The R Wave Amplitude in Lead aVL Could Predict Successful Catheter Ablation of Ventricular Arrhythmias Originating below the His Bundle Region of the Right Ventricle.

Radiofrequency catheter ablation (RFCA) to treat ventricular arrhythmias (VAs) originating below the His bundle (HB) region of the right ventricular (RV) septum could impair the atrioventricular node conduction. This study aimed to clarify the parameters of the 12-lead electrocardiography that predict successful RFCA of VAs originating from this region. This study included 20 consecutive patients (13 men; mean age, 68 ± 7 years) with monomorphic VAs in whom the earliest ventricular activation during the VA was below the HB region of the RV septum. According to the ablation results, the patients were divided into two groups: successful ablation (S-group; n = 10) and failed ablation groups (F-group; n = 10). The electrocardiographic parameters during the VAs and RFCA results were assessed. The R wave amplitudes in leads aVL (P = 0.001) and I (P = 0.010) in the S-group were both smaller than those in the F-group. In addition, the S-group had smaller negative deflection amplitudes in leads III (P = 0.002) and aVF (P = 0.003) than the F-group. According to the receiver operating characteristic curve analysis, the most useful electrocardiographic parameter for predicting successful ablation was the R wave amplitude in lead aVL (area under the curve, 0.895; P < 0.001); a cutoff value of < 1.3 mV predicted a successful RFCA with the highest accuracy (sensitivity, 90%; specificity, 80%; positive predictive value, 82%; negative predictive value, 89%). The R wave amplitude in lead aVL was the most useful parameter for predicting a successful RFCA to treat VAs originating below the HB region of the RV septum.

Catheter ablation of ventricular tachycardia in dilated-phase hypertrophic cardiomyopathy: Substrate characterization and ablation outcome.

INTRODUCTION: Catheter ablation is a therapeutic option to suppress ventricular tachycardia (VT) in the setting of dilated-phase hypertrophic cardiomyopathy (DHCM). However, the characteristics of the arrhythmogenic substrate and the ablation outcome are not fully illustrated. METHOD: A total of 23 ablation procedures for drug-refractory sustained monomorphic VTs in 13 DHCM patients (60 ± 11 years, one female, the left ventricular [LV] ejection fraction 39% ± 9%, the LV mass index 156 ± 39 g/m2 ) were performed. The distribution of VT substrate as endocardial or epicardial/intramural was based on detailed mapping and ablation response during VT. RESULT: Two patients underwent ablation of sustained monomorphic VT that was not scar-mediated tachycardia. Of the remaining 11 patients, eight (73%) patients had VT substrate in the basal regions, most frequently at the epicardial and/or intramural basal antero-septum. None of the patients had VT substrate located at the LV inferolateral region. Ablation at the right ventricular septum and the aortic cusps was done in four and five patients, respectively. Other approaches including bipolar and chemical ablations, were done in three and two patients, respectively. Six (55%) out of 11 patients (two patients lost follow-up) had VT recurrence. All the six patients had basal substrate. However, anti-tachycardia pacing was sufficient for VT termination except in one patient. CONCLUSION: Catheter ablation of VT in patients with DHCM is challenging because of the predominant basal anteroseptal epicardial/intramural location of arrhythmogenic substrate. An ablation approach from multiple sites and/or adjunctive interventional techniques are often required.

Preprocedural restoration of sinus rhythm and left atrial strain predict outcomes of catheter ablation for long-standing persistent atrial fibrillation.

