The relationship between the incision line and position of the latissimus dorsi muscle for subcutaneous implantable cardioverter-defibrillator intermuscular implantations.

INTRODUCTION: Intermuscular implantations of subcutaneous implantable cardioverter-defibrillators (S-ICD) have been recommended, but the position of the anterior border of the latissimus dorsi muscle (LDM) has not previously been evaluated in establishing an incision line to facilitate the intermuscular approach. The objective of this study is to evalua the position and trend of the anterior border of the LDM in patients who are candidates for implantable cardioverter-defibrillators. METHODS: The distance from the back to the anterior border of the LDM (A) and the anterior-posterior width of the chest wall (B) were measured on computed tomography retrospectively, and the ratio (=A/B) was used as the position of the anterior border of the LDM. In addition, the variability and factors affecting the values were evaluated. RESULTS: An analysis was performed on 78 patients, and the position of the anterior border of the LDM (=A/B) exhibited a normal distribution, with a mean value of 0.53 ± 0.062 (0.41-0.69). The position of the anterior border of the LDM tended to be more anterior in younger, taller, male, primary prevention, nonheart failure, low brain natriuretic peptide level, and nondiabetic patients. CONCLUSION: The position of the anterior border of the LDM varied from case to case with variable results. Conventional incisions on the midaxillary line may be inappropriate for intermuscular implantations, and the position of the anterior border of the LDM should be evaluated in each individual case to establish the incision line.

The impact of the procedural parameters on the lesion characteristics associated with AF recurrence: Late-gadolinium enhancement magnetic resonance imaging (LGE-MRI) analysis.

BACKGROUND: Lesion gaps assessed by late-gadolinium enhancement magnetic resonance imaging (LGE-MRI) are associated with the atrial fibrillation (AF) recurrence after pulmonary vein isolation. Animal studies have demonstrated that the catheter-contact force (CF), stability, and orientation are strongly associated with lesion formation. However, the impact of those procedural factors on the lesion characteristics associated with AF recurrence has not been well discussed. METHODS: A total of 30 patients with paroxysmal AF who underwent catheter ablation were retrospectively enrolled. Radiofrequency (RF) applications were performed with 35 W for 30 s in a point-by-point fashion under esophageal temperature monitoring. The inter-lesion distance was 4 mm. The lesions were visualized by LGE-MRI 3 months postprocedure and assessed by the LGE volume (ml), gap number (GN), and average gap length (AGL [mm]). The gaps were defined as nonenhancement sites of >4 mm. The procedural factors including the catheter-CF, stability, and orientation were calculated on the NavX system. RESULTS: Six (20%) of 30 patients had AF recurrences 12 months postablation. A univariate analysis demonstrated that the AGL was associated with AF recurrence (hazard ratio [HR]: 1.20, confidence interval [CI]: 1.03-1.42, p = .02). All AF recurrence were found in patients with an AGL of >7 mm. The catheter-CF and stability were associated with an AGL of >7 mm, but not the orientation (CF-HR: 0.62, CI: 0.39-0.97, p = .038; stability-HR: 0.8, CI: 0.66-0.98, p = .027). CONCLUSIONS: RF ablation with a low CF and poor catheter stability has a potential risk of creating large lesion gaps associated with AF recurrence.

EASY-WPW: a novel ECG-algorithm for easy and reliable localization of manifest accessory pathways in children and adults.

AIMS: Accessory pathway (AP) ablation is a standard procedure for the treatment of Wolff-Parkinson-White syndrome (WPW). Twelve-lead electrocardiogram (ECG)-based delta wave analysis is essential for predicting ablation sites. Previous algorithms have shown to be complex, time-consuming, and unprecise. We aimed to retrospectively develop and prospectively validate a new, simple ECG-based algorithm considering the patients' heart axis allowing for exact localization of APs in patients undergoing ablation for WPW. METHODS AND RESULTS: Our multicentre study included 211 patients undergoing ablation of a single manifest AP due to WPW between 2013 and 2021. The algorithm was developed retrospectively and validated prospectively by comparing its efficacy to two established ones (Pambrun and Arruda). All patients (32 ± 19 years old, 47% female) underwent successful pathway ablation. Prediction of AP-localization was correct in 197 patients (93%) (sensitivity 92%, specificity 99%, PPV 96%, and NPV 99%). Our algorithm was particularly useful in correctly localizing antero-septal/-lateral (sensitivity and specificity 100%) and posteroseptal (sensitivity 98%, specificity 92%) AP in proximity to the tricuspid valve. The accuracy of EASY-WPW was superior compared to the Pambrun (93% vs. 84%, P = 0.003*) and the Arruda algorithm (94% vs. 75%, P < 0.001*). A subgroup analysis of children (n = 58, 12 ± 4 years old, 55% female) revealed superiority to the Arruda algorithm (P < 0.001*). The reproducibility of our algorithm was excellent (Ï°>0.8; P < 0.001*). CONCLUSION: The novel EASY-WPW algorithm provides reliable and accurate pre-interventional ablation site determination in WPW patients. Only two steps are necessary to locate left-sided AP, and three steps to determine right-sided AP.

