Ventricular Arrhythmias From the Infundibular Muscles

HomeCirculation: Arrhythmia and ElectrophysiologyVol. 11, No. 3Ventricular Arrhythmias From the Infundibular Muscles Free AccessEditorialPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessEditorialPDF/EPUBVentricular Arrhythmias From the Infundibular MusclesAnother Step in Understanding the Complex Right Ventricular Anatomy Andres Enriquez, MD and Fermin Garcia, MD Andres EnriquezAndres Enriquez From the Section of Cardiac Electrophysiology, Hospital of the University of Pennsylvania, Philadelphia (A.E., F.G.); and Arrhythmia Service, Hospital Guillermo Grant Benavente, Concepcion, Chile (A.E.). and Fermin GarciaFermin Garcia From the Section of Cardiac Electrophysiology, Hospital of the University of Pennsylvania, Philadelphia (A.E., F.G.); and Arrhythmia Service, Hospital Guillermo Grant Benavente, Concepcion, Chile (A.E.). Originally published16 Mar 2018https://doi.org/10.1161/CIRCEP.118.006248Circulation: Arrhythmia and Electrophysiology. 2018;11:e006248See Article by Yamada et alIdiopathic ventricular arrhythmias (VAs) most often arise from the outflow tract regions of the right ventricle (RV) and left ventricle (LV).1–4 Outcomes of catheter ablation with the current technological developments are overall high, with curing rates exceeding 80%,5 and ablation has become a first-line therapy for patients who are symptomatic or have a decreased ejection fraction because of frequent ventricular tachycardia/premature ventricular contractions (PVCs).6 However, there are 2 groups of idiopathic VAs where ablation results particularly challenging and outcomes remain modest, even in high-volume centers. The first one is LV summit arrhythmias, where ablation is limited by proximity to the major coronary arteries, the presence of epicardial fat, and sometimes a deep origin of the arrhythmogenic source within the LV wall.7 The second one is VAs originating from intracavitary structures within both ventricles, including the papillary muscles (PMs) of the tricuspid valve (TV) and mitral valve apparatus,8–10 false tendons11 and in the RV also the moderator band,11,12 and other muscular bands or ridges crossing the endocardial surface, such as the crista supraventricularis and the infundibular muscles.13 These structures are highly variable in anatomy and cannot be visualized by fluoroscopy or standard electroanatomic mapping. In addition, catheter contact and stability becomes an issue when targeting a mobile structure or a narrow ridge in a beating heart.In this issue of Circulation: Arrhythmia and Electrophysiology, Yamada et al14 report 19 patients with idiopathic VAs originating from the RV infundibular muscles: 14 cases from the parietal band (PB) and 5 cases from the septal band. Anatomic localization was achieved with phased-array intracardiac echocardiography (ICE) and RV angiogram. The clinical and electrocardiographic characteristics, as well as the procedural findings, are described. Echocardiography and exercise stress testing or coronary angiography ruled out structural heart disease, and in patients with depressed ejection fraction, a cardiac magnetic resonance imaging revealed no local evidence of scar. Catheter ablation was reported to be challenging, requiring a large amount of radiofrequency energy delivery with a relatively high recurrence rate over follow-up. The authors suggest that the most likely mechanism of these VAs was abnormal automaticity or triggered activity because entrainment was not demonstrated and no abnormal ventricular electrograms suggesting reentry were recorded at the sites of successful ablation. According to the present series, these arrhythmias are rare, accounting for only 6% of idiopathic VAs originating from the RV.Understanding the anatomy is key for a safe and successful ablation of VAs, and this article is a contribution to better understand the anatomic complexity of the RV endocardial surface, which is far from the smooth aspect often depicted by electroanatomic maps. Although outflow tract VAs are the most common, almost every structure in the ventricles containing myocardiocytes is a potential source of idiopathic VAs, and the more widespread application of ICE during ventricular tachycardia/PVC ablation has led to