INTRODUCTION: Catheter ablation (CA) for long-standing persistent atrial fibrillation (LS-AF) remains challenging. We aimed to explore whether sinus rhythm (SR) restoration and left atrium (LA) function after pretreatment with antiarrhythmic drugs (AAD's) and electrical cardioversion (ECV) predict procedural outcomes. METHODS AND RESULTS: We included 100 consecutive patients with LS-AF who were treated with AAD/ECV for at least 3 months before CA. The echocardiographic LA strain during reservoir phase (LASr) was assessed after pretreatment as a marker of LA fibrosis. The recurrence was recorded for ≥1 year after the last procedure. During a 34 ± 16-month follow-up period, the single and multiple procedures and pharmaceutically assisted success rates were 40% and 71%, respectively. Patients with preprocedural SR restoration and higher LASr showed a significantly higher recurrence-free probability after the last CA (logrank P = .001 and P < .001, respectively). Failure of preprocedural SR restoration and LASr ≤8.6% were independently associated with recurrence after the last CA (hazard ratio [HR]: 3.13, 95% confidence interval [CI]: 1.42-6.91, P = .005; HR: 3.89, 95% CI: 1.65-9.17, P = .002, respectively). These parameters added incrementally to the predictive value of AF duration and LA dilatation (P = .03 and P = .002, respectively) and improved the recurrence-risk stratification (net reclassification improvement = 0.39; 95% CI = 0.13-0.65; P = .003). CONCLUSION: In patients with LS-AF, the inability to restore SR and lower LASr after AAD/ECV treatment independently and incrementally predicts the recurrence after CA. These findings might be useful for determining LS-AF ablation candidates.

Stepwise approach to induce infrequent premature ventricular complex using bolus isoproterenol and epinephrine infusion.

BACKGROUND: Paucity of a premature ventricular complex (PVC) during ablation procedures may occur and be associated with a lower success rate. Isoproterenol (ISP) injections are commonly used to induce PVC; however, the induced tachycardia sometimes prevents the appearance of PVC. Epinephrine (EPI) administration may be an alternative strategy to induce PVC due to its smaller effect on heart rate (HR). This study sought to examine the electrophysiological impact of EPI injection, with a stepwise induction protocol, for infrequent intraprocedural PVC. METHODS: We studied 78 consecutive patients who underwent catheter ablation of idiopathic frequent PVC. If no PVC was observed at the beginning of the procedure, ISP (10 µg) was injected. If clinical PVC was not induced by ISP administration, EPI (10 µg) was injected. RESULTS: Of 18 patients without PVC at baseline, ISP injection induced PVC in five patients. Of the remaining 13 patients, EPI injection successfully induced PVC in seven patients (53%). The maximum HR and increments of HR after EPI injection were significantly lower than those after ISP injection (99 ± 15 vs 137 ± 15 bpm, P = .001; 22 ± 10 vs 53 ± 12 bpm, P < .001, respectively). There were no complications related to the induction protocol. CONCLUSION: EPI injection following ISP injection is an effective and safe stepwise approach for the induction of infrequent PVC in the electrophysiology laboratory. It is hypothesized that α- and ß-adrenergic receptor stimulation by EPI injections, with reduced HR acceleration compared to that with ISP injections, may result in the successful induction of PVC.

Circulatory dynamics changes are an additional predictor of successful pulmonary vein isolation during cryoballoon ablation.

The association between circulatory dynamics changes during cryoballoon applications and a successful pulmonary vein isolation (PVI) is unknown. Seventy atrial fibrillation patients who underwent PVI with 28-mm second-generation cryoballoons and single 3-min freezes were included. Intra-procedural parameters including circulatory dynamics changes during cryoapplications, were compared between 113 successful applications (30 left superior PVs[LSPVs], 30 left inferior PVs[LIPVs], 25 right superior PVs[RSPVs], and 28 right inferior PVs[RIPVs]) and 47 failed applications (10 LSPVs, 9 LIPVs, 8 RSPVs, and 20 RIPVs). In all individual PVs, lower nadir balloon temperatures (MinTemps) and longer thawing times (ThawTimes) significantly predicted a successful PVI. In addition, greater systolic blood pressure drops following releasing the PV occlusion (SBP-drops) significantly predicted a successful right PV PVI, and longer elapse times during SBP-drops significantly predicted a successful RIPV PVI. Composite parameters incorporating MinTemps and ThawTimes, SBP-drops, and ThawTimes showed the highest area under the curve to predict a successful left PV (0.876 for LSPVs, 0.851 for LIPVs) and right PV (0.927 for RSPVs, 0.980 for RIPVs) PVI, respectively. If the ThawTime (≥ 30 s) and SBP-drop (≤ - 21 mmHg) cutoff values were achieved for the RIPVs, the positive predictive value was 100%. In contrast, if both criteria were not achieved for the RIPVs, the negative predictive value was 100%. In the second-generation cryoballoon PVI, the MinTemp and ThawTime were significantly associated with acute success for all four PVs. In addition, SBP-drops further improved the accuracy of predicting a successful right PV PVI, especially of the RIPV.

