Treatment with catheter ablation for patients with arrhythmia-induced cardiomyopathy caused by atrial fibrillation promises a good prognosis.

Clinical outcomes after catheter ablation in patients with reduced left ventricular (LV) ejection fraction (EF) and atrial fibrillation (AF) remain unclear. This study aimed to explore the clinical outcomes of patients with arrhythmia-induced cardiomyopathy (AIC) and the influence of pharmacological treatment on clinical outcomes in patients with AIC after the procedure. Ninety-six patients with AF with a reduced LVEF (LVEF < 50%, 66.7 ± 10.9 years; 72 males) underwent AF ablation. AIC was defined as patients whose LVEF recovered ≥ 50% after catheter ablation (n = 67) and patients whose LVEF remained reduced were defined as non-AIC (n = 29). During a median follow-up of 25 (13-40) months, Kaplan-Meier analysis demonstrated that patients with AIC were associated with less frequent cardiovascular death (p = 0.025) and hospitalization for worsening heart failure (p < 0.001) than those without AIC. Freedom from AF recurrence was similar between the two groups (p = 0.47). In multivariate analysis, the LV end-diastolic diameter (p = 0.0002) and the CHA2DS2-VASc scores (p = 0.0062) were independent predictors of AIC. Among the 67 patients with AIC, no significant differences in baseline characteristics, except for LV chamber size and cryoballoon use, were observed between patients with AIC with (n = 31) and without renin-angiotensin system (RAS) inhibitors (n = 36). In the Kaplan-Meier analysis, cardiovascular death, hospitalization for worsening heart failure, and AF recurrence after catheter ablation did not differ between patients treated with and without RAS inhibitors (all p > 0.05). Catheter ablation in patients with AIC due to AF is associated with a good post-procedural prognosis.IRB information The study was approved by the Research Ethics Committee of the University of Fukui (No. 20220151) and clinical trial registration (UMIN000050391).

Declines in serum uric acid level after catheter ablation of atrial fibrillation.

BACKGROUND: Few studies have examined whether catheter ablation for AF patients improves biomarkers other than serum levels of brain natriuretic peptide (BNP) and renal function. This study was to explore whether catheter ablation for atrial fibrillation (AF) patients affects uric acid (UA), glucose and lipid metabolism. METHODS AND RESULTS: A total of 206 patients (66.6 ± 10.4 years; 132 men) who underwent initial AF ablation without changes to oral medications were included. Baseline BNP and UA levels significantly decreased at 1 year after ablation (p < 0.05 each). Changes in UA level correlated significantly with pre-procedural UA level (r = 0.57). In multivariable logistic regression modeling, pre-procedural UA level, persistent AF, and hemoglobin A1c (p < 0.05 each) were independent predictors of post-procedural UA level decline. Significant improvements in both persistent and paroxysmal AF patients were identified, and the magnitude of post-procedural serum UA level decline after ablation (ΔUA) was significantly greater in patients with persistent AF (0.8 ± 1.0 mg/dl) than in those with paroxysmal AF (0.2 ± 0.8 mg/dl, p < 0.001). Of the 48 patients with high UA level before procedure, 28 patients showed improvement in UA level to normal range. CONCLUSIONS: Catheter ablation for AF patients significantly improved serum UA levels without obvious influences of heart failure, renal function, or inflammation, suggesting that AF ablation may be effective for AF patients with hyperuricemia. Trial registration The study was approved by the Research Ethics Committee of University of Fukui (no. 20210132) and clinical trial registration (UMIN000044669).

Mapping and ablation of left atrial roof-dependent tachycardias using an ultra-high resolution mapping system.