Factors related to the skin thickness of cardiovascular implantable electronic device pockets.

INTRODUCTION: The skin overlying cardiovascular implantable electronic devices (CIEDs) sometimes becomes very thin after implantations, which could cause a device erosion. The factors related to the skin thickness of device pockets have not been elucidated. This study aimed to evaluate the skin thickness of CIED pockets and search for the factors associated with the thickness. METHODS: Seventeen skin thickness points around the CIED pocket were measured through ultrasonography in each patient. RESULTS: A total of 101 patients (76 ± 11 years, 26 female) were enrolled. The median duration from the implantation to the examination was 95 months (quartile: 52.5-147.5). The median skin thickness overlying the device was 4.1 mm (3.3-5.9). Patients with heart failure and malignancy had thinner skin overlying the CIED than those without. A significant correlation existed between skin thickness and body mass index (BMI), hemoglobin, serum creatinine, estimated glomerular filtration rate (eGFR), and left ventricular ejection fraction. In contrast, age, gender, and device size did not exhibit a significant correlation with skin thickness. A multivariate logistic regression analysis revealed that chronic heart failure and a decrease in the eGFR and BMI were independent predictive factors of "very thin (≦3.3 mm)" skin of the CIED pocket late after an implantation. CONCLUSION: Aside from a low BMI, the comorbidities (low hemoglobin, heart failure, and renal dysfunction) had a stronger impact on the skin thickness overlying the device than the device size. A careful observation of the device pocket should be performed in patients with those risk factors.

Sex Differences in the Regional Analysis of Nonpulmonary Vein Foci and Epicardial Adipose Tissue in Patients With Atrial Fibrillation.

BACKGROUND: The mechanism underlying the sex differences in atrial fibrillation (AF) recurrence following pulmonary vein (PV) isolation is not fully understood. We hypothesized that non-PV foci and epicardial adipose tissue (EAT) play a key role.Methods and Results: Data from 304 consecutive patients (75% males) who underwent contrast-enhanced computed tomography and catheter ablation of AF were reviewed. The EAT around the atrium was measured separately in 4 parts of the atrium. All patients underwent high-dose isoproterenol infusions to assess the non-PV foci. Significantly more non-PV foci and less EAT around the atrium were observed in female patients than in male patients. In males, those with non-PV foci on the left atrial (LA) anterior wall had significantly greater EAT for the same lesions than those without non-PV foci. During a median follow-up of 27 months, the predictors of AF recurrence after first catheter ablation were female sex, presence of non-PV foci, LA diameter, and septal EAT index. A sex-specific analysis revealed that LA diameter was a predictor only in males and that the presence of non-PV foci in the septal region was a strong predictor in males (hazard ratio [HR]: 2.24) and females (HR: 3.65). CONCLUSIONS: Sex-specific differences were observed in non-PV foci sites and local EAT and in regard to the predictors of AF recurrence.

Development of a Visualization Deep Learning Model for Classifying Origins of Ventricular Arrhythmias.