The Usefulness and Limitations of Impedance Cardiography for Cardiac Resynchronization Therapy Device Optimization.

Identifying the optimal atrioventricular (AV) or interventricular (VV) delay is beneficial for patients using cardiac resynchronization therapy (CRT) devices. Ultrasonic echocardiography (UCG) has been the most commonly used method; however, it requires high technical knowledge. Impedance cardiography (ICG) can calculate stroke volume by measuring changes in transthoracic electric impedance. This study sought to assess the clinical utility of ICG in comparison with that of UCG for the optimization of CRT devices.Patients who underwent CRT device implantation were retrospectively analyzed. One week after implantation, optimization of AV delay (AVD) was performed in every patient with ICG (AVD-ICG) and UCG (AVD-UCG). VV delay (VVD) was then determined according to the optimal AVD using these two methods.Forty-two patients were enrolled. Average AVD-ICG was significantly shorter than AVD-UCG (128 ± 49 versus 146 ± 41 milliseconds, P = 0.018). Five patients (12%) had the same optimized AVD with two methods, and the difference between AVD-ICG and AVD-UCG was ≤ 20 milliseconds in 19 patients (45%). In the multivariate analysis, the presence of postoperative mitral regurgitation (MR) was an independent predictor of AVD-ICG/AVD-UCG mismatch, defined as a difference over 20 milliseconds (odds ratio = 10.71; 95% confidence interval = 1.72 to 66.72; P = 0.018). The results of optimized VVD were similar using both methods.ICG might be a promising tool for the rapid optimization of CRT devices. However, in patients with moderate-to-severe MR, ICG may not be able to optimize AVD.

A case of bidirectional conduction block within the superior vena cava induced by cryoballoon pulmonary vein isolation.

A 53-year-old male underwent a pulmonary vein isolation (PVI) of atrial fibrillation (AF) with a second-generation cryoballoon (CB). Although the patient maintained sinus rhythm after the PVI, a superior vena cava (SVC) fibrillation was recorded by a circular-multipolar-electrode catheter positioned inside the SVC that suggested conduction block between the right atrium (RA)-SVC connection. An adenosine triphosphate intravenous injection induced a dormant reconnection of the SVC myocardial sleeve and converted sinus rhythm to an AF rhythm. This case demonstrated that a CB application for the isolation of a right superior pulmonary vein could induce an electrical conduction block between the RA-SVC connection.

Utility of low-dose adenosine triphosphate sensitivity in slow-fast atrioventricular nodal reentrant tachycardia.

PURPOSE: Low-dose adenosine triphosphate (LD-ATP) is useful for diagnosing ATP-sensitive atrial tachycardia. However, the clinical implications of the sensitivity of LD-ATP in atrioventricular nodal reentrant tachycardia (AVNRT) still remain unknown. This study aimed to evaluate the mechanism of LD-ATP sensitivity in slow-fast AVNRT. METHODS: We estimated the sensitivity of LD-ATP in slow-fast AVNRT by a 2-4-mg ATP intravenous injection during the tachycardia. We evaluated the atrial-His (A-H) interval, tachycardia termination mode, prevalence of a lower common pathway (LCP), and successful ablation site in slow-fast AVNRT with LD-ATP sensitivity. LCPs were defined as His-atrial interval differences of at least 5 ms between that during ventricular pacing at the tachycardia cycle length and that during the tachycardia. RESULTS: Twenty-eight patients (mean age = 58 ± 11 years old, 18 females) with slow-fast AVNRT, who underwent catheter ablation of the antegrade slow pathway, were enrolled. Seventeen of 28 (61%) patients had LD-ATP sensitivity defined as termination of the tachycardia and/or a prolongation of the A-H interval of over 30 ms after an LD-ATP injection. The patients with LD-ATP sensitivity had a significantly higher prevalence of an LCP than those without (15/17 vs0/11, P < 0.0001). The successful ablation site in the LD-ATP sensitive group was significantly closer to the His bundle area than that in the LD-ATP nonsensitive group (13.3 ± 3.8 vs 20.5 ± 5.4 mm; distance to His bundle area in the left anterior oblique fluoroscopic view, P < 0.0001). CONCLUSIONS: LD-ATP sensitivity in slow-fast AVNRT may suggest the existence of an LCP. The successful ablation site in patients with LD-ATP sensitivity could be closer to the His bundle region.