BACKGROUND: Left atrial roof-dependent tachycardias (LARTs) are common macroreentrant atrial tachycardias (ATs). We sought to characterize clinical LARTs using an ultra-high resolution mapping system. METHODS: This study included 22 consecutive LARTs in 21 patients who underwent AT mapping/ablation using Rhythmia systems. RESULTS: Three, 13, 4, and 2 LART patients were cardiac intervention naïve (Group-A), post-roof line ablation (Group-B), post-atrial fibrillation ablation without linear ablation (Group-C), and post-cardiac surgery (Group-D), respectively. The mean AT cycle length was 244 ± 43 ms. Coronary sinus activation was proximal-to-distal or distal-to-proximal in 16 (72.7%) ATs. The activation map revealed 13 (59.1%) clockwise and 9 (40.9%) counter-clockwise LARTs. A 12-lead synchronous isoelectric interval was observed in 10/19 (52.6%) LARTs. The slow conduction area was identified on the LA roof, anterior/septal wall, and posterior wall in 18, 6, and 2 ATs, respectively. Twenty concomitant ATs among 13 procedures were also eliminated, and peri-mitral AT coexisted in 7 of 9 non-group-B patients. In group-B, the conduction gap was predominantly located on the mid-roof. Sustained LARTs were terminated by a single application and linear ablation in 6 (27.3%) and 9 (40.9%), while converting to other ATs in 7 (31.8%) LARTs. Complete linear block was created without any complications in all, however, ablation at the mid-posterior wall was required to achieve block in 4 (18.2%) procedures. During 14.0 (6.5-28.5) months of follow-up, 17 (81.0%) and 19 (90.5%) patients were free from any atrial tachyarrhythmias after single and last procedures. CONCLUSIONS: The LART mechanisms were distinct in individual patients, and elimination of all concomitant ATs was required for the management.

Abdominal Fat Pad Fine-Needle Aspiration for Diagnosis of Cardiac Amyloidosis in Patients with Non-Ischemic Cardiomyopathy.

The diagnosis of cardiac amyloidosis is frequently delayed because histological confirmation is often challenging. Few studies have attempted to clarify the utility and safety of abdominal fat pad fine-needle aspiration (FPFNA) for an initial screening test in patients with suspected cardiac amyloidosis.This study included 77 consecutive patients with suspected non-ischemic cardiomyopathy who had left ventricular dysfunction and/or hypertrophy. All patients underwent abdominal FPFNA and an endomyocardial biopsy. In all patients, the abdominal FPFNA could be performed within less than 5 minutes with no complications; however, in 1 patient (1.3%), the obtained specimen was too small to evaluate. Among the remaining 76 patients, 5 (6.6%) were positive for amyloid (FPFNA[+]) and 7 (9.2%), including the 5 FPFNA[+], were diagnosed with cardiac amyloidosis (AL = 1, ATTR = 6) by endomyocardial biopsy. Positive abdominal FPFNAs indicated cardiac amyloidosis with high accuracy (sensitivity, 71.4%; specificity, 100%).Positive abdominal FPFNAs are directly linked to diagnoses of cardiac amyloidosis. Abdominal FPFNA is simple and useful for the initial screening test for cardiac amyloidosis in patients with non-ischemic cardiomyopathy.

The advantages and disadvantages of the novel fourth-generation cryoballoon as compared to the second-generation cryoballoon in the current short freeze strategy.

BACKGROUND: The novel fourth-generation cryoballoon (4th-CB) is characterized by a shorter-tip that potentially facilitates better time-to-isolation (TTI) monitoring. We sought to clarify the advantages and disadvantages of the 4th-CB compared to the second-generation cryoballoon (2nd-CB) in pulmonary vein isolation (PVI). METHODS: Forty-one and 49 consecutive atrial fibrillation patients underwent 2nd-CB and 4th-CB PVIs using 28-mm balloons and short freeze strategies. When effective freezing was not obtained, the CB was switched to the other CB. RESULTS: The rate of successful PVIs was significantly higher for 2nd-CBs than 4th-CBs (162/162[100%] vs. 178/193[92.2%] PVs, p < 0.0001). The difference was significant for lower PVs, especially right inferior PVs (RIPVs)(p = 0.005). In a total of 15 PVs in 11 patients, 4th-CBs were switched to 2nd-CBs, and 14/15(93.3%) PVs were successfully isolated. The balloon temperature tended to reach -55℃ more frequently with 2nd-CBs than 4th-CBs during RIPV ablations (15/41[36.6%] vs. 12/49[24.5%], p = 0.21). The TTI monitoring capability was significantly higher with 4th-CBs than 2nd-CBs (131/188[69.7%] vs. 83/160[51.9%] PVs, p = 0.0007). The difference was significant for right superior and left inferior PVs, but not for left superior PVs. Even if PVs requiring crossover were excluded, the total freeze duration (715±152 vs. 755±215 seconds, p = 0.31) tended to be shorter for 2nd-CBs than 4th-CBs. The incidence of phrenic nerve injury was similar for 2nd-CB and 4th-CB ablation (0/41 vs. 2/49, p = 0.12) CONCLUSIONS: The 4th-CB's shorter balloon tip enabled a significantly higher capability of TTI monitoring; however, it resulted in significantly lower rates of successful PVIs than the 2nd-CB, especially for the RIPVs.

