The electrocardiogram of a 14-year-old boy with recurrent palpitation showed a wide QRS regular tachycardia with a right bundle branch block and right-axis deviation of 226 beats per minute. Verapamil infusion terminated the tachycardia after a few minutes. Electrophysiological study revealed that this tachycardia was considered as a reentrant tachycardia associated with the anterograde left posterior accessory pathway (AP) and retrograde right septal AP. Radiofrequency application was performed and eliminated both APs, and there was no recurrence of wide QRS tachycardia. .

The Maze IV procedure during cardiac surgery is an established treatment for patients with atrial fibrillation (AF) concomitant with a mitral valve repair or replacement. Recurrent atrial tachyarrhythmias are mainly left atrial (LA) flutter, which is associated with gaps on previous surgical lesions. Herein, we report a case in which a 3-dimensional mapping system could demonstrate a typical perimitral atrial flutter but radiofrequency (RF) ablation of a gap on a previous lesion could not terminate the tachycardia.

Mitral annular calcification (MAC) is frequently observed, but it rarely causes left ventricular outflow tract (LVOT) obstruction (LVOTO). An 83-year-old woman with hypertension, diabetes, and dyslipidemia was admitted to our hospital because of exertional dyspnea. She was diagnosed with hypertensive heart disease. Her symptoms were exacerbated by exertion, and she had no symptoms at rest. Transthoracic echocardiography showed massive posterior MAC, a sigmoid septum, and LVOTO, with a peak gradient of 15.4 mmHg at rest. Systolic anterior motion of the anterior mitral leaflet was not found. Moreover, the LVOT gradient in the stress condition was evaluated, and an increased LVOT gradient (47.3 mmHg) and chest discomfort was noted after 20 μg/kg/min of dobutamine was administered and the Valsalva maneuver was used. Hence, the patient was diagnosed with latent LVOTO. Interestingly, the distance between the septal wall, which was protruding into the left ventricular cavity, and the mitral valve coaptation, which was pushed up by the posterior MAC, had become closer, causing dynamic LVOTO. Since it is difficult to treat LVOTO with medication, ultimately, septal myectomy and mitral valve replacement were performed, which improved her symptoms. Evaluating the LVOT pressure gradient in stress condition is important in patients with MAC. .

Background: We reviewed the effectiveness and safety of cardiac resynchronization therapy (CRT) for patients with New York Heart Association (NYHA) class IV non-ambulatory heart failure (NAHF).Methods: From 2006 to 2011, 310 patients underwent CRT at Kobe University Hospital and Himeji Cardiovascular Center because of heart failure. Of these, 29 NAHF patients were retrospectively analyzed. The control group comprised 21 age- and ejection fraction-matched patients with NAHF who did not undergo CRT from the ICU database of Kobe University Hospital. The primary endpoint was all-cause death and hospitalization for heart failure. Response was defined as a >15% reduction in left ventricular end-systolic volume (LVESV).Results: CRT was performed successfully without serious complications in all patients. Twenty-three patients (79%) were discharged 19 +/- 15 days after CRT implantation, while 6 (21%) died during their hospital stay due to progressive heart failure. Compared with the control group, patients in the CRT group showed significant improvements in the primary endpoint (log-rank p=0.04). Six patients (21%) were defined as responders and the Kaplan-Meier curve showed that responders experienced a better outcome than non-responders (log-rank p=0.029). LV dyssynchrony before implantation was significantly related to the occurrence of the primary endpoint (p=0.02).Conclusions: CRT can be safely used in patients with NAHF and can improve long-term patient outcomes, especially in treatment responders. (C) 2015 Japanese Heart Rhythm Society. Published by Elsevier B.V.

