Successful Transseptal Catheter Ablation of PrematureVentricular Contractions Arising from the MitralAnnulus: A Case with a Pure Annular OriginTAKUMI YAMADA, M.D., PH.D., H. THOMAS MCELDERRY, M.D., J. SCOTT ALLISON, M.D.,HARISH DOPPALAPUDI, M.D., ANDREW E. EPSTEIN, M.D., VANCE J. PLUMB, M.D.,and G. NEAL KAY, M.D.From the Division of Cardiovascular Disease, University of Alabama at Birmingham, Birmingham, Alabama

A 74-year-old man with symptomatic premature ventricular contractions (PVCs) with a right bundlebranch block and right inferior axis QRS morphology underwent electrophysiologic testing. During thePVCs, coronary sinus mapping revealed ventricular prepotentials with the earliest activation in the distalgreat cardiac vein (GCV) where the local ventricular electrograms were smaller in amplitude than theatrial electrograms. The transaortic approach could not reach the earliest activation site within the GCV,but the transseptal catheter ablation successfully eliminated the PVCs on the mitral valve. With catheterablation of ventricular arrhythmias with pure mitral annular origins, a transseptal approach may benecessary. (PACE 2009; 32:680–682)

premature ventricular contraction, mitral annulus, transseptal, radiofrequency catheter ablation

IntroductionThe mitral annulus has been demonstrated to

be one of the major sources of idiopathic ventricu-lar arrhythmias (VAs) originating from the left ven-tricle.1,2 In most VAs arising from the mitral annu-lus, successful catheter ablation may be achievedunderneath the mitral valve using the transaorticapproach.1,2 However, in some of those VAs, suc-cessful catheter ablation may be achieved only byusing another approach. This report describes theelectrophysiological characteristics and catheterablation of a mitral annular VA, which was elimi-nated only by using the transseptal approach.

Case ReportA 74-year-old man with symptomatic idio-

pathic premature ventricular contractions (PVCs)was referred for catheter ablation. At baseline,monomorphic PVCs were frequent and exhibiteda right bundle branch block and right inferior axisQRS morphology (Fig. 1). Coronary sinus mappingusing a decapolar catheter via the femoral vein re-vealed the earliest ventricular activation preced-ing the QRS onset in the distal great cardiac vein(GCV) during the PVCs (Fig. 1). At that earliestventricular activation site, a small prepotential fol-lowed by a large potential within the ventricular

There was no financial support for this study.

Address for reprints: Takumi Yamada, M.D., Ph.D., Divisionof Cardiovascular Disease, University of Alabama at Birming-ham, VH B147, 1670 University Boulevard, 1530 3rd AVE S,Birmingham, AL 35294. Fax: 205-975-4720; e-mail: takumi-y@fb4.so-net.ne.jp

Received June 9, 2008; revised July 23, 2008; accepted July 24,2008.

activity and an atrial potential that was larger inamplitude than the ventricular potential were ob-served (Fig. 1). First, activation mapping was per-formed in the right ventricular outflow tract usingan ablation catheter via the femoral vein duringthe PVCs, and it revealed no ventricular activationpreceding the QRS onset. Then, activation map-ping was performed in the left ventricular outflowtract using a transaortic ablation catheter duringthe PVCs, and it revealed no ventricular activa-tion preceding the earliest ventricular activationwithin the GCV in or underneath the left coro-nary cusp. The ablation catheter could not be ad-vanced close to the electrode pair recording theearliest ventricular activation within the GCV, andthe ventricular activation obtained underneath themitral valve was later than the earliest ventricularactivation within the GCV. Additionally, as com-pared to the local electrogram at the earliest acti-vation site within the GCV, the local electrogramrecorded underneath the mitral valve exhibited atiny far-field atrial potential and no prepotentialsin the ventricular activity. Next, we advanced theablation catheter to the GCV via the femoral vein,but catheter ablation was unsuccessful becauseof high impedance. Following that, a transseptalcatheterization was performed with fluoroscopicguidance. The transseptal ablation catheter couldbe easily positioned on the mitral valve in the an-teroparaseptal aspect just underneath the targetelectrode pair within the GCV, and at that site asmall potential with the earliest ventricular acti-vation, followed by a large potential in the ven-tricular activity, was observed (Figs. 1 and 2). Asingle radiofrequency application at that site suc-cessfully eliminated the PVCs. No complicationsoccurred.

C©2009, The Authors. Journal compilation C©2009 Wiley Periodicals, Inc.

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MITRAL PVCS SUCCESSFULLY ABLATED TRANSSEPTALLY

Figure 1. Successful ablation site. ABL d(p) = the distal (proximal) electrode pair of the ablationcatheter; CS = coronary sinus; V-QRS = the local ventricular activation time relative to the QRSonset.

DiscussionTo the best of our knowledge, this is the

first report describing the successful transseptalcatheter ablation of VAs arising from the mitralannulus. The VA origin in this case was located in

Figure 2. Catheter positions. LAO = the left anterior oblique view; RAO = the right anterioroblique view. The other abbreviations are as in Figure 1.

the anteroparaseptal aspect of the mitral annulus.A VA origin in this site may be rare1,2 becausethis site is located adjacent to the fibrous trigoneseparating the mitral annulus and aortic root.3,4

The anatomical location of the VA origin in this

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case might have rendered catheter manipulationchallenging in the transaortic approach. Becausean atrial potential that was larger in amplitudethan the ventricular potential was recorded atthe successful ablation site in this case, the VAorigin might have been located closer to theatrioventricular groove in contrast to the VAorigins in the previous reports.1,2 Therefore, theVA origin in this case may be called a pure mitralannular origin. In the catheter ablation of VAswith a pure mitral annular origin, the transseptal

approach may be necessary. A prepotential maybe a good predictor of a successful catheterablation of VAs originating from the mitral annu-lus.1,2 When coronary sinus mapping during VAsreveals ventricular prepotentials with the earliestactivation at the site where the local ventricularelectrograms are smaller in amplitude than theatrial electrograms, those findings may suggesta pure mitral annular origin and the transsep-tal approach may be considered the first-lineapproach.

References1. Tada H, Ito S, Naito S, Kurosaki K, Kubota S, Sugiyasu A, Tsuchiya

T, et al. Idiopathic ventricular arrhythmia arising from the mitralannulus: A distinct subgroup of idiopathic ventricular arrhythmias.J Am Coll Cardiol 2005; 45:877–886.

2. Kumagai K, Yamauchi Y, Takahashi A, Yokoyama Y, Sekiguchi Y,Watanabe J, Iesaka Y, et al. Idiopathic left ventricular tachycardia

originating from the mitral annulus. J Cardiovasc Electrophysiol2005; 16:1029–1036.

3. McAlpine WA. Heart and Coronary Arteries. New York, Springer-Verlag, 1975.

4. Anderson RH. Clinical anatomy of the aortic root. Heart 2000;84:670–673.

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