Safety and durability of cavo-tricuspid isthmus linear ablation in the current era: Single-center 9-year experience from 1078 procedures.

BACKGROUND: Cavo-tricuspid isthmus (CTI) linear ablation is performed not only for atrial flutter (AFL) but empirically during atrial fibrillation (AF) ablation in real-world practice.  PURPOSE: We sought to evaluate the safety and durability of the CTI ablation.  METHODS: This retrospective study included 1078 consecutive patients who underwent a CTI ablation. AFL was documented before or during the procedure in 249 (23.1%) patients, and an empirical CTI and AF ablation were performed in 829 (76.9%) patients.  RESULTS: CTI block was successfully created in 1051 (97.5%) patients with a 10.3 ± 6.6 min total radiofrequency time. Repeat procedures were performed for recurrent arrhythmias in 187 (17.3%) patients at a median of 11.0 (5.0-30.0) months postprocedure, and conduction resumption was identified in 68/174 (39.1%). Among those undergoing a CTI ablation with an AF ablation, the durability was significantly higher in those with than without documented AFL (78.1% vs. 58.2%, p = .031).  The total radiofrequency time was significantly shorter (9.0 ± 5.3 vs. 10.0 ± 6.4 [mins], p = .024) and durability significantly higher (78.1 vs. 58.7[%], p = .043) in the large-tip than irrigated-tip catheter group. Iatrogenic AFL was observed after the empiric CTI ablation in 11 (1.3%) patients. Procedure-related complications occurred in 15 (1.4%) patients. Eight patients experienced coronary artery spasms, including one with ventricular fibrillation following ST elevation on the ward. The other six patients experienced transient atrioventricular block and one experienced cardiac tamponade requiring drainage.  CONCLUSIONS: Despite a high acute CTI ablation success, the conduction block durability was relatively low after the empiric ablation. An empiric CTI ablation at the time of the AF ablation is not recommended.

Superior vena cava isolation using a novel ablation catheter incorporating local impedance monitoring.

BACKGROUND: A novel technology able to measure the local impedance (LI) during radiofrequency ablation has become available for clinical use. We investigated the change in the LI characteristics during superior vena cava isolations (SVCIs) using a novel catheter equipped with mini-electrodes. METHODS: Twenty paroxysmal atrial fibrillation patients (68 ± 9 years; 14 males) underwent an SVCI by targeting breakthroughs. Subsequently, dormant conduction provoked by adenosine triphosphate (ATP) was evaluated. RESULTS: Electrical SVCIs were successfully achieved in all with 7.2 ± 3.0 radiofrequency applications (RFA) without any complications. The procedure and fluoroscopic times were 13.1 ± 8.1 and 2.8 ± 2.3 min. No ablation was required at the anteroseptal SVC in 19 (95.0%) patients. The baseline LI and generator impedance (GI) were 125 ± 23 and 105 ± 14Ω. LI drops during RFA were significantly greater than GI drops (17 ± 12 vs. 4 ± 4Ω, p < 0.001). The correlation between the LI drops and GI drops was relatively high (R = 0.69, p < 0.001). LI drops were highest at the septal SVC and lowest at the lateral followed by antero-lateral SVC. The baseline electrogram amplitude between the mini-electrodes and tip-ring electrodes was 1.2 ± 1.4 and 0.8 ± 0.6 mV. The mini-electrode amplitude is more sharply attenuated with a greater magnitude than the tip-ring amplitude (p < 0.001). ATP-provoked dormant conduction was exposed in 10/17 (58.8%) patients and antero-lateral SVC gap locations in 7. Antero-lateral SVC LI drops were similar between patients with and without dormancy. CONCLUSIONS: The LI drop magnitude during RFA significantly differed among the SVC segments. Antero-lateral SVC ATP-provoked dormant conduction was often exposed, and additional applications are recommended following the isolation for a robust SVCI.

Significance of day-to-day glucose variability in patients after acute coronary syndrome.