BACKGROUND: Several algorithms have been proposed for differentiating the right and left outflow tracts (RVOT/LVOT) arrhythmia origins from 12-lead electrocardiograms (ECGs); however, the procedure is complicated. A deep learning (DL) model, a form of artificial intelligence, can directly use ECGs and depict the importance of the leads and waveforms. This study aimed to create a visualized DL model that could classify arrhythmia origins more accurately.Methods and Results: This study enrolled 80 patients who underwent catheter ablation. A convolutional neural network-based model that could classify arrhythmia origins with 12-lead ECGs and visualize the leads that contributed to the diagnosis using a gradient-weighted class activation mapping method was developed. The average prediction results of the origins by the DL model were 89.4% (88.2-90.6) for accuracy and 95.2% (94.3-96.2) for recall, which were significantly better than when a conventional algorithm is used. The ratio of the contribution to the prediction differed between RVOT and LVOT origins. Although leads V1 to V3 and the limb leads had a focused balance in the LVOT group, the contribution ratio of leads aVR, aVL, and aVF was higher in the RVOT group. CONCLUSIONS: This study diagnosed the arrhythmia origins more accurately than the conventional algorithm, and clarified which part of the 12-lead waveforms contributed to the diagnosis. The visualized DL model was convincing and may play a role in understanding the pathogenesis of arrhythmias.

Circulating intermediate monocytes and atrial structural remodeling associated with atrial fibrillation recurrence after catheter ablation.

BACKGROUND: Inflammation, such as that associated with intermediate CD14++ CD16+ monocytes and atrial structural remodeling (SRM), may be important in the recurrence of atrial fibrillation (AF) after catheter ablation. However, the relationship between the intermediate CD14++ CD16+ monocytes, SRM, and AF recurrence is unclear. METHODS: Twenty-four patients with AF were enrolled. The proportion of intermediate monocytes (PIM) was assessed before ablation by flow cytometry. As a surrogate marker of SRM, the volume ratio (VR) of signal intensity greater than 1 standard deviation on late-gadolinium enhancement magnetic resonance imaging (LGE-MRI) was calculated. We investigated whether PIM correlated with SRM on LGE-MRI and determined the optimal cutoff value for predicting AF recurrence. RESULTS: Univariate analysis revealed positive correlations between PIM and BNP with SRM (PIM: r = .593, p = .002; BNP: r = .567, p = .004). Multivariable analysis revealed that PIM was independently associated with VR on LGE-MRI (ß = .522; p = .033). The finding of an area under the receiver operating characteristic curve of 0.750 revealed that a VR ≥ 13.3% on LGE-MRI as the optimal cutoff value to predict AF recurrence with 80% sensitivity and 71% specificity, which was associated with PIM ≥ 10.0%. CONCLUSION: Intermediate monocytes were significantly positively correlated with SRM. PIM ≥ 10% was associated with a VR ≥ 13.3% on LGE-MRI, which predicted AF recurrence after catheter ablation.

Feasibility of catheter ablation in patients with persistent atrial fibrillation guided by fragmented late-gadolinium enhancement areas.

BACKGROUND: A computer simulation model has demonstrated that atrial fibrillation (AF) driver can be attached to heterogeneous fibrosis assessed by late gadolinium enhancement magnetic resonance imaging (LGE-MRI). However, it has not been well elucidated in patients with persistent AF. The aim of this study was to investigate whether radiofrequency (RF) applications in the fragmented LGE area (FLA) could terminate AF or convert it to atrial tachycardia (AT) and improve the rhythm outcome. METHODS: A total of 31 consecutive persistent AF patients with FLAs were enrolled (FLA ablation group, mean age: 69 ± 8 years, mean left atrial diameter: 42 ± 6 mm). A favorable response was defined as direct AF termination or AT conversion during RF applications at the FLA. The rhythm outcome was compared between the FLA ablation group and FLA burden-matched pulmonary vein isolation (PVI) group. RESULTS: Favorable responses were found in 15 (48%) of 31 patients in the FLA group (AF termination in seven, AT conversion in eight patients), but not in the PVI group. AF recurrence at 12 months follow-up was significantly less in the FLA ablation group than in the PVI group (4 [13%] vs. 12 [39%] of 31 patients, log-rank p = .023). In patients with a favorable response, AT recurred in 1 (7%) of 15 patients, but AF did not. CONCLUSIONS: FLA ablation could terminate AF or convert it to AT in half of the patients. No AF recurrence was documented in patients with a favorable response.

Late-gadolinium enhancement properties associated with atrial fibrillation rotors in patients with persistent atrial fibrillation.

