Achieving durable mitral isthmus block

Challenges, pitfalls, and methods of assessment

Naktal S. Hamoud, Victor A. Abrich, Win Kuang Shen, Siva Mulpuru, Komandoor Srivathsan

Research output: Contribution to journalArticle

Abstract

Background and objectives: Macroreentrant atrial tachycardias often occur following atrial fibrillation ablation, most commonly due to nontransmural lesions in prior ablation lines. Perimitral atrial flutter is one such arrhythmia which requires ablation of the mitral isthmus. Our objectives were to review the literature regarding ablation of the mitral isthmus and to provide our approach for assessment of mitral isthmus block. Methods: We review anatomical considerations, ablation strategies, and assessment of conduction block across the mitral isthmus, which is subject to several pitfalls. Activation sequence and spatial differential pacing techniques are discussed for assessment of both endocardial and epicardial bidirectional mitral isthmus block. Results: Traditional methods for verifying mitral isthmus block include spatial differential pacing, activation mapping, and identification of double potentials. Up to 70% of cases require additional ablation in the coronary sinus (CS) to achieve transmural block. Interpretation of transmural block is subject to six pitfalls involving pacing output, differentiation of endocardial left atrial recordings from epicardial CS recordings, identification of a slowly conducting gap in the line, and catheter positioning during spatial differential pacing. Interpretation of unipolar electrograms can identify nontransmural lesions. We employ a combined epicardial and endocardial assessment of mitral isthmus block, which involves using a CS catheter for epicardial recording and a duodecapolar Halo catheter positioned around the mitral annulus for endocardial recording. Conclusions: The assessment of transmural mitral isthmus block can be challenging. Placement of an endocardial mapping catheter around the mitral annulus can provide a precise assessment of conduction across the mitral isthmus.

Original languageEnglish (US)
JournalJournal of cardiovascular electrophysiology
DOIs
StateAccepted/In press - Jan 1 2019

Fingerprint

Coronary Sinus
Catheters
Atrial Flutter
Tachycardia
Atrial Fibrillation
Cardiac Arrhythmias

Keywords

  • ablation
  • atypical atrial flutter
  • mitral isthmus

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

Cite this

Achieving durable mitral isthmus block : Challenges, pitfalls, and methods of assessment. / Hamoud, Naktal S.; Abrich, Victor A.; Shen, Win Kuang; Mulpuru, Siva; Srivathsan, Komandoor.

In: Journal of cardiovascular electrophysiology, 01.01.2019.

Research output: Contribution to journalArticle

@article{ea15c51a7812448e91057d2558eab78e,
title = "Achieving durable mitral isthmus block: Challenges, pitfalls, and methods of assessment",
abstract = "Background and objectives: Macroreentrant atrial tachycardias often occur following atrial fibrillation ablation, most commonly due to nontransmural lesions in prior ablation lines. Perimitral atrial flutter is one such arrhythmia which requires ablation of the mitral isthmus. Our objectives were to review the literature regarding ablation of the mitral isthmus and to provide our approach for assessment of mitral isthmus block. Methods: We review anatomical considerations, ablation strategies, and assessment of conduction block across the mitral isthmus, which is subject to several pitfalls. Activation sequence and spatial differential pacing techniques are discussed for assessment of both endocardial and epicardial bidirectional mitral isthmus block. Results: Traditional methods for verifying mitral isthmus block include spatial differential pacing, activation mapping, and identification of double potentials. Up to 70{\%} of cases require additional ablation in the coronary sinus (CS) to achieve transmural block. Interpretation of transmural block is subject to six pitfalls involving pacing output, differentiation of endocardial left atrial recordings from epicardial CS recordings, identification of a slowly conducting gap in the line, and catheter positioning during spatial differential pacing. Interpretation of unipolar electrograms can identify nontransmural lesions. We employ a combined epicardial and endocardial assessment of mitral isthmus block, which involves using a CS catheter for epicardial recording and a duodecapolar Halo catheter positioned around the mitral annulus for endocardial recording. Conclusions: The assessment of transmural mitral isthmus block can be challenging. Placement of an endocardial mapping catheter around the mitral annulus can provide a precise assessment of conduction across the mitral isthmus.",
keywords = "ablation, atypical atrial flutter, mitral isthmus",
author = "Hamoud, {Naktal S.} and Abrich, {Victor A.} and Shen, {Win Kuang} and Siva Mulpuru and Komandoor Srivathsan",
year = "2019",
month = "1",
day = "1",
doi = "10.1111/jce.14079",
language = "English (US)",
journal = "Journal of Cardiovascular Electrophysiology",
issn = "1045-3873",
publisher = "Wiley-Blackwell",

}

TY - JOUR

T1 - Achieving durable mitral isthmus block

T2 - Challenges, pitfalls, and methods of assessment

AU - Hamoud, Naktal S.

AU - Abrich, Victor A.

AU - Shen, Win Kuang

AU - Mulpuru, Siva

AU - Srivathsan, Komandoor

PY - 2019/1/1

Y1 - 2019/1/1

N2 - Background and objectives: Macroreentrant atrial tachycardias often occur following atrial fibrillation ablation, most commonly due to nontransmural lesions in prior ablation lines. Perimitral atrial flutter is one such arrhythmia which requires ablation of the mitral isthmus. Our objectives were to review the literature regarding ablation of the mitral isthmus and to provide our approach for assessment of mitral isthmus block. Methods: We review anatomical considerations, ablation strategies, and assessment of conduction block across the mitral isthmus, which is subject to several pitfalls. Activation sequence and spatial differential pacing techniques are discussed for assessment of both endocardial and epicardial bidirectional mitral isthmus block. Results: Traditional methods for verifying mitral isthmus block include spatial differential pacing, activation mapping, and identification of double potentials. Up to 70% of cases require additional ablation in the coronary sinus (CS) to achieve transmural block. Interpretation of transmural block is subject to six pitfalls involving pacing output, differentiation of endocardial left atrial recordings from epicardial CS recordings, identification of a slowly conducting gap in the line, and catheter positioning during spatial differential pacing. Interpretation of unipolar electrograms can identify nontransmural lesions. We employ a combined epicardial and endocardial assessment of mitral isthmus block, which involves using a CS catheter for epicardial recording and a duodecapolar Halo catheter positioned around the mitral annulus for endocardial recording. Conclusions: The assessment of transmural mitral isthmus block can be challenging. Placement of an endocardial mapping catheter around the mitral annulus can provide a precise assessment of conduction across the mitral isthmus.

AB - Background and objectives: Macroreentrant atrial tachycardias often occur following atrial fibrillation ablation, most commonly due to nontransmural lesions in prior ablation lines. Perimitral atrial flutter is one such arrhythmia which requires ablation of the mitral isthmus. Our objectives were to review the literature regarding ablation of the mitral isthmus and to provide our approach for assessment of mitral isthmus block. Methods: We review anatomical considerations, ablation strategies, and assessment of conduction block across the mitral isthmus, which is subject to several pitfalls. Activation sequence and spatial differential pacing techniques are discussed for assessment of both endocardial and epicardial bidirectional mitral isthmus block. Results: Traditional methods for verifying mitral isthmus block include spatial differential pacing, activation mapping, and identification of double potentials. Up to 70% of cases require additional ablation in the coronary sinus (CS) to achieve transmural block. Interpretation of transmural block is subject to six pitfalls involving pacing output, differentiation of endocardial left atrial recordings from epicardial CS recordings, identification of a slowly conducting gap in the line, and catheter positioning during spatial differential pacing. Interpretation of unipolar electrograms can identify nontransmural lesions. We employ a combined epicardial and endocardial assessment of mitral isthmus block, which involves using a CS catheter for epicardial recording and a duodecapolar Halo catheter positioned around the mitral annulus for endocardial recording. Conclusions: The assessment of transmural mitral isthmus block can be challenging. Placement of an endocardial mapping catheter around the mitral annulus can provide a precise assessment of conduction across the mitral isthmus.

KW - ablation

KW - atypical atrial flutter

KW - mitral isthmus

UR - http://www.scopus.com/inward/record.url?scp=85070057821&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85070057821&partnerID=8YFLogxK

U2 - 10.1111/jce.14079

DO - 10.1111/jce.14079

M3 - Article

JO - Journal of Cardiovascular Electrophysiology

JF - Journal of Cardiovascular Electrophysiology

SN - 1045-3873

ER -