BACKGROUND: Several studies have recently addressed the importance of glycemic variability (GV) in patients with acute coronary syndrome (ACS). Although daily GV measures, such as mean amplitude of glycemic excursions, are established predictors of poor prognosis in patients with ACS, the clinical significance of day-to-day GV remains to be fully elucidated. We therefore monitored day-to-day GV in patients with ACS to examine its significance. METHODS: In 25 patients with ACS, glucose levels were monitored for 14 days using a flash continuous glucose monitoring system. Mean of daily differences (MODD) was calculated as a marker of day-to-day GV. N-terminal pro-brain natriuretic peptide (NT-proBNP) was evaluated within 4 days after hospitalization. Cardiac function (left ventricular end-diastolic volume, left ventricular ejection fraction, stroke volume) was assessed by echocardiography at 3-5 days after admission and at 10-12 months after the disease onset. RESULTS: Of the 25 patients, 8 (32%) were diagnosed with diabetes, and continuous glucose monitoring (CGM)-based MODD was high (16.6 to 42.3) in 17 patients (68%). Although MODD did not correlate with max creatine kinase (CK), there was a positive correlation between J-index, high blood glucose index, and NT-proBNP (r = 0.83, p < 0.001; r = 0.85, p < 0.001; r = 0.41, p = 0.042, respectively). CONCLUSIONS: In patients with ACS, MODD was associated with elevated NT-proBNP. Future studies should investigate whether day-to-day GV in ACS patients can predict adverse clinical events such as heart failure.

Association between Changes in the Systolic Blood Pressure from Evening to the Next Morning and Night Glucose Variability in Heart Disease Patients.

Objectve To assess the impact of glycemic variability on blood pressure in hospitalized patients with cardiac disease. Methods In 40 patients with cardiovascular disease, the glucose levels were monitored by flash continuous glucose monitoring (FGM; Free-Style Libre™ or Free-Style Libre Pro; Abbott, Witney, UK) and self-monitoring blood glucose (SMBG) for 14 days. Blood pressure measurements were performed twice daily (morning and evening) at the same time as the glucose level measurement using SMBG. Results The detection rate of hypoglycemia using the FGM method was significantly higher than that with the 5-point SMBG method (77.5% vs. 5.0%, p<0.001). Changes in the systolic blood pressure from evening to the next morning [morning - evening (ME) difference] were significantly correlated with night glucose variability (r=0.63, P<0.001). A multiple regression analysis showed that night glucose variability using FGM was more closely correlated with the ME difference [r=0.62 (95% confidence interval, 0.019-0.051); p<0.001] than with the age, body mass index, or smoking history. Night glucose variability was also more closely associated with the ME difference in patients with unstable angina pectoris (UAP) than in those with acute myocardial infarction (AMI) or heart failure (HF) (r=0.83, p=0.058). Conclusion Night glucose variability is associated with the ME blood pressure difference, and FGM is more accurate than the 5-point SMBG approach for detecting such variability.

Cardiac rehabilitation after catheter ablation of atrial fibrillation in patients with left ventricular dysfunction.

Few studies have examined the efficacy and safety of cardiac rehabilitation in patients with atrial fibrillation (AF) who underwent AF ablation. We explored the feasibility of additional cardiac rehabilitation after AF ablation in patients with a reduced left ventricular ejection fraction (LVEF). Fifty-four patients with heart failure (HF) and a reduced LVEF (HFrEF) (LVEF < 50%; 67.1 ± 11.6 years; 43 men) who underwent initial AF ablation procedures were included. Fourteen (25.9%) patients underwent cardiac rehabilitation (rehabilitation-group) and the remaining 40 (74.1%) did not (non-rehabilitation-group) after the procedure. The rehabilitation-group patients were relatively older, more likely female (p = 0.024), and had more likely a history of an HF hospitalization (p < 0.01) and cardiac device implantation (p = 0.041). The baseline LVEF was significantly lower (p = 0.043) and brain natriuretic peptide (BNP) (p < 0.01) and C-reactive protein (CRP) (p < 0.01) values were significantly higher in the rehabilitation-group. The 6-min walk distance significantly improved after 21.4 ± 11.5 days of cardiac rehabilitation during hospitalization (226.1 ± 155.9 vs. 398.1 ± 77.5 m, p = 0.016) without any adverse events. During an 18.9 ± 6.3 month follow-up period, the freedom from AF recurrence (p = 0.52) and re-hospitalizations due to HF (p = 0.63) were similar between the 2 groups. No death or strokes were observed. During the follow-up period, the LVEF significantly improved similarly in both groups, and the change in the BNP and CRP values significantly decreased in the rehabilitation-group. Despite the rehabilitation-group patients having a more severe HF status, the clinical outcomes and AF freedom were similar between the 2 groups, suggesting the favorable impact of cardiac rehabilitation after AF ablation in HFrEF patients.