BACKGROUND: A computational model demonstrated that atrial fibrillation (AF) rotors could be distributed in patchy late-gadolinium enhancement (LGE) areas and play an important role in AF drivers. However, this was not validated in humans. OBJECTIVE: The purpose of this study was to evaluate the LGE properties of AF rotors in patients with persistent AF. METHODS: A total of 287 segments in 15 patients with persistent AF (long-standing persistent AF in 9 patients) that underwent AF ablation were assessed. Non-passively activated areas (NPAs), where rotational activation (AF rotor) was frequently observed, were detected by the novel real-time phase mapping (ExTRa Mapping). The properties of the LGE areas were assessed using the LGE heterogeneity and the density which was evaluated by the entropy (LGE-entropy) and the volume ratio of the enhancement voxel (LGE-volume ratio), respectively. RESULTS: NPAs were found in 61 (21%) of 287 segments and were mostly found around the pulmonary vein antrum. A receiver operating characteristic curve analysis yielded an optimal cutoff value of 5.7% and 10% for the LGE-entropy and LGE-volume ratio, respectively. The incidence of NPAs was significantly higher at segments with an LGE-entropy of >5.7 and LGE-volume ratio of >10% than at the other segments (38 [30%] of 126 vs. 23 [14%] of 161 segments; p = .001). No NPAs were found at segments with an LGE-volume ratio of >50% regardless of the LGE-entropy. Of five patients with AF recurrence, NPAs outside the PV antrum were not ablated in three patients and the remaining NPAs were ablated, but their LGE-entropy and LGE-volume ratio were low. CONCLUSION: AF rotors are mostly distributed in relatively weak and much more heterogenous LGE areas.

Incidence and Characteristics of Coronary Artery Spasms Related to Atrial Fibrillation Ablation Procedures　- Large-Scale Multicenter Analysis.

BACKGROUND: Coronary artery spasms (CASs), which can cause angina attacks and sudden death, have been recently reported during catheter ablation. The aim of the present study was to report the incidence, characteristics, and prognosis of CASs related to atrial fibrillation (AF) ablation procedures.Methods and Results:The AF ablation records of 22,232 patients treated in 15 Japanese hospitals were reviewed. CASs associated with AF ablation occurred in 42 of 22,232 patients (0.19%). CASs occurred during ablation energy applications in 21 patients (50%). CASs also occurred before ablation in 9 patients (21%) and after ablation in 12 patients (29%). The initial change in the electrocardiogram was ST-segment elevation in the inferior leads in 33 patients (79%). Emergency coronary angiography revealed coronary artery stenosis and occlusions, which were relieved by nitrate administration. No air bubbles were observed. A comparison of the incidence of CASs during pulmonary vein isolation between the different ablation energy sources revealed a significantly higher incidence with cryoballoon ablation (11/3,288; 0.34%) than with radiofrequency catheter, hot balloon, or laser balloon ablation (8/18,596 [0.04%], 0/237 [0%], and 0/111 [0%], respectively; P<0.001). CASs most often occurred during ablation of the left superior pulmonary vein. All patients recovered without sequelae. CONCLUSIONS: CASs related to AF ablation are rare, but should be considered as a dangerous complication that can occur anytime during the periprocedural period.

Device nurse intervention facilitates the patients' adaptation to cardiac shock devices in the remote monitoring era.

BACKGROUND: A substantial number of patients with shock devices (implantable cardioverter defibrillators [ICDs] or ICDs with resynchronization [CRTDs]) experience psychological distress. OBJECTIVE: We investigated the device nurse telephone intervention's effect on improving the patient's adaptation to shock devices, quality of life (QOL), and anxiety in the remote monitoring era. METHODS: The patient's adaptation to the device, health-related QOL, and anxiety were investigated by the modified Implanted Devices Adjustment-Japan score (IDAS), Short Form-36, and State-Trait Anxiety Inventory (STAI) before and 1-year after the device nurse telephone intervention, performed every 3 months. A total of 95 patients (median age 69 years and 25 females) participated. Sixty patients had ICDs and 35 CRTDs. Structural heart disease was observed in 72 patients, and idiopathic ventricular arrhythmias in the others. The mean left ventricular ejection fraction was 46% ± 15%. The median duration since the device implantation was 5.2 years. RESULTS: The total IDAS score significantly improved from 28.42 ± 7.11 at baseline to 26.77 ± 7.68 (p = 0.0076) at 1 year. Both the state and trait anxiety significantly improved (from 38.9 ± 9.6 to 35.3 ± 9.0 [<0.0001] and 38.8 ± 10.3 to 36.2±9.8 [p = 0.0044], respectively). The prevalence of patients with a state and trait anxiety of more than 40 decreased from 44 (46%) and 38 (40%) patients before the study to 27 (28 %) and 32 (34 %) at 1 year. The SF-36 mental component summary score significantly increased (50.8 ± 8.3 at baseline to 53.1 ± 7.7 at 1 year, p = 0.0031). CONCLUSIONS: The device nurse intervention facilitated the patient's adaptation to the shock device, increased the health-related QOL, and reduced the patient's anxiety.