Electrocardiographic morphology of multiple ventricular arrhythmias originating from the right ventricular outflow tract: inverse correlation of the amplitude in the inferior leads and anatomic height of the origin.

It is unclear whether the electrocardiogram amplitude in the inferior leads (Amp-I) can always predict the height of the origin of right ventricular outflow tract arrhythmias (RVOT-VAs). We analyzed patients who received catheter ablation of multiple RVOT-VAs in the same session in our hospital from 2011 to 2016. Two distinguished RVOT-VAs, those with anatomically higher origins (HOs) and lower origins (LOs), were identified and compared to measure the longitudinal distance. Amp-I was uniquely determined for each OTVA as the highest amplitude in leads II, III, and aVF and compared between the HO-VAs and LO-VAs. In total, out of 187 patients who underwent catheter ablation of RVOT-VAs, 9 (4.8%) had multiple right OTVAs successfully treated. Four cases (Group A) had HO-VAs (10.8 ± 5.3 mm from an LO) with a lower Amp-I (1.28 ± 0.46 mV) than the LO-VAs (1.81 ± 0.59 mV), whereas the other 4 patients (Group B) had HO-VAs with a higher Amp-I (1.91 ± 0.23 mV) than the LO-VAs (1.26 ± 0.35 mV). In Group A, all HO-VAs originated from the lateral free wall and had notched R waves in the inferior leads, whereas all LOs with higher Amp-Is were located on the septum. In one patient, the HO and LO were at almost the same height, while a VA from a lateral origin had lower notched R waves in the inferior leads. A divided excitation from high lateral origins may result in not only QRS notching, but also a reduction in the QRS amplitude. In patients harboring multiple RVOT-VAs, VAs arising from the high lateral free wall could have lower Amp-Is than VAs from low septal origins.

Management of cardiac tamponade in catheter ablation of atrial fibrillation: single-centre 15 year experience on 5222 procedures.

Aims: Cardiac tamponade during atrial fibrillation (AF) ablation is infrequent but potentially fatal. This study aimed to retrospectively investigate the incidence, management, and outcomes of tamponade in large patient series. Methods and results: The study analysed 5222 AF ablation procedures in 3483 patients between 2002 and 2016 under a heparin-bridge anticoagulation protocol. Cardiac tamponade occurred in 51 procedures/patients, and the incidence was 0.98% per procedure and 1.46% per patient and was noted during the procedure in 42 patients and in the ward in the remaining 9 patients. No clinical factors were associated with the occurrence, but it was lower during cryoballoon than radiofrequency ablation (P = 0.025). Pericardiocentesis was required in 44 (86.3%) patients, and the haemodynamic state stabilized after a total of 377 (260-530) mL of pericardial blood drainage except for in 2 (3.9%) patients requiring subsequent emergent surgical repairs. The pericardial drain was successfully removed after a median of 1.0 (1.0-2.0) days. In 44 patients, anticoagulation therapy was restarted a median of 3.0 (1.0-7.0) days after the procedure. Thirty (58.8%) patients experienced early recurrent AF with low-grade fevers (37.4 ± 0.5 °C) and an elevated C-reactive protein [2.4 (1.1-8.5) mg/dL]. After successful management of tamponade, 2 (3.9%) patients exhibited cerebral infarctions despite restarting anticoagulation therapy. One patient died, and the other completely recovered without any neurological deficit. Recurrent post-cardiac injury syndrome (PCIS) occurred on post-procedural Day 13 in another patient, requiring oral prednisone administration for 10 months. During a median follow-up of 23 (5.4-46.1) months, 34 (66.7%) patients were arrhythmia free. Conclusions: Despite an infrequent incidence, surgical backup is essential for performing AF ablation. Even after successful management of tamponade, care should be taken for subsequent complications.

