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We modeled the Qfix Encompass™ immobilization system and further verified the calculated dose distribution of the AcurosXB (AXB) dose calculation algorithm using SRS MapCHECKⓇ (SRSMC) in the HyperArc™ (HA) clinical plan. An Encompass system with a StereoPHAN™ QA phantom was scanned by SOMATOM go.Sim and imported to an Eclipse™ treatment planning system to create a treatment plan for Encompass modeling. The Encompass modeling was performed in the StereoPHAN with a pinpoint ion chamber for 6 MV and 6 MV flattening filter free (6 MV FFF), and 2 × 2 cm2, 4 × 4 cm2, and 6 × 6 cm2 irradiation field sizes. The dose calculation algorithm used was AXB ver. 15.5 with a 1.0 mm calculation grid size. The Hounsfield unit (HU) values of the Encompass modeling were set to 400, −100, −200, and −300 for Encompass, and −400, −600, −700, and −800 for the Encompass base. We evaluated the dose distribution after Encompass modeling by SRSMC using gamma analysis in 12 patients. We adopted HU values of −200 for Encompass, −800 for Encompass base for 6 MV, and −200 for Encompass and −700 for Encompass. Base for 6 MV FFF was adopted as the HU values for the Encompass modeling based on the measurement results. The proposed Encompass modeling resulted in a mean pass rate evaluation >98% for both 6 MV and 6 MV FFF when the 1%/1 mm criterion was used, demonstrating that the proposed HU value can be adopted to calculate more accurate dose distributions. [ABSTRACT FROM AUTHOR]

Endocardial catheter ablation of ventricular arrhythmias (VAs) originating from the left ventricular summit (LVS) at remote structures adjacent to the LVS may be an alternative (anatomic approach) but may not be so successful. This type of catheter ablation is successful most commonly in the left ventricular outflow tract followed by the aortic cusps and rarely in the right ventricular outflow tract. A right bundle branch block QRS morphology and anatomic distance between the earliest ventricular activation site in the coronary venous system and endocardial ablation site (<13 mm) could be predictors of a successful endocardial catheter ablation of LVS VAs. [ABSTRACT FROM AUTHOR]

Idiopathic ventricular arrhythmias (VAs) most commonly originate from the ventricular outflow tracts. Because the anatomy of this region is complex and some of those VA origins are intramural and epicardial, it may sometimes be difficult to locate the site of the VA origin. Meticulous mapping in multiple different locations such as the right and left ventricular outflow tracts, endocardial and epicardial sites, and above and below the aortic and pulmonic valves may be required to achieve successful catheter ablation of those VAs. Special ablation techniques may be considered to improve the outcome of catheter ablation of intramural and epicardial VAs. [ABSTRACT FROM AUTHOR]

In this paper, we extend a piezoelectric and laser ultrasonic system (PLUS) to a high-frequency version for high-sensitivity three-dimensional (3D) ultrasonic imaging by utilizing a unique characteristic of PLUS. PLUS combines a piezoelectric transmitter and a two-dimensional (2D) scan of a laser Doppler vibrometer (LDV). A high frequency can be used simply by adopting a high-frequency piezoelectric transmitter with a center frequency, such as 15 MHz, since the LDV has a broad bandwidth reception of 0–25 MHz. Furthermore, a 2D array receiver with a small interelement pitch can be achieved by precisely scanning a small laser irradiation spot. We experimentally demonstrate its 3D imaging capability for flat-bottom-hole and fatigue-crack specimens. [ABSTRACT FROM AUTHOR]

The structure and properties of a thermoplastic polyester elastomer (TPEE) containing a small amount of poly(butylene terephthalate) (PBT) were investigated by focusing on the residual crystals in the molten state. When the pure TPEE was extruded at a slightly higher temperature than its melting point, the crystallization rate increased. This phenomenon has been called the melt memory effect and has been attributed to unmolten crystals that act as nuclei. The addition of PBT widened the temperature range of the melt memory effect, because PBT crystals were present at the higher temperatures. Moreover, the addition of PBT induced phase separation, leading to a decrease in the dissolution of hard segments in the soft matrix. As a result, the glass transition temperature of the soft matrix decreased. Furthermore, the modulus at room temperature increased with good rubber elasticity. [Display omitted] • Melt memory effect of a thermoplastic polyester elastomer (TPEE) was investigated. • The addition of PBT widened the temperature range that showed melt memory effect. • Tg shifted to low temperature owing to well-developed phase separation. • The modulus of strands increased by the melt memory effect. [ABSTRACT FROM AUTHOR]