Ventricular tachycardia based on cardiac sarcoidosis with a narrow QRS complex, ablated on the left ventricle free-wall.

A septuagenarian female with cardiac sarcoidosis suffered from drug refractory ventricular tachycardia (VT) requiring multiple implantable cardioverter-defibrillator shocks. The QRS complex during the VT was very similar to that during sinus rhythm although the QRS width during the VT (142 ms) was relatively wider than that during sinus rhythm (107 ms). The VT exit was located on the ventricular septum close to the His-bundle recording region. However, the critical pathway of this VT was detected on the anterior free wall of the left ventricle (LV), and a radiofrequency application at that site could terminate the VT. No Purkinje potentials were recorded there during the VT or sinus rhythm. According to the electrophysiological study, 3-D mapping, and the response to the ablation, the critical circuit of the VT was surrounded by a protected area of scar associated with cardiac sarcoidosis. As a result, the VT circuit was connected to the basal septal area close to the His-Purkinje system as an outer loop of the VT circuit. This unique trajectory of the VT might have caused a similar QRS morphology to that of sinus rhythm, and the relatively narrow QRS complex despite the critical isthmus was located on the anterior free wall of the LV.

Different tissue thermodynamics between the 40 W and 20 W radiofrequency power settings under the same ablation index/lesion size index.

INTRODUCTION: The ablation index (AI) and lesion size index (LSI) are novel markers for predicting the ablation lesion quality, however, collateral damage is still a concern. This study aimed to compare the lesion characteristics and tissue temperature profiles between 20 W (20 Ws) and 40 W (40 Ws) ablation settings under the same AI and LSI. METHODS: An ex vivo model consisting of swine myocardium (5-6 mm thickness) in a circulating, warmed saline bath was used. Twenty-one tissue temperature electrodes were used. Radiofrequency applications with different power settings were performed with a 10 to 12 g contact force until the AI and LSI reached 350 and 4.5, respectively. RESULTS: A total of 120 radiofrequency (RF) applications and 2520 tissue temperature profiles were analyzed. The speed of the tissue temperature rise with 40 Ws was significantly faster than that with 20 Ws. However, the maximum tissue temperature did not significantly differ between 20 and 40 Ws with the same AI (44.6°C ± 3.9°C vs 45.1°C ± 6.4°C, P = .73), and was significantly lower for 40 Ws with the same LSI (42.8°C ± 3.4°C vs 40.0°C ± 3.4°C, P = .003). For both the AI and LSI, the number of electrodes exhibiting high temperatures (≥39°C) was significantly larger and the duration of high tissue temperatures was significantly longer with 20 Ws. The thermal latency with 40 Ws was greater. CONCLUSIONS: Although the targeted AI and LSI were the same for both 20 and 40 Ws, the tissue temperature profiles differed greatly depending on the RF power setting. A high power setting based on the AI and LSI may reduce the collateral thermal damage.

Lesion characteristics between cryoballoon ablation and radiofrequency ablation with a contact force-sensing catheter: Late-gadolinium enhancement magnetic resonance imaging assessment.

