Upper turnaround point in a reentry circuit of the idiopathic left posterior fascicular ventricular tachycardia.

BACKGROUND: The anatomic extent of the reentry circuit in idiopathic left posterior fascicular ventricular tachycardia (LPF-VT) is yet to be fully elucidated. We hypothesized that entrainment mapping could be used to delineate the reentry circuit of an LPF-VT, especially including the upper turnaround point. METHODS: Twenty-three consecutive LPF-VT patients (mean age, 29 ± 9 years, 18 males) were included. We performed overdrive pacing with entrainment attempts at the left bundle branch (LBB) and the left His bundle (HB) region. RESULTS: Overdrive pacing from the LBB region showed concealed fusion in all 23 patients (post-pacing interval [PPI], 322.1 ± 64.3 ms; tachycardia cycle length [TCL], 319.0 ± 61.6 ms; PPI-TCL, 3.1 ± 4.6 ms) with a long stimulus-to-QRS interval (287.9 ± 58.0 ms, approximately 90% of the TCL). Pacing from the same LBB region at a slightly faster pacing rate showed manifest fusion with antidromic conduction to the LBB and minimal in-and-out time to the LBB potential (PPI-TCL, 21.3 ± 13.7 ms). Overdrive pacing from the left HB region showed manifest fusion with a long PPI-TCL (53.9 ± 22.5 ms). CONCLUSIONS: Our pacing study results suggest that the upper turnaround point in a reentry circuit of the LPF-VT may extend to the proximal His-Purkinje conduction system near the LBB region but below the left HB region. The LPF may constitute the retrograde limb of the reentry circuit.

Usefulness of cardiac magnetic resonance images for prediction of sudden cardiac arrest in patients with mitral valve prolapse: a multicenter retrospective cohort study.

BACKGROUND: An association has been identified between mitral valve prolapse (MVP) and sudden cardiac arrest (SCA), and ventricular arrhythmias (VA). This study aimed to elucidate predictive factors for SCA or VA in MVP patients. METHODS: MVP patients who underwent cardiac magnetic resonance (CMR) were retrospectively included. Patients with other structural heart disease or causes of aborted SCA were excluded. Clinical characteristics (sex, age, body mass index, histories of diabetes, hypertension, and dyslipidemia) and electrocardiographic (PR interval, QRS duration, corrected QT interval, inverted T wave in the inferior leads, bundle branch block, and atrial fibrillation), echocardiographic [mitral regurgitation grade, prolapsing mitral leaflet, and right ventricular systolic pressure (RVSP)], and CMR [left atrial volume index, both ventricular ejection fractions, both ventricular end-diastolic and systolic volume indexes, prolapse distance, mitral annular disjunction, systolic curling motion, presence of late gadolinium enhancement (LGE), LGE volume and proportion] parameters were analyzed. RESULTS: Of the 85 patients [age, 54.0 (41.0-65.0) years; 46 men], seven experienced SCA or VA. Younger age and wide QRS complex were observed more often in the SCA/VA group than in the no-SCA/VA group. The SCA/VA group exhibited lower RVSP, more systolic curling motion and LGE, greater LGE volume, and higher LGE proportion. The presence of LGE [hazard ratio (HR), 19.8; 95% confidence interval (CI) 2.65-148.15; P = 0.004], LGE volume (HR 1.08; 95% CI 1.02-1.14; P = 0.006) and LGE proportion (HR 1.32; 95% CI 1.08-1.60; P = 0.006) were independently associated with higher risk of SCA or VA in MVP patients together with systolic curling motion in each model. CONCLUSIONS: The presence of systolic curling motion, high LGE volume and proportion, and the presence of LGE on CMR were independent predictive factors for SCA or VA in MVP patients.

Natural Course of New-Onset Postoperative Atrial Fibrillation after Noncardiac Surgery.

