Common and distinctive electrocardiographic characteristics and effective catheter ablation of idiopathic ventricular arrhythmias originating from different areas of ventricular septum adjacent to atrioventricular annulus

Electrocardiographic Characteristics of Ventricular Arrhythmias Originating from Different Areas Adjacent to the Mitral Annulus

BACKGROUND

This study aimed to explore the electrocardiographic (ECG) characteristics of ventricular arrhythmias (VAs) arising from epicardial and endocardial areas adjacent to the mitral annulus (MA).

METHODS

This study involved 283 patients with MA-VAs who received radiofrequency catheter ablation at the center. The ECG characteristics of these patients were analyzed retrospectively.

RESULTS

The origin of MA-VAs was judged based on the ECG variables. Among all MA-VAs, intrinsicoid deflection time (IDT) > 77 ms or maximum deflection index (MDI) > 0.505 predicted the VAs arising from the epicardium (sensitivity of 70.20% and 73.51%, specificity of 94.70% and 82.58%, positive predictive value (PPV) of 93.81% and 82.84%, and negative predictive value (NPV) of 73.53% and 73.15%). Among all epicardial MA-VAs, the RV1/RV2 ratio > 0.87 predicted the VAs originating from the epicardial anteroseptal wall adjacent to the MA. It had a sensitivity, specificity, PPV, and NPV of 62.86%, 98.06%, 91.67%, and 88.60%, respectively. Among all endocardial MA-VAs, Q(q)R(r) morphology in lead V1 predicted the VAs arising from the endocardial septal wall adjacent to the MA. It had a sensitivity, specificity, PPV, and NPV of 92.98%, 100%, 100%, and 94.94%, respectively. Among all endocardial septal MA-VAs, a predominant positive wave in lead II and a predominant negative wave in lead III predicted the VAs arising from the endocardial midseptal portion adjacent to the MA. It had a sensitivity, specificity, PPV, and NPV of 86.04%, 100%, 100%, and 70.00%, respectively.

CONCLUSION

the ECG characteristics of VAs from the different sites adjacent to the MA can enable judging the arrhythmia's origin and designing the ablation plan accordingly.

Catheter ablation of ventricular premature depolarizations originating from mid interventricular septum: Significance of electrocardiographic morphology for predicting origin

BACKGROUND

Ventricular premature depolarizations (VPDs) originating from the mid interventricular septum (IVS) adjacent to the atrioventricular annulus between the His bundle and coronary sinus ostium (mid IVS VPDs) have not been characterized.

OBJECTIVE

The aim of this study was to investigate the electrophysiological characteristics of mid IVS VPDs.

METHODS

Thirty-eight patients with mid IVS VPDs were enrolled. The VPDs were divided into different types according to precordial transition of the electrocardiogram (ECG) and the QRS morphology in lead V1.

RESULTS

4 types of VPDs were divided. The precordial transition zone appeared earlier and earlier from types 1 to 4. The notch in V1 moved gradually backwards, its amplitude gradually became higher, resulting in transition from left to right bundle branch block morphology in V1 from types 1 to 4. Based on activation and pace mapping, ablation response, and the 3830 electrode pacing morphology in the mid IVS, the 4 types of ECG morphology corresponded, respectively, to an origin in the right endocardial side, right/mid intramural region, left intramural region, and left endocardial side of the mid IVS. An intramural origin was identified for 50% of the VPDs. 89% of mid IVS VPDs could be eliminated. Bilateral ablation (waiting for delayed efficacy) or bipolar ablation was sometimes needed for intramural VPDs.

CONCLUSIONS

Mid IVS VPDs were found to have unique electrophysiological characteristics. The ECG characteristics of mid IVS VPDs was important in terms of prediction of its exact origin, the choice of ablation method, and the likelihood of treatment being successful.

The characteristics of a 12-lead electrocardiogram measuring premature ventricular contractions originating from the tricuspid annulus using the clock position method

OBJECTIVE

This study aimed to analyze the conventional surface electrocardiogram (ECG) characteristics of premature ventricular contractions (PVCs) originating from the tricuspid annulus and to investigate the efficacy of locating their origins according to ECG results.