further refinement in the topographical localization of these arrhythmias. Thus, ventricular tachycardia or PVCs that in previous series were simply cataloged as RV arrhythmias are now circumscribed to discrete anatomic locations.As mentioned, other RV intracavitary structures have been reported as potential sources of VAs in previous studies. In 2010, Crawford et al10 characterized a series of 8 patients with 15 distinct VAs mapped to the RV PMs (septal in 8, anterior in 4, and posterior in 3). All these arrhythmias displayed a left bundle branch block morphology with a QS or rS pattern in V1 and left superior or left inferior axis. Precordial transition was later in VAs originating from the anterior or posterior RV PMs (>V4) compared with those from the septal RV PM (≤V4). The PVC burden was effectively reduced from 17% pre-ablation to 0.6% post-ablation. In 2015, Sadek et al12 reported a series of 10 patients with VAs arising from the RV moderator band, including 7 patients presenting with idiopathic ventricular fibrillation. These arrhythmias were characterized by a left bundle branch block pattern, relatively wide QRS (152.7±15.2 ms), left superior axis, and late precordial transition (>V4). Ablation was acutely successful in all patients; however, 6 patients underwent a second procedure for arrhythmia recurrence, whereas 1 patient with PVC-triggered ventricular fibrillation had recurrent asymptomatic PVCs not triggering ventricular fibrillation and declined a second procedure.ICE Guidance for Ablation of RV StructuresPhased-array ICE has contributed to reducing the gap between 3-dimensional mapping and actual anatomy during electrophysiology procedures and has become an invaluable tool for ablation of VAs.15 ICE provides a quick survey of the RV/LV anatomy, including anatomic variations, and allows real-time visualization of the ablation catheter, ensuring adequate contact and orientation of the catheter tip. This is even more relevant for mapping of intracavitary structures, which are not well represented by fluoroscopy. The real-time ICE images can be integrated into the mapping system display, and any structure of interest can be incorporated separately into the 3-dimensional map.The best ICE views to characterize the RV intracavitary structures are obtained by advancing the transducer across the TV into the RV outflow tract, which provides a view of the inferior RV and moderator band. From here, the catheter is clocked to bring the septum into view, and the septal band can be identified as the septal continuation of the moderator band. On the other side, visualization of the PB can be achieved with the transducer located in the right atrium by applying slight clockwise torque from the home view until the TV and the RV outflow tract are imaged at the same time. In this view, the PB can be recognized as a prominent muscular band that separates the TV (inlet) from the RV outflow tract (outlet).Electrocardiographic CharacteristicsMost of the VAs reported in this series (12/14 cases from the PB and 5/5 cases from the septal band) had a left bundle branch block pattern with left and inferior axis, showing some similarity to VAs originating from the posterior RV outflow tract. Precordial transition was variable, fluctuating between leads V2 and V6. R waves were taller in lead II than in III, and a few patients with PB VAs also exhibited positive/negative discordance. A slow onset of the QRS complex, reflected by a maximum deflection index >0.5, was observed in 26% of cases, suggesting a deep origin relative to the endocardial surface, with prolonged conduction time from the site of arrhythmia origin to the Purkinje system.Need to Map the Infundibular Muscles in Parahisian VAsAn interesting observation by the authors is that a far-field looking ventricular electrogram with an early activation was consistently recorded in the His-bundle region, suggesting rapid conduction between the arrhythmia source and the basal RV septum. Thus, mapping of the infundibular muscles should be kept in mind when dealing with allegedly parahisian VAs. It is also our experience that some patients with prior failed ablation of so-called parahisian PVCs are finally ablated from the crista supraventricularis or septal band. Apart from both