Background Postoperative atrial fibrillation (POAF) is common after cardiac surgery, but little is known about its incidence and natural course after noncardiac surgery. We evaluated the natural course and clinical impact of POAF and the long-term impact of anticoagulation therapy in patients without a history of atrial fibrillation (AF) undergoing noncardiac surgery. Methods and Results We retrospectively analyzed the database of Asan Medical Center (Seoul, Korea) to identify patients who developed new-onset POAF after undergoing noncardiac surgery between January 2006 and January 2016. The main outcomes were AF recurrence, thromboembolic event, and major bleeding during follow-up. Of 322 688 patients who underwent noncardiac surgery, 315 patients (mean age, 66.4 years; 64.4% male) had new-onset POAF with regular rhythm monitoring after discharge. AF recurred in 53 (16.8%) during 2 years of follow-up. Hypertension (hazard ratio, 2.12; P=0.02), moderate-to-severe left atrial enlargement (hazard ratio, 2.33; P=0.007) were independently associated with recurrence. Patients with recurrent AF had higher risks of thromboembolic events (11.2% versus 0.8%; P<0.001) and major bleeding (26.9% versus 4.1%; P<0.001) than those without recurrence. Patients with recurrent AF and without anticoagulation were especially predisposed to thromboembolic events (P<0.001). Overall, anticoagulation therapy was not significantly associated with thromboembolic events (1.4% versus 2.5%, P=0.95). Conclusions AF recurred in 16.8% of patients with POAF after noncardiac surgery. AF recurrence was associated with higher risks of adverse clinical outcomes. Considering the high risk of anticoagulation-related bleeding, the benefits of routine anticoagulation should be carefully weighed in this population. Active surveillance for AF recurrence is warranted.

Esophageal Thermal Injury after Catheter Ablation for Atrial Fibrillation with High-Power (50 Watts) Radiofrequency Energy.

BACKGROUND AND OBJECTIVES: Data regarding the safety of atrial fibrillation (AF) ablation using high-power (50 W) radiofrequency (RF) energy in Asian populations are limited. This study was conducted to evaluate the incidence and pattern of esophageal injury after high-power AF ablation in an Asian cohort. METHODS: We searched the prospective AF ablation registry to identify patients who underwent AF ablation with 50 W RF energy using the smart touch surround flow catheter (Biosense Webster, Diamond Bar, CA, USA). Visitag™ (Biosense Webster) was used for lesion annotation with predefined settings of catheter stability (3 mm for 5 seconds) and minimum contact force (50% of time >5 g). All patients underwent upper gastrointestinal endoscopy at 1 or 3 days after the ablation. RESULTS: A total of 159 patients (mean age: 63±9 years, male: 69%, paroxysmal AF: 45.3%, persistent AF: 27.7%, long-standing persistent AF: 27.0%) were analyzed. Initially, 26 patients underwent pulmonary vein isolation with 50 W for 5 seconds at each point. The remaining 133 patients underwent prolonged RF duration (anterior 10 seconds and posterior 6 seconds). The incidence rates of esophageal erythema/erosion and superficial ulceration were 1.3% for each type of the lesion. Food stasis, a suggestive finding of gastroparesis, was observed in 25 (15.7%) patients. There were no cases of cardiac tamponade, stroke, or death. CONCLUSIONS: In Asian patients, AF ablations using 50 W resulted in very low rates of mild esophageal complications.

The shape of the left lateral ridge as a predictor of long-term outcome of catheter ablation for atrial fibrillation based on clinical and experimental data.

BACKGROUND: The left lateral ridge (LLR) is an important structure for ablation of atrial fibrillation (AF). This study assessed how the LLR shape is associated with the long-term outcomes of AF ablation and investigated the relationship with radiofrequency (RF) lesion formation. METHODS AND RESULTS: Clinical study - we assessed multi-detector computed tomography (MDCT) images in 247 patients who underwent AF ablation. Patients were classified into two groups according to the shape of the LLR: Narrow LLR group (n = 116; 47%) and Wide LLR group (n = 131; 53%). After a follow-up period 475 ± 245 days, the AF-free rate was significantly higher in the wide LLR than Narrow LLR group (83.2% vs. 62.9%, p = 0.0004). A multivariate analysis showed that the shape of the LLR was an independent predictor of AF recurrence after ablation (hazard ratio 2.58; 95% confidential interval = 1.48-4.51, p = 0.001). Experimental study - Two types of the ridge models were made with porcine atrial tissues: "Narrow ridge(4.2 ± 0.9 mm)" and "Wide ridge(9.7 ± 1.8 mm)" RF ablation was performed on each ridge model using a contact force (CF)-sensing catheter. The mean CF and the RF lesion volume of the narrow ridge were significantly less than those of the wide ridge model (5.42 ± 3.13 g vs. 10.37 ± 3.98 g, p = 0.001; 19.8 ± 9.9 mm3 vs. 44.2 ± 13.6 mm3, p < 0.001, respectively). CONCLUSIONS: AF recurrence after ablation was more frequent in patients with a narrow LLR. LLR shape as assessed using MDCT is associated with long-term outcomes after AF ablation. CF and lesion formation data using the porcine atrial tissue model support our clinical results.

