Treatment of pulmonary sinus cusp-derived ventricular arrhythmia with reversed U-curve catheter ablation

Intracardiac Echocardiography to Guide Catheter Ablation of Idiopathic Ventricular Arrythmias

Catheter ablation is the most effective treatment option for idiopathic ventricular arrhythmias. Intracardiac echocardiography (ICE) has been increasingly used during ablation procedures, allowing real-time visualization of cardiac anatomy, and improving our understanding of the relationships between different cardiac structures. In this article we review the adjuvant role of ICE to guide mapping and ablation of ventricular arrhythmias in the structurally normal heart.

Electrocardiographic and electrophysiological characteristics of idiopathic ventricular arrhythmias originating from the vicinity of tricuspid annulus

Electrocardiographic and electrophysiological characteristics of VAs originating from the vicinity of the TA are not fully understood. Hence, 104 patients (mean age 52.6 ± 17.9 years; 62 male) with VAs originating from the vicinity of the TA were enrolled. After electrophysiological evaluation and ablation, data were compared among those patients. The ECGs and the correction of the ECGs based on the long axis of the heart calculated from the chest X-Ray were also analyzed. VAs originating from the vicinity of TA had distinctive ECG characteristics that were useful for identifying the precise origin. Our localization algorithm adjusted by the angle between the cardiac long axis and the horizon was found to be accurate in predicting the exact ablation site in 92.3% (n = 96) cases. Logistic regression analysis showed fractionated electrograms, the magnitudes of the local atrial electrograms and a/V ratio were critical factors for successful ablation. Among the 104 patients with VAs, complete elimination could be achieved by RFCA in 96 patients (success rate 92.3%) during a follow-up period of 35.2 ± 19.6 months. This study suggests that the ablation site could be localized by ECG analysis adjusted by the angle between the cardiac long axis and the horizon. Fractionated electrograms, the magnitudes of the local atrial electrograms and a/V ratio were demonstrated to be critical factors for successful ablation.

Stepwise approach for visualization and reconstruction of pulmonary valve with intracardiac echocardiography

Ventricular tachycardia and premature ventricular complexes (PVCs) arising from right ventricular outflow tract (RVOT) are the most common type of ventricular arrhythmias (VAs) in patients without structural heart disease. Radiofrequency ablation is now the gold standard of treatment in this setting due to high efficacy rates and optimal safety profile. During the last few years, the pulmonary valve (PV) and the pulmonary artery (PA) have attracted much attention as reliable sites of origin of RVOT-type arrhythmias. In the mean while intracardiac echocardiogram (ICE) has undoubtedly improved our understanding of the cardiac anatomy. Aim of this paper is to provide an illustrated step-by-step guide on how to use ICE with the CARTOSOUND module to visualize and reconstruct 3D shell of the RV, the PV, as well of other contiguous anatomical structures (i.e., the aortic valve and coronary arteries) to perform aware and safe ablation in this region.

Spatial relationship between the pulmonary trunk and the left coronaries: Systematic risk assessment based on automated three-dimensional distance measurements

BACKGROUND

Catheter ablation of right ventricular outflow tract ventricular arrhythmias from above the pulmonary valve is being increasingly reported.

OBJECTIVE

The purpose of this study was to systematically analyze the spatial relationship between the pulmonary trunk and the left coronaries.

METHODS

Contrast-enhanced computed tomographic scans from 58 patients were analyzed. After segmentation of the pulmonary trunk and the proximal left coronaries, 3-dimensional geometries were generated. Minimal distance between the pulmonary trunk and the coronaries was automatically determined using a newly developed mathematical algorithm.

RESULTS

The minimal distance between the pulmonary trunk and the coronaries was 1.4 ± 0.11 mm. Closest relationship was detected 13.8 ± 0.87 mm above the pulmonary valve annulus. Considering a safety margin of 5 mm to render coronary damage unlikely, 84% of patients were found to be at potential risk within the bottom 10 mm of the left sinus cusp. In contrast, positions within or above the right and anterior cusps were less likely to exhibit a close relationship. We identified the anterior aspect of the left cusp as the most critical region. Positions 10-20 mm above the left cusp were found to be critical in 97% of patients. Clinical parameters such as gender, age, height, weight, and body mass index were not predictive of a close spatial relationship.