METHODS

Eight patients who underwent radiofrequency ablation in the First Hospital of Shanxi Medical University (China) were included in the study. Pace mapping (PM) was used to analyze the characteristics of the PVCs originating from the tricuspid annulus recorded via 12-lead body surface ECGs.

RESULTS

An R-wave was found in leads I, V₅ , and V₆ . The QRS wave was narrower when the PVCs originated from the septum and shifted in lead V₃ (R-wave amplitude/S-wave amplitude in the precordial lead-1). The QRS wave was broadest when the PVCs originated from the 7 to 9 o'clock position. The augmented vector left lead showed RS, QS, or RSR-type waves with a low amplitude when the PVCs originated from the upper part of the annulus. When the PVCs originated from the lower part of the annulus, the augmented vector right lead reflected multidirectional and QS-type waves.

CONCLUSION

The ECG-lead characteristics related to the origin of PVCs in the tricuspid annulus indicate some level of significance and can be used to formulate a specific diagnosis.

Premature ventricular contractions with acute successful radiofrequency catheter ablation near the atrioventricular node using reversed C curve technique

Background

We sought to clarify the electrophysiological (EP) characteristics of premature ventricular contractions (PVCs) with acute successful radiofrequency catheter ablation (RFCA) near the atrioventricular node (AVN).

Methods and results

Eighteen patients with acute successful RFCA near the AVN were included in this study. Systematic mapping was performed with two mapping methods: antegrade mapping technique (group A) and reversed C curve mapping technique (group R). RFCA was preferentially performed underneath the tricuspid valve (TV) with reversed C curve technique in all patients. The a amplitude/v amplitude ratio during sinus rhythm in group A was significantly larger than in group B (0.19 ± 0.10 vs 0.06 ± 0.02, p < 0.01). The earliest bipolar activation preceded the QRS onset in group A was significantly smaller than in group R (19.6 ± 4.9 vs 24.4 ± 6.6 ms (ms), p < 0.01). Pace mapping in group A and group R demonstrated perfect QRS morphology (12/12) match only in 5.6% (one patient) and 16.7% (3 patients) of patients, respectively. The mean duration of successful RFCA was 8.2 ± 2.4 s in 13 patients (72.2%). Early (within 3 days) and late (one-year) recurrence rates were 5.6% (one patient) and 16.7% (3 patients), respectively. No atrioventricular block occurred during RFCA or the one-year follow up.

Conclusions

PVCs near the AVN are a subgroup of idiopathic PVCs with distinctive EP features. RFCA using reversed C curve technique is effective and safe for the acute elimination of these challenging AVN-PVCs.

A Systemic Mapping Approach for Right and Left Parahisian Ventricular Arrhythmias Ablation

Background

Catheter ablation for parahisian ventricular arrhythmias (PHVA) is technically challenging and associated with increased risks of atrioventricular block (AVB). We developed a systemic mapping approach to improve the efficacy and safety of PHVA ablation.

Methods

Forty-three patients (29 males; average age 65.8 ± 10.5 years) with PHVAs were enrolled. A systemic mapping approach comprising differential electrocardiogram, sequential mapping, and ablation beneath/above the septal leaflet of the tricuspid valve (SLTV) and at the neighboring/contralateral regions (the aortic root and sub-aortic valve region) was applied for PHVA. The effectiveness and safety of this approach was evaluated at 1 year's follow-up.

Results

Sequential ablation beneath the SLTV (B-SLTV) succeeded in 24 (66.7 %) of 36 with right PHVA and ablation above the SLTV succeeded in 6 of the remaining 12 with failed B-SLTV ablation. Target-His bundle (HB) distance &gt; 4.5 mm significantly predicted successful right PHVA ablation (OR 1.703; 95% CI 1.084–2.676, P = 0.02). “Seeming” right PHVA by electrocardiogram in 4 and apparent left PHVA in 3 was successfully ablated at the sub-aortic parahisian region. At 1 year's follow-up, 27 (75%) of 36 patients with right PHVA and 6 (85.7%) of 7 patients with left PHVA were free of PHVA recurrence off anti-arrhythmic drugs. The total success rate was 76.7% by using the systemic mapping approach for PHVA. One patient with A-SLTV ablation underwent pacemaker implantation due to complete AVB.