The mechanisms of left septal and anterior wall reentrant atrial tachycardias analyzed with ultrahigh resolution mapping: The role of functional block in the circuit.

BACKGROUND: Low voltage areas (LVAs) are most commonly observed on the left atrial (LA) septal/anterior wall. OBJECTIVE: We explored the mechanisms of LA septal/anterior wall reentrant tachycardias (LASARTs) using ultrahigh resolution mapping. METHODS: This study included seven consecutive LASARTs in six patients (75 [62.2-82.8] years, 4 women) who underwent atrial tachycardia (AT) mapping and ablation using Rhythmia systems. RESULTS: The AT cycle length was 266 (239-321) ms. During ATs, 11.0 (9.0-12.9) cm2 of LVAs were identified in all, and 0.8 (0.7-1.7) cm2 of dense scar was identified in four patients. Five ATs rotated around dense scar, while two rotated around functional linear block, which was confirmed during atrial pacing after AT termination. The AT circuit length was 8.7 ± 2.1 cm with a conduction velocity of 30.4 ± 3.7 cm/s. A median of 3.0 (2.0-4.0) slow conduction areas per circuit were identified, and 17/23 (73.9%) areas were present in LVAs, while they were at the border of the LVA and normal voltage areas in the remaining 6/23 (26.1%). Global activation histograms facilitated the identification of the critical isthmus in all. Tailor-made ablation at critical isthmuses successfully eliminated all ATs. However, one patient with AT related to functional linear block experienced recurrent AT related to dense scar, which progressed after the procedure. During a mean 14 ± 13 month follow-up after the last procedure, no patients experienced recurrent ATs without any complications. CONCLUSION: LASARTs consist of not only fixed conduction blocks but also functional conduction blocks. Ultrahigh resolution mapping is highly useful to decide the optimal tailor-made ablation strategy based on the mechanisms.

Impact of Medical Castration on Malignant Arrhythmias in Patients With Prostate Cancer.

Background Medical castration, gonadotropin-releasing hormone agonists, and antiandrogens have been widely applied as a treatment for prostate cancer. Sex steroid hormones influence cardiac ion channels. However, few studies have examined the proarrhythmic properties of medical castration. Methods and Results This study included 149 patients who underwent medical castration using gonadotropin-releasing hormones with/without antiandrogen for prostate cancer. The changes in the ECG findings during the therapy and associations of the electrocardiographic findings with malignant arrhythmias were studied. The QT and corrected QT (QTc) intervals prolonged during the therapy compared with baseline (QT, 394±32 to 406±39 ms [P<0.001]; QTc, 416±27 to 439±31 ms [P<0.001]). The QTc interval was prolonged in 119 (79.9%) patients during the therapy compared with baseline. In 2 (1.3%) patients who had no structural heart disease, torsade de pointes (TdP) and ventricular fibrillation (VF) occurred ≥6 months after starting the therapy. In patients with TdP/VF, the increase in the QTc interval from the pretreatment value was >80 ms. However, in patients without TdP/VF, the prevalence of an increase in the QTc interval from the pretreatment value of >50 ms was 11%, and an increase in the QTc interval from the pretreatment value >80 ms was found in only 4 (3%) patients. Conclusions Medical castration prolongs the QT/QTc intervals in most patients with prostate cancer, and it could cause TdP/VFs even in patients with no risk of QT prolongation before the therapy. An increase in the QTc interval from the pretreatment value >50 ms might become a predictor of TdP/VF. Much attention should be paid to the QTc interval throughout all periods of medical castration to prevent malignant arrhythmias.

Discrepancy between CARTO and Rhythmia maps for defining the left atrial low-voltage areas in atrial fibrillation ablation.