Inter/Intra-Atrial Dissociation in Patients With Maze Procedure and Its Clinical Implications: Pseudo-Block and Pseudo-Ventricular Tachycardia.

Background Severe conduction delay and inter/intra-atrial dissociation may occur in patients who undergo an extensive catheter ablation or a maze procedure for atrial tachyarrhythmia. We report a series of patients with inter/intra-atrial dissociation that mimicked complete atrioventricular block or ventricular tachycardia. Methods and Results We retrospectively reviewed the medical records of 7 patients who were referred for the evaluation of atrioventricular block (patients 1-6) or ventricular tachycardia (patient 7) that occurred after biatrial maze procedure and valvular surgery. During the electrophysiologic study, slow atrial or junctional escape rhythm dissociated from isolated atrial activity mimicked complete atrioventricular blocks. Intra-atrial dissociation of the right atrium or left atrium was observed. Atrioventricular nodal conduction from the nondissociated atrium to the ventricle was preserved in all patients, while the conduction from the dissociated atrium was blocked. In patient 7, the pacing of the ventricle by tracking of atrial tachycardia from the nondissociated left atrium/coronary sinus mimicked ventricular tachycardia during pacemaker interrogation. A total of 5 patients received new permanent pacemaker implantations during the index hospitalization for the surgery (n=2) or as a deferred procedure (n=3) according to the treatment for sick sinus syndrome. Conclusions Pseudo-atrioventricular block or pseudo-ventricular tachycardia may occur because of inter/intra-atrial dissociation after a maze procedure. The selection of patients for permanent pacemaker implantation should be determined based on the patient's symptoms and the status of the escape pacemaker and not on the apparent atrioventricular block. Proper diagnosis is important to avoid unnecessary implantation of a pacemaker or a defibrillator.

Association of pericardial effusion after pulmonary vein isolation and outcomes in patients with paroxysmal atrial fibrillation.

BACKGROUND: The clinical implications of pericardial effusion (PE) after catheter ablation for atrial fibrillation (AF) are not well understood. We evaluated the association between newly developed PE after pulmonary vein isolation (PVI) for paroxysmal AF and arrhythmic recurrence. METHODS: From a prospective AF ablation registry, 184 patients (mean age 59 ± 10 years, 65% male) who underwent first-time PV isolation using a smart touch surround flow catheter (Biosense Webster, Diamond Bar, CA) were analyzed. Postablation transthoracic echocardiography (TTE) was performed within 1-3 days after ablation, and the occurrence of PE was assessed. RESULTS: PE developed in 91 patients (49.5%), and most were of minimal severity (minimal, 93.4%; mild, 6.6%). Patients with PE had significantly lower body mass index and underwent cavotricuspid isthmus ablation more frequently. Early arrhythmic recurrence (EAR) (within 3 months) was observed in 28.8% of patients and was not different according to the PE development (PE [+]: 29.7% vs PE [-]: 28.0%; P = .80). During a median follow-up of 696 days, the cumulative rate of the late arrhythmic recurrence (LAR) (after 3 months) was 36.4%, and there was no difference between groups (PE [+]: 36.7% vs PE [-]: 35.1%; P = .988). The only predictor of LAR was EAR, and no echocardiographic parameters showed a significant correlation with LAR. CONCLUSIONS: Minimal or mild PE after PVI for paroxysmal AF is a frequent echocardiographic finding, and it had no significant association with AF recurrence. Routine TTE after AF ablation has no clinical implication.

Long-term Clinical Outcomes of Radiofrequency Catheter Ablation versus Permanent Pacemaker Implantation in Patients with Tachycardia-Bradycardia Syndrome.

