Wide QRS tachycardia associated with multiple accessory pathways in a patient with Wolff-Parkinson-White syndrome.

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. .

Impact of esophageal temperature monitoring guided atrial fibrillation ablation on preventing asymptomatic excessive transmural injury.

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 °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.

Topographic variability of the left atrium and pulmonary veins assessed by 3D-CT predicts the recurrence of atrial fibrillation after catheter ablation.

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 MA, the left superior PV and MA, 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 AF. 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, CI: 1.02-1.12, p=0.001; odds ratio: 0.41, CI: 0.21-0.77, p=0.006). CONCLUSION: Enlargement of the mitral isthmus and a smaller right superior PV cross-sectional area were associated with AF recurrence.

Incidence of esophageal injury after pulmonary vein isolation in patients with a low body mass index and esophageal temperature monitoring at a 39 °C setting.

BACKGROUND: Esophageal injury following catheter ablation of atrial fibrillation (AF) is reported to occur in 35% of patients. Even with a low energy setting (20-25 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 °C could prevent esophageal injury even in patients with a BMI <24.9 kg/m(2). 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 °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 1-5 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.

Left atrial anomalous muscular band detected by computed tomography before catheter ablation in a patient with atrial fibrillation.

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.

The effectiveness of cardiac resynchronization therapy for patients with New York Heart Association class IV non-ambulatory heart failure.

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.

Novel Compression Tool to Prevent Hematomas and Skin Erosions After Device Implantation.

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.

Left ventricular outflow tract obstruction caused by massive mitral annular calcification in a patient with hypertensive heart disease.

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. .

Evaluation of platelet reactivity using P2Y12 reaction units in acute coronary syndrome with essential thrombocythemia: A case report.

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 (81 mg/day) and clopidogrel (75 mg/day) was subsequently initiated. We evaluated platelet reactivity in P2Y12 reaction units, and subsequently determined anti-platelet drugs and corresponding doses. .

Optimal strength and number of shocks at upper limit of vulnerability testing required to predict high defibrillation threshold without inducing ventricular fibrillation.

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.

Rate-dependent and site-specific conduction block at the posterior right atrium and drug effects evaluated using a noncontact mapping system in patients with typical atrial flutter.

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.

Recognition of inferiorly dislocated fast pathways guided by three-dimensional electro-anatomical mapping.

PURPOSE: Slow pathway (SP) ablation of atrioventricular (AV) nodal reentrant tachycardia (AVNRT) can be complicated by unexpected AV block even at sites >10 mm inferior to the bundle of His (HB), and one cause is thought to be the inferior dislocation of an antegrade fast pathway (A-FP). We assessed locations of FPs guided by CARTO. METHODS: Sites of FPs were mapped guided by CARTO before SP ablation in 18 patients with slow-fast AVNRT. The A-FP was defined as the site with the minimum interval between the stimulus and HB potential when pace mapping in the right atrial septum. RESULTS: The A-FP was 7.9 ± 7.5 mm inferior and 2.9 ± 5.0 mm posterior to the HB. In 6 of 18 patients (33%), the A-FP was inferiorly dislocated >10 mm to the HB. SP ablation was successfully performed in all patients at sites >10 mm from both the HB and the A-FP without AV block. In the inferiorly dislocated A-FP group, A-FPs seemed to be positioned much more on atrial sites and sufficiently posterior to SP ablation sites. CONCLUSIONS: The A-FP inferiorly dislocated >10 mm to the HB in one third of patients with AVNRT and seemed to be positioned deep on atrial sites. It is again emphasized that SP ablation within the triangle of Koch should be performed at a very ventricular annulus site, particularly in the inferiorly dislocated A-FP group.

Utility of virtual unipolar electrogram morphologies to detect transverse conduction block and turnaround points of typical atrial flutter.

BACKGROUND: Noncontact mapping is useful for the diagnosis of various arrhythmias. Virtual unipolar electrogram morphologies (VUEM) of the conduction block and the turnaround points, however, are not well defined. We compared the VUEM characteristics of a transverse conduction block in the posterior right atrium (RA) with those of contact bipolar electrograms obtained during typical atrial flutter (AFL). METHODS: Contact bipolar electrograms were used to map the posterior RA during typical AFL in 16 patients. Twenty points of the VUEM recorded along the block line were analyzed and compared with contact bipolar electrograms. RESULTS: Seventeen AFLs were analyzed. Fifteen AFLs showed an incomplete transverse conduction block in the posterior RA by contact bipolar mapping. A double potential on the block line corresponded to the two components of the VUEM, in which the second component showed an Rs, RS, or rS pattern. At the turnaround point, a fused double potential of the contact bipolar electrograms corresponded to a change of the second component of the VUEM from an rS to a QS morphology. Two AFLs showed a complete block line in the posterior RA. The contact bipolar electrogram showed double potentials from the inferior vena cava to the superior vena cava, whereas the second component of the VUEM remained in an unchanged Rs, RS, or rS pattern. CONCLUSION: VUEM analysis was a reliable method for identifying the posterior block line during AFL. This method may also be applicable for detecting block lines and turnaround points of circuits in other unmappable arrhythmias.

Dilated phase of hypertrophic cardiomyopathy caused by Fabry disease with atrial flutter and ventricular tachycardia.

