Yasuyo Taniguchi

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

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.

The incidence of discrepant regional myocardial uptake between 201 thallium and 123 I-BMIPP SPECT in patients with coronary heart disease

Myocardial perfusion and fatty acid uptake at rest were assessed by SPECT with 201Tl (Tl) and 123I-BMIPP (BMIPP) in 50 consecutive patients with coronary heart disease. Discrepant regional myocardial uptake was observed in 19 patients and classified into the following two groups: mismatch (MM; Tl uptake > BMIPP uptake, n = 14, mean age, 66 years) and paradoxical mismatch (PM; Tl uptake < BMIPP uptake, n = 5, mean age, 68 years). In the MM group, 77% was single- or zero-vessel disease and the artery-perfused region in the mismatched area was almost always ischemia related. Sixty percent of the regions observed with the PM were related to the inferior wall. In the PM group, 80% of cases were associated with multivessel stenoses and 60% of cases was suffered from ischemic attack within a week before scintigraphy. In conclusion, mismatch was related to abnormal fatty acid uptake caused by coronary heart disease. Although the paradoxical mismatch might mainly be related to diaphragmatic attenuation of Tl scans and augmented artifacts of BMIPP scans in the inferior wall, we should not overlook severe coronary heart disease in patients with paradoxical mismatched phenomenon.

Longitudinal strain combined with delayed-enhancement magnetic resonance improves risk stratification in patients with dilated cardiomyopathy

Objective Late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging has been reported to be associated with unfavourable outcomes; however, few studies have addressed the prognostic value of left ventricular (LV) deformation parameter indicated by global longitudinal strain (GLS) in two-dimensional speckle-tracking (2DST) echocardiography in patients with non-ischaemic dilated cardiomyopathy (DCM). This study aims to investigate whether the combination of GLS and LGE is useful in stratifying the risk in patients with DCM. Methods We studied 179 consecutive symptomatic patients with DCM (age, 61±15 years; 121 males; left ventricular ejection fraction (LVEF) 33%±9%; New York Heart Association (NYHA) class II: n=71, III: n=107, IV: n=1) who underwent CMR and echocardiography with conventional assessment and 2DST analysis. Results There were 40 rehospitalisations for heart failure, including 7 cardiac deaths and 2 implantations of LV assist device during follow-up (3.8±2.5 years). Univariable Cox proportional hazard regression analysis showed that NYHA class, blood pressure, B-type natriuretic peptide, LV end-diastolic and end-systolic volumes, LVEF, left atrium volume, GLS and LGE were significantly associated with long-term outcome. Multivariable analysis revealed that GLS and LGE were independently associated with long-term outcome (p<0.05, both). In additional analyses, we found independent associations between GLS and LV reverse remodelling after the optimal medical therapy, and between LGE and life-threatening arrhythmias (p<0.05, both). Conclusion Combining GLS and LGE could be useful for risk stratification and prognostic assessment in patients with DCM.

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

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/m2) 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/m2.

Visualizing radiofrequency lesions using delayed-enhancement magnetic resonance imaging in patients with atrial fibrillation: A modification of the method used by the University of Utah group

Atrial tissue fibrosis has previously been identified using delayed‐enhancement MRI (DE‐MRI) in patients with atrial fibrillation (AF). Although the clinical importance of DE‐MRI is well recognized, the visualization of atrial fibrosis and radiofrequency (RF) lesions has still not been achieved in Japan, primarily because of the differences in contrast agents, volume‐rendering tools, and technical experience. The objective of this study was to visualize RF lesions by using commercially available tools.

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

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.

Acquisition of the pulmonary venous and left atrial anatomy with non-contrast-enhanced MRI for catheter ablation of atrial fibrillation: Usefulness of two-dimensional balanced steady-state free precession

Usually, the pulmonary venous and left atrial (PV–LA) anatomy is assessed with contrast‐enhanced computed tomographic imaging for catheter ablation of atrial fibrillation (AF). A non‐contrast‐enhanced magnetic resonance (MR) imaging method has not been established. Three‐dimensional balanced steady‐state free precession (3D b‐SSFP) sequences cannot visualize the PV–LA anatomy simultaneously because of the signal intensity defect of pulmonary veins. We compared two‐dimensional (2D) b‐SSFP sequences with 3D b‐SSFP sequences in depicting the PV–LA anatomy with non‐contrast‐enhanced MR imaging for AF ablation.

Comparison of conventional and cadmium–zinc–telluride single-photon emission computed tomography for analysis of thallium-201 myocardial perfusion imaging: an exploratory study in normal databases for different ethnicities

The aim of this study was to clarify the differences in thallium-201–chloride (thallium-201) myocardial perfusion imaging (MPI) scans evaluated by conventional anger-type single-photon emission computed tomography (conventional SPECT) versus cadmium–zinc–telluride SPECT (CZT SPECT) imaging in normal databases for different ethnic groups. MPI scans from 81 consecutive Japanese patients were examined using conventional SPECT and CZT SPECT and analyzed with the pre-installed quantitative perfusion SPECT (QPS) software. We compared the summed stress score (SSS), summed rest score (SRS), and summed difference score (SDS) for the two SPECT devices. For a normal MPI reference, we usually use Japanese databases for MPI created by the Japanese Society of Nuclear Medicine, which can be used with conventional SPECT but not with CZT SPECT. In this study, we used new Japanese normal databases constructed in our institution to compare conventional and CZT SPECT. Compared with conventional SPECT, CZT SPECT showed lower SSS (p < 0.001), SRS (p = 0.001), and SDS (p = 0.189) using the pre-installed SPECT database. In contrast, CZT SPECT showed no significant difference from conventional SPECT in QPS analysis using the normal databases from our institution. Myocardial perfusion analyses by CZT SPECT should be evaluated using normal databases based on the ethnic group being evaluated.

Visualization of the radiofrequency lesion after pulmonary vein isolation using delayed enhancement magnetic resonance imaging fused with magnetic resonance angiography.

The radiofrequency (RF) lesions for atrial fibrillation (AF) ablation can be visualized by delayed enhancement magnetic resonance imaging (DE‐MRI). However, the quality of anatomical information provided by DE‐MRI is not adequate due to its spatial resolution. In contrast, magnetic resonance angiography (MRA) provides similar information regarding the left atrium (LA) and pulmonary veins (PVs) as computed tomography angiography. We hypothesized that DE‐MRI fused with MRA will compensate for the inadequate image quality provided by DE‐MRI.

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.