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Background: Ventricular fibrillation and atrial fibrillation are well-known arrhythmias in patients with Brugada syndrome. This study evaluated the characteristics of the atrial arrhythmogenic substrate using the signal-averaged electrogram (SAECG) in patients with Brugada syndrome. Methods: SAECGs were performed during normal sinus rhythm in 23 normal volunteers (control group), 21 patients with paroxysmal atrial fibrillation (PAF; PAF group), and 21 with Brugada syndrome (Brugada group). Results: The filtered P wave duration (fPd) in the control, Brugada, and PAF groups was 113.9 ± 12.9 ms, 125.3 ± 15.0 ms, and 137.1 ± 16.3 ms, respectively. The fPd in the PAF group was significantly longer compared to that in the control and Brugada groups (p

Key Clinical Message Ganglionated plexus (GP) plays an important role in the initiation and maintenance of atrial fibrillation (AF). The GP ablation has been found to be effective for AF treatment. In this case, we reported an AF case in which the pulmonary vein (PV) potentials of the anterior region of the left superior PV were eliminated by an inferior right GP ablation.

A 64 year-old man underwent percutaneous coronary intervention (PCI), and the conus branch was occluded. Ventricular fibrillation (VF) occurred five hours after the PCI procedure with a Brugada-like electrocardiogram. A continuous injection of amiodarone was effective for the suppression of VF.

Time-Domain T-Wave Alternans and Brugada Syndrome Aims T-wave alternans (TWA) is an indicator of vulnerability to ventricular arrhythmias and is useful for predicting sudden cardiac death (SCD) in patients with various structural heart diseases. We evaluated whether high levels of time-domain TWA on ambulatory ECG (AECG) are associated with a history of ventricular fibrillation (VF) in Brugada syndrome (BrS) patients. Methods and Results We examined the associations among VF history, family history of SCD, spontaneous type 1 electrocardiogram (ECG), late potentials, VF induction by programmed electrical stimulation, and TWA in 45 BrS patients (44 males; mean age, 45 ± 15 years). TWA analyzed from 24-h AECG recordings using the modified moving average method was positive in 13 of 43 patients (30%). Patients with a history of VF had a significantly higher incidence of a positive TWA test (82% vs. 13%; P < 0.001) and spontaneous type 1 ECG (92% vs. 38%; P = 0.007) than those without VF history. Multivariate analysis indicated that positive TWA (OR 7.217; 95% CI 2.503–35.504; P = 0.002) and spontaneous type 1 ECG (OR 5.530; 95% CI 1.651–34.337; P = 0.020) were closely associated with VF history. Spontaneous type 1 ECG had high sensitivity (92%) but low specificity (63%). Positive TWA was a reliable marker with high sensitivity and specificity (82% and 88%, respectively). Conclusion Elevated time-domain TWA on AECG confirms arrhythmia risk in symptomatic BrS patients without the need for provocative stimuli.

Incomplete Cure of TIC with Rate ControlBackground It is uncertain whether rate or rhythm control is more favorable for patients experiencing tachycardia-induced cardiomyopathy (TIC) secondary to rapid atrial fibrillation (AF). Methods and Results We compared the electrophysiological and hemodynamic properties and outcome after AF ablation in 20 patients with a history of decompensated TIC who maintained sinus rhythm or had paroxysmal AF (group 1), 32 with a history of decompensated TIC who had persistent or longstanding persistent AF (group 2), 377 without TIC who had paroxysmal AF (group 3), and 225 without TIC who had persistent or longstanding persistent AF (group 4). The corrected sinus node recovery time was more prolonged in group 2 than in groups 1, 3, or 4 (1,066 ± 946 vs. 416 ± 188, 450 ± 322 and 590 ± 329 milliseconds; P < 0.001, respectively). The mean left atrial pressure in group 2 was greater than that in groups 1, 3, or 4 (13.9 ± 6.5 vs. 7.5 ± 3.1, 8.2 ± 4.1 and 10.8 ± 4.2 mmHg; P < 0.001, respectively). The left ventricular ejection fraction assessed after the recovery from the decompensation was more decreased in group 2 than in group 1; however, it almost returned to normal if sinus rhythm was maintained after the AF ablation in group 2. The presence of a history of TIC did not predict an AF recurrence after the ablation. Conclusions Heart rate control during AF without sinus conversion may result in an incomplete cure of TIC, suggesting the advantages of rhythm control with ablation in patients with TIC.

