Recurrent episodes of atrioventricular nodal reentrant tachycardia: Sites of ablation success, ablation endpoint, and primary culprits for recurrence.

Background: Atrioventricular nodal reentrant tachycardia (AVNRT) sometimes recurs even after anatomical slow pathway (SP) ablation targeting the rightward inferior extension (RIE). This multicenter study aimed to determine the reasons for AVNRT recurrence. Methods and Results: Forty-six patients were treated successfully for recurrent AVNRT. Initial treatment was for 38 slow-fast AVNRTs, 3 fast-slow AVNRTs, 2 slow-slow AVNRTs, 2 slow-fast and fast-slow AVNRTs, and 1 noninducible AVNRT. All initial treatments were of RF application to the RIE; SP elimination was achieved in 11, dual AVN physiology was seen in 29, and AVNRT remained inducible in 5. The recurrent AVNRTs included 34 slow-fast AVNRTs, 6 fast-slow AVNRTs, 3 slow-slow AVNRTs, 2 slow-fast and fast-slow AVNRTs, and 1 slow-fast and slow-slow AVNRTs. Successful ablation site was within the RIE in 39 and left inferior extension in 7. In 30 of 39, the successful RIE site was in the same area or higher than that of the initial procedure. Conclusion: For a high majority (around 85%) of patients in whom AVNRT recurs after initial ablation success, the site of a second successful procedure will be within the RIE even though the RIE was originally targeted. Furthermore, a high majority (around 86%) of sites of successful ablation will be higher than those originally targeted.

Narrow QRS ectopy with concealed connections from a para-Hisian origin to the proximal left fascicles.

INTRODUCTION: Catheter ablation of ectopy originating from the vicinity of the His bundle can be challenging. METHODS AND RESULTS: We report a case of a 33-year-old man with narrow QRS ectopy with preferential conduction from a para-Hisian origin to the proximal left fascicles, which was successfully eliminated by radiofrequency ablation in the right coronary cusp, guided by ultrahigh-resolution mapping of the His bundle, bundle branch, and fascicular electrograms. CONCLUSION: Some narrow QRS ectopy may originate from the vicinity of the conduction system, instead of the "true" conduction system, and have concealed connections from its origin to the conduction system.

Novel automated atrial pacemapping technique based on intracardiac pattern matching to identify the location of ectopic atrial activity.

Atrial ectopy from the pulmonary veins and non-pulmonary vein foci can trigger atrial fibrillation. In addition, the elimination of atrial ectopy is important to prevent recurrence. The intracardiac pattern matching technique has been reported as a useful method to manually visualize the location of triggers regardless of their frequency. We combined the original intracardiac pattern matching method with the automapping setting of CARTO CONFIDENCE and discovered the automated atrial pacemapping technique. We report two cases in which this technique was used to eliminate the atrial triggers. This technique achieved a time reduction and high-resolution mapping.

Prognostic Importance of B-Type Natriuretic Peptide Level in Patients Undergoing Catheter Ablation for Atrial Fibrillation.

BACKGROUND: This study assessed the prognostic importance of B-type natriuretic peptide (BNP) concentrations for clinical events after catheter ablation for atrial fibrillation (AF).Methods and Results: We enrolled 1,750 consecutive patients undergoing initial AF ablation whose baseline BNP data were available from a large-scale multicenter observational cohort (TRANQUILIZE-AF Registry). The prognostic impact of BNP concentration on clinical outcomes, including recurrent tachyarrhythmias and a composite of heart failure (HF) hospitalization or cardiac death, was evaluated. Median baseline BNP was 94.2 pg/mL. During a median follow-up of 2.4 years, low BNP (<38.3 pg/mL) was associated with lower rates of recurrent atrial tachyarrhythmias than BNP concentrations ≥38.3 pg/mL (19.9% vs. 30.6% at 3 years; P<0.001) and HF (0.8% vs. 5.3% at 3 years; P<0.001). Multivariable Cox regression analyses revealed that low BNP was independently associated with lower risks of arrhythmia recurrence (hazard ratio [HR] 0.63; 95% confidence interval [CI] 0.47-0.82; P<0.001) and HF (HR 0.17; 95% CI 0.04-0.71; P=0.002). The favorable impact of low BNP on arrhythmia recurrence was prominent in patients with paroxysmal, but not non-paroxysmal, AF, particularly among those with long-standing AF. CONCLUSIONS: Low BNP concentrations had a favorable impact on clinical outcomes after AF ablation. The heterogeneous impact of baseline BNP concentrations on arrhythmia recurrence for the subgroups of patients divided by AF type warrants future larger studies with longer follow-up periods.

Risk of Adverse Outcomes Associated With Cardiac Sarcoidosis Diagnostic Schemes.

