Takaaki Komatsu

The influence of the external structures in atrial fibrillation patients: Relationship to focal low voltage areas in the left atrium.

INTRODUCTION Left atrial (LA) low voltage areas (LVAs) are suggested as an important factor for maintaining atrial fibrillation (AF). The relationship between focal LVAs and anatomical contact is still unclear. METHODS Thirty paroxysmal AF (PAF) and 30 persistent AF (PsAF) patients underwent high density voltage mapping during sinus rhythm before any radiofrequency applications were performed. The relationship between the LVA (<0.5mV) and contact area (CoA) demonstrated by enhanced CT and the distance to near external structures were investigated. RESULTS The anterior region, posterior wall and left pulmonary vein (LPV) antrum were the three most frequent LVA sites that corresponded to CoA sites, and LVAs mostly overlapped with CoAs (PAF 47/61: 77%, PsAF 63/74: 85%). In the PAF group, patients with posterior-LVAs had a shorter distance to the vertebrae than those without (2.8 ± 1.1 vs. 4.4 ± 1.9 mm; P=0.0086). The distance to the vertebrae was the only predictive factor of the existence of a posterior-LVA and the cut-off value was ≤2.9 mm (P<0.0001). Similarly, an LPV-LVA also had the same results (2.0 ± 0.5 vs. 2.7 ± 0.8mm, P=0.0127) and the cut-off value was ≤2.6mm (P=0.0391). In contrast, the PsAF patients had no difference in the distance when compared to the existence of an LVA. CONCLUSIONS Anatomical CoAs demonstrated a spatial relationship to the LVAs in AF patients. In PAF patients, the distance to near external structures in the posterior region was a predictive factor for the existence of an LVA and may have had some influence on maintaining AF, while in PsAF patients no relationship was suggested.

Impact of Insulin Resistance on Neointimal Tissue Proliferation after 2nd-Generation Drug-Eluting Stent Implantation

Percutaneous coronary intervention is established as an effective treatment for patients with ischemic heart disease; in particular, drug-eluting stent implantation is known to suppress in-stent restenosis. Diabetes mellitus