The usefulness of ventricular pacing during atrial fibrillation ablation in a persistent left superior vena cava: A case report.

A 69-year-old woman with palpitations was referred to our hospital for a second session of atrial fibrillation (AF) catheter ablation. She had a history of AF ablation including pulmonary vein (PV) isolation and persistent left superior vena cava (PLSVC) isolation. Electrophysiologic studies showed the veno-atrial connections that had recovered. After PV isolation was performed, AF was induced by atrial premature contraction (APC) from the PLSVC, and AF storm occurred. During PLSVC isolation, AF was not induced by APC from the PLSVC. PLSVC isolation continued during sinus rhythm. The elimination of the PLSVC potential was difficult to confirm because of the far-field potential of the left ventricle. Then, we performed right ventricular pacing. The remaining PLSVC potential was identified. After that, the PLSVC isolation was successful during right ventricular pacing. Complications were not observed. The patient had no recurrence of AF thereafter.

Electrophysiological characteristics of non-pulmonary vein triggers excluding origins from the superior vena cava and left atrial posterior wall: Lessons from the self-reference mapping technique.

BACKGROUND: The detailed electrophysiological characteristics of atrial fibrillation (AF) initiating non-pulmonary vein (PV) triggers excluding origins from the superior vena cava (SVC) and left atrial posterior wall (LAPW) (Non-PV-SVC-LAPW triggers) remain unclear. This study aimed to clarify the detailed electrophysiological characteristics of non-PV-SVC-LAPW triggers. METHODS: Among 446 AF ablation procedures at 2 institutions, patients with reproducible AF initiating non-PV-SVC-LAPW triggers were retrospectively enrolled. The trigger origin was mapped using the self-reference mapping technique. The following electrophysiological parameters were evaluated: the voltage during sinus rhythm and at the onset of AF at the earliest activation site, coupling interval of the trigger between the prior sinus rhythm and AF trigger, and voltage change ratio defined as the trigger voltage at the onset of AF divided by the sinus voltage. RESULTS: Detailed electrophysiological data were obtained at 28 triggers in 21 patients. The median trigger voltage at the onset of AF was 0.16mV and median trigger coupling interval 182msec. Normal sinus voltages (≧0.5mV) were observed at 16 triggers and low voltages (<0.5mV) at 12 triggers. The voltage change ratio was significantly lower for the normal sinus voltage than low sinus voltage (0.20 vs. 0.60, p = 0.002). The trigger coupling intervals were comparable between the normal sinus voltage and low sinus voltage (170ms vs. 185ms, p = 0.353). CONCLUSIONS: The trigger voltage at the onset of AF was low, regardless of whether the sinus voltage of the trigger was preserved or low.

Clinical Significance of B-Type Natriuretic Peptide Levels at 3 Months after Atrial Fibrillation Ablation.

The role of B-type natriuretic peptide (BNP) levels as a predictor of arrhythmia recurrence (AR) after atrial fibrillation (AF) ablation remains unclear. In this study, we investigated the association of BNP levels before and 3 months after ablation with the risk of AR. A total of 234 patients undergoing their first session of AF ablation were included (68% male, mean age of 69 years). The cut-off value for discriminating AR was determined based on the maximum value of the area under the receiver operating characteristic (ROC) curve. The impact of BNP levels on AR was evaluated using Cox regression analysis. ROC curve analysis showed that the area under the curve for BNP at 3 months after the procedure was larger (0.714) compared to BNP levels before ablation (0.593). Elevated levels of BNP 3 months after the procedure (>40.5 pg/mL, n = 96) was associated with a higher risk of AR compared to those without elevated levels (34.4% vs. 10.9%, p < 0.01). Multivariate Cox regression analysis revealed that elevated BNP levels were associated with an increased risk of AR (hazard ratio 2.43; p = 0.014). Elevated BNP levels 3 months after AF ablation were a significant prognostic factor in AR, while baseline BNP levels were not.

Clinical impact of a self-reference mapping technique to detect non-pulmonary vein triggers: A multi-center study.

BACKGROUND: The method to perform a precise mapping of non-pulmonary vein (PV) triggers has not been fully investigated. The purpose of this study was to assess the efficacy of self-reference mapping for eliminating non-PV triggers in a large series of patients including the long-term outcomes. METHOD: Among 446 atrial fibrillation (AF) ablation procedures in 431 patients at 2 institutions, we prospectively enrolled patients who had reproducible non-PV triggers. Non-PV triggers from the left atrial posterior wall (LAPW) and superior vena cava (SVC) were excluded. Ablation procedure and long-term clinical outcomes were evaluated. The origin of non-PV triggers were detected using a self-reference mapping technique, which does not require any other reference catheters. Instead of using signals obtained from a fixed intracardiac catheter as the reference, an operator repeatedly moved a multi-electrode catheter to the earliest site creating a new reference each time to map the non-PV trigger. RESULTS: A total of 32 non-PV triggers excluding origins from the LAPW and SVC were induced in 23 patients. All triggers were mapped using a self-reference mapping technique with 11.0 ± 10.2 min and eliminated by radiofrequency ablation with 10.7 ± 10.0 points application. No major complications were observed. During the follow-up (529 ± 270 days), 18 patients (77%) were free from atrial tachyarrhythmias after a 3-month blanking period. Three patients received additional ablation procedures. No non-PV triggers ablated during the previous procedure were observed. CONCLUSIONS: A novel self-reference mapping technique is useful for eliminating non-PV triggers for the short- and long-term outcomes.