Background: Even with the use of a reduced energy setting (20-25 W), excessive transmural injury (ETI) following catheter ablation of atrial fibrillation (AF) is reported to develop in 10% of patients. However, the incidence of ETI depends on the pulmonary vein isolation (PVI) method and its esophageal temperature monitor setting. Data comparing the incidence of ETI following AF ablation with and without esophageal temperature monitoring (ETM) are still lacking.Methods: This study was comprised of 160 patients with AF (54% paroxysmal, mean: 24.0 +/- 2.9 kg/m(2)). Eighty patients underwent ablation accompanied by ETM. The primary endpoint was defined as the occurrence of ETI assessed by endoscopy within 5 d after the AF ablation. The secondary endpoint was defined as AF recurrence after a single procedure. If the esophageal temperature probe registered > 39 degrees C, the radiofrequency (RF) application was stopped immediately. RF applications could be performed in a point-by-point manner for a maximum of 20 s and 20 W. ETI was defined as any injury that resulted from AF ablation, including esophageal injury or periesophageal nerve injury (peri-ENI).Results: The incidence of esophageal injury was significantly lower in patients whose AF ablation included ETM compared with patients without ETM (0 [0%] vs. 6 [7.5%], p=0.028), but not the incidence of peri-ENI (2 [2.5%] vs. 3 [3.8%], p=1.0). AF recurrence 12 months after the procedure was similar between the groups (20 [25%] in the ETM group vs. 19 [24%] in the non-ETM group, p=1.00).Conclusions: Catheter ablation using ETM may reduce the incidence of esophageal injury without increasing the incidence of AF recurrence but not the incidence of peri-ENI. (C) 2015 Japanese Heart Rhythm Society. Published by Elsevier B.V. All rights reserved.

BACKGROUND:The incidence of hematoma formation following implantation of a cardiovascular implantable electronic device (CIED) is estimated to be 5% even if a pressure dressing is applied. It is unclear whether a pressure dressing can really compress the pocket in different positions. Furthermore, the adhesive tape for fixing pressure dressings can tear the skin. We developed a new compression tool for preventing hematomas and skin erosions.METHODS AND RESULTS:We divided 46 consecutive patients receiving anticoagulation therapy who underwent CIED implantation into 2 groups (Group I: conventional pressure dressing, Group II: new compression tool). The pressure on the pocket was measured in both the supine and standing positions. The incidence of hematomas was compared between the 2 groups. The pressure differed between the supine and standing positions in Group I, but not in Group II (Group I: 14.8±7.1 mmHg vs. 11.3±9.9 mmHg, P=0.013; Group II: 13.5±2.8 mmHg vs. 13.5±3.5 mmHg, P=0.99). The incidence of hematomas and skin erosions was documented in 2 (8.7%) and 3 (13%) Group I patients, respectively. No complications were documented in Group II.CONCLUSIONS:The new compression tool can provide adequate continuous pressure on the pocket, regardless of body position. This device may reduce the incidence of hematomas and skin erosions after CIED implantation.

Background: Catheter ablation (CA) is an established therapy for atrial fibrillation (AF). However, the assessment of anatomical information and predictors of AF recurrence remain unclear. We investigated the relationship between anatomical information on the left atrium (LA) and pulmonary veins (PVs) from three-dimensional computed tomography images and the recurrence of AF after CA,Methods: Sixty-seven consecutive AF patients (mean age: 62 10 years, median AF history: 42 (12; 60) months, mean LA size: 41 7 mm, paroxysmal: 56%) underwent CA and were followed for 19 +/- 10 months. The segmented surface areas (antral, posterior, septal, and lateral) and dimensions (between the anterior and posterior walls, the right inferior PV and mitral annulus [MA], the right superior PV and [VIA, the left superior PV and [VIA, and the mitral isthmus) of the LA were evaluated three dimensionally using the NavX system The cross-sectional areas of the PVs were also evaluated.Results: After the follow-up period, 49 patients (73%) remained free from AE.A multivariate analysis showed that the diameter of the mitral isthmus and cross-sectional area of the right upper PV were associated with AF recurrence (odds ratio: 1,070, Cl: 1.02-1.12, p=0.001; odds ratio: 0,41, Cl: 021-0.77, p=0.006).Conclusion: Enlargement of the mitral isthmus and a smaller right superior PV cross-sectional area were associated with AF recurrence. (C) 2015 Japanese Heart Rhythm Society, Published by Elsevier B.V. All rights reserved.