Idiopathic ventricular arrhythmias (VAs) are ventricular tachycardias (VTs) or premature ventricular contractions (PVCs) whose mechanisms are not related to myocardial scar. Idiopathic VAs occur most commonly without structural heart disease, but can occur with structural heart disease. Imaging tests, such as echocardiography, nuclear test, and cardiac magnetic resonance imaging, are helpful for excluding any association of an idiopathic VA occurrence with myocardial scar. Since catheter ablation emerged, the sites of idiopathic VA origins, commonly endocardial but sometimes epicardial, have been increasingly recognized. Idiopathic VAs usually originate from specific anatomical structures, and exhibit characteristic electrocardiograms based on their anatomical background. Idiopathic VAs are basically benign, but they require medical treatment or catheter ablation when idiopathic VAs are symptomatic, incessant, or produce left ventricular dysfunction. This review describes the up-to-date information on the prevalence of idiopathic VA origins relevant to the anatomy, and diagnosis, and treatment of idiopathic VAs. [ABSTRACT FROM AUTHOR]

Highlights from the article: Considering the duration of the radiation exposure, electrical interference of over a breath cycle for an average CT could impose a risk on a CIED patient, although that with a helical CT is unlikely. 21 Pan T, Lee TY, Rietzel E, Chen GT. 4D-CT imaging of a volume influenced by respiratory motion on multi-slice CT. Med Phys. 23 Pan T, Mawlawi O, Luo D. Attenuation correction of PET cardiac data with low-dose average CT in PET/CT. Med Phys.

Background: Despite cardiac resynchronization therapy (CRT), some patients with heart failure progress and undergo left ventricular assist device (LVAD) implantation. Management of CRT after LVAD implantation has not been well studied. The purpose of this study was to determine whether RV pacing or biventricular pacing measurably affects acute hemodynamics in patients with an LVAD and a CRT device.Methods and Results: Seven patients with CRT and LVAD underwent right heart catheterization. Pressures and oximetry were measured and LVAD parameters were recorded during 3 different conditions: RV pacing alone, biventricular pacing, and intrinsic atrioventricular conduction. Paired t tests were used to evaluate changes within subjects. There were no significant changes in right atrial pressure, pulmonary arterial pressures, pulmonary capillary wedge pressure, cardiac index, or any LVAD parameter (P > .05).Conclusions: Our data suggest that CRT probably has no acute hemodynamic effect in patients with LVADs, but further study is needed. [ABSTRACT FROM AUTHOR]

Background: Idiopathic ventricular arrhythmias (VAs) can be rarely ablated from the noncoronary cusp (NCC) of the aorta. Objective: The purpose of this study was to investigate the prevalence and the clinical, electrocardiographic, and electrophysiologic characteristics of idiopathic NCC VAs. Methods: We studied 90 consecutive patients who underwent successful catheter ablation of idiopathic aortic root VAs (left coronary cusp [LCC] 33, right coronary cusp [RCC] 32, junction between LCC and RCC 19, NCC = 6). Results: NCC VAs occurred in significantly younger patients (all <40 years old) and exhibited a shorter QRS duration (all but one <150 ms), smaller R-wave amplitude ratio in leads II and III (III/II), earlier ventricular activation in the His bundle (HB) region (all but one preceded QRS onset by >25 ms), and larger atrial to ventricular electrogram amplitude ratio (A/V) at the successful ablation site (all but one >1) than the other VAs. QRS morphology of the NCC VAs was similar to that of RCC VAs, but NCC VAs always exhibited a left bundle branch block and left superior (n = 1) or inferior axis (n = 5). All NCC VAs exhibited ventricular tachycardias, although premature ventricular contractions were dominant in the other VAs. Conclusion: NCC VAs were very rare (7%) and occurred in significantly younger patients than those among the other aortic root VAs. In a limited set of six patients, the ECG and electrophysiologic characteristics of NCC VAs were similar to those of RCC VAs but were characterized by narrower QRS duration, smaller III/II ratio, earlier ventricular activation in the HB region, and A/V ratio >1 at the successful ablation site. [Copyright &y& Elsevier]