BACKGROUND: Pulmonary vein isolation (PVI) lesions after cryoballoon ablation (CBA) are characterized as a wider and more continuous than that after conventional radiofrequency catheter ablation (RFCA) without the contact force (CF)-sensing technology. However, the impact on the lesion characteristics of ablation with a CF-sensing catheter has not been well discussed. We sought to assess the lesions using late-gadolinium enhancement magnetic resonance imaging (LGE-MRI) and to compare the differences between the two groups (CB group vs. RF group). METHODS: A total of 30 consecutive patients who underwent PVI were enrolled (CB group, 18; RF group, 12). The RF applications were delivered with a target lesion size index (LSI) of 5. The PVI lesions were assessed by LGE-MRI 3 months after the PVI. The region around the PV was divided into eight segments: roof, anterior-superior, anterior carina, anterior inferior, bottom, posterior inferior, posterior carina, and posterior superior segment. The lesion width and visual gap of each segment were compared between the two groups. The visual gaps were defined as no-enhancement site of >4 mm. RESULTS: The mean LSI was 4.7 ± 0.7. The lesion width was significantly wider but the visual gaps were more frequently documented at the bottom segment of right PV in the CBA group (lesion width: 8.1 ± 2.2 vs. 6.3 ± 2.2 mm; p = .032; visual gap at the bottom segment or right PV: 39% vs. 0%; p = .016). CONCLUSIONS: The PVI lesion was wider after CBA, while the visual gaps were fewer after RFCA with a CF-sensing catheter.

Circulating intermediate monocytes and toll-like receptor 4 correlate with low-voltage zones in atrial fibrillation.

Inflammation has been suggested to play a key role in the pathogenesis of atrial fibrillation (AF). Our hypothesis was that this inflammation, mediated by intermediate monocytes and toll-like receptor 4 (TLR4), causes the formation and expansion of low-voltage zones (LVZs). Prior to ablation, the monocyte subsets of 78 AF patients and TLR4 expression of 66 AF patients were analyzed via a flow cytometric analysis. Based on the CD14/CD16 expression, the monocytes were divided into three subsets: classical, intermediate, and non-classical. At the beginning of the ablation session, voltage mapping was performed. LVZs were defined as all bipolar electrogram amplitudes of < 0.5 mV. Correlations between the flow cytometric analysis results and presence of LVZs, as well as the total area of the LVZ, were examined. Patients with LVZs clearly had a higher proportion of intermediate monocytes (10.0 ± 3.6% vs. 7.2 ± 2.7%, p < 0.001) than those without LVZs. TLR4 was much more frequently expressed in the intermediate monocytes than other two monocyte subsets (p < 0.001). Moreover, the TLR4 expression level in intermediate monocytes correlated positively with the total area of the LVZs (r = 0.267, p = 0.030), especially in patients with paroxysmal AF (r = 0.365, p = 0.015). The intermediate monocytes and TLR4 expression positively correlated with LVZs in AF patients.

Lesion distribution after cryoballoon ablation and hotballoon ablation: Late-gadolinium enhancement magnetic resonance imaging analysis.

INTRODUCTION: Pulmonary vein isolation (PVI) lesions after cryoballoon ablation (CBA) are wide and continuous, however, the distribution can depend on the pulmonary vein (PV) size. We sought to assess the relationship between the lesion distribution and PV size after CBA and hotballoon ablation (HBA). METHODS AND RESULTS: A total of 80 consecutive patients who underwent PVI were enrolled (40 with CBA). The lesions were visualized by late-gadolinium enhancement magnetic resonance imaging. The lesion width, lesion gaps, and distance from the PV ostium (PVos) to distal lesion edge (DLE) were assessed. If the DLE extended inside the PV, the value was expressed as a negative value. Although the lesion width was significantly wider in the CB group (7.8 ± 2.0 vs 4.9 ± 1.0 mm, P < .001), the number of lesion gaps was significantly less in the HB group (2.9 ± 2.4 vs 1.3 ± 1.4 gaps, P = .001). The distance from the PVos to DLE was a negative value in both groups, but the impact was significantly greater (-1.5 ± 1.8 vs -0.2 ± 1.2 mm, P < .001) and negatively correlated with PV size in the CB group, but not in HB group (r = -0.27, P = .007). The AF recurrence 12 months after the procedure did not differ (5 [12.5%] of 40 in the CB group vs 4 [10%] of 40 in the HB group, P = .695). CONCLUSIONS: The PVI lesions after HBA were characterized by (a) narrower, but (b) more continuous, (c) smaller lesion inside the PV, and (d) irrespective of PV size as compared to that after CBA.

Predictors and Clinical Outcomes of Transient Responders to Cardiac Resynchronization Therapy.