BACKGROUND AND OBJECTIVES: Pacemaker (PM) implantation is a well-accepted treatment option for patients with paroxysmal atrial fibrillation (AF) and related tachycardia-bradycardia syndrome (TBS). Data on the long-term clinical outcomes after radiofrequency catheter ablation (RFCA) or PM implantation are sparse. METHODS: The medical records of 217 patients with TBS were retrospectively assessed. Outcomes in patients who underwent RFCA (n=108, 49.8%) were compared to those with PM implantation (n=109, 50.2%). The clinical outcomes were sinus rhythm maintenance, conversion to persistent AF, additional procedure or crossover, and the composite of cardiovascular hospitalization and death. RESULTS: During the follow-up period (mean 3.5±2.0 years), the RFCA group, compared to the PM group, showed better sinus rhythm maintenance (adjusted hazard ratio [aHR], 0.27; 95% confidence interval [CI], 0.15-0.46; p=0.002) and less progression to persistent AF (aHR, 0.20; 95% CI, 0.06-0.63; p=0.006). Additional procedure or crossover did not differ significantly between the groups (aHR, 2.07; 95% CI, 0.71-6.06; p=0.185 and aHR, 0.69; 95% CI, 10.8-2.67; p=0.590, respectively). Most RFCA patients (92.6%) did not require pacemaker implantation during long term follow-up period (>3.5 years). The composite endpoint of cardiovascular rehospitalization and death was not significantly different between the groups (aHR, 0.92; 95% CI, 0.50-1.66; p=0.769). CONCLUSIONS: RFCA is an effective alternative to PM implantation in patients with TBS. In these patients, successful RF ablation of AF is related to a higher rate of sinus rhythm maintenance compared to PM implantation, and the composite outcome of cardiovascular rehospitalization and death is similar.

Clinical Implications of Ventricular Repolarization Parameters on Long-Term Risk of Atrial Fibrillation　- Longitudinal Follow-up Data From a General Ambulatory Korean Population.

BACKGROUND: This study investigated 12-lead electrocardiogram (ECG) predictors associated with atrial fibrillation (AF) or flutter (AFL), specifically whether ventricular repolarization abnormalities in surface ECG (i.e., non-specific ST-T abnormalities [NSSTTA], QT prolongation, early repolarization [ER]) were associated with the development of AF or AFL.Methods and Results:This study included 16,793 ambulatory Koreans (mean age 48.2 years, 62.3% male) who underwent medical check-ups at Asan Medical Center in 2002 (NSSTTA, n=1,037 [6.2%]; ER, n=1,493 [8.9%]). The primary outcome was the incidence of ECG-documented AF or AFL. During follow-up, new-onset AF or AFL was documented in 334 subjects (2.0%). The incidence of AF or AFL at the 10-year follow-up was higher in patients with than without NSSTTA (3.5% vs. 1.6%; hazard ratio [HR] 1.79, 95% confidence interval [CI] 1.28-2.50). The QT interval was associated with a higher risk of AF or AFL (HR 1.12 [95% CI 1.07-1.17] per 10 ms), and the risk was even higher in patients with multiple-region NSSTTA (HR 2.30; 95% CI 1.64-3.21) and NSSTTA with QT prolongation (HR 4.06; 95% CI 2.14-7.69). ER was not associated with a higher risk of AF or AFL (HR 1.02; 95% CI 0.71-1.46). CONCLUSIONS: NSSTTA and QT prolongation, but not ER, were associated with a higher risk of future AF or AFL in a general ambulatory population after adjusting for parameters of atrial depolarization.

Clinical Implications of Preoperative Nonvalvular Atrial Fibrillation with Respect to Postoperative Cardiovascular Outcomes in Patients Undergoing Non-Cardiac Surgery.

BACKGROUND AND OBJECTIVES: Atrial fibrillation (AF) is associated with a higher long-term risk of major cardiovascular events. However, its clinical implications with respect to peri-operative cardiovascular outcomes in patients undergoing non-cardiac surgery is unclear. We tried to examine the association between pre-operative AF and peri-operative cardiovascular outcomes. METHODS: We retrospectively analyzed data from 26,501 consecutive patients who underwent comprehensive preoperative cardiac evaluations for risk stratification prior to receiving non-cardiac surgery at our center. Preoperative AF was diagnosed in 1,098 patients (4.1%), and their cardiovascular outcomes were compared with those of patients without AF. The primary outcome was the rate of major adverse cardiac and cerebrovascular events (MACCE) during immediate post-surgery period (<30 days). RESULTS: Patients with AF were older and had higher proportion of male sex, higher rate of extra-cardiac comorbidities, higher CHA2DS2-VASc score, and higher revised cardiac risk index (RCRI) compared with those without AF. The rate of MACCE was significantly higher in AF patients compared to non-AF patients (4.6% vs. 1.2%, p<0.001). Preoperative AF was associated with higher risk of MACCE, even after multivariable adjustment (odds ratio, 2.97; 95% confidence interval, 2.13-4.07, p<0.001). The relative contribution of AF to MACCE was larger in patients with lower RCRI (p for interaction=0.010). The discriminating performance of RCRI was significantly enhanced by addition of AF. CONCLUSIONS: In patients undergoing non-cardiac surgery, preoperative AF was associated with a higher risk of peri-operative cardiovascular outcomes.