We describe a case of a 60-year-old male with dilated phase of hypertrophic cardiomyopathy caused by Fabry disease. He was diagnosed to have a cardiac variant of Fabry disease by an enzyme assay and a right ventricular endomyocardial biopsy which revealed specific features of this disease and cardiac involvement was the sole manifestation. He has developed dilated cardiomyopathy with sustained atrial flutter and frequent non-sustained ventricular tachycardia requiring isthmus ablation and cardiac resynchronization therapy with defibrillator.

Upper turnover portion of the reentry circuit for typical and reverse typical atrial flutter.

BACKGROUND: The posteromedial right atrium (PMRA) forms a block line during typical atrial flutter (AFL). However, whether upper turnover portion exists at the anterior or posterior superior vena cava (SVC) has not been determined. METHODS: We performed right atrial mapping during AFL in 20 patients (typical AFL, n = 17; reverse typical AFL, n = 3) using an electroanatomical mapping system. RESULTS: Mean AFL cycle length was 224 +/- 20 ms and mean number of mapping points was 140 +/- 27. PMRA formed a block line during both typical and reverse AFL in all patients. However, in 16 of 17 patients mapped with typical AFL, PMRA did not extend superiorly to the orifice of the SVC and AFL wave propagated between the upper limit of the PMRA and the posterior SVC. In the remaining patient mapped with typical AFL, a double potential was recorded along the PMRA continuously between the orifices of the inferior vena cava (IVC) and SVC. In the three patients mapped with reverse typical AFL, a posterior barrier was detected from IVC to the upper limit of the PMRA and AFL wave propagated between the upper limit of the PMRA and the posterior SVC. Mean length from IVC to upper limit of the PMRA was 81 +/- 8% of the length from IVC to SVC. CONCLUSIONS: PMRA forms a functional block line during both typical and reverse typical AFL. The upper turnover portion of reentry circuit for AFL was observed between the upper limit of the PMRA and the posterior SVC in the majority of isthmus-dependent AFL patients.

Endocardial substrate mapping for monomorphic ventricular tachycardia ablation in ischemic and non-ischemic cardiomyopathy.

We investigated the differences in the endocardial substrates between ischemic cardiomyopathy (ICM) and non-ICM (NICM) by using electro-anatomical mapping and pace-mapping. We studied 18 patients (ICM and NICM, 9 each) with monomorphic ventricular tachycardia (VT) documented by 12-leads ECG. Low voltage area was defined by signal amplitude <1.5 mV. A pace-map QRS morphology that matched VT in >10 of the 12-leads ECG was regarded as a pace-map match. And conduction delay during pace-mapping was defined as the stimulus to QRS interval >or=40 ms. Low voltage area was 53.8 +/- 21.5 and 20.8 +/- 16.7 cm2 in ICM and NICM patients, respectively (P = 0.002). Pace-mapping was assessed in 6 ICM and 9 NICM. Pace-map match with conduction delay were obtained in all the 6 ICM patients. But in NICM patients, pace-map match with conduction delay was obtained in 3 patients. Pace-map match sites where conduction delay was not observed were obtained in 5 patients. Pace-map match could not be obtained in 1 patient. We attempted ablation in 6 ICM and 7 NICM patients. Subsequently, VT recurrence was not observed in ICM but it was observed in 6 of 7 NICM patients (log-rank P = 0.0016). In NICM patients, the arrhythmogenic substrate that represented the abnormal electrogram and conduction delay was observed less within the endocardial surface when compared with that observed in ICM. VT recurrence rate subsequent to endocardial ablation was higher in NICM than in ICM patients.

Identification of the right ventricular pacing site for cardiac resynchronization therapy (CRT) guided by electroanatomical mapping (CARTO).

BACKGROUND: The optimal left ventricle (LV) pacing site for cardiac resynchronization therapy (CRT) has been investigated, but less is known about the optimal site in the right ventricle (RV). The present study examined whether electrical resynchronization guided by electroanatomical mapping (CARTO) results in mechanical resynchronization. METHODS AND RESULTS: The study group included 13 patients indicated for CRT: 10 with nonischemic cardiomyopathy, 2 with ischemic cardiomyopathy and 1 with cardiac sarcoidosis, (mean LV ejection fraction: 32+/-10%). CARTO of the RV septum was performed to identify the site with the most delayed conduction time during LV pacing. Hemodynamic measurements were performed during conventional biventricular pacing with the RV apex and LV (C-BVP) and during biventricular pacing with the most delayed site of the RV (d-RV) and LV (D-BVP). Lead placement at 15 coronary sinus veins was examined in the 13 patients. During pacing from anterolateral veins (n=2), the d-RV was the RV apex (RVA) in 1 patient and the mid-septum in the other. During pacing from lateral veins (n=9), the d-RV comprised the RVA (n=3), the mid-septum (n=5), and the right ventricular outflow tract (RVOT) (n=1). During pacing from the posterolateral veins (n=3), the d-RV was the RVOT in all cases. In 11 of 15 sites, d-RV differed from conventional RVA. Compared with C-BVP, D-BVP produced a significant improvement in LV dp/dt. Furthermore, RV mid-septum and LV pacing markedly increased LV dp/dt and pulse pressure (PP), but RVOT and LV pacing did not. D-BVP vs C-BVP: %LV dp/dt 30+/-20 and 15+/-15%, p<0.05; RV mid-septum and LV pacing vs C-BVP: %LV dp/dt 35+/-20 and 10+/-15%, p<0.02, and vs PP 33+/-20 and 10+/-29 mmHg, p<0.02. CONCLUSIONS: For pacing from the LV lateral vein, potential improvement of cardiac performance compared with that by conventional RVA placement may be realized with concomitant pacing from the d-RV (mid-septum).