CONCLUSION

Our data provide evidence for a close spatial relationship between the pulmonary trunk and coronary arteries. These results should be considered when performing catheter ablation from above the pulmonary valve.

Utility of local atrial electrogram pattern for predicting left main coronary artery anatomical distance during mapping in the left pulmonary sinus of valsalva

BACKGROUND

Ablation of right ventricular outflow tract (RVOT) ventricular arrhythmia (VA) within the left pulmonary sinus of Valsalva (LPSV) may increase the risk of left main coronary artery (LMCA) injury.

PURPOSE

To delineate the anatomical characteristics between LMCA and LPSV and their association with atrial potential (AP) mapping in LPSV.

METHODS

A total of 104 consecutive patients with RVOT-VA undergoing cardiac-gated computed tomography coronary angiography (CTCA) after ablation were retrospectively analyzed.

RESULTS

The LMCA-LPSV anatomic relationship was classified into three types based on the CTCA measurements. Types 1 and 2 had a shorter LMCA-LPSV distance than that of type 3 (P < .001). The left atrial appendage (LAA)-LMCA distance and LAA-LPSV distance were associated with the incidence of AP in LPSV (odds ratio [OR] = 3.43, 95% confidence interval [CI]: 1.86-6.34, P < .001; OR = 1.196, 95% CI: 1.09-1.31, P < .001, respectively). Furthermore, the LMCA-LPSV distance showed a linear correlation with the LAA-LPSV distance (r²  = 0.93, P < .001). According to receiver operating characteristic (ROC) analysis, a LMCA-LPSV distance <5.4 mm could predict the possibility of AP during LPSV mapping (sensitivity 83%, specificity 81%, and area under the ROC curve 0.86).

CONCLUSIONS

The presence of AP in the LPSV may be useful to predict a short distance from the LPSV to the LMCA and to identify patients at higher risk of LMCA injury. This information may contribute to efficient and safe ablation in this area but should be confirmed in future studies.

Types of anatomic relationship between left main coronary artery and pulmonary sinus of Valsalva: Implications for balloon pulmonary angioplasty and catheter ablation in the pulmonary root

BACKGROUND

Concerns have been raised upon the risk of left main coronary artery (LMCA) injury when balloon angioplasty or ablation is performed within the pulmonary sinus of Valsalva (PSV).

OBJECTIVE

To investigate the LMCA and PSV anatomic relationship (LMCA-PSV_ar) variants potentially susceptible to procedure complication.

METHODS

We retrospectively studied 100 consecutive patients undergoing computed tomography coronary angiography (CTCA). Three types of LMCA-PSV_ar were observed on the basis of the relative location between the LMCA ostium and left pulmonary sinus of Valsalva (LPSV): type 1, intimate contact between the LMCA ostium and LSPV; type 2, LMCA ostium opposite to LPSV and the proximal part coursing anteriorly around LSPV; and type 3, no contact between LMCA ostium and LSPV.

RESULTS

LMCA-PSV_ar types 1, 2, and 3 were present in 20(20%), 43(43%), and 37(37%) patients, respectively. For the three types of LMCA-PSV_ar, the minimal distance between LMCA and LPSV was 1.66 ± 0.53 mm, 4.63 ± 1.64 mm and 8.24 ± 1.65 mm, and the distance ≤5 mm were in 100%, 87% and 9% patients, respectively. Additionally, the distance from right coronary artery (RCA) to right pulmonary sinus of Valsalva (RPSV)/RVOT was ≤5 mm in 71 patients (71%).

CONCLUSION

The LMCA is intimately related to LPSV in majority of patients (mainly involving the types 1 and 2), whereas the RCA is often close to RPSV/RVOT. These anatomic features pose potential vulnerability to coronary injury, and should be heightened to avoid complications in this area.

Catheter ablation of ventricular arrhythmias originating from the junction of the pulmonary sinus cusp via a nonreversed U curve approach

BACKGROUND

Ventricular arrhythmias (VAs) can originate from the pulmonary sinus cusp, and reversed U curve ablation has been highly efficient treatment.

