered; and class III, procedure/treatment should not be performed/administered. Level of evidence A indicates multiple (3-5) population risk strata evaluated with general consistency of direction and magnitude of effect; level B, limited (2-3) population risk strata evaluated; and level C, very limited (1-2) population risk strata evaluated. WPW indicates Wolff-Parkinson-White; AF, atrial fibrillation; SVT, supraventricular tachycardia; AV, atrioventricular; EP, electrophysiology.
^aOther marker of risk includes resuscitation from cardiac arrest, familial WPW syndrome, Ebstein anomaly, presence of multiple accessory pathways, and short refractory period of accessory pathway (< 250 ms).^15
bRate control indicates pharmacologic treatment with beta-blockers, diltiazem, verapamil, and/or digoxin to achieve acceptable ventricular rate at rest and with exertion.^40
cGood candidate for catheter ablation of atrial fibrillation includes: Younger age, small left atrial size, no or mild structural heart disease, paroxysmal AF, shorter duration of persistent AF, no or mild comorbidities.^61
dAblate and pace indicates permanent pacemaker implantation and catheter ablation of the AV node to achieve AV block as a permanent rate control strategy.^40,45- 46
eConsider surgical ablation if patient has separate indication for cardiac surgery, such as coronary artery disease or valvular heart disease.