Abstract: We report a case of a 28-year-old man with a complete C5 level spinal cord injury who developed persistent redness over his ischial tuberosities due to his wheelchair cushion cover''s hammock effect. He had purchased wheelchairs and cushions in 2004 and 2008. Persistent redness occurred over his ischial tuberosities when using the second cushion purchased in 2008. Pressure mapping did not detect any differences in pressure over the ischial tuberosities with different cushions. When comparing cushions without their covers, we noticed that the first cushion had a greater air volume than the second cushion. We exchanged the cushion covers to evaluate the hammock effect due to different covers. We found that the redness occurred at any time the second cushion cover was used. After the patient''s family changed the top of the second cushion cover to a more elastic material, the redness resolved. As we were unable to detect the influence of the hammock effect using pressure mapping, it would be useful to develop an alternative method to evaluate this phenomenon. It would also be valuable to find a readily available solution for other patients experiencing this problem. [ABSTRACT FROM AUTHOR]

Background: Because sudden cardiac death increases with age, implantable cardioverter-defibrillators (ICDs) might greatly benefit the elderly. However, elderly patients are underrepresented in clinical trials, and comorbid conditions may attenuate benefit. Objective: The purpose of this study was to examine ICD prescription in the elderly. Methods: The ages, indications, and implanted ICD type of patients enrolled in the Advancements in ICD Therapy (ACT) Registry were compared to those from the National Cardiovascular Data Registry (NCDR). Results: The ACT Registry included 4,566 patients who underwent first ICD or cardiac resynchronization therapy ICD (CRT-D) implantation. Among these patients, 2.6% were 18–39 years old, 8.6% were 40–49 years, 20.1% were 50–59 years, 27.6% were 60–69 years, 29.0% were 70–79 years, and 12.0% were ≥80 years. In the six age groups, 82.5%, 79.4%, 77.3%, 80.1%, 77.7%, and 74.6% received devices for primary prevention, and single-chamber ICDs were implanted in 41.4%, 42.8%, 38.7%, 33.8%, 25.2%, and 28.1%, respectively (P <.0001). Two-year mortality rates increased incrementally from 5.80% to 17.80% in the six groups (P <.05). Noncardiac death was more common in older than in younger patients. Among patients ≥80 years old receiving a CRT-D, 78% had QRS duration and New York Heart Association class that met accepted implantation criteria. Age distribution, indication, and type of device were similar in the ACT Registry and in 74,476 patients in the NCDR. Conclusion: More than 40% of new ICDs and CRT-Ds are implanted in patients >70 years old and more than 10% in patients ≥80 years old. A significant proportion of those receiving a CRT-D did not fulfill accepted criteria for implantation. Noncardiac death occurred more frequently in older patients, but cardiac death rates were similar. [Copyright &y& Elsevier]

An appropriate processing protocol was proposed to improve the rubber elasticity of a thermoplastic polyester elastomer (TPEE). Rheology measurements at the processing temperature and thermal measurements determined the critical temperature at which small numbers of crystals exist. It was found from dynamic mechanical analyses, wide- and small-angle X-ray measurements, and electron microscope observations that cooling from the critical temperature markedly promoted the crystallization of hard segments. Moreover, tensile tests revealed that the modulus and yield stress increased. Most importantly, compared with films obtained by cooling from high temperatures, the residual strain at a fixed stress was low—i.e., the rubber elasticity was improved owing to its well-developed crystalline structure. These effects were accelerated by a more optimized process—i.e., subsequent heating at slightly below the critical temperature. The technique is noteworthy because a TPEE with high modulus generally shows poor elasticity. [Display omitted] • The rubber elasticity of a thermoplastic polyester elastomer (TPEE) was evaluated. • Melt processing was available for the TPEE at 220 °C, although it had a few crystals. • The crystals at 220 °C acted as nuclei, leading to well-developed crystalline structure. • The effect was accelerated by the 2nd heating process at 200 °C. • The well-developed crystals were responsible for improvement of rubber elasticity. [ABSTRACT FROM AUTHOR]