Persistence of an iatrogenic atrial septal defect after a second-generation cryoballoon ablation of atrial fibrillation.

Persistent iatrogenic atrial septal defects (iASDs) can be observed after intervention requiring a left atria (LA) access, including pulmonary vein isolation (PVI) of atrial fibrillation (AF). We investigated the incidence of iASDs post-second-generation cryoballoon ablation and the pre-procedural predictors. Eighty-three paroxysmal AF patients underwent PVI using second-generation cryoballoons. The LA was accessed with single 15-Fr steerable sheaths following a radiofrequency transseptal puncture, and the iASD was evaluated with transthoracic echocardiography (TTE), a median of 9.3 (7.1-13.3) months post-procedure. All patients underwent pre-procedural contrast-enhanced multi-detector computed tomography (CT) to evaluate the LA and PV anatomy. iASDs were detected by TTE in 7 (8.4%) patients, a median of 15.5 (6.8-17.3) months post-procedure. Patients with iASDs had significantly larger LA volumes and smaller atrial septal angles, defined as the angle between the atrial septum and sagittal line on the horizontal section at the height of the fossa ovalis, which could be the transseptal puncture site measured on CT, and more likely hypertension than those without. Multivariate analyses revealed that the atrial septal angle was the sole predictor of iASDs [odds ratio 0.764, 95% confidence interval (CI) 0.624-0.935, p = 0.009], and the optimal cut-off value was 57.5° (sensitivity 85.7%, specificity 88.2%, 95% CI 0.873-0.995, p < 0.0001). Patients with iASDs were asymptomatic and had no adverse clinical events during a 17.7 (14.4-25.8) month median follow-up. iASDs were still detectable in 8.4% of patients a median of 15.5 months after the second-generation CB ablation, and the atrial septal angle might aid in predicting persistent iASDs.

Autonomic nervous system modulation and clinical outcome after pulmonary vein isolation using the second-generation cryoballoon.

BACKGROUND: The intrinsic cardiac autonomic nervous system (ANS) plays a significant role in atrial fibrillation (AF) mechanisms. This study evaluated the incidence and impact of intraprocedural vagal reactions and ANS modulation by pulmonary vein isolation (PVI) using second-generation cryoballoons on outcomes. METHODS: One hundred three paroxysmal AF patients underwent PVI with one 28-mm second-generation balloon. The median follow-up was 15.0 (12.0-18.0) months. ANS modulation was defined as a >20% cycle length decrease on 3-minute resting electrocardiograms at 1, 3, 6, and 12 months postindex procedure relative to baseline if sinus rhythm was maintained. RESULTS: Marked sinus arrests/bradycardia and atrioventricular block (intraprocedural vagal reaction) occurred in 14 and 2 patients, and all sinus arrest/bradycardia occurred in 44 patients with left superior pulmonary veins (PVs) targeted before right PVs. ANS modulation was identified in 66 of 95 (69.5%) patients, and it persisted 12-month postprocedure in 36 (37.9%) patients. Additional ß-blocker administration was required in 9 patients for sinus tachycardia. ANS modulation was similarly observed in patients with and without intraprocedural vagal reactions (P = 0.443). Forty-eight (46.6%) patients experienced early recurrences, and the single procedure success at 12 months was 72.7%. Neither intraprocedural vagal reactions nor ANS modulation predicted AF freedom within or after the blanking period. Thirty-three patients underwent second procedures, and reconnections were detected in 39 of 130 (30.0%) PVs among 23 (69.7%) patients. The incidence of reconnections was similar in patients with and without ANS modulation. CONCLUSIONS: Increased heart rate persisted in 37.9% of patients even at 12-month post-second-generation cryoballoon PVI. Neither intraprocedural vagal reactions nor increased heart rate predicted a single procedure clinical outcome.

Validation of electrical ostial pulmonary vein isolation verified with a spiral inner lumen mapping catheter during second-generation cryoballoon ablation.