Background:Postoperative atrial fibrillation (POAF) is a common complication of cardiac surgery and may result in stroke or heart failure and poor prognosis. This study aimed to evaluate a novel index of total atrial conduction time derived from the P-wave onset (lead II) to the peak A’ wave on tissue Doppler imaging (PA-TDI duration). The PA-TDI duration was compared with previously reported predictors of POAF, and the optimal cutoff value of PA-DTI was calculated in patients undergoing aortic valve replacement (AVR) for AV stenosis (AS).Methods and Results:We enrolled 63 patients undergoing isolated AVR. They underwent transthoracic echocardiography with TDI preoperatively and were monitored postoperatively with continuous electrocardiographic telemetry for 7 days. The hospital stay was significantly longer in the 41 patients with POAF than in the 22 without POAF (33.8±19.7 vs. 24.1±8.1 days, P=0.03). Multivariate analysis revealed that PA-TDI duration (odds ratio [OR], 1.07; 95% confidence interval [CI], 1.02–1.13; P=0.0072) and age (OR, 1.14; CI, 1.03–1.28; P=0.016) were significant independent predictors of POAF. Receiver-operating characteristic curve analysis showed the optimal cutoff values of PA-TDI duration and age were 147.3 ms and 74 years, respectively.Conclusions:The PA-TDI duration was an independent predictor of POAF after AVR for AS. Patients with PA-TDI duration >147 ms should be considered high risk and treated appropriately to improve outcomes. (Circ J 2014; 78: 2173–2181)

Background The indications for catheter ablation have been expanded to include persistent atrial fibrillation (AF) to enable a high degree of sinus rhythm maintenance. We occasionally encounter patients undergoing pacemaker implantation in whom sick sinus syndrome became clinically evident after ablation. This study investigated whether underlying sinus node dysfunction (SND) during persistent AF can be predicted before deciding the indications for ablation. Methods and results In total, 87 consecutive patients with persistent AF who underwent catheter ablation between January 2010 and July 2011 were enrolled in the study. Nocturnal polysomnography as well as transthoracic and transesophageal echocardiography were performed in all patients before ablation. We used the double Lasso catheter and electroanatomical mapping-guided extensive encircling pulmonary vein isolation (EEPVI) method. We performed electrophysiological studies after EEPVI, and SND was defined as a corrected SN recovery time of ≥550 ms. SND was detected in 42 (48%) patients (SND group); the other patients showed normal sinus node function (NSN group). The apnea/hypopnea index (AHI) was significantly greater in the SND group than in the NSN group (25.7 ± 13 vs. 17.5 ± 11, p = 0.002). Multivariate analysis revealed that moderate to severe sleep-disordered breathing (defined as AHI ≥ 15) was an independent predictor of SND after catheter ablation for persistent AF. Conclusion The results suggest that underlying SND in patients with persistent AF can be predicted by evaluating sleep-disordered breathing before catheter ablation.

Atrioventricular (AV) conduction disturbances have often been considered as an etiology of prolonged pauses during atrial fibrillation (AF). We aimed to test whether there was a significant difference in the AV conduction properties between patients with and without clinically significant pauses who underwent ablation of longstanding persistent AF. Ninety-nine patients undergoing ablation of longstanding persistent AF were divided into three groups according to the extent of pauses documented on the ambulatory electrocardiogram during AF; patients without pauses (n = 25), with pauses of

Aims We aimed to determine how many electrical cardioversions (ECs) should be applied to treat repetitive persistent recurrences of atrial fibrillation (AF) following ablation of persistent AF within the early post-procedural period. Methods and results A total of 40 patients with >1 episode of recurrent AF in the form of persistent atrial arrhythmias within 3 months following the ablation were recruited from 108 patients who underwent ablation for persistent or long-standing persistent AF. Electrical cardioversions were applied up to six times, if necessary, to restore sinus rhythm at clinical visits at 2-week intervals until 3 months after the ablation. Fourteen (35%) ablation failures defined as recurrences of AF identified from the 3rd month after the ablation procedure were finally diagnosed during the follow-up period (14 ± 4 month). The patients with an ablation failure more frequently required ECs than those without (3.7 ± 0.3 vs. 1.2 ± 0.2 times; P < 0.0001). A receiver-operating characteristic curve identified a number of ECs of ≥3 as the optimal cut-off value for predicting an ablation failure (area under the curve 0.91; sensitivity, 86%, and specificity, 96%; P = 0.0007). In the multivariate logistic regression analysis, a number of ECs of ≥3 was the only independent predictor of an ablation failure (odds ratio, 11.32; 95% confidence interval, 3.83–58.22; P = 0.0019). Conclusion It was difficult to maintain sinus rhythm in patients with persistent AF who required several ECs for recurrences of AF within the early post-ablation period.