Background: Idiopathic ventricular tachycardia (VT) can arise from the epicardium, usually near the summit of the left ventricle (LV). Objective: The purpose of this study was to describe a distinct syndrome of epicardial VT that arises from the crux of the heart. Methods: Among 340 patients with idiopathic VT referred for ablation, four were identified with VT that was mapped to the epicardium at the crux. Results: VT was sustained in all patients and was associated with syncope or presyncope in three. Rapid VT (mean cycle length 264 ms) was induced with programmed stimulation or burst pacing from the ventricle but required isoproterenol infusion in three. ECG during VT demonstrated a left superior axis QRS morphology with a precordial maximal deflection index ≥0.55 in all patients (mean 0.61). Intracardiac mapping revealed earliest activation in the middle cardiac vein or proximal coronary sinus at the crux in all patients. Irrigated radiofrequency ablation in the middle cardiac vein or proximal coronary sinus was attempted in all patients and successfully abolished VT in one. Percutaneous epicardial radiofrequency ablation was attempted in 2 of 3 remaining patients and successfully abolished VT in both. Simultaneous coronary angiography demonstrated the site of earliest activation within 5 to 10 mm of the proximal posterior descending coronary artery, with no acute narrowing of that artery following ablation. Conclusion: Idiopathic VT may arise by a focal mechanism from the epicardium at the crux in close proximity to the posterior descending coronary artery. This syndrome can result in rapid, catecholamine-sensitive VT and requires careful attention to the posterior descending coronary artery during ablation. [Copyright &y& Elsevier]

Objectives: This study investigated the prevalence and electrocardiographic and electrophysiologic characteristics of aortic root ventricular arrhythmias (VAs). Background: Idiopathic VAs originating from the ostium of the left ventricle may be ablated at the base of the aortic cusps. Methods: We studied 265 patients with idiopathic VAs with an inferior QRS-axis morphology. Results: The successful ablation site was within (or below) the aortic cusps in 44 patients (16.6%). The site of the origin was the left coronary cusp (LCC) in 24 (54.5%), the right coronary cusp (RCC) in 14 (31.8%), the noncoronary cusp (NCC) in 1 (2.3%), and at the junction between the LCC and RCC (L-RCC) in 5 (11.4%) cases. The maximum amplitude of the R-wave in the inferior leads was significantly greater with an LCC than with an RCC origin (p < 0.05). The ratio of the R-wave amplitude in leads II and III was significantly greater with an LCC than with an RCC origin (p < 0.01) and was significantly smaller in the NCC than in the other sites (p < 0.0001). The ventricular deflection in the His bundle electrogram was significantly later relative to the surface QRS with an LCC or L-RCC origin than with an RCC or NCC origin (p < 0.0001). The ratio of the atrial-to-ventricular deflection amplitude was significantly greater in the NCC than in the other sites (p < 0.0001). No other factors predicted the site of origin. Conclusions: Idiopathic VAs are more common in the LCC than in the RCC and rarely arise from the NCC. The electrocardiogram is useful for differentiating the site of origin. [Copyright &y& Elsevier]

Abstract: A 53-year-old man with a ventricular tachycardia (VT) electrical storm during the chronic phase of an extensive anteroseptal myocardial infarction underwent electrophysiologic testing and catheter ablation. An electroanatomical map during 7 induced macroreentrant VTs demonstrated multiple centrifugal endocardial activations from sites that were located at the circumferential border zone of a large scar area. Interestingly, during the radiofrequency catheter ablation of 4 of the VTs, the elimination of the substrate of the previous VTs converted one VT to another probably because those VTs might have shared a central common pathway of the macroreentrant circuit with different exits. [Copyright &y& Elsevier]

Abstract: It has been demonstrated that most paroxysmal atrial fibrillation (AF) is triggered by ectopic beats originating from the pulmonary veins (PVs). It has been recently reported that some AF episodes are maintained by focal drivers and AF substrates in the PVs and atrium. Left atrial ablation combined with PV isolation targeting AF triggers and drivers may be effective for eliminating atrial arrhythmias. However, multiple AF drivers in the PVs and atrium and acute conduction recovery after the PV isolation may sometimes render that technique less reliable. In this article, we describe the current status of the catheter ablation of focal triggers and drivers of AF in the PVs and atrium, illustrating with case presentations. [Copyright &y& Elsevier]

