Radiofrequency catheter ablation allows safe and efficient elimination of idiopathic premature ventricular contractions (PVCs) originating from the aortic root. When the ablation target is above the aortic valve, coronary artery (CA) ostia location (figure 1 and figure 2: arrows) is crucial to avoid ablating closer than 5mm.

Figure 1

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Figure 2

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We present 3 cases with normal cardiac magnetic resonance studies and high-density PVCs with left bundle branch block morphology, V2-V3 transition and inferior axis. Right ventricular outflow tract was mapped first (figure 1A and figure 2A: square) using the PentaRay catheter (Biosense-Webster Inc., United States) (figure 1B and figure 2B: asterisks); no local electrogram preceded the QRS except in 1 case where right-sided ablation was unsuccessful. The aortic root was explored with optimal pace-mapping and earliest activation time in the commissure between the coronary cusps preceding the QRS by > -32ms (figure 2B: red pin). Sweeping the aortic root with the PentaRay catheter splines (figure 2B bottom right, location data for map construction) pinpointed the CA ostia in the electroanatomic map (CARTO 3, Biosense-Webster Inc, United States). Given the distant location of the CA ostia, radiofrequency applications safely and successfully eliminated PVCs in all cases.

The proximity of the CA ostia to the ablation catheter (figure 1B and figure 2A: circle) is often evaluated by coronary angiography using a dedicated catheter or by infusion of iodinated contrast through the ablation catheter (off-label use). These procedures increase overall risk given the need for a second arterial access or the use of contrast. The use of intracardiac echocardiography has been proven safe but is expensive and invasive. The floppy PentaRay catheter splines safely provide anatomic information with zero-fluoroscopy and no contrast infusion.