Reported mapping procedures of left atrial (LA) low-voltage areas (LVAs) vary widely. This study aimed to compare the PentaRay®/CARTO®3 (PentaRay map) and Orion™/Rhythmia™ (Orion map) systems for LA voltage mapping. This study included 15 patients who underwent successful pulmonary vein isolation (PVI) for atrial fibrillation. After PVI, PentaRay and Orion maps created for all patients were compared. LVAs were defined as sites with ≥ 3 adjacent low-voltage points < 0.5 mV. LVAs were indicated in 8 (53%) among 15 patients, and the average values of the measured LVAs was comparable between the systems (PentaRay map = 5.4 ± 8.7 cm2; Orion map = 4.3 ± 6.4 cm2, p = 0.69). However, in 2 of 8 patients with LVAs, the Orion map indicated LVAs at the septum and posterolateral sites of the LA, respectively, whereas the PentaRay map indicated no LVAs. In those patients, sharp electrograms of > 0.5 mV were properly recorded at the septum and posterolateral sites during appropriate beats in the PentaRay map. The PentaRay map had a shorter procedure time than the Orion map (12 ± 3 min vs. 23 ± 8 min, respectively; p < 0.01). Our study results showed a discrepancy in the LVA evaluation between the PentaRay and Orion maps. In 2 of 15 patients, the Orion map indicated LVAs at the sites where > 0.5-mV electrograms were properly recorded in the PentaRay map.

Effects of PCSK9 Inhibitor on Favorable Limb Outcomes in Patients with Chronic Limb-Threatening Ischemia.

AIM: The aim of this study was to examine the effects of evolocumab on favorable limb events in patients with chronic limb-threatening ischemia (CLTI). METHODS: A single-center, prospective observational study was performed on 30 patients with CLTI. The subjects were divided into 2 groups based on evolocumab administration: evolocumab-treated (E) group ( n=14) and evolocumab non-treated (non-E) group (n=16). The primary outcome was 12-month freedom from major amputation. The secondary outcomes were 12-month amputation-free survival (AFS), overall survival (OS), and wound-free limb salvage. The mean follow-up period was 18±11 months. RESULTS: No significant difference was detected between the two groups for the 12-month freedom from major amputation (log-rank p=0.15), while the 12-month AFS rate was significantly higher in the E group than that in the non-E group (log-rank p=0.02). The 12-month OS rate in the E group was shown a tendency for improvement, as compared with that in the non-E group (log-rank p=0.056). Evolocumab administration was not associated with a significant change in freedom from major amputation (HR, 0.23, 95% CI, 0.03-2.07, p=0.19). However, evolocumab administration was related to a tendency for improvement of AFS and OS (HR, 0.13, 95% CI, 0.02-1.06, p=0.056; HR, 0.16, 95% CI, 0.02-1.37, p=0.09, respectively). Moreover, The E group had a higher proportion of wound-free limb salvage at 12 months (92% vs. 42%, p=0.03). CONCLUSION: Evolocumab administration was associated with a better AFS outcome in patients with CLTI. Long-term administration of evolocumab over 12 months contributed to improving proportion of wound-free limb salvage.

Mapping and ablation of clinical spontaneous perimitral atrial tachycardias using an ultra-high-resolution mapping system.

BACKGROUND: Perimitral atrial tachycardias (PMATs) are common atrial tachycardias (ATs), yet their mechanisms vary. OBJECTIVE: The purpose of this study was to characterize clinical spontaneous PMATs using an ultra-high-resolution (UHR) mapping system. METHODS: The study included 32 consecutive PMATs in 31 patients who had undergone AT mapping/ablation using a UHR mapping system. RESULTS: Six, 10, 11, and 5 PMATs occurred in cardiac intervention-naïve (group A), post-lateral/posterior mitral isthmus linear ablation (group B), post-atrial fibrillation ablation without mitral isthmus linear ablation (group C), and post-cardiac surgery (group D) patients, respectively. Group A patients tended to be older, more likely were female, and had sinus node or atrioventricular conduction disturbances more frequently. A 12-lead synchronous isoelectric interval was observed in 15 PMATs (46.9%). Coronary sinus activation was proximal to distal or distal to proximal except in 3 PMATs with straight patterns due to epicardial gaps. Left atrial anterior/septal wall (LAASW) low-voltage areas were smallest in group B. Slow conduction areas (SCAs) were identified in 26 PMATs (81.2%) and were located on the LAASW in all group A and group D patients. Conduction velocity in the SCAs was slowest in group B. In group B, all PMATs were terminated by single applications, and the gaps were located epicardially in 5 of 10 (50%). Anterior (n = 23) or lateral/posterior (n = 9) mitral isthmus linear block was successfully created without any complications in all. Twenty-five concomitant ATs among 18 patients (58.1%) also were eliminated. During a median of 20.0 (11.0-40.0) months of follow-up, 28 patients (90.3%) were free from any atrial tachyarrhythmias. CONCLUSION: An UHR mapping-guided approach with identification of the individual tachycardia mechanism should be the preferred strategy given the distinct and complex arrhythmia mechanisms.