BACKGROUND: Multiple cardiac sarcoidosis (CS) diagnostic schemes have been published. OBJECTIVES: This study aims to evaluate the association of different CS diagnostic schemes with adverse outcomes. The diagnostic schemes evaluated were 1993, 2006, and 2017 Japanese criteria and the 2014 Heart Rhythm Society criteria. METHODS: Data were collected from the Cardiac Sarcoidosis Consortium, an international registry of CS patients. Outcome events were any of the following: all-cause mortality, left ventricular assist device placement, heart transplantation, and appropriate implantable cardioverter-defibrillator therapy. Logistic regression analysis evaluated the association of outcomes with each CS diagnostic scheme. RESULTS: A total of 587 subjects met the following criteria: 1993 Japanese (n = 310, 52.8%), 2006 Japanese (n = 312, 53.2%), 2014 Heart Rhythm Society (n = 480, 81.8%), and 2017 Japanese (n = 112, 19.1%). Patients who met the 1993 criteria were more likely to experience an event than patients who did not (n = 109 of 310, 35.2% vs n = 59 of 277, 21.3%; OR: 2.00; 95% CI: 1.38-2.90; P < 0.001). Similarly, patients who met the 2006 criteria were more likely to have an event than patients who did not (n = 116 of 312, 37.2% vs n = 52 of 275, 18.9%; OR: 2.54; 95% CI: 1.74-3.71; P < 0.001). There was no statistically significant association between the occurrence of an event and whether a patient met the 2014 or the 2017 criteria (OR: 1.39; 95% CI: 0.85-2.27; P = 0.18 or OR: 1.51; 95% CI: 0.97-2.33; P = 0.067, respectively). CONCLUSIONS: CS patients who met the 1993 and the 2006 criteria had higher odds of adverse clinical outcomes. Future research is needed to prospectively evaluate existing diagnostic schemes and develop new risk models for this complex disease.

The impact of home electrocardiograph measurement rate on the detection of atrial fibrillation recurrence after ablation: A prospective multicenter observational study.

Background: This multicenter prospective observational study examined the impact of additionally using a home electrocardiograph (ECG) to detect atrial fibrillation (AF) recurrence after ablation. Methods: Between May 2019 and December 2020, 128 patients undergoing ablation were enrolled in the study. After performing ablation, they were instructed to measure their ECGs at home using Complete (ECG paired with a blood pressure monitor; Omron Healthcare, Japan) every day and to visit the hospital every 3 months until after 12 months for 24-hour Holter ECG and 12-lead ECG as usual care (UC). Results: After ablation, 94 patients were followed up, and AF recurrence at 12 months was detected more commonly in adjudicators-interpreted Complete (31 [33 %]) than in UC (18 [9 %]) (hazard ratio 1.95, 95 % confidence interval [95 %CI] 1.35-2.81, P < 0.001). In patients with recurrent AF found via both modalities (n = 16), the time to first AF detection by Complete was 40.9 ± 73.9 days faster than that in UC (P = 0.04). Notably, when the adherence to Complete measurement was divided by 80 %, the add-on effect of Complete on the detection of recurrent AF in UC indicated the hazard ratio (HR) of 1.71 (95 %CI 0.92-3.18, P = 0.09) for the low adherence (<80 %) group, but it was significant for the high adherence (≥80 %) group, with HR of 2.19 (95 %CI 1.43-3.36, P < 0.001). Conclusions: Despite a shorter measurement time, Complete detected recurrent AF more frequently and faster compared with UC after AF ablation. A significant adherence-dependent difference of Complete was found in detecting AF recurrence.

Improvement in quality of life and cardiac function after catheter ablation for asymptomatic persistent atrial fibrillation.

BACKGROUND: Catheter ablation (CA) for atrial fibrillation (AF) is widely performed. However, the indication for CA in patients with asymptomatic persistent AF is still controversial. METHODS: Among 259 consecutive patients who were hospitalized for initial CA of AF, a total of 45 patients who had asymptomatic persistent AF were retrospectively analyzed. Quality of life (QOL) before and 1 year after CA was evaluated, and changes in the cardiac function over 5 years after CA were also examined. QOL was assessed using the AF QOL questionnaire (AFQLQ) developed by the Japanese Heart Rhythm Society. In addition, cardiac function was assessed by measuring the plasma B-type natriuretic peptide (BNP) level, left ventricular ejection fraction (LVEF), left atrial diameter (LAD) with transthoracic echocardiogram, and left atrial (LA) volume with computed tomography (CT). RESULTS: The AFQLQ significantly improved after CA in terms of "symptom frequency" and "activity limits and mental anxiety." The plasma BNP level, LVEF, and LAD significantly improved in the first 3 months after the first CA, with no significant changes thereafter (from 149.0 pg/dL [95% confidence intervals {CI}, 114.5-183.5 pg/dL] to 49.8 pg/dL [95% CI, 26.5-70.1], P < .0001; from 60.8% [95% CI, 58.1%-63.6%] to 65.0% [95% CI, 62.6-67.4], P = .001; and from 41.3 mm [95% CI, 39.7-42.9] to 36.8 [95% CI, 34.5-39.1 mm], P < .0001, respectively). LA volume revealed LA reverse remodeling after CA. CONCLUSION: Improvement in the QOL and cardiac function after CA of asymptomatic persistent AF was revealed. Asymptomatic persistent AF should be appropriately treated by CA.