Radiofrequency catheter ablation of accessory pathways at the site of prior valve surgery.

BACKGROUND: Radiofrequency catheter ablation (RFCA) for accessory pathways (APs) at the site of prior valve surgery (VS) remains challenging. We aimed to clarify the factors associated with successful RFCA for such APs. METHODS: Upon reviewing a RFCA registry and previous case reports, we included nine patients who underwent RFCA of APs at the site of prior VS (total-VS group; age, 34.0 [24.5-45.0] years; men, 4/9) and 196 patients who underwent RFCA of APs with no history of VS (no-VS group; age, 40.5 [23.0-54.0] years; men, 114/196). Electrophysiological features, procedural details, and outcomes were examined. RESULTS: Accessory pathway exhibited decremental conduction in four of nine patients in the total-VS group. The number of RFCA attempts was significantly higher in the total-VS group than in the no-VS group (10.0 [4.5-14.5] vs 2.0 [1.0-3.0]; P < 0.001). In four patients who underwent mitral VS, successful RFCA was achieved using the transaortic approach, coronary sinus (CS) approach, or bipolar ablation. In three patients who underwent tricuspid VS, successful RFCA was achieved using the above-prosthetics or trans-prosthetics approach. In two patients, RFCA failed. The trans-prosthetics approach and bipolar ablation technique were effective. The transaortic and CS approaches were occasionally effective. The transseptal approach was ineffective. CONCLUSIONS: Successful RFCA of APs at the site of prior VS can be achieved by detailed mapping of the areas both above and below the prosthetic valve, as well as by ensuring effective radiofrequency energy delivery using various catheter approaches and RFCA techniques.

Impact of fasciculoventricular bypass tracts on the diagnosis and treatment of concomitant arrhythmias and cardiac diseases.

BACKGROUND: Fasciculoventricular (FV) bypass tracts (BTs) are the rarest form of ventricular preexcitation. Although they are not involved in clinically significant reentrant tachycardia, they may cause diagnostic and therapeutic confusion if not properly understood. This study aimed to assess the impact of FV BTs on the diagnosis and treatment of concomitant arrhythmias and cardiac diseases. METHODS: Twenty-two patients with FV BTs who underwent electrophysiologic (EP) study were evaluated. The prevalence of concomitant arrhythmias and cardiac diseases in FV BTs was evaluated. The mechanisms of concomitant arrhythmias were determined by EP study and cardiac diseases were diagnosed by echocardiography. RESULTS: One patient had FV BT with complete infra-Hisian atrioventricular (AV) block that mimicked a slow ventricular escape rhythm. Two patients had FV BT with atrial fibrillation or atrial flutter, which was misinterpreted as AV BT requiring emergency DC cardioversion. Eight patients had accompanying AV BTs. In 2 patients with AV BTs, unnecessary RF application was delivered after successful ablation of AV BT because conduction through a FV BT was mistaken for conduction through a residual AV BT. Five patients had no concomitant arrhythmia; however, two of them had hypertrophic cardiomyopathy with symptoms requiring beta-blocker. Patients had not been prescribed beta-blockers to avoid a proarrhythmic response before the EP study because the FV BTs mimicked AV BTs. CONCLUSION: FV BTs were frequently accompanied by AV BTs or other arrhythmias and cardiac diseases. They may cause misdiagnosis and inappropriate therapy and even unnecessary RF delivery when misinterpreted as AV BTs.

Thromboembolic Risk of Imaging-Confirmed Coronary Artery Disease Without Myocardial Infarction in Patients With Nonvalvular Atrial Fibrillation.