Ultra-high resolution mapping and ablation of accessory pathway conduction.

BACKGROUND: Detailed mapping studies of accessory pathway (AP) conduction have not been previously performed using ultra-high resolution mapping systems. We sought to evaluate the clinical utility of ultra-high resolution mapping systems and the novel "Lumipoint" algorithm in AP ablation. METHODS: This study included 17 patients who underwent AP mapping using minielectrode basket catheters and Rhythmia systems. Ablation was performed with 4-mm irrigated-tip catheters. RESULTS: Antegrade and retrograde AP conduction was observed in 6 and 16 patients. Atrial activation map was obtained during orthodromic tachycardia and ventricular pacing in 13 (76.5%) and 14 (82.3%) patients, and the earliest activation area was identical. Ventricular activation maps were created during atrial pacing in 3 patients. All maps showed focal activation patterns on global activation histograms, and the valley on the histogram highlighted the earliest activation area. "Complex activation" features further highlighted limited areas with continuous electrical activity during the time period in the majority. APs were located at the mitral and tricuspid annuli in 15 and 2 patients, and all were successfully eliminated with 3.4 ± 0.6 s applications. No patients had recurrences during a median follow-up of 15 [10.5-22.5] months. At successful ablation sites, the local atrial and ventricular electrogram amplitudes and ratio tended to be greater, and fusion or continuous electrical activity between the atrial and ventricular components was more frequently observed on the minielectrode than ablation catheter (17/17 vs. 12/17, p = 0.005). CONCLUSIONS: Ultra-high resolution activation mapping and a novel algorithm facilitated the AP localization. The local electrogram characteristics differed between the minielectrode and ablation catheters.

Early repolarization in the inferolateral leads predicts the presence of vasospastic angina: a novel predictor in patients with resting angina.

BACKGROUND: An association between early repolarization and ventricular fibrillation has recently been reported in patients with vasospastic angina (VSA). However, no studies have clarified whether the presence of early repolarization can predict VSA. METHODS: Participants comprised 286 patients (136 males) with clinically suspected VSA who underwent intracoronary provocation tests using acetylcholine or ergonovine. Patients were divided into a VSA group [n = 94, positive provocation test as induction of coronary arterial spasm (>90% stenosis)] and a non-VSA group (n = 192). Detailed early repolarization data were compared between groups. RESULTS: The VSA group showed a higher frequency of smokers (28.7%) than the non-VSA group (17.2%; P = 0.02). On baseline 12-lead ECG, early repolarization (defined as a J-point elevation ≥0.1 mV from baseline in both or either of inferolateral leads) was found in 39 patients (inferior leads, n = 27; inferolateral leads, n = 12). Early repolarization was found more frequently in the VSA group (28.7%) than in the non-VSA group (6.2%, P < 0.01). Multivariate analysis revealed early repolarization as an independent predictor of VSA (odds ratio, 5.22; 95% confidence interval, 2.41-11.2; P < 0.01). Early repolarization pattern features including inferior lead, higher amplitude, notched type and horizontal/descending ST segments were associated with increased risk of VSA. CONCLUSION: In patients with resting chest pain, early repolarization was a predictor of VSA that could be particularly related to the inferior lead, higher amplitude, notched type and horizontal/descending ST segment.

Idiopathic right ventricular arrhythmias requiring additional ablation from the left-sided outflow tract: ECG characteristics and efficacy of an anatomical approach.

INTRODUCTION: Despite the characteristic electrocardiogram (ECG) findings of early activation during ventricular tachyarrhythmias (VAs) and/or excellent pacemapping in the right ventricular outflow tract (RVOT), some VAs may require additional, left-sided ablation for a cure. METHODS AND RESULTS: This study included five patients with idiopathic VAs whose QRS morphologies were highly suggestive of an RVOT origin. The ECG characteristics and intracardiac electrocardiograms during catheter ablation were assessed. In all patients, the clinical VAs had an LBBB QRS morphology and inferior axis with a precordial R/S transition through leads V3-V5, and negative components in lead I. The earliest activation during the VAs (local electrogram-QRS interval = -34 ± 6.8 ms) and excellent pacemapping were obtained at the posterior portion of the RVOT just beneath the pulmonary valve. However, ablation at those sites failed, and the QRS morphology of the VAs changed. During left-sided OT mapping, the earliest activation was found at sites just contralateral to the initially ablated sites of the RVOT (junction of the left and right coronary cusps = 2, left coronary cusp = 3). In spite of the late activation time and poor pacemapping scores, catheter ablation at those sites cured the VAs. Those successful sites were also near the transitional zone from the great cardiac vein to the anterior interventricular vein (GCV-AIV). CONCLUSIONS: Some VAs, highly suggestive of having RVOT origins, require catheter ablation in the left-sided OT near the initially ablated RVOT site. Those VAs have the same ECG characteristics and might have intramural origins in the superobasal LV surrounded by the RVOT, LVOT, and GCV-AIV.