Background: Ventricular arrhythmias (VAs) may arise from the aortic sinuses and have electrocardiographic and electrophysiological characteristics that suggest a left (LCC) or right coronary cusp (RCC) origin. However, VAs that arise near the junction of those two cusps (L-RCC) may have unusual features. Objectives: The purpose of this study was to examine the electrocardiographic and electrophysiological characteristics of VAs arising from the L-RCC. Methods: We studied 155 patients with idiopathic VAs with either left or right bundle branch block and an inferior QRS axis morphology and five control subjects undergoing a pacing study. Results: For 146 of the 155 patients, the origin determined by the successful ablation site was at the L-RCC in five, LCC in 13, RCC in six, non–coronary cusp in two, right ventricular outflow tract in 108, left ventricular outflow tract in five, left ventricular epicardium in four, and pulmonary artery in three. A qrS pattern in leads V1–V3 was observed only in the VAs with an L-RCC origin. The propagation map revealed that the direction of the propagating wave front from the L-RCC origin produced a vector compatible with a q wave and that the anterior activation to the right ventricular outflow tract via the LCC or RCC formed the r wave. Pacing performed at multiple sites in the aortic root in the control subjects demonstrated that only pacing from the L-RCC could reproduce a qrS pattern in leads V1–V3. Conclusions: This study revealed that a qrS pattern in leads V1–V3 suggests a site of origin at the L-RCC. [Copyright &y& Elsevier]

Background: There is a close anatomical relationship between the right coronary cusp (RCC) and noncoronary aortic cusp (NCC) and sites recording His bundle (HB) activation in the right ventricle (RV). Objective: The purpose of this study was to examine the electrocardiographic and electrophysiological characteristics of ventricular arrhythmias (VAs) that originate near the HB and their potential as predictors of successful catheter ablation sites. Methods: We studied 147 consecutive patients undergoing successful catheter ablation of idiopathic VAs originating from the ventricular outflow tract of either ventricle or the HB region. Results: In 13 (9%) patients with an origin in the RCC (n = 5), NCC (n = 1), or RV HB region (n = 7), the local RV activation in the HB region preceded the QRS onset. In two VAs originating from the RCC or NCC, failed radiofrequency applications near the HB region in the RV delayed the near-field ventricular electrogram and separated the far-field electrograms before the QRS onset in the HB region. The QRS transition in the precordial leads did not discriminate between an RV origin near the HB and an NCC or RCC origin. A QS pattern in lead aVL might be helpful for predicting an RCC origin. Conclusions: VAs originating near the HB have similar electrocardiographic and electrophysiological characteristics, regardless of whether the ablation site is in the RV or aortic sinuses because of the close anatomical relationship of these structures and rapid transseptal conduction. When RV mapping reveals an earliest ventricular activation in the HB region during VAs, mapping in the RCC and NCC should be added to accurately identify the site of origin. [Copyright &y& Elsevier]

Background: The left atrial appendage (LAA) is one of the major sources of focal atrial tachycardias (ATs).Objective: The purpose of this study was to investigate the detailed electrophysiologic characteristics and catheter ablation of focal ATs originating from the LAA.Methods: The study population consisted of 47 consecutive patients with 50 focal ATs originating from the left atrium (LA): LAA in 13, left pulmonary veins (PVs) in 14, right PVs in 12, and mitral annulus in 11. Programmed electrical stimulation and pharmacologic testing were performed to examine the mechanism of LAA AT. Left atriography was performed prior to radiofrequency ablation to identify the focus in the LAA.Results: The mechanism of LAA AT was automaticity in 11 and triggered activity in 2. The 13 LAA foci were located mainly at the LAA base: 11 on the medial side and 2 on the lateral side. Atrial activation sequences within the distal coronary sinus were helpful in differentiating these LAA foci. The criterion of a negative P wave in leads I and aVL indicating an LAA AT focus was associated with sensitivity of 92.3%, specificity 97.3%, positive predictive value 92.3%, and negative predictive value 97.3%. No complications occurred in any of the 13 patients. All 13 patients were free of atrial arrhythmias without any antiarrhythmic drugs during follow-up of 8 +/- 3 years.Conclusion: LAA ATs have typical electrophysiologic and electrocardiographic characteristics that are helpful in guiding radiofrequency catheter ablation. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to examine the relationship between the origin and breakout site of idiopathic ventricular tachycardia (VT) or premature ventricular contractions (PVCs) originating from the myocardium around the ventricular outflow tract. Background: The myocardial network around the ventricular outflow tract is not well known. Methods: We studied 70 patients with idiopathic VT (n = 23) or PVCs (n = 47) with a left bundle branch block and inferior QRS axis morphology. Electroanatomical mapping was performed in both the right ventricular outflow tract (RVOT) and aortic sinus cusp (ASC) during VT or PVCs. Results: The earliest ventricular activation (EVA) was recorded in the RVOT in 55 patients (group R) and in the ASC in 15 (group A). In all group R patients, the closest pace map and successful ablation were achieved at the EVA site. Although a successful ablation was achieved at the EVA site in all group A patients, the closest pace map was obtained at the EVA site in 8 and RVOT in 7 (with an excellent pace map in 4). The stimulus to QRS interval was 0 ms during pacing from the RVOT and 36 ± 8 ms from the ASC. The distance between the EVA and perfect pace map sites in those 4 patients was 11.9 ± 3.0 mm. Conclusions: Ventricular arrhythmias originating from the ASC often show preferential conduction to the RVOT, which may render pace mapping or some algorithms using the electrocardiographic characteristics less reliable. In some of those cases, an insulated myocardial fiber across the ventricular outflow septum may exist. [Copyright &y& Elsevier]