BACKGROUND: Achieve catheters are cryoballoon guidewires that enable pulmonary vein (PV) potential mapping. The single catheter approach in conjunction with the Achieve catheter is currently standard practice in second-generation cryoballoon ablation, yet circumferential mapping catheters are the gold standard for evaluating PV isolation (PVI). The study sought to validate the ostial PVI verified by an Achieve catheter alone. METHODS: One hundred fifty-one paroxysmal atrial fibrillation patients undergoing PVI using exclusively 28-mm second-generation cryoballoons were enrolled. PV recordings were analyzed during (real-time recordings) and after cryoballoon applications with 20-mm Achieve mapping catheters, and subsequently validated by 20-mm conventional circumferential mapping catheters. RESULTS: Out of 596 PVs, 576 (96.6%) were isolated using cryoballoons, and 20 required touch-up ablation. PVI was verified during cryoballoon applications with real-time monitoring in 299, and after applications in 280 PVs by Achieve catheters alone. The time-to-isolation was 27.2 ± 22.0 seconds. Validation with standard circumferential mapping catheters confirmed ostial PVIs in 296 of 299 (99.0%) PVs that real-time PVI was obtained during applications, and in 242 of 280 (86.5%) PVs that PV activities were not visible during applications and PVI was verified after the applications. The accuracy of ostial PVIs with Achieve catheters in PVs without obtaining real-time PV recordings was 40/47 (85.1%), 58/65 (89.2%), 77/79 (97.5%), 61/81 (75.3%), and 6/8 (75.0%) in left superior, left inferior, right superior, right inferior, and left common PVs, respectively. CONCLUSIONS: In second-generation 28-mm cryoballoon ablation, verification of ostial PVIs using Achieve mapping catheters alone might not be sufficient to accurately confirm an ostial PVI when real-time PVI was not obtained.

Fragmented QRS Is a Novel Risk Factor for Ventricular Arrhythmic Events After Receiving Cardiac Resynchronization Therapy in Nonischemic Cardiomyopathy.

INTRODUCTION: A fragmented QRS (fQRS) is reported to be associated with a poor prognosis or sudden cardiac death (SCD) in patients with Brugada syndrome or ischemic heart disease. However, no studies have clarified the impact of the presence of an fQRS on SCD or ventricular arrhythmic events in patients receiving cardiac resynchronization therapy (CRT). This study aimed to clarify this point in patients with nonischemic cardiomyopathy. METHODS AND RESULTS: This study included 137 heart failure patients with nonischemic cardiomyopathy who received CRT (NYHA functional class: II/III/IV = 25/84/28). The 12-lead ECGs before and after CRT were analyzed. The presence of an fQRS was decided in accordance with the definition in previous papers. Before the CRT, an fQRS was observed in 67 patients (fQRS-pre; 49%). However, it was masked in 35 (52% of fQRS-pre) patients after the CRT. Inversely, in 70 patients in whom an fQRS was absent before the CRT, it appeared after the CRT in 15 (21%) patients. As a result, 47 patients (34%) had an fQRS after the CRT (fQRS-post), and it was less than that before the CRT (P = 0.014). During 18 months of follow-up, SCD or ventricular arrhythmic events were observed more frequently in patients with an fQRS-post than in those without (36.2% vs. 3.3%, P < 0.001). A Cox regression analysis revealed that an fQRS-post was significantly associated with those events (hazard ratio = 9.18; 95% confidence interval = 2.45-34.48, P = 0.001). CONCLUSION: In patients with nonischemic cardiomyopathy who received CRT, an fQRS-post was independently associated with SCD or ventricular arrhythmic events.

Electrophysiological Characteristics and Radiofrequency Catheter Ablation Treatment of Idiopathic Ventricular Arrhythmias Successfully Ablated From the Ostium of the Coronary Sinus.