sides of the basal septum, other neighbor structures to be mapped in these cases include the region underneath the septal leaflet of the TV, the right coronary cusp, noncoronary cusp, and the right atrium opposite to the posterior superior process of the LV.16Future DirectionsFuture efforts should concentrate on improving outcomes of catheter ablation in these patients. Although phased-array ICE has represented a major progress for intraprocedural cardiac imaging, it is not perfect and additional work needs to be done in terms of real-time image definition. Higher resolution systems are needed, as well as further development of 3-dimensional volumetric ICE catheters,17 which eventually could lead to better outcomes by guiding mapping under direct intracavitary navigation in a beating heart, with greater anatomic information and better special orientation. Other adjuvant elements include the use of long steerable sheaths to enhance catheter–tissue contact, and contact-force technology (not used in this study), which allows not only to monitor contact at the ablation site but also, and importantly, to assess adequate orientation of the catheter tip vector. Finally, cryoablation may also play a role in view of promising results recently reported for PM VAs.18,19DisclosuresNone.FootnotesThe opinions expressed in this article are not necessarily those of the editors or of the American Heart Association.Circ Arrhythm Electrophysiol is available at http://circep.ahajournals.org.Correspondence to: Fermin Garcia, MD, Section of Cardiac Electrophysiology, Hospital of the University of Pennsylvania, 9 Founders Pavilion, 3400 Spruce St, Philadelphia, PA 19104. E-mail [email protected]References1. Coggins DL, Lee RJ, Sweeney J, Chein WW, Van Hare G, Epstein L, Gonzalez R, Griffin JC, Lesh MD, Scheinman MM. Radiofrequency catheter ablation as a cure for idiopathic tachycardia of both left and right ventricular origin.J Am Coll Cardiol. 1994; 23:1333–1341.CrossrefMedlineGoogle Scholar2. Movsowitz C, Schwartzman D, Callans DJ, Preminger M, Zado E, Gottlieb CD, Marchlinski FE. Idiopathic right ventricular outflow tract tachycardia: narrowing the anatomic location for successful ablation.Am Heart J. 1996; 131:930–936.CrossrefMedlineGoogle Scholar3. Callans DJ, Menz V, Schwartzman D, Gottlieb CD, Marchlinski FE. Repetitive monomorphic tachycardia from the left ventricular outflow tract: electrocardiographic patterns consistent with a left ventricular site of origin.J Am Coll Cardiol. 1997; 29:1023–1027.CrossrefMedlineGoogle Scholar4. Kanagaratnam L, Tomassoni G, Schweikert R, Pavia S, Bash D, Beheiry S, Neibauer M, Saliba W, Chung M, Tchou P, Natale A. Ventricular tachycardias arising from the aortic sinus of valsalva: an under-recognized variant of left outflow tract ventricular tachycardia.J Am Coll Cardiol. 2001; 37:1408–1414.CrossrefMedlineGoogle Scholar5. Latchamsetty RY, Yokokawa M, Morady F, Kim HM, Mathew S, Tilz R, Kuck K-H, Nagashima K, Tedrow U, Stevenson WG, Yu R, Tung R, Shivkumar K, Sarrazin J-F, Arya A, Hindricks G, Vunnam R, Dickfeld T, Daoud EG, Oza NM, Bogun F. Multicenter outcomes for catheter ablation of idiopathic premature ventricular complexes.J Am Coll Cardiol EP. 2015; 1:116–123.Google Scholar6. Pedersen CT, Kay GN, Kalman J, Borggrefe M, Della-Bella P, Dickfeld T, Dorian P, Huikuri H, Kim YH, Knight B, Marchlinski F, Ross D, Sacher F, Sapp J, Shivkumar K, Soejima K, Tada H, Alexander ME, Triedman JK, Yamada T, Kirchhof P, Lip GY, Kuck KH, Mont L, Haines D, Indik J, Dimarco J, Exner D, Iesaka Y, Savelieva I; EP-Europace,UK. EHRA/HRS/APHRS expert consensus on ventricular arrhythmias.Heart Rhythm. 2014; 11:e166–e196. doi: 10.1016/j.hrthm.2014.07.024.CrossrefMedlineGoogle Scholar7. Yamada T, McElderry HT, Doppalapudi H, Okada T, Murakami Y, Yoshida Y, Yoshida N, Inden Y, Murohara T, Plumb VJ, Kay GN. Idiopathic ventricular arrhythmias originating from the left ventricular summit: anatomic concepts relevant to ablation.Circ Arrhythm Electrophysiol. 2010; 3:616–623. doi: 10.1161/CIRCEP.110.939744.LinkGoogle Scholar8. Doppalapudi H, Yamada T, McElderry HT, Plumb VJ, Epstein AE, Kay GN. Ventricular tachycardia originating from the posterior papillary muscle in the left ventricle: a distinct clinical syndrome.Circ Arrhythm Electrophysiol. 