Objectives: The aim of this study was to investigate the prevalence and severity of left atrial (LA) edema after pulmonary vein (PV) ablation and its effect on the cardiac function. Background: Though extensive LA catheter ablation has been demonstrated to be more effective in curing paroxysmal atrial fibrillation (PAF) than segmental ostial pulmonary vein isolation (S-PVI), it might cause life-threatening complications, including congestive heart failure associated with LA edema. Methods: Fifty patients underwent S-PVI (Group S) and 27 underwent circumferential PV antrum ablation (Group C) for drug-refractory PAF. Enhanced electron beam tomography (EBT) was performed before, 1 or 2 days after, and 1 month after the PV ablation, and transthoracic ultrasound cardiography (UCG) was performed 1 month after the PV ablation in all patients. Results: The EBT assessment revealed LA edema immediately after the PV ablation in 47 Group S patients and all Group C patients. The severity of the LA edema, number of radiofrequency applications, and amount of radiofrequency energy delivered during the PV ablation was significantly greater in Group C than in Group S. One month after the PV ablation, in all patients, the EBT assessment revealed that those edematous changes had disappeared, and the UCG assessment showed no reduction in the cardiac function. Conclusions: Left atrial edema was observed in a large portion of the patients immediately after the PV ablation, and the severity of the LA edema depended on the extent and amount of the radiofrequency energy delivered in the PV ablation. The LA edema soon disappeared naturally and did not reduce the cardiac function. [Copyright &y& Elsevier]

It has been reported that plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels are elevated in patients with atrial fibrillation (AF). The aim of this study was to investigate the change in these patients after pulmonary vein isolation (PVI). In 66 patients with paroxysmal AF (PAF) and without any structural heart disease, plasma ANP and BNP levels were measured before and 3 months after successful PVI. At baseline, in 14 patients, ANP and BNP levels were elevated, and in 52 patients, only BNP levels were elevated. There were no significant relations between the attack frequency or the duration of PAF episodes and ANP or BNP levels. Neither ANP nor BNP level at baseline was a valid predictor of AF recurrence. Even in 31 patients (47%) with recurrent PAF, attacks of PAF were significantly reduced. In 66 patients with elevated ANP and/or BNP levels at baseline, levels were significantly reduced after PVI independent of PAF recurrence (ANP: 69.0 ± 23.0 vs 25.0 ± 7.7 pg/ml, p <0.0001; BNP: 58.4 ± 50.7 vs 22.5 ± 27.1 pg/ml, p <0.0001). In 42 patients without AF recurrences, ANP and BNP levels were reduced to within the normal range. In conclusion, in patients with PAF without any structural heart disease, ANP and/or BNP levels were elevated. In those patients, relief of the AF burden by successful PVI significantly reduced elevated plasma ANP and BNP levels. [Copyright &y& Elsevier]