Conclusions

The systemic mapping approach was effective and safe for treating PHVA. The target-HB distance was a significant predictor for right PHVA ablation.

R/S Ratio in Lead III Predicts Successful Ablation of Ventricular Arrhythmias Originating in Para-Hisian Region

OBJECTIVES

The aim of this study was to investigate the electrocardiographic characteristics of ventricular arrhythmias (VAs) originating near the His bundle (HB) and use the R/S ratio in lead III (R_III/S_III ratio) to predict successful ablation of para-Hisian VAs.

BACKGROUND

Catheter ablation for idiopathic VAs near the HB is often challenging, and data are limited.

METHODS

The present study included 134 consecutive patients undergoing catheter ablation of para-Hisian VAs. The electrocardiographic characteristics in these patients were retrospectively evaluated with successful ablation and failed ablation.

RESULTS

Successful ablation was achieved in 115 (85.8%) of the 134 patients. There was no significant difference in QRS duration between the successful and the failed ablation groups. The ablation success rate was significantly lower for para-Hisian VAs with a predominantly positive R wave in lead III than those with a predominantly negative S wave in lead III. The significant factor associated with successful ablation was the R_III/S_III ratio. The R_III/S_III ratio ≤1.1 predicted the successful ablation of para-Hisian VAs with high sensitivity (80.9%) and specificity (94.7%). The R_III/S_III ratio of >1.2 had high sensitivity (100.0%) and specificity (82.8%) to predict the distance <5 mm from the site of origin of para-Hisian VAs to the site recording the largest HB potential.

CONCLUSIONS

The R_III/S_III ratio was a helpful predictor of the successful ablation of VAs originating in the vicinity of the HB. This may be useful for planning ablation of para-Hisian VAs and minimizing the risk of inadvertent atrioventricular block.

Implication of the distinctive bipolar intracardiac electrograms for ventricular arrhythmias arising from different regions of ventricular outflow tract

AIMS

To investigate the characteristics of bipolar intracardiac electrograms (bi-EGMs) in target sites of ventricular arrhythmias (VAs) originating from different regions of ventricular outflow tract (VOT).

METHODS AND RESULTS

Two hundred and seventy patients undergoing first-time ablation for VAs originated from distal great cardiac vein (DGCV), aortic sinus cusps (ASCs), or pulmonary sinus cusps (PSCs) were enrolled in present study. Local intracardiac bipolar recordings on 243 successful sites and 506 attempted but unsuccessful ablation sites were analysed. Specific potentials in bi-EGMs on successful sites were more common compared with unsuccessful sites (76.95%, 187/243 vs. 25.49%, 129/506, P < 0.05). A total of 60.00% (81/135) patients in ASCs group presented a presystolic short-duration fractionated potential, higher than 23.21% (13/56) in DGCV and 23.08% (12/52) in PSCs (all P < 0.05); 44.23% (23/52) patients in PSC group showed a presystolic high-amplitude discrete potential, while 1.79% (1/56) in DGCV and 2.22% (3/135) in ASCs (all P < 0.05); 41.07% (23/56) patients in DGCV group showed bi-EGMs of presystolic long-duration multicomponent fractionated potential, which was significantly higher than 3.85% (2/52) in PSCs and 4.44%(6/135) in ASCs (all P < 0.05).

CONCLUSION

Distinctive morphology of bi-EGMs during VAs can be found in different regions of VOT, which probably due to changes in the arrangements of myocardial sleeves. Correct identification and better understanding of the distinctive features of these bi-EGMs with regards to the anatomic location was important, the presence of specific potentials may add help in successful ablation.