OBJECTIVE

The purpose of this study was to clarify the characteristics of VAs originating from the pulmonary sinus junction (PSJ): left cusp-anterior cusp (LC-AC), right cusp-left cusp (RC-LC), and right cusp-anterior cusp (RC-AC).

METHODS

One hundred twenty-five consecutive patients with right ventricular outflow (RVOT)-type VAs were enrolled in the study and analyzed.

RESULTS

Seventeen RVOT-type VAs (13.6%) had an anatomic origin at the PSJ (9 at LC-AC, 6 at RC-LC, 4 at RC-AC). For PSJ-VA patients, the earliest activation site was identified at the PSJ 22.65 ± 2.47 mm above the pulmonary sinus base and preceded QRS onset by 35.7 ± 12.7 ms (P <.001). Fourteen of the 17 PSJ-VA patients underwent successful ablation via a nonreversed U curve after failed reversed U curve ablation. The bipolar proximal potential was earlier, equal to, or later than the distal potential when the reversed U curve catheter tip was positioned at the bottom, middle, or junction region of individual sinus. Electrocardiographic analysis revealed a lower amplitude of RC-AC than LC-AC and RC-LC VAs (P <.001).

CONCLUSION

The PSJ is a nonrare but distinct origin of RVOT-type VAs. The nonreversed U curve approach is a more feasible alternative for PSJ-VAs than the reversed U curve approach.

Usefulness of Reversed U-Curve Technique to EnhanceMapping and Ablation Efficiency in the Treatment ofPulmonary Sinus Cusp-Derived Ventricular Arrhythmias

Reversed U-curve and nonreversed U-curve (conventional technique) were both reported to be effective in treating pulmonary sinus cusp (PSC)-derived ventricular arrhythmia (VA). The aim of this study was to evaluate the characteristics between two methods. We enrolled 37 consecutive patients with PSC-derived VA who underwent radiofrequency catheter ablation using a contact force (CF)-sensing catheter. Reversed U-curve and conventional method were routinely used for each patient. For the 37 patients with PSC-VA (14 cases in left cusp [LC], 12 in right cusp, and 11 in anterior cusp), only 7 patients from the LC were ablated using conventional method whereas the others underwent successful reversed U-curve ablation. For the reversed U-curve mapping, presence of a near-field sharp potential and QS wave at the best mapping site were observed with a higher frequency; CF in 3 sinuses was always higher except for LC (p <0.001, p <0.001, and p = 0.18, respectively); the bipolar potential amplitude was significantly higher (1.52 ± 1.75 mV vs 1.02± 2.37 mV, p <0.001), and increased with CF (p <0.001). In conclusion, reversed U-curve technique allows for sufficient contact and better catheter stability, enhancing mapping and ablation efficiency in the treatment of PSC-derived VA, particularly for right and anterior sinuses.

Insights on the pulmonary artery-derived ventricular arrhythmia

Pulmonary artery-derived ventricular arrhythmia is gradually being recognized, which in a clinical context is recognized as an arterial ectopic beat. Our study aimed to provide new insights on the epidemiological characteristics, origin site, electrocardiogram (ECG) characteristics, intracardiac electrophysiological characteristics and radiofrequency catheter ablation (RFCA) strategies for pulmonary artery-derived ventricular arrhythmia. Patients with a distance between the origin site and the pulmonary valve of >10 mm have what is known as pulmonary trunk-derived ventricular arrhythmia, while patients with a distance between the origin site and the pulmonary valve of ≤10 mm have what is known as pulmonary sinus cusp-derived ventricular arrhythmia. It is very difficult to differentiate pulmonary artery-derived ventricular arrhythmia from right ventricular outflow tract-derived ventricular arrhythmia on ECGs as both share similar anatomical features, but pulmonary artery-derived ventricular arrhythmia shows obvious intracardiac electrophysiological characteristics. Currently, conclusions based on the epidemiological characteristics of pulmonary artery-derived ventricular arrhythmia, relationship between the origin site and the pulmonary valve, electrophysiological characteristics, and RFCA strategies are controversial and still need further study.