The sirolimus-eluting stent (SES) has dramatically reduced restenosis in patients with most types of coronary lesions, but bifurcation lesions remain a predictor of poor prognosis even in SES implantation. We aimed to determine the clinical outcomes of the left main trunk (LMT) side branches (SB) treated with a single SES strategy. SES implantation was successfully performed on 70 patients with LMT stenosis from August 2005 to August 2008. Of the 70 patients, 55 patients (59 SB) were treated with a single SES and a jailed SB. The 56 SB were divided into two groups according to percent diameter stenosis immediately following percutaneous coronary intervention (PCI) (Group 1: >50%; Group 2

Left ventricular thrombus (LVT) after acute myocardial infarction (AMI) is a risk factor for embolic complications. Although warfarin has traditionally been used to treat LVT, it has relevant disadvantages that limit its use. We herein describe the case of a 78-year-old man with AMI who had a history of paroxysmal atrial fibrillation. Following 10 days of urgent coronary reperfusion therapy, transthoracic echocardiography revealed a moderately sized LVT in the apex, which subsequently disappeared after 18 days of treatment with dabigatran. This case demonstrates that dabigatran may represent an alternative to warfarin as a therapeutic option in patients with LVT after AMI.

Left atrial (LA) remodeling progresses to electrical remodeling, contractile remodeling, and subsequently structural remodeling. Little is known about the relationship between LA electrical and anatomical remodeling and LA mechanical function.We aimed to clarify the relationship between LA mechanical function using 3-dimensional speckle-tracking echocardiography (3D-STE) and LA electrical remodeling using an electroanatomic mapping system (CARTO 3) and to estimate atrial fibrillation (AF) substrate in patients with paroxysmal AF (PAF).A total of 52 patients with PAF (41 (79%) men; mean age 61 ± 11 years) undergoing their initial pulmonary vein isolation (PVI) were examined. The standard deviation of the time to peak strain in each LA segment (%SD-TPS) was analyzed as an index of LA dyssynchrony using 3D-STE before PVI. Contact LA bipolar voltage and activation maps were constructed during sinus rhythm before PVI using CARTO 3. The LA total activation time was measured and low-voltage zones (LVZs) were determined with a local bipolar electrogram amplitude of0.5 mV. The patients were divided into those with an LVZ (LVZ group; n = 23) and those without an LVZ (non-LVZ group; n = 29).The %SD-TPS was significantly higher (14.1 ± 5.7 vs 8.0 ± 5.1; P=.0002) in the LVZ group than in the non-LVZ group and was an independent determinant of the LVZ (odds ratio 1.21; 95% confidence interval 1.04-1.49; P=.01). In addition, the LA total activation time was weakly correlated with the %SD-TPS.LA dyssynchrony and conduction delay exist in patients with PAF. The 3D-STE enabled noninvasive estimation of LA electrical remodeling and AF substrate.

Background Postoperative atrial fibrillation (POAF) is a common complication of cardiac surgery and results in increased health-care utilization. This study identified new transthoracic echocardiographic predictors of POAF using an index of the total atrial conduction time derived on tissue Doppler imaging (PA-TDI duration) in patients undergoing off-pump coronary artery bypass grafting (OPCAB). Methods and results A total of 88 patients undergoing isolated OPCAB were enrolled. They were examined preoperatively on transthoracic echocardiography with tissue Doppler evaluations and monitored postoperatively with continuous electrocardiographic telemetry for 7 days. POAF occurred in 35 patients (39.8%). Patients with POAF had a significantly longer duration of hospital stay than those without (44.9±6.2 vs. 37.3±3.3 days, P=0.04). Multivariate analysis showed that PA-TDI duration (odds ratio [OR], 1.11; 95% confidence interval [CI]: 1.06-1.16; P=0.0001) and left atrial volume index (LAVI; OR, 1.11; 95% CI: 1.02-1.20; P=0.01) were independent predictors of POAF. Moreover, PA-TDI duration was more reliable, given an area under the receiver operating characteristic curve of 0.85 (sensitivity, 74.3%; specificity, 86.8%). Conclusions PA-TDI duration was an independent predictor of POAF following OPCAB. Awareness of risk of POAF may lead to the prevention of POAF, a rapid response to POAF, shortened hospital stay, and improved prognosis.