Successful Transcatheter Aortic Valve Implantation in a Patient with Radiation-induced Aortic Stenosis for Mediastinal Hodgkin Lymphoma.

Aortic stenosis (AS), a late complication of thoracic radiation therapy for chest lesions, is often coincident with porcelain aorta or hostile thorax. We herein report a 59-year-old man with a history of mediastinal Hodgkin lymphoma treated with radiation therapy but later presenting with heart failure caused by severe AS. Severe calcification in the mediastinum and around the ascending aorta made it difficult to perform surgical aortic valve replacement. The patient therefore underwent transcatheter aortic valve implantation (TAVI). It is important to recognize radiation-induced AS early, now that TAVI is a well-established treatment required by increasing numbers of successfully treated cancer patients.

Propranolol Attenuates Late Sodium Current in a Long QT Syndrome Type 3-Human Induced Pluripotent Stem Cell Model.

BACKGROUND: Long QT syndrome type 3 (LQT3) is caused by gain-of-function mutations in the SCN5A gene, which encodes the α subunit of the cardiac voltage-gated sodium channel. LQT3 patients present bradycardia and lethal arrhythmias during rest or sleep. Further, the efficacy of ß-blockers, the drug used for their treatment, is uncertain. Recently, a large multicenter LQT3 cohort study demonstrated that ß-blocker therapy reduced the risk of life-threatening cardiac events in female patients; however, the detailed mechanism of action remains unclear. OBJECTIVES: This study aimed to establish LQT3-human induced pluripotent stem cells (hiPSCs) and to investigate the effect of propranolol in this model. METHOD: An hiPSCs cell line was established from peripheral blood mononuclear cells of a boy with LQT3 carrying the SCN5A-N1774D mutation. He had suffered from repetitive torsades de pointes (TdPs) with QT prolongation since birth (QTc 680 ms), which were effectively treated with propranolol, as it suppressed lethal arrhythmias. Furthermore, hiPSCs were differentiated into cardiomyocytes (CMs), on which electrophysiological functional assays were performed using the patch-clamp method. RESULTS: N1774D-hiPSC-CMs exhibited significantly prolonged action potential durations (APDs) in comparison to those of the control cells (N1774D: 440 ± 37 ms vs. control: 272 ± 22 ms; at 1 Hz pacing; p < 0.01). Furthermore, N1774D-hiPSC-CMs presented gain-of-function features: a hyperpolarized shift of steady-state activation and increased late sodium current compared to those of the control cells. 5 µM propranolol shortened APDs and inhibited late sodium current in N1774D-hiPSC-CMs, but did not significantly affect in the control cells. In addition, even in the presence of intrapipette guanosine diphosphate ßs (GDPßs), an inhibitor of G proteins, propranolol reduced late sodium current in N1774D cells. Therefore, these results suggested a unique inhibitory effect of propranolol on late sodium current unrelated to ß-adrenergic receptor block in N1774D-hiPSC-CMs. CONCLUSION: We successfully recapitulated the clinical phenotype of LQT3 using patient-derived hiPSC-CMs and determined that the mechanism, by which propranolol inhibited the late sodium current, was independent of ß-adrenergic receptor signaling pathway.

Impact of right ventricular function on development of significant tricuspid regurgitation in patients with chronic atrial fibrillation.

BACKGROUND: Chronic atrial fibrillation (AF) can cause significant tricuspid regurgitation (TR), which may result from tricuspid annulus and right atrial enlargement. However, the impact of right ventricular (RV) function on TR development remains unclear. METHODS: We retrospectively examined 175 consecutive patients with lone chronic AF (duration >1 year) without left ventricular dysfunction. TR severity was graded by the jet area and vena contracta, and moderate or severe TR were defined as significant TR. Patients were classified as significant TR (TR group) or without (NTR group) for comparison of clinical factors and transthoracic echocardiographic (TTE) parameters. To explore factors associated with TR development, we also compared previous TTE parameters among patients in TR group who showed no prior significant TR [TR-preTR(-)] and those in NTR group [NTR-preTR(-)]. RESULTS: The mean age was 78 years (61% men). Significant TR was observed in 61 patients (35%). Compared with NTR group, the TR group was older, and had longer AF duration and larger right-sided cardiac parameters on index TTE. At previous TTE, the TR-preTR(-) group showed a larger basal RV dimension index (26.8 vs. 22.4mm/m2), reduced RV free wall longitudinal strain (RVLS-FW) (-18.96 vs. -23.23), and lower tricuspid annular diameter change during a cardiac cycle (8.8% vs. 14.1%) than NTR-preTR(-) group. CONCLUSION: Significant TR was observed in 35% of patients with chronic AF. These patients showed enlarged RV, reduced RVLS-FW, and low tricuspid annular diameter changes before significant TR develops. RV dysfunction may be associated with TR development in chronic AF.

