Acute and long-term success of left atrial anterior line and mitral isthmus line ablation in patients after mitral valve surgery

Background

Perimitral flutter and atrial fibrillation may occur in patients with prior surgical mitral valve (MV) repair or replacement and can be challenging for percutaneous catheter ablation.

Objective

This study sought to determine the feasibility, acute success and durability of catheter ablation of atrial fibrillation or atrial tachycardia by way of a mitral isthmus line (MIL) or an anterior line (AL).

Methods

A total of 81 patients (49 males, mean age 62±11 years) with prior MV replacement (n=30) or repair (n=51) underwent creation of a MIL (n=34) and/or an AL (n=72). Control group patients without prior surgery were matched 1:1 with the valve group (MIL, n=34; AL, n=72).

Results

Acute bidirectional block of the MIL was successfully achieved in 24/34 cases and of the AL in 64/72 patients with prior MV surgery. In the control group, acute bidirectional block was achieved in 31/34 MIL patients and 65/72 AL patients. In terms of durability, the MIL valve subgroup showed the poorest results (probability of long-term failure 2.224, as opposed to 0.605 in the MIL control subgroup; hazard ratio [HR]=0.27, 95% confidence interval [CI], 0.11–0.65; p=0.004). In the AL subgroups, long-term outcomes were similar (probability of failure in AL valve subgroup 0.844 vs. AL control subgroup 1.03; HR=1.22, 95% CI, 0.66–2.26; p=0.523).

Conclusions

Percutaneous creation of MIL and AL is feasible and safe in patients with prior MV replacement/repair. Because of poor long-term outcomes, MIL creation appears not advisable in patient with prior MV surgery.

Funding Acknowledgement

Type of funding sources: None.

Low rate of life-threatening events and limitations in predicting invasive and noninvasive markers of symptoms in a cohort of type 1 Brugada syndrome patients: Data and insights from the GenBra registry

BACKGROUND

Brugada syndrome (BrS) has diagnostic challenges and controversial risk assessment. We aimed to investigate invasive and noninvasive parameters in symptomatic and asymptomatic patients from a Brazilian cohort of type-1 BrS.

METHODS

Patients with spontaneous and drug-induced type-1 BrS were classified into two groups, asymptomatic (n = 116, 84.1%) and symptomatic (n = 22, 15.9%; 13 with arrhythmogenic syncope, 9 with aborted sudden cardiac death). Genetic testing, EPS parameters, and electrocardiogram (ECG) parameters were analyzed.

RESULTS

A total of 138 consecutive patients were eligible, 101 men (73.2%), mean 41.4 years, mostly probands (79%). Spontaneous pattern, observed in 77.5% of the patients, was associated with symptoms only if expressed in V1 and V2 standard position (not high precordial leads; p = .014). All symptomatic patients were probands. The presence of right ventricular outflow tract conduction delay (RVOTcd) signs, positive EPS, and SCN5A status was similar between symptomatic and asymptomatic subjects. During the mean 75-month follow-up, eight patients had appropriate therapies. All had spontaneous type-1 ECG pattern and 2/8 (25%) were asymptomatic, with positive EPS. The overall LAE incidence of 1.1% per year dropped to 0.27% in asymptomatic patients. RVOTcd occurred more frequently in SCN5A carriers (QRS-f 33.3% vs. 7.7%; p = .005, AVR sign 58.3% vs. 13.6%; p < .001; deep S in lead I 75% vs. 48.5%, p = .025%), as well as longer HV interval (66 vs. 49 ms; p < .001).

CONCLUSIONS

Spontaneous type-1 Brugada pattern in standard leads and proband status were more frequent in symptomatic subjects. RVOTcd, more common in SCN5A carriers, did not predict symptoms in BrS patients. EPS exhibited limited prognostic value for this low-risk population.