To avoid fatal complications after extensive pulmonary vein (PV) ablation, it has been proved important to comprehend the anatomic relation between the PVs and the esophagus. In 42 consecutive patients with atrial fibrillation, PV ostial isolation was performed using a basket catheter. The shortest distance and anatomic relation between the esophageal lead and PV ostium, determined by successful PV ostial isolation, was analyzed in biplane fluoroscopic views. In 18 left superior PVs (LSPVs) (43%), 13 left inferior PVs (32%) (LIPVs), and all the right PVs (group A), the shortest distance was >10 mm in ≥1 of the biplane fluoroscopic views. In 4 LSPVs (10%) and 2 LIPVs (5%) (group B), the shortest distance was ≤5 mm in the fluoroscopic views. In the remaining PVs (group C), the esophagus was situated directly behind 10 LSPVs (24%) and 12 LIPVs (29%) (group C1), posteromedial to 1 LSPV (2%) and 9 LIPVs (22%) (group C2), and medial to 9 LSPVs (21%) and 5 LIPVs (12%) (group C3). The risk of esophagus-associated complications with ablation around the left PV ostia was suggested to be high in group B, very low in group A, and relatively low in group C. In group C3, extensive PV ablation might increase the risk of that complication. In conclusion, esophageal leads are useful for determining strategies for PV ablation to avoid esophagus-associated complications, because they enable comprehension of the anatomic relation between the PVs and the esophagus. [Copyright &y& Elsevier]

Background: How extensive should an appropriate pulmonary vein (PV) ablation be is a matter of controversy.Objective: The study's aim was to investigate the efficacy of minimally extensive PV ablation for isolating the PV antrum (PVA) with the guidance of electrophysiological parameters.Methods: Fifty-five consecutive symptomatic paroxysmal atrial fibrillation (PAF) patients underwent PV mapping with a multielectrode basket catheter (MBC). A 31-mm MBC was deployed in 3-4 PVs as proximally as possible without dislodgement, and the longitudinal PV mapping enabled us to recognize single sharp potentials formed by the total fusion of the PV and left atrial potentials around the PV ostium or the transverse activation patterns that were observed. Those potentials were defined as PVA potentials. Radiofrequency ablation was performed circumferentially targeting PVA potentials with the end point being their elimination.Results: After circumferential PVA ablation, electrical disconnection was achieved in 77% and residual PVA conduction gaps were observed in 23% of all targeted PVs. Those residual conduction gaps were mainly located at the border between ipsilateral PVs (42%) and between the left PVs and left atrial appendage (33%) and were eliminated by a mean of 3 +/- 2 minutes of local radiofrequency deliveries. During the follow-up period (11 +/- 5 months), 46 (84%) patients were free of symptomatic PAF without any anti-arrhythmic drugs. No PV stenosis or spontaneous left atrial flutter occurred.Conclusions: Electrophysiological PVA ablation with an MBC is feasible and effective for curing PAF because this minimally extensive PVA isolation technique targets the optimal sites, achieving both high efficacy and safety. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to investigate the efficacy of a novel catheter mapping technique for predicting atrial fibrillation (AF) foci.Background: Most AF originates from pulmonary veins (PVs), but some originate from the right atrium.Methods: We developed an algorithm by correlating the cardiac recordings obtained from multielectrode catheters placed in the posterior right atrium (RA) and esophagus during pacing from the PVs and superior vena cava (SVC) or crista terminalis (CT) in 10 AF patients. We tested the algorithm's accuracy prospectively in 46 AF patients.Results: During pacing from the left PVs, the esophageal potentials preceded all other potentials. During pacing from both the right PVs and SVC-CT, the first component (FP) of the double potential (DP) recorded in the posterior RA preceded all other potentials. The amplitude of the FP was higher than that of the second DP component during pacing from the SVC-CT, whereas the reverse occurred from the right PVs. The activation sequence of the FPs and esophageal potentials was from superior to inferior during pacing from the superior PVs, whereas the reverse occurred from the inferior PVs. The accuracy of predicting 34 foci in the right PVs, 28 foci in left PVs, and 6 foci in SVC-CT was 100% for all, respectively. The accuracy of discriminating foci in the superior PVs from those in the inferior PVs was 97% in the right PVs and 96% in the left PVs.Conclusions: The technique using mapping catheters placed in the posterior RA and esophagus is feasible and effective for mapping and ablating AF. [ABSTRACT FROM AUTHOR]