Essential thrombocythemia (ET) has been reported to cause acute coronary disease. However, the efficacy of anti-platelet therapy for ET is unclear since there are individual differences in the platelet function of ET patients. Here we report a case of a 62-year-old man with ET who was admitted to our hospital because of acute coronary syndrome. He underwent coronary angioplasty. Dual anti-platelet therapy with aspirin (81mg/day) and clopidogrel (75mg/day) was subsequently initiated. We evaluated platelet reactivity in P2Y12 reaction units, and subsequently determined anti-platelet drugs and corresponding doses.

A 65-year-old man was referred to our hospital with persistent atrial fibrillation (AF). Before the ablation procedure, 3-dimensional computed tomography revealed a left atrial anomalous muscular band connecting the posterior side of the left atrial roof and the right edge of the fossa ovalis. During the first ablation procedure, the band interfered with the manipulation of the catheter, resulting in only the left pulmonary vein (PV) being isolated. However, AF recurred. During the second procedure, careful catheter manipulation permitted complete right PV isolation, after which, the patient has not had AF recurrence for more than 3 years.

We report a case of Ebstein׳s anomaly in which radiofrequency catheter ablation of an accessory pathway was successfully performed under intra-cardiac echocardiography. A 50-year-old woman was referred to our hospital for radiofrequency catheter ablation of a paroxysmal supraventricular tachycardia. A 12-lead surface electrocardiogram revealed ventricular pre-excitation associated with type B Wolff–Parkinson–White syndrome. In the baseline electrophysiological study, an orthodromic atrioventricular reciprocating tachycardia with a right posterior accessory pathway was induced. A phased-array intra-cardiac echo probe was positioned in the right atrium to visualize the atrioventricular junction. The key structures for catheter ablation, such as the atrialized right ventricle, atrioventricular junction, and tricuspid valve, were clearly visualized on intra-cardiac echocardiography. Radiofrequency current was successfully delivered at the atrioventricular junction, where a Kent potential was recorded. During a 6-month follow-up period, the patient was free from arrhythmias. The findings in this case suggest that phased-array intra-cardiac echocardiography is useful for ablation of right-sided accessory pathways in patients with Ebstein׳s anomaly.

Background: The efficacy of cpicarclial catheter ablation for ventricular tachycardia has been reported. Hovvever, the safest anatomical method for pericardial puncture has nor been determined.Methods: Thirty patients who underwent 3-dimensional computed tomography (3D-CT)preceding catheter ablations for atrial fibrillation were enrolled in this study. We used the skin surface 1 cm below the xiphistemum as the puncture site. For the anterior approach, the attainment site was the pericardium of the mid portion of right ventricular anterior site, and for the posterior approach it was the pericardium of the inferior ventricular site. The distance and the angle between the 2 sites were measured using 3D-CT.Results: For the anterior approach, the distance was 54 +/- 11 degrees mm and the needle angle was 37 +/- 11 degrees toward the left scapula and 34 +/- 12 towards the back of the body. For the posterior approach, the distance was 56 +/- 10 mm and the corresponding needle angles were 60 +/- 9 degrees and 86 +/- 13 degrees. The distance correlated with BMl for the anterior and posterior approaches (anterior approach: r(2)=0.43, P<0.001; posterior approach: r(2) = 0.4 9, P<0.001). Liver existed along the pathway of the posterior approach in 11 (37%) of 30 patients, and through in 2 (ln) of 11 patients. The liver and lung were not located along the pathway of the anterior approach in any patients.Conclusions: Performing subxiphoid pericardiocentesis is anatomically safer via the ante nor approach than via the posterior approach. (C) 2014 Japanese Heart Rhythm Society. Published by Elsevier B.V. All rights reserved.