Femoral vascular complications after catheter ablation in the current era: The utility of computed tomography imaging.

BACKGROUND: Few studies have examined the characteristics of catheter ablation vascular complications, and recently physicians increasingly use computed tomography angiography (CTA) for diagnosing. OBJECTIVE: We sought to investigate the incidence of femoral vascular complications in catheter ablation and factors associated with complications in the current era. METHODS: This single-center observational study consisted of 311 consecutive (atrial fibrillation, atrial flutter, paroxysmal supraventricular tachycardia, and ventricular arrhythmias in 222 [71.4%], 7 [2.3%], 43 [13.8%], and 39 [12.5%]) patients who underwent catheter ablation. The detailed patient data and clinical outcomes were obtained from the medical records. RESULTS: Emergent CTA was performed in a total of 8 (2.6%) patients at a median of 4.5 (2.0-12.5) days postprocedure, and the precise diagnosis was obtained in all. Among them, pseudoaneurysms, arteriovenous fistulae (AVF), and actively bleeding hematomas were identified in two, one, and one patient, respectively, and all required readmissions after discharge. AVF was diagnosed by a Doppler ultrasound examination in another patient. In total, 5 (1.6%) patients exhibited major femoral vascular complications including two pseudoaneurysms, two AVFs, and one active bleeding hematoma. The pseudoaneurysms and AVFs were successfully eliminated by direct compression, and extravasation from the femoral circumflex artery required coil embolization. Antiplatelet therapy and the use of larger arterial sheaths (≥7-Fr) increased the major femoral arterial complications, but atrial fibrillation ablation under uninterrupted anticoagulation therapy or the use of larger venous sheaths did not. CONCLUSION: Vascular complications are still not negligible procedure-related complications during catheter ablation in the current era. CTA provides a rapid and precise diagnosis for optimal treatment strategies.

Preprocedural Troponin T Levels Predict the Improvement in the Left Ventricular Ejection Fraction After Catheter Ablation of Atrial Fibrillation/Flutter.

Background Left ventricular (LV) systolic dysfunction is reversible in some patients once the arrhythmia is controlled. However, identifying this arrhythmia-induced cardiomyopathy among patients with LV systolic dysfunction is challenging. We explored the factors predicting the reversibility of the LV ejection fraction (LVEF) after catheter ablation of atrial fibrillation and/or atrial flutter in patients with LV systolic dysfunction. Methods and Results Forty patients with a reduced LVEF (LVEF <50%; 66.2±10.7 years; 32 men) who underwent atrial fibrillation/atrial flutter ablation were included. Transthoracic echocardiography was performed before and during the early (<4 days) and late phases (>3 months) after the ablation. Responders were defined as having a normalized LVEF (≥50%) during the late phase after the ablation. The LVEF improved from 39.8±8.8 to 50.9±10.9% at 1.2±0.6 days after the procedure, and to 56.2±12.2% at 9.6±8.0 months after the procedure (both for P<0.001). Thirty (75.0%) patients were responders. The preprocedural echocardiographic parameters were comparable between the responders and nonresponders. In the multivariate analysis, the preprocedural high-sensitivity troponin T was the only independent predictor of the recovery of the LV dysfunction during the late phase after ablation (odds ratio, 1.17; 95% CI, 1.06-1.33; P=0.001), and a level of ≤12 pg/mL predicted recovery of the LV dysfunction with a high accuracy (sensitivity, 90.0%; specificity, 76.7%; positive predictive value, 56.3%; and negative predictive value, 95.8%). Conclusions Preprocedural high-sensitivity troponin T levels might be a simple and useful parameter for predicting the reversibility of the LV systolic dysfunction after atrial fibrillation/atrial flutter ablation in patients with a reduced LVEF.