BACKGROUND: Idiopathic ventricular arrhythmias (VAs) rarely arise from the epicardium at the crux of the heart. However, the electrophysiological characteristics of VAs successfully ablated from the ostium of the coronary sinus (CSO) have not yet been documented.Methods and Results:Electrocardiographic and electrophysiological data were analyzed in patients with idiopathic VAs successfully ablated from the CSO.Among 309 patients with idiopathic VAs treated with radiofrequency catheter ablation (RFCA), 6 (1.94%; 3 men; age: 66.3±9.7 years) had VAs successfully ablated from the CSO. Only 1 patient had sustained ventricular tachycardia. The morphology of the QRS showed a left superior axis and QS pattern in leads III and aVF. Furthermore, the precordial maximum deflection index was >0.55 in all patients and a right bundle branch block pattern was recorded in 5 of 6 patients. All VAs were successfully eliminated by RFCA within the CSO. Intracardiac ECGs at sites where VAs were eliminated by RFCA showed clear atrial and ventricular potentials (atrial amplitude: 0.21±0.11 mV; ventricular amplitude: 0.43±0.24 mV), except in 1 case of atrial fibrillation. No patients had recurrence during the 3.4±1.8-year follow-up period. CONCLUSIONS: The idiopathic VAs in our study were eliminated by RFCA within the CS, where a clear atrial amplitude was recorded.

Efficacy of Intensive Radiofrequency Energy Delivery to the Localized Dense Scar Area in Post-Infarction Ventricular Tachycardia Ablation　- A Comparative Study With Standard Strategy Targeting the Infarcted Border Zone.

BACKGROUND: Several reports have demonstrated the importance of severely low voltage areas as arrhythmogenic substrates of ventricular tachycardia (VT). However, a comparative study of dense scar-targeted and infarcted border zone-targeted strategies has not been reported.Methods and Results:We divided 109 consecutive patients with VT post-infarction from 6 centers into 2 groups according to the ablation strategy used: dense scar-targeted ablation (DS ablation, 48%) or border zone-targeted ablation (BZ ablation, 52%). During DS ablation, we attempted to identify VT isthmuses in the dense scar areas (≤0.6 mV) using detailed pace mapping, and linear ablation lesions were applied mainly to those areas. During BZ ablation, linear ablation of standard low voltage areas (0.5-1.5 mV) was performed along with good pace map sites of the clinical VT. Acute success was defined as complete success (no VTs inducible) or partial success (clinical VT was noninducible). The acute complete success rate was significantly higher for DS ablation than for BZ ablation (62% vs. 42%, P=0.043). During a median follow-up of 37 months, the VT-free survival rate was significantly higher for DS ablation than for BZ ablation (80% vs. 58% at 48 months; log-rank P=0.038). CONCLUSIONS: DS ablation may be a more effective therapy for post-infarction VT than BZ ablation in terms of the acute complete success rate and long-term follow-up.

J Waves Are Associated With the Increased Occurrence of Life-Threatening Ventricular Tachyarrhythmia in Patients With Nonischemic Cardiomyopathy.

INTRODUCTION: Recent studies showed that J waves were associated with higher incidence of ventricular tachyarrhythmia (VT/VF) in patients with idiopathic ventricular fibrillation (VF) and myocardial infarction. We sought to assess the association between J waves and VT/VF in patients with nonischemic cardiomyopathy (NICM). METHODS AND RESULTS: We retrospectively enrolled 109 patients (79 men; mean age, 60 ± 15 years) with NICM who underwent implantable cardioverter defibrillator (ICD) implantation. The primary endpoint of this study was the occurrence of appropriate device therapy due to sustained VT/VF. The J wave was electrocardiographically defined as an elevation of the terminal portion of the QRS complex of >0.1 mV in at least 2 contiguous inferior or lateral leads. Among the 109 patients, 37 (34%) experienced an episode of appropriate device therapy during a median follow-up period of 25.9 (IQR 11.5-54.3) months. Kaplan-Meier curves showed that the presence of J waves on the 12-lead ECG obtained before device implantation was associated with an increased occurrence of appropriate device therapy (P < 0.001). Multivariate Cox proportional regression analysis revealed that the presence of J waves (HR 2.95; 95% CI 1.31-6.64; P = 0.009) was an independent predictor for the occurrence of appropriate device therapy. In the subgroup analysis of the patients with dilated or hypertrophic cardiomyopathy, J wave tended to increase the occurrence of appropriate device therapy (P = 0.056 and P = 0.092, respectively). CONCLUSIONS: The presence of J waves was an independent predictor for the occurrence of appropriate device therapy in patients with NICM who underwent ICD implantation.