The implication of coronary artery disease (CAD) without the clinical manifestation of myocardial infarction (non-MI-CAD) on thromboembolic events in patients with nonvalvular atrial fibrillation (NVAF) is not well evaluated. We hypothesized that non-MI-CAD would have a similar risk of future thromboembolism as MI-CAD. Clinical data for 17,073 consecutive patients (mean age, 64.3 years; males, 64.9%) diagnosed with NVAF at our center were analyzed. CAD was defined as stenosis of ≥50% stenosis of major coronary arteries identified using coronary artery angiography or coronary computed tomographic angiography. The main outcome of the present study was the rate of thromboembolic events (ischemic stroke and systemic embolism) during the follow-up period (3.1 ± 2.4 years). A total of 1,011 patients (5.9%) were diagnosed with CAD without clinical manifestation of MI (non-MI-CAD) and 708 (4.1%) had a history or diagnosis of MI-CAD. Thromboembolic events occurred in 1,007 patients (5.9%) during follow-up. The groups were at high risk of future thromboembolic events determined using univariate (hazard ratio [HR] 1.55; 95% confidence interval [CI] 1.25 to 1.91; p <0.001 for non-MI-CAD and HR 2.14; 95% CI 1.70 to 2.69; p <0.001 for MI-CAD) and multivariate analysis adjusted for CHA2DS2-VASc score components and relevant variables (HR 1.42; 95% CI 1.15 to 1.77; p = 0.001 for non-MI-CAD and HR 1.62; 95% CI 1.28 to 2.06; p <0.001 for MI-CAD); this trend was consistent in patients who did not receive anticoagulants during follow-up (n = 8,032, 47.0%). In conclusion, non-MI-CAD is an important predictor of thromboembolic events in patients with NVAF.

Assessing Accuracy of Wrist-Worn Wearable Devices in Measurement of Paroxysmal Supraventricular Tachycardia Heart Rate.

BACKGROUND AND OBJECTIVES: Wrist-worn wearable devices provide heart rate (HR) monitoring function via photoplethysmography technology. Recently, these devices have been used by patients to measure the HR when palpitation occurs, but few validation studies of these instruments have been conducted. We assessed the accuracy of these devices for measuring a HR. METHODS: This study enrolled 51 consecutive patients with a history of paroxysmal supraventricular tachyarrhythmia (SVT) or paroxysmal palpitations who were scheduled to undergo an electrophysiological study (EPS). Three devices were assessed: Apple Watch Series 2 (Apple), Samsung Galaxy Gear S3 (Galaxy), and Fitbit Charge 2 (Fitbit). Patients were randomly assigned to wear 2 different devices. The HR at baseline and induced SVT were measured during the EPS. After successful ablation of SVT, HR measurements was also done during atrial and ventricular pacing study. RESULTS: The mean patient age was 44.4±16.6 years and 27 patients were male (53%). The accuracy (within ±5 beats per minute [bpm] of an electrocardiogram [ECG] measurement) of the baseline HR measurements was 100%, 100%, and 94%, for Apple, Galaxy, and Fitbit, respectively. The HR during induced SVT ranged from 108 bpm to 228 bpm and the accuracy (within ±10 bpm of an ECG) was 100%, 90%, and 87% for the Apple, Galaxy, and Fitbit, respectively. During pacing study, accuracy of these devices was also acceptable but tended to decrease as the HR increased, and showed differences between the devices. CONCLUSIONS: Wrist-worn wearable devices accurately measure baseline and induced SVT HR. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0002282.

Incidence and predictors of moderate to severe tricuspid regurgitation after dual-chamber pacemaker implantation.

INTRODUCTION: The incidence and predictors of tricuspid regurgitation (TR) after permanent pacemaker (PM) implantations have not been well evaluated. We attempted to determine TR's natural course and predictors, especially focusing on the influence of atrial fibrillation (AF). METHODS: Data from 530 patients with dual-chamber PMs were evaluated. The main study outcomes were moderate to severe TR and isolated TR (moderate to severe TR without other structural heart diseases [SHDs]) in follow-up echocardiography. RESULTS: Over a median follow-up period of 7.6 years, moderate to severe TR developed in 14.5% patients. Of those, concomitant SHD was observed in 51.9% of patients, and 48.1% presented with isolated TR. A multivariable analysis identified the independent predictors of moderate to severe TR (diabetes mellitus [DM], chronic lung disease, preexisting mild TR, peripheral artery disease, moderate to severe aortic regurgitation, and persistent AF [PeAF]) and isolated TR (DM, preexisting mild TR, and PeAF). PeAF (n = 67, 12.6%) was an independent predictor of both moderate to severe TR (hazard ratio [HR] 2.59, 95% confidence interval [CI]: 1.22-5.51) and isolated TR (HR 4.54, 95% CI: 1.60-12.90). The patients with PeAF exhibited a higher incidence of moderate to severe TR (21.8% vs 12.9% vs 11.6% PeAF, paroxysmal AF, and without AF, respectively) and isolated TR (18.6% vs 6.6% vs 4.2%, respectively) during the follow-up. CONCLUSION: Moderate to severe TR after PM implantations developed with or without the influence of concomitant SHD. Patients with PeAF exhibited a higher risk of moderate to severe TR after PM implantations.

Alternative strategies to improve success rate of mitral isthmus block.