Unexplained cardiac arrest (UCA) with documented ventricular fibrillation (VF) is a major cause of sudden cardiac death. Abnormal sympathetic innervations have been shown to be a trigger of ventricular fibrillation. Further, adequate expression of SEMA3A was reported to be critical for normal patterning of cardiac sympathetic innervation. We investigated the relevance of the semaphorin 3A (SEMA3A) gene located at chromosome 5 in the etiology of UCA. Eighty-three Japanese patients diagnosed with UCA and 2,958 healthy controls from two different geographic regions in Japan were enrolled. A nonsynonymous polymorphism (I334V, rs138694505A>G) in exon 10 of the SEMA3A gene identified through resequencing was significantly associated with UCA (combined P = 0.0004, OR 3.08, 95%CI 1.67–5.7). Overall, 15.7% of UCA patients carried the risk genotype G, whereas only 5.6% did in controls. In patients with SEMA3A I334V, VF predominantly occurred at rest during the night. They showed sinus bradycardia, and their RR intervals on the 12-lead electrocardiography tended to be longer than those in patients without SEMA3A I334V (1031±111 ms versus 932±182 ms, P = 0.039). Immunofluorescence staining of cardiac biopsy specimens revealed that sympathetic nerves, which are absent in the subendocardial layer in normal hearts, extended to the subendocardial layer only in patients with SEMA3A I334V. Functional analyses revealed that the axon-repelling and axon-collapsing activities of mutant SEMA3A I334V genes were significantly weaker than those of wild-type SEMA3A genes. A high incidence of SEMA3A I334V in UCA patients and inappropriate innervation patterning in their hearts implicate involvement of the SEMA3A gene in the pathogenesis of UCA., Author Summary Unexplained cardiac arrest with documented ventricular fibrillation (UCA) is defined as spontaneous ventricular fibrillation (VF) that is not associated with known structural or electrical heart diseases and is one of the major causes of sudden cardiac death. Identification of the genes responsible for UCA may further increase our understanding of mechanisms of UCA and facilitate more accurate diagnosis and preventive treatment, especially in asymptomatic disease-carrying relatives of the patient. However, molecular mechanisms of UCA have not been fully clarified due to the high mortality rate and difficulty of diagnosis. In this study, UCA patients are shown to have a high incidence of a polymorphism in the Semaphorin 3A gene (rs138694505, SEMA3A I334V). The result confirms previous reports that the abnormal sympathetic innervation is a trigger of UCA because SEMA3A is crucial for the establishment of normal innervation patterns in the heart. Furthermore, experimental data presented here indicate that SEMA3A I334V disrupts the SEMA3A function and impairs appropriate innervation patterning. Finally, the study suggests that SEMA3A I334V is a risk factor for human UCA and contributes to the etiology of UCA.

Sinus node dysfunction (SND) occasionally coexists with long-standing atrial fibrillation (AF) but is unidentifiable during AF. We aimed to identify the predictors of underlying SND when deciding the indications for long-standing persistent AF ablation.We included 105 patients undergoing ablation of long-standing persistent AF to assess the frequency of a permanent pacemaker implantation (PMI) for SND that manifested after sinus conversion and to determine the relationship between the corrected sinus node recovery time (CSNRT) and other clinical parameters obtained before the ablation including the atrial fibrillatory cycle length (AFCL).We identified 7 patients (7%) requiring a PMI for SND after AF termination. The patients with a PMI were nearly all females (6/7) and had a significantly longer CSNRT (1197 ± 647 vs 612 ± 349 milliseconds; P = .0046) and more prolonged AFCL (179 ± 19 vs 153 ± 22 milliseconds; P = .0028) than those without. The age (r = 0.26; P = .011), female sex (r = 0.25; P = .012), hypertension (r = 0.22; P = .038), and AFCL (r = 0.4; P.0001) were significantly correlated with the CSNRT. A stepwise multivariate linear regression analysis including these parameters revealed that the AFCL was the only independent determinant of the CSNRT (β = 0.38; P = .0012). A receiver operating characteristic curve identified an AFCL of more than 162 milliseconds as the optimal cutoff value for predicting SND requiring a PMI (area under the curve, 0.84; sensitivity, 86%; specificity, 74%; P = .0066).A prolonged AFCL was significantly associated with SND. Thus, assessing the AFCL in the patients with long-standing persistent AF may be helpful for the risk stratification of underlying SND.