Occurrence of right ventricular dysfunction immediately after pericardiocentesis.

The changes in cardiac function that occur after pericardiocentesis are unclear. An understanding of the effect of pericardiocentesis on right ventricular (RV) and left ventricular (LV) function is clinically important. This study was performed to assess RV and LV function with echocardiography before and after pericardiocentesis. In total, 19 consecutive patients who underwent pericardiocentesis for more than moderate pericardial effusion were prospectively enrolled from August 2015 to October 2017. Comprehensive transthoracic echocardiography was performed before, immediately after (within 3 h), and 1 day after pericardiocentesis to investigate the changes in RV and LV function. The mean age of all patients was 72.6 ± 12.2 years. No pericardiocentesis-related complications occurred during the procedure, but one patient died of right heart failure 8 h after pericardiocentesis. After pericardiocentesis, RV inflow and outflow diameters increased (p < 0.05 versus values before pericardiocentesis), and the parameters of RV function (tricuspid annular plane systolic excursion, tricuspid lateral annular systolic velocity, fractional area change, and RV free wall longitudinal strain) significantly decreased (p < 0.001 versus values before pericardiocentesis). These abnormal values or RV dysfunction remained 1 day after pericardiocentesis (p > 0.05 versus values immediately after pericardiocentesis). Conversely, no parameters of LV function changed after pericardiocentesis. Of 19 patients, 13 patients showed RV dysfunction immediately after pericardiocentesis and 6 patients did not. RV free wall longitudinal strain before pericardiocentesis in patients with post-procedural RV dysfunction was reduced compared to those without post-procedural RV dysfunction ( - 18.9 ± 3.6 versus - 28.4 ± 6.3%; p = 0.005). The area under the curve values for prediction of post-procedural RV dysfunction was 0.910 for RV free wall longitudinal strain. The occurrence of RV dysfunction after pericardiocentesis should be given more attention, and pre-procedural RV free wall longitudinal strain may be a predictor of post-procedural RV dysfunction.

Very long-term follow-up data of non-ischemic idiopathic dilated cardiomyopathy after beta-blocker therapy: recurrence of left ventricular dysfunction and predictive value of 123I-metaiodobenzylguanidine scintigraphy.

The management of idiopathic dilated cardiomyopathy (DCM) is well established. However, a subset of patients do not have recovery from or have recurrences of left ventricular (LV) dysfunction despite receiving optimal medical therapy. There are limited long-term follow-up data about LV function and the predictive value of iodine-123-metaiodobenzylguanidine (123I-MIBG) scintigraphy, especially among the Japanese population. We retrospectively investigated 81 consecutive patients with DCM (mean LV ejection fraction (EF) 28 ± 7.5%) who had undergone 123I-MIBG scintigraphy before starting ß-blockers. According to chronological changes in LVEF, study patients were classified into three subgroups: sustained recovery group, recurrence group, and non-recovery group. The outcome measure was cardiac death. Mean age was 59 ± 11 years and median follow-up was 11.5 (5.8-15.0) years. Thirty-six patients had recovery, 11 had recurrences, and 34 did not have recovery. The sustained recovery group had the best cardiac death-free survival, followed by the recurrence and non-recovery groups. Prolonged time to initial recovery was associated with recurrence of LV dysfunction. Large LV end-diastolic diameter and reduced heart to mediastinum ratio were associated with poor prognosis. In conclusion, with ß-blocker therapy, 14% of patients showed recurrences of LV dysfunction. Thus, careful follow-up is needed, keeping in mind the possibility of recurrence, even if LVEF once improved, especially in patients whose time to initial recovery was long. 123I-MIBG scintigraphy provides clinicians with additional prognostic information.

Subacute aortic regurgitation due to traumatic tear in the aortic wall.

A 37-year-old man presented with heart failure caused by severe aortic regurgitation (AR). He had a history of being involved in a traffic accident 3 months earlier. Imaging tests at admission detected no abnormalities in the aortic valve or aortic wall; however, the left coronary cusp prolapsed slightly on transthoracic echocardiography. He underwent aortic valve replacement because of uncontrolled heart failure and severe AR. Intraoperatively, the intima of the aortic wall just above the commissure of the left and right coronary cusps was torn to the short axial direction. Local aortic tear was the final diagnosis for the subacute AR. .