P1361Impact of radiation/chemotherapy for breast cancer on the electroanatomic features in patients receiving catheter ablation for left atrial arrhythmia

Background

Atrial fibrillation (AF) is a common cardiac arrhythmia and catheter ablation a viable treatment option for patients with AF. Extensive left atrial (LA) scars, frequently seen in patients with persistent AF, can limit its efficacy. Radiation for breast cancer treatment is known to have serious long-term effects (e.g. fibrosis) on the targeted tissue. At the same time, chemotherapy often leads to organ dysfunction. We sought to examine the effects of radiation and chemotherapy on the electroanatomic features of the LA in patients who received catheter ablation for left atrial arrhythmias with prior breast cancer treatment.

Methods and Results

We compared 38 patients (mean age 68.4 ± 7.1 years) who underwent catheter ablation for LA arrhythmia and had a previous diagnosis of breast cancer with 38 patients (mean age 65.4 ± 7.3 years) without breast cancer who formed our control group. LA scar area, as well as its distribution was measured during the electrophysiology (EP) study and graded according to the Utah classification.

The existence of LA scarring did not differ significantly between both groups (71.1% vs. 76.3%, p = 0.602). LA scar area (excluding PVs) was 107.5cm2 ± 19.0cm2 in the breast cancer group compared to 110.1cm2 ± 18.5cm2 in the control group (p = 0.536). The distribution of the scar area revealed no significant difference between both groups, however an involvement of the anterior wall was common (65.8% vs. 73.7%; p = 0.454). We further investigated whether the location of breast cancer had an impact on the LA scar development of the patients in our study cohort. Here, we found no significant difference in the amount of LA scarring when comparing patients with left-sided breast cancer to patients with right-sided breast cancer (66.7% vs. 73.9%). In a sub-analysis patients with breast cancer and persistent AF showed a non-significant trend towards greater LA scar areas (17.4cm2 vs. 6.8cm2) in comparison to patients of the control group with similar LA volumes.

The patient’s age (&gt;65 years) was the only independent predictor for greater LA scarring we could identify. Neither former radiotherapy, nor chemotherapy showed a positive correlation with greater LA scarring.

Conclusion

There is no change in the distribution as well as an increase of the extent of LA scars after thoracic irradiation and/or chemotherapy. A trend towards greater LA scar areas was seen in patients with breast cancer and persistent AF. The patient’s age was identified as an independent predictor for LA scar development.

P6566Noninvasive Panoramic Mapping of Phase Singularities with Signal Complexity Analysis in Patients with Persistent Atrial Fibrillation

Background

An assessment of positive outcome probability of ablation therapy based on the comprehensive signal complexity analysis is a promising working hypothesis while electrocardiographic imaging (ECGI) can detect and visualize zones of phase singularities (PS) associated with stable sources of atrial fibrillation (AF).

Methods

Ten consecutive patients with persistent AF (three female, median (min–max) – 63.5 (45–75) years) underwent ECGI using “Amycard 01C EP lab” system with cardiac MRI (1.5-T Magnetom Avanto) followed by pulmonary vein isolation. Each T-Q segment with a length >800 ms during AF was processed to find PS. Sites with rotations around stable pivot points were considered as PS and then marked and visualized on the reconstructed anatomical 3D atrial model. Finally, a signal complexity cluster analysis was performed to define and depict phase-aggregation zones.

Results

ECGI analysis identified a total number of 410 PS, with 196 (47.8%) occurring in the LA and 214 (52.2%) in the RA. The median (25–75% IQR) number of revealed PS per patient was n=20 (14–30) for RA and n=20 (11–22) for the LA. The majority of the PS in the LA was located on the inferior wall n=66 (min-max 1–17). In eight patients, comprehensive signal complexity analysis revealed stability of phase-clustered zones over time. The mean number (min-max) of PS in a clustered area was 10 (6–15). In two patients, PS were distributed disordered on the entire LA and RA surface.

Distribution of phase singularities

Conclusions

This is the first clinical study demonstrating signal complexity analysis capability of clustering noninvasively mapped PS and relating them to specific atrial anatomical regions. Thereby obtained clusters may be a potential zones of conduction block, and could contribute to a better understanding of the temporal AF complexity.