Zusammenfassung
Die Katheterablation von Vorhofflattern ist eine etablierte elektrophysiologische Methode mit hoher primärer Erfolgsrate. In wenigen Fällen gelingt jedoch das Erreichen eines bidirektionalen Leitungsblock am abladierten Isthmus nicht. Hierfür sind bisher in erster Linie anatomische Besonderheiten verantwortlich gemacht worden. Wir beschreiben die Katheterablation eines Patienten mit typischem Vorhofflattern in der Anamnese, bei der trotz effektiver RF-Applikationen im Bereich des inferioren Isthmus scheinbar kein bidirektionaler Leitungsblock zu erzielen war. Durch den Einsatz eines noncontact-mapping-Systems (EnSite3000) konnte als Ursache hierfür ein bidirektional schnell leitender Gap im Bereich der inferioren Crista terminalis nachgewiesen werden mit konsekutiv rascher Erregung der kontralateralen Segmente des effektiv abladierten Isthmus. Da eine residuale Leitung im inferioren Isthmus nicht nachzuweisen war, konnte von weiteren RF-Applikationen abgesehen werden. Es handelt sich um den ersten dokumentierten Fall einer bidirektional transversalen Leitung über die Crista terminalis, die mit Hilfe dieses noncontact-mapping-Systems aufgedeckt wurde und zu einer Maskierung eines bereits vorliegenden Leitungsblocks im inferioren Isthmus geführt hat.
Summary
Catheter ablation of the posterior isthmus is an effective tool to cure typical atrial flutter. In some cases, however, bidirectional block cannot be obtained despite extensive RF applications. Anatomic obstacles or abnormalities are thought to be the most common reasons for failed or prolonged procedures. We present a case of recurrent typical atrial flutter that seemed to be refractory to all ablation attempts in the region of the posterior isthmus although no anatomic abnormalities could be detected. Despite extensive RF application, bidirectional conduction was unchanged. Using a novel noncontact mapping system (En-Site 3000) the existence of a fast conducting gap in the region of the inferior terminal crest was revealed. Rapid conduction over this gap to the opposite side of the isthmus led to the impression that bidirectional isthmus block was not established. As a result no further RF applications were necessary because isthmus block was complete at that time. This is the first time that transverse conduction across the terminal crest could be detected by this novel noncontact mapping system masquerading as unchanged bidirectional isthmus conduction.
References
Arenal A, Almendral J, Alday JM, Villacastin J, Ormaetxe JM, Sande JLM, PerezCastellano N, Gonzalez S, Ortiz M, Delcan PL (1999) Rate-dependent conduction block of the crista terminalis in patients with typical atrial flutter—influence on evaluation of cavotricuspid isthmus conduction block. Circulation 99:2771–2778
Chen J, de Chillou C, Basiouny T, Sadoul N, Filho JD, Magnin-Poull I, Messier M, Aliot E (1999) Cavotricuspid isthmus mapping to assess bidirectional block during common atrial flutter radiofrequency ablation. Circulation 100:2507–2513
Fischer B, Jais P, Shah D, Chouairi S, Haissaguerre M, Garrigues S, Poquet F, Gencel L, Clementy J, Marcus FI (1996) Radiofrequency catheter ablation of common atrial flutter in 200 patients. J Cardiovasc Electrophysiol 7:1225–1233
Heidbuchel H, Willems R, van Rensburg H, Adams J, Ector H, Van de WF (2000) Right atrial angiographic evaluation of the posterior isthmus: relevance for ablation of typical atrial flutter. Circulation 101:2178–2184
Saffitz JE, Kanter HL, Green KG, Tolley TK, Beyer EC (1994) Tissue-specific determinants of anisotropic conduction velocity in canine atrial and ventricular myocardium. Circ Res 74:1065–1070
Scaglione M, Riccardi R, Calo L, Di Donna P, Lamberti F, Caponi D, Coda L, Gaita F (2000) Typical atrial flutter ablation: conduction across the posterior region of the inferior vena cava orifice may mimic unidirectional isthmus block. J Cardiovasc Electrophysiol 11:387–395
Scanavacca M, Sosa E, Velarde JL, D’Avila A, Hachul D, Reolao B, Sanches O, Silva M, Darrieux F (1998) Type I atrial flutter radiofrequency ablation. Importance of bidirectional block of isthmus between the inferior vena cava and of tricuspid valve ring. Arq Bras Cardiol 71:705–711
Schilling RJ, Peters NS, Goldberger J, Kadish AH, Davies DW (2001) Characterization of the anatomy and conduction velocities of the human right atrial flutter circuit determined by noncontact mapping. J Amer Coll Cardiol 38:385–393
Schumacher B, Jung W, Schmidt H, Fischenbeck C, Lewalter T, Hagendorff A, Omran H, Wolpert C, Luderitz B (1999) Transverse conduction capabilities of the crista terminalis in patients with atrial flutter and atrial fibrillation. J Am Coll Cardiol 34:363–373
Takahashi R, Iesaka Y, Takahashi A, Hiroe M, Marumo F (2000) Clinical significance of residual slow cavotricuspid isthmus conduction after ablation of typical atrial flutter. Pace Pac Clin Electrophys 23:1902–1907
Yang Y, Cheng J, Bochoeyer A, Hamdan MH, Kowal RC, Page R, Lee RJ, Steiner PR, Saxon LA, Lesh MD, Modin GW, Scheinman MM (2001) Atypical right atrial flutter patterns. Circulation 103:3092–3098
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Wieczorek, M., Djajadisastra, I. & Hoeltgen, R. Transversal crista terminalis conduction suggests ineffective bidirectional isthmus block. Herzschr. Elektrophys. 16, 274–277 (2005). https://doi.org/10.1007/s00399-005-0471-z
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s00399-005-0471-z