Background:Esophageal injury following catheter ablation of atrial fibrillation (AF) is reported to occur in 35% of patients. Even with a low energy setting (2025 W), lesions develop in 10% of patients. Body mass index (BMI) has been reported to be a predictor of esophageal injury, indicating that patients with a low BMI (<24.9 kg/m(2)) are at a higher risk. We hypothesized that catheter ablation with a lower energy setting of 20 W controlled by esophageal temperature monitoring (ETM) at 39 degrees C could prevent esophageal injury even in patients with a BMI <24.9 kg/m2.Methods: Twenty patients with AF were included (age, 63 +/- 8 years; BMI, 22.9 +/- 1.3 kg/m(2), left atrium diameter, 44 +/- 11 mm). If the esophageal temperature probe registered a temperature of >39 degrees C, radiofrequency (RF) application was stopped immediately. RF application could be performed in a point by point manner for a maximum of 20 s. Endoscopy was performed 15 days after ablation.Results: Esophageal mucosal injury was not observed in any patient in the study.Conclusions: Catheter ablation using ETM reduced the incidence of esophageal injuries, even in patients with a low BMI. (C) 2014 Japanese Heart Rhythm Society. Published by Elsevier B.V. All rights reserved.

BACKGROUND The upper limit of vulnerability (ULV) closely correlates with the defibrillation threshold (DFT). The aim of this study was to establish the optimal protocol for using the ULV test to predict high DFT (>20 J) without inducing ventricular fibrillation (VF). METHODS AND RESULTS The 10-J and 15-J ULV test with 3 coupling intervals (-20, 0, and +20 ms to the peak of T-wave) and the DFT test were performed in 96 patients receiving implantable cardioverter defibrillator. ULV ≤ 10 J was confirmed in 47 (49%). ULV ≤ 15 J was confirmed in 70 (77%) of 91 patients (15-J ULV test could not be done in 5). The sensitivity and negative predictive value of both ULV >10 J and >15 J for predicting high DFT were 100%. The specificity and positive predictive value of ULV >15 J were higher than those for ULV >10 J (85% vs. 55%, 43% vs. 22%, respectively). The rate of VF inducibility for confirming ULV ≤ 15 J was lower than that for ULV ≤ 10 J (23% vs. 51%, P<0.0001). On analysis of single 15-J ULV test only at the peak of T-wave, VF was not induced in 79 of 91 patients, but 4 of these had high DFT. CONCLUSIONS The 15-J ULV test with 3 coupling intervals could correctly identify high-DFT patients and reduce the necessity for VF induction at defibrillator implantation.

Functional Block in the Posterior Right Atrium . Introduction: Conduction block in the posterior right atrium (RA) plays an important role in perpetuating atrial flutter (AFL). Although conduction blocks have functional properties, it is not clear how the block line changes with the pacing rate, pacing site, and administration of antiarrhythmic drugs. Methods and Results: Forty patients with typical AFL were enrolled. Pacing (110, 170, 230 ppm) from the coronary sinus ostium (CSo) and low lateral RA was performed. After 1 mg/kg pilsicainide (pure sodium channel blockade) administration, the pacing protocol was repeated. Conduction block was assessed based on a color‐coded isopotential map and 20 points of virtual unipolar electrograms in the posterior RA using noncontact mapping. Block line proportion was defined as the percentage of length of the block line between the superior and inferior vena cava. The pacing rate‐dependent extension of the block proportion was significant during pacing from both sides (pacing from the CSo: 59 ± 17% at 110 ppm, 69 ± 16% at 230 ppm, P < 0.05; pacing from the low lateral RA: 43 ± 19% at 110 ppm, 55 ± 22% at 230 ppm, P < 0.05). The block line was significantly longer during CSo pacing than during low lateral RA pacing at each rate (all P < 0.05). After pilsicainide administration, the block line extended further. Conclusion: In addition to pacing rate‐dependent and site‐dependent changes in the block line, pilsicainide further extended the block line length. This phenomenon explains the clinical observation that counterclockwise AFL occurs more frequently than clockwise AFL, and the mechanism of class IC AFL. (J Cardiovasc Electrophysiol, Vol. 23, pp. 827‐834, August 2012)