Achieving bidirectional conduction block (BDB) across the mitral isthmus (MI) is technically challenging. We describe our experience using different ablation strategies for achieving successful MI block.We reviewed the records of patients who had undergone MI ablation for peri-mitral (PM) flutter at our institution from January 2010 to May 2015. We investigated ablation strategies for achieving MI block and their long-term outcomes in terms of recurrence of atrial tachyarrhythmia.Single endocardial MI ablation with or without distal coronary sinus (CS) ablation achieved MI block in 129 out of 236 (54.7%) patients. After failure of MI block, a new MI line ablation, ablation targeting the vein of Marshall (VOM), or anterior line ablation was performed in selected patients. The MI block was achieved in 13 (52.0%) out of 25 patients with new MI line ablation and in 13 (68.4%) out of 19 patients with VOM ablation. Anterior line ablation was tried in 23 patients and the line of block was achieved in 12 (52.2%) patients. Finally, overall PM BDB (PMB, MI block or anterior line block) was achieved in 167 (70.8%) of 236 patients. The incidence atrial tachyarrhythmia was similar between the patients with successful PMB and those with failed PMB (32.9% vs 42.0%, P = .18). In multivariable Cox regression analysis, the PMB was not associated with recurrence of atrial tachyarrhythmia (hazard ratio [HR]: 0.70, 95% confidence interval [CI]: 0.43-1.12).In conclusion, single endocardial MI line with or without distal CS ablation showed limited success for achieving MI block. Additional substrate modifications such as a new MI line ablation, anterior line ablation, or ablation targeting the VOM may improve the success rate of PMB block. However, the benefits of PMB were not clear in this study.

Sick Sinus Syndrome After the Maze Procedure Performed Concomitantly With Mitral Valve Surgery.

Background To characterize the development of sick sinus syndrome ( SSS ) after the additive maze procedure ( MP ) during mitral valve surgery. Methods and Results Follow-up data (median, 3.6 years) of 750 patients with a prevalence of rheumatic cause of 57.6% were analyzed. SSS occurred in 35 patients with a time-dependent increase: the incidence rates at 1, 2, and 4 years after surgery were 2.9%, 3.7%, and 4.3%, respectively. The additive MP showed higher risks of SSS development (hazard ratio, 7.44; 95% confidence interval, 3.45-16.05; P<0.001) and pacemaker implantation (hazard ratio, 3.61; 95% confidence interval, 1.95-6.67; P<0.001). Patients who developed SSS showed higher 4-year rates of clinical events (death, stroke, and hospital admission) (67.5±8.5% versus 33.0±1.9%; P<0.001). After adjustment for age and preoperative peak systolic pulmonary artery pressure, the lesion extent (biatrial versus left atrial MP ), not the underlying cause (rheumatic versus nonrheumatic), was independently associated with SSS development (hazard ratio, 3.58; 95% confidence interval, 1.08-11.86; P=0.037). The adverse effect of the biatrial MP was confirmed in patients with trivial or mild preoperative tricuspid regurgitation showing higher SSS incidence (4.6±1.4% versus 1.0±0.7%; P=0.023), not in those with moderate-to-severe tricuspid regurgitation (6.8±1.7% versus 3.8±3.8%; P=0.337). Recurrence of atrial fibrillation was not associated with the lesion extent of the MP . Conclusions After the additive MP , the ongoing risk of SSS development should be acknowledged irrespective of the underlying cause. Considering additive risk of biatrial MP with similar atrial fibrillation recurrence rate, minimizing lesion extent is warranted.

Metabolic Syndrome and the Risk of New-Onset Atrial Fibrillation in Middle-Aged East Asian Men.

BACKGROUND: Although the prevalence of both atrial fibrillation (AF) and metabolic syndrome (MetS) has been increasing in East Asia, the association between them is uncertain.Methods and Results:A total of 24,741 middle-aged Korean men without baseline AF were enrolled in a health screening program from January 2003 to December 2008. Among them, 21,981 subjects were evaluated to determine the risk of AF based on baseline MetS status through December 2016. At every visit, the subjects were evaluated for AF using ECG. MetS was defined using the criteria of the International Diabetes Federation and was present in 2,529 subjects (11.5%). Mean (±standard deviation) age was 45.9±5.3 years. During a mean follow-up of 8.7 years, 168 subjects (0.8%) were diagnosed with AF. The age-adjusted and multivariate-adjusted hazard ratios (HR) for MetS with AF were 1.62 (P=0.02) and 1.57 (P=0.03), respectively. Among the components of MetS, central obesity (age-adjusted HR 1.62, P<0.01) and raised blood pressure (age-adjusted HR 1.43, P=0.02) were associated with an increased risk of AF. CONCLUSIONS: MetS is associated with an increased risk of AF in middle-aged East Asian men. Of the components of MetS, central obesity is the most potent risk factor for the development of AF in this population.