Sinus node dysfunction (SND) occasionally coexists with atrial flutter (AFL). However, the identification of SND during AFL is difficult. We investigated whether we could predict underlying SND in patients with persistent AFL using the flutter cycle length (FCL).We retrospectively studied 211 successfully ablated patients with persistent cavotricuspid isthmus (CTI)-dependent AFL and measured the FCL before the ablation and corrected sinus node recovery time (CSNRT) after the ablation. Twenty-four patients (11%) required a permanent pacemaker implantation (PMI) for significant SND after AFL termination and had a longer FCL (295 ± 37 vs. 236 ± 34 ms; P0.0001) and greater CSNRT (1727 ± 1014 vs. 603 ± 733 ms; P0.0001) than those not requiring a PMI. A receiver-operating characteristic curve identified an FCL of273 ms as the optimal cut-off value for predicting SND requiring a PMI (area under the curve 0.91; sensitivity, 83% and specificity, 89%; P0.0001). Multiple linear and logistic regression analyses revealed that the left ventricular ejection fraction (LVEF) (β = -0.2; P= 0.0016) and FCL (β = 0.46; P0.0001) were independently associated with the CSNRT, and that females [odds ratio (OR), 2.43; 95% confidence interval (CI), 1.32-4.62; P= 0.0046], an LVEF50% (OR, 2.10; 95% CI, 1.20-3.87; P= 0.012), and an FCL of273 ms (OR, 5.34; 95% CI, 3.08-10.08; P0.0001) were independent predictors of SND requiring a PMI.Although this study was based on a review of a database, the results suggest that assessing the FCL in patients with persistent CTI-dependent AFL could be helpful in the risk stratification of underlying SND.

Background: Indication of ablation has been expanded to include chronic atrial fibrillation (CAF) for enabling high degree of sinus rhythm maintenance. We have encountered patients undergoing pacemaker implantation, in whom sick sinus syndrome became clinically evident after ablation. The study aims to investigate whether underling sinus node dysfunction (SND) during CAF can be predicted before deciding the indication for ablation. Methods and Results: Sixty consecutive patients with CAF who underwent ablation between January to December 2010 were enrolled in the study. Nocturnal polysomnography as well as echocardiography was performed for all patients before ablation. We used the double Lasso catheter and electro anatomical mapping guided extensive encircling pulmonary vein isolation (EEPVI). We performed electrophysiological studies after EEPVI, and SND was defined as corrected SN recovery time of ≥550 ms. SND was detected in 26 (43%) patients (SND group); the other patients showed normal sinus node function (NSN group). The apnea/hypopnea index (AHI) was significantly greater in the SND group than in the NSN group (25.7±13 vs 15.8±10, P=0.0022). On multivariate analysis, sleep apnea syndrome (SAS) was an independent predictor of SND after ablation for CAF. Conclusion: This study suggested that underlying SND in CAF patients can be predicted by evaluating SAS before ablation.

Background Myocardial thickness is particularly thick at the ridge between the left pulmonary vein (PV) and the left atrial appendage (LAA) by dissection. We investigated whether atrial fibrillation (AF) ablation outcome was influenced by altering ablation strategies according to the thickness of the PV–LAA ridge using preprocedural multidetector computed tomography (MDCT). Methods and results Patients with AF scheduled for extensive encircling circumferential pulmonary vein isolation (EEPVI) (110 patients) were divided into 2 groups. In the nonmodulation group (32 patients), EEPVI lines were created using a 3.5-mm tip irrigated catheter at a maximum power of 30 W for 20–30 s at each site. In the modulation group (78 patients), ablation was extended (40–60 s) at the PV–LAA ridge if its thickness was >4.0 mm on MDCT examination. Extended ablation at the PV–LAA ridge was noted in 37 patients in the modulation group. During 25 ± 9 months of follow-up, recurrence was significantly less in the modulation group than in the nonmodulation group (10% vs. 28%; p = 0.018). Logistic regression analysis showed that modifications in the ablation time and left atrium volume index were independent predictors of arrhythmia-free recovery after ablation. Conclusions Recurrence following EEPVI could be reduced by modifications in the ablation time at the PV–LAA ridge.