2008; 1:23–29. doi: 10.1161/CIRCEP.107.742940.LinkGoogle Scholar9. Bogun F, Desjardins B, Crawford T, Good E, Jongnarangsin K, Oral H, Chugh A, Pelosi F, Morady F. Post-infarction ventricular arrhythmias originating in papillary muscles.J Am Coll Cardiol. 2008; 51:1794–1802. doi: 10.1016/j.jacc.2008.01.046.CrossrefMedlineGoogle Scholar10. Crawford T, Mueller G, Good E, Jongnarangsin K, Chugh A, Pelosi F, Ebinger M, Oral H, Morady F, Bogun F. Ventricular arrhythmias originating from papillary muscles in the right ventricle.Heart Rhythm. 2010; 7:725–730. doi: 10.1016/j.hrthm.2010.01.040.CrossrefMedlineGoogle Scholar11. Abouezzeddine O, Suleiman M, Buescher T, Kapa S, Friedman PA, Jahangir A, Mears JA, Ladewig DJ, Munger TM, Hammill SC, Packer DL, Asirvatham SJ. Relevance of endocavitary structures in ablation procedures for ventricular tachycardia.J Cardiovasc Electrophysiol. 2010; 21:245–254. doi: 10.1111/j.1540-8167.2009.01621.x.CrossrefMedlineGoogle Scholar12. Sadek MM, Benhayon D, Sureddi R, Chik W, Santangeli P, Supple GE, Hutchinson MD, Bala R, Carballeira L, Zado ES, Patel VV, Callans DJ, Marchlinski FE, Garcia FC. Idiopathic ventricular arrhythmias originating from the moderator band: e lectrocardiographic characteristics and treatment by catheter ablation.Heart Rhythm. 2015; 12:67–75. doi: 10.1016/j.hrthm.2014.08.029.CrossrefMedlineGoogle Scholar13. Yamada T, Yoshida N, Itoh T, Litovsky SH, Doppalapudi H, McElderry HT, Kay GN. Idiopathic v entricular a rrhythmias originating from the parietal band: electrocardiographic and electrophysiological characteristics and outcome of catheter ablation.Circ Arrhythm Electrophysiol. 2017; 10:e005099. doi: 10.1161/CIRCEP.117.005099.LinkGoogle Scholar14. Yamada T, Yoshida N, Litovsky SH, Itoh T, Doppalapudi H, Kay GN. Idiopathic ventricular arrhythmias originating from the infundibular muscles: prevalence, electrocardiographic and electrophysiological characteristics, and outcome of catheter ablation.Circ Arrhythm Electrophysiol. 2018; 11:e005749. doi: 10.1161/CIRCEP.117.005749.LinkGoogle Scholar15. Enriquez A, Saenz L, Rosso R, Silvestry F, Callans D, Marchlinski F, Garcia F. Use of intracardiac echocardiography in interventional cardiology: working with the anatomy rather than fighting it.Circulation. 2018. In press.LinkGoogle Scholar16. Enriquez A, Tapias C, Rodriguez D, Liang J, Marchlinski F, Saenz L, Garcia F. How to map and ablate parahisian ventricular arrhythmias [published online ahead of print March 6, 2018].Heart Rhythm. doi: 10.1016/j.hrthm.2018.02.028. https://www.sciencedirect.com/science/article/pii/S1547527118301395.Google Scholar17. Silvestry FE, Kadakia MB, Willhide J, Herrmann HC. Initial experience with a novel real-time three-dimensional intracardiac ultrasound system to guide percutaneous cardiac structural interventions: a phase 1 feasibility study of volume intracardiac echocardiography in the assessment of patients with structural heart disease undergoing percutaneous transcatheter therapy.J Am Soc Echocardiogr. 2014; 27:978–983. doi: 10.1016/j.echo.2014.04.022.MedlineGoogle Scholar18. Rivera S, Ricapito Mde L, Tomas L, Parodi J, Bardera Molina G, Banega R, Bueti P, Orosco A, Reinoso M, Caro M, Belardi D, Albina G, Giniger A, Scazzuso F. Results of cryoenergy and radiofrequency-based catheter ablation for treating ventricular arrhythmias arising from the papillary muscles of the left ventricle, guided by intracardiac echocardiography and image integration.Circ Arrhythm Electrophysiol. 2016; 9:e003874. doi: 10.1161/CIRCEP.115.003874.LinkGoogle Scholar19. Gordon J, Zado E, Hutchinson M, Garcia F, Santangeli P, Betensky B, Fahed J, Mendelson T, Shaw G, Supple G. Effectiveness of cryoablation on papillary muscle PVCs and VT after radiofrequency has failed.Heart Rhythm. 2016; 13:PO06–PO150.Google Scholar Previous Back to top Next FiguresReferencesRelatedDetails March 2018Vol 11, Issue 3 Advertisement Article InformationMetrics © 2018 American Heart Association, Inc.https://doi.org/10.1161/CIRCEP.118.006248PMID: 29874172 Originally publishedMarch 16, 2018 KeywordsEditorialscatheter ablationechocardiographypapillary musclesventricular tachycardiaPDF download Advertisement SubjectsCatheter Ablation and Implantable Cardioverter-Defibrillator