Conduction disturbance after isolated surgical aortic valve replacement in degenerative aortic stenosis.

OBJECTIVE: Conduction disturbances are common in patients with aortic stenosis. We investigated the incidence, reversibility, and prognosis of conduction disorders requiring permanent pacemaker implantation in patients with degenerative aortic stenosis after isolated aortic valve replacement. METHODS: This was a retrospective study conducted at a tertiary care center. We evaluated the incidence of conduction disturbances in patients who underwent isolated surgical aortic valve replacement for aortic stenosis between January 2005 and May 2015. Relevant clinical information was obtained from the patients' medical records. RESULTS: We reviewed results of 663 patients with pathologically proven degenerative aortic stenosis (bicuspid aortic valve, n = 285 [43.0%]) who underwent isolated aortic valve replacement (mechanical valve, n = 310 [46.8%]). Patients' mean age was 67.1 ± 8.1 years, and 362 were male (54.6%). Immediate postoperative intraventricular conduction disorders occurred in 56 patients (8.4%), and atrioventricular block occurred in 68 patients (10.3%). Ten patients with symptomatic second-degree or third-degree atrioventricular block underwent permanent pacemaker implantation within 30 days of aortic valve replacement. During the mean follow-up period of 1288 ± 1122 days, 64 patients (9.7%) developed irreversible conduction disorders (bundle branch block n = 24 and first-degree atrioventricular block n = 42). Of the 10 patients requiring permanent pacemakers, 4 remained depend on the permanent pacemaker during follow-up. Beyond 30 days after aortic valve replacement, 1 patient underwent permanent pacemaker implantation for de novo conduction disturbance 44 months postoperatively. CONCLUSIONS: After isolated aortic valve replacement, permanent pacemaker implantation for conduction disturbance is rare (n = 10/663, 1.5%). Isolated aortic valve replacement for degenerative aortic stenosis has a low risk of conduction disturbances during long-term follow-up.

Extremely low-frame-rate digital fluoroscopy in catheter ablation of atrial fibrillation: A comparison of 2 versus 4 frame rate.

Despite the technological advance in 3-dimensional (3D) mapping, radiation exposure during catheter ablation of atrial fibrillation (AF) continues to be a major concern in both patients and physicians. Previous studies reported substantial radiation exposure (7369-8690 cGy cm) during AF catheter ablation with fluoroscopic settings of 7.5 frames per second (FPS) under 3D mapping system guidance. We evaluated the efficacy and safety of a low-frame-rate fluoroscopy protocol for catheter ablation for AF.Retrospective analysis of data on 133 patients who underwent AF catheter ablation with 3-D electro-anatomic mapping at our institute from January 2014 to May 2015 was performed. Since January 2014, fluoroscopy frame rate of 4-FPS was implemented at our institute, which was further decreased to 2-FPS in September 2014. We compared the radiation exposure quantified as dose area product (DAP) and effective dose (ED) between the 4-FPS (n = 57) and 2-FPS (n = 76) groups.The 4-FPS group showed higher median DAP (599.9 cGy cm; interquartile range [IR], 371.4-1337.5 cGy cm vs. 392.0 cGy cm; IR, 289.7-591.4 cGy cm; P < .01), longer median fluoroscopic time (24.4 min; IR, 17.5-34.9 min vs. 15.1 min; IR, 10.7-20.1 min; P < .01), and higher median ED (1.1 mSv; IR, 0.7-2.5 mSv vs. 0.7 mSv; IR, 0.6-1.1 mSv; P < .01) compared with the 2-FPS group. No major procedure-related complications such as cardiac tamponade were observed in either group. Over follow-up durations of 331 ±â€Š197 days, atrial tachyarrhythmia recurred in 20 patients (35.1%) in the 4-FPS group and in 27 patients (35.5%) in the 2-FPS group (P = .96). Kaplan-Meier survival analysis revealed no significant different between the 2 groups (log rank, P = .25).In conclusion, both the 4-FPS and 2-FPS settings were feasible and emitted a relatively low level of radiation compared with that historically reported for DAP in a conventional fluoroscopy setting.