Atrial tachycardia related to local abnormal atrial activity.

A 42-year-old woman without a history of catheter ablation or cardiac surgery was referred to our institution for a paroxysmal atrial tachycardia (AT). Programed stimulation could not induce any AT. The AT spontaneously initiated during a continuous isoproterenol infusion. The earliest activation during the AT was recorded at the cavo-tricuspid isthmus, and local abnormal atrial activity (LAATA) was recorded during sinus rhythm at that same site. When rapid atrial activity was recorded at the cavo-tricuspid isthmus where the LAATA was recorded, an AT was induced. Radiofrequency ablation was performed over the entire area where the LAATA was recorded during sinus rhythm, rendering the AT non-inducible.

The utility of atrial overdrive pacing during catheter ablation of premature ventricular contractions originating from the posterior-superior process of the left ventricle.

A 76-year-old man presented with frequent premature ventricular contractions (PVCs). The electrophysiological findings revealed the origin of the PVCs was in the posterior-superior process of the left ventricle (PSP-LV), which is anatomically adjacent to the infero-medial aspect of the right atrium (RA). After a failed ablation from the LV, ablation in the RA eliminated the PVCs. During additional ablation, the atrio-his (AH) interval was monitored by atrial overdrive pacing, and ablation was terminated immediately after the AH interval prolonged to 174 ms. We believe that the atrial overdrive pacing was useful for monitoring the AH interval to prevent atrioventricular block during ablation of PVCs from the PSP-LV. .

Usefulness and safety of percutaneous coronary interventions for cardiac transplant vasculopathy.

Late morbidity and death as a result of progressive coronary vascular obliteration remains a major unsolved problem after orthotopic heart transplantation. Various percutaneous catheter intervention (PCI) methods have been used to treat transplant coronary artery disease (CAD), but few reports have assessed the longitudinal results of these procedures. Of 1,440 cardiac transplant patients at University of California, Los Angeles, Medical Center, treated between 1984 and 2004, 65 patients who had undergone orthotopic heart transplantation underwent PCI on a total of 156 coronary artery lesions because of transplant CAD between July 1993 and August 2004. The procedural success rate was 93%. Angiographic follow-up was available for 42 patients and 101 lesions 9.5 +/- 5.8 months after PCI. The global restenosis rate was 36%. Multivariate analysis was used to assess 49 clinical, angiographic, and immunologic variables per lesion. The use of a cutting balloon increased the risk of restenosis (odds ratio 11.5, p <0.01) and the use of stents decreased the risk of restenosis (odds ratio 0.34, p <0.05) compared with other PCI methods. The restenosis rate with drug-eluting stents was 19%, lower than that with bare metal stents (31%). Of the 65 patients, 20 (31%) died within 1.9 +/- 1.8 years after PCI. The actuarial survival rate was 56% at 5 years after the first PCI. In conclusion, although the restenosis rate after PCI was higher than that in nontransplant patients with CAD, the immediate and long-term results were acceptable in this high-risk population. Despite the intense inflammation associated with transplant CAD, drug-eluting stents appeared to reduce the occurrence of restenosis. Compared with historical controls, PCI may also improve the actuarial survival rate of patients undergoing orthotopic heart transplantation.

Cutting Balloon angioplasty for cardiac transplant vasculopathy.

We performed Cutting Balloon angioplasty on 20 lesions in 11 heart transplant recipients 7.5 +/- 3.8 years after transplantation. The mean percentage of diameter stenosis decreased from 88.3% +/- 13.8% to 19.6% +/- 13.7% after Cutting Balloon angioplasty without complication. Seven patients underwent follow-up angiography at 4.9 +/- 1.7 months in a total of 12 lesions, and all lesions showed restenosis with a mean diameter stenosis of 84.4% +/- 19.2%. Cutting Balloon angioplasty can be used to treat obstructions in cardiac transplant coronary arteries; however, it may cause exacerbation and produce a high restenosis rate.

Subacute stent thrombosis associated with a heparin-coated stent and heparin-induced thrombocytopenia.

Subacute stent thrombosis occurred in a patient 34 days after receiving a heparin-coated (HC) stent. The patient developed heparin-induced thrombocytopenia and diffuse thrombosis after the stent was placed. This raises the concern that patients who develop heparin-associated antibodies in the context of a recently placed HC stent may have an increased risk for subacute stent thrombosis.

Intracoronary radiation to treat in-stent restenosis in six cardiac transplant patients.

Transplant vasculopathy significantly limits the survival of cardiac transplant patients and occurs in 50% of patients by 5 years posttransplant. We report our experience with six cardiac transplant patients who underwent intracoronary brachytherapy for in-stent restenosis. At four centers, six patients underwent intracoronary radiation for in-stent restenosis. All patients received extended antiplatelet therapy with clopidogrel and aspirin. Follow-up angiography was performed in all patients. Two of the six patients underwent subsequent target lesion revascularization. Patient 1 presented with total occlusion of her radiated lesion. She had a complex procedure requiring stenting for a dissection after the radiation dwell. Patient 2 had high-grade restenosis following brachytherapy. Patient 3 had a 50% restenotic lesion. Patients 4, 5, and 6 had follow-up angiography that showed no evidence of restenosis. There are few good options to treated accelerated transplant vasculopathy. Radiation therapy may be a viable option in this difficult patient population.