BACKGROUND: Left ventricular end-systolic volume (LVESV) changes at 6 months and clinical status are useful for assessing responses to cardiac resynchronization therapy (CRT). Regression of the LVESV following CRT has not been described beyond 6 months. This study aimed to assess the proportion, predictors, and clinical outcomes of responders whose LVESVs had regressed. METHODS: We retrospectively analyzed 104 consecutive CRT patients. A responder was defined as a patient with a relative reduction in the LVESV ≥15% at 6 months after CRT. Fifty-six responders participated in this study. A transient responder was defined as a responder without a relative reduction in the LVESV ≥15% at 2 years after CRT or who died of cardiac events during the 24-month follow-up period. RESULTS: Of the 56 responders, 16 (29%) were transient responders. Multivariable logistic regression analysis showed that chronic atrial fibrillation (odds ratio [OR] = 19.2, 95% confidence interval [CI] [1.93, 190], P = 0.012) and amiodarone usage (OR = 60.9, 95% CI [4.18, 886], P = 0.003) were independent predictors of transient responses. Hospitalizations for heart failure were significantly higher among the transient responders than among the lasting responders during a mean follow-up period of 7.6 years (log-rank P < 0.001), and all-cause mortality tended to be higher among the transient responders (log-rank P = 0.093). CONCLUSIONS: One-third of the responders were transient responders at 2 years after CRT, and their long-term prognoses were poor. Careful attention should be paid to maintain the reduction in LVESV especially in patients with chronic AF.

Usefulness of non-contrast-enhanced MRI with two-dimensional balanced steady-state free precession for the acquisition of the pulmonary venous and left atrial anatomy pre catheter ablation of atrial fibrillation: Comparison with contrast enhanced CT in clinical cases.

BACKGROUND: To investigate the feasibility of substituting non-contrast-enhanced MR (non-CE-MR) imaging with a two-dimensional (2D) balanced steady-state free precession (b-SSFP) sequence for contrast-enhanced computed tomography (CE-CT) for atrial fibrillation (AF) ablation. METHODS: Fifty-four patients that underwent AF ablation under the guidance of a 3D electro-anatomical mapping system with CE-CT (n = 27) or non-CE-MR images (n = 27) were studied. Procedural results were compared between the two groups. Furthermore, in 22 patients who underwent both CE-CT and non-CE-MRI, two cardiologists independently scored the multiplanar reformatted images on a scale of 1 to 4 (from 1, poor, to 4, excellent). RESULTS: The image score was nearly 0.5 point higher with the CE-CT method. However, the procedural results such as the surface registration error (1.0 [0.8-1.6] mm versus 1.0 [0.8-1.35] mm, P = 0.88) and procedure time (185 [159-199] min versus 185 [142-221] min, P = 0.86) did not significantly differ between the CE-CT and non-CE-MR groups. CONCLUSION: The non-CE-MR method with a 2D-b-SSFP sequence can give us adequate information on AF ablation without any radiation exposure or contrast medium usage

Characteristics of Residual Atrial Posterior Wall and Roof-Dependent Atrial Tachycardias after Pulmonary Vein Isolation.

BACKGROUND: Roof-dependent atrial tachycardia (roof AT) sometimes occurs after pulmonary vein isolation (PVI) of atrial fibrillation (AF). This study aimed to investigate the relationship between the anatomy of the residual left atrial posterior wall and occurrence of roof AT. METHODS: A total of 265 patients with AF who underwent PVI were enrolled. After the PVI, induced or recurrent roof AT was confirmed by an entrainment maneuver or activation mapping using a three-dimensional (3D) mapping system. To identify the predictors of roof AT, the minimum distance between both PVI lines (d-PVI) was measured by a 3D mapping system and the anatomical parameters, including the left atrial (LA) diameter, left atrial volume index (LAVi), and shape of the left atrial roof, were analyzed by 3D computed tomography. RESULTS: Roof AT was documented in 11 (4.2%) of 265 patients. A multivariable analysis demonstrated that the d-PVI, Deep V shape of the LA roof, and LAVi were associated with roof AT occurrences (d-PVI: odds ratio: 0.72, confidence interval [CI]: 0.61-0.86, P < 0.001; Deep V shape: odds ratio: 0.19, CI: 0.04-0.82, P = 0.03; LAVi: odds ratio: 1.05, CI: 1.02-1.07, P = 0.001). A receiver-operating characteristic curve analysis yielded an optimal cut-off value of 15.5 mm and 55.7 mL/m2 for the d-PVI and LAVi, respectively. CONCLUSION: The shorter d-PVI at the LA roof, greater LAVi, and Deep V shape were associated with the occurrence of a roof AT.