Prognostic impact of supraventricular premature complexes in community-based health checkups: the Ibaraki Prefectural Health Study.

AIMS: The long-term prognosis of subjects with supraventricular premature complexes (SVPCs) remains unclear in the general population. The aim of this study was to examine the prognostic significance of SVPCs in community-based health checkups. METHODS AND RESULTS: We assessed 63 197 individuals (mean age, 58.8 ± 9.9 years; 67.6% women) who participated in annual community-based health checkups in 1993 and were followed until 2008. The primary endpoint was stroke death, cardiovascular death (CVD), or all-cause death during a 14-year mean follow-up, and the secondary endpoint was first atrial fibrillation (AF) event in subjects without self-reported heart diseases or AF at baseline. Compared with subjects without SVPCs, the multivariate-adjusted hazard ratios (HRs) [95% confidence interval (CI)] of stroke death, CVD, and all-cause death in subjects with SVPCs were 1.24 (0.98-1.56) for men and 1.63 (1.30-2.05) for women, 1.22 (1.04-1.44) for men and 1.48 (1.25-1.74) for women, and 1.08 (0.99-1.18) for men and 1.21 (1.09-1.34) for women, respectively. Atrial fibrillation occurred in 386 subjects during the follow-up (1.05/1000 person-years). The presence of SVPCs at baseline was the significant predictor of AF onset [HRs (95% CI): 4.87 (3.61-6.57) for men and 3.87 (2.69-5.57) for women]. Propensity score matched analyses also revealed the presence of SVPCs was significantly associated with increased risks of AF incidence and CVD even after adjusting the potential confounders. CONCLUSION: The presence of SVPCs in 12-lead electrocardiograms was a strong predictor of AF development, and associated with increased risk of CVD in general population.

The QRS morphology pattern in V5R is a novel and simple parameter for differentiating the origin of idiopathic outflow tract ventricular arrhythmias.

AIMS: There are many reports on the ECG characteristics of idiopathic outflow tract ventricular arrhythmias (OT-VAs) to predict their origin. However, differentiating near regions using 12-lead ECGs is still complicated. The synthesized 18-lead ECG derived from the 12-lead ECG can provide virtual waveforms of the right-sided chest leads (V3R, V4R, and V5R) and back leads (V7, V8, and V9). The aim of this study was to develop a simple and useful parameter for differentiating OT-VA origins using the 18-lead ECG. METHODS AND RESULTS: We studied 28 and 73 patients with idiopathic VAs in a pacemapping study and validation cohort, respectively. In the pacemapping study, several sites out of five different sites were paced in each patient: the anterior and posterior right ventricular OT (RVOT-ant and RVOT-post), right and left coronary cusps (RCC and LCC), and junction of both cusps (RLJ). The 18-lead ECGs during pacemapping among the five sites were compared for establishing a simple parameter to predict VA origins. A novel parameter using 18-lead ECGs was tested prospectively in 73 patients. In the pacemapping study, the dominant QRS morphology pattern in the synthesized V5R significantly differed among those sites (RVOT-ant:Rs, RVOT-post:rS, RCC:QS, RLJ:qR, and LCC:R). The patients in the validation cohort were divided into five groups depending on those QRS morphology patterns during VAs in the synthesized V5R. Each V5R QRS morphology pattern could predict a precise origin of the OT-VAs with an overall accuracy of 75%. CONCLUSION: The QRS morphology pattern in V5R was a simple and useful parameter for differentiating detailed OT-VA origins.

Hybrid epicardial and endocardial ablation of a persistent atrial tachycardia arising from the marshall bundle: the importance of a detailed analysis of the local potentials.

Radiofrequency catheter ablation of an atrial tachycardia (AT) and atrial fibrillation (AF) was performed in a patient with a history of pulmonary vein isolation for paroxysmal AF. The AT exhibited a centrifugal pattern with the posterolateral LA as the earliest activation site. The AT was not terminated by ablation at the endocardial earliest site, but its cycle length was prolonged by ablation at an opposite site within the Vein of Marshall. Finally, the AT was terminated by an energy application at a site 7 mm posteroinferior to the initial earliest activation site. We analyzed the local potentials of each energy delivery site in detail.