Journal of the American Society of Echocardiography
Clinical InvestigationAtrial DysrhythmiasUsefulness of Pre-Procedure Cavotricuspid Isthmus Imaging by Modified Transthoracic Echocardiography for Predicting Outcome of Isthmus-Dependent Atrial Flutter Ablation
Section snippets
Study Population
This prospective study included 42 consecutive patients (30 men, 12 women; mean age, 62 ± 14 years) who underwent electrophysiologic evaluation and RF catheter ablation for recurrent or refractory symptomatic CTI-dependent atrial flutter. Nineteen patients (45%) had structural heart disease, including coronary artery disease (n = 11), hypertensive cardiovascular disease (n = 3), valvular heart disease (n = 1), dilated nonischemic cardiomyopathy (n = 3), and congenital heart disease (n = 1). One
Ablation Time and Ablation Outcomes
Complete bidirectional isthmus block was achieved within 10 min of RF application in 28 patients (straightforward group) but could not be achieved with 10 min of ablation in 14 patients (difficult group). The ablation time in the difficult group was significantly longer than that in the straightforward group (1,638.6 ± 1,461.3 vs 369.9 ± 138.5 sec, P = .006). Baseline characteristics were similar between the two groups (Table 1).
ER Morphology and Ablation Outcomes
The echocardiography images of the 42 patients were of sufficient
Discussion
The CTI plays a critical role in the reentrant circuit of CTI-dependent atrial flutter and is the target for catheter ablation. Linear RF catheter ablation across the CTI can achieve bidirectional conduction block across the CTI and abolish the reentrant circuit and thereafter eliminate the isthmus-dependent atrial flutter.1, 2, 5, 6, 7, 8 However, complete bidirectional isthmus conduction block may be difficult to achieve after a prolonged ablation procedure in some patients with CTI-dependent
Conclusions
Transthoracic echocardiography using a modified apical long-axis view is useful to evaluate the anatomy of the CTI before ablation procedures for CTI-dependent atrial flutter. The presence of an extensive ER on echocardiography is a strong predictor for a difficult ablation procedure. Early decision and the selection of a more aggressive ablation strategy are suggested for these patients before the procedure, particularly in patients who are at high risk for developing procedure-related
Acknowledgments
We thank Hsiu-Chen Lu for her help in figure creation. We are also grateful to Pei-Chi Hung and the staffs of our echocardiography and electrophysiology laboratories for their kind support of this study.
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Anatomy of the cavotricuspid isthmus for radiofrequency ablation in typical atrial flutter
2019, Heart RhythmCitation Excerpt :In addition, the only procedural complication occurred in a patient with a pouchlike recess. In small studies using intracardiac or 2-dimensional transthoracic echocardiography, a difficult ablation procedure was related to the presence of a prominent ER.14,15 The ER prominence in the anatomic specimens was 3.3 ± 2.3 mm and was muscular in composition in only 2.8% of the hearts.
Anatomic characterization of cavotricuspid isthmus by 3D transesophageal echocardiography in patients undergoing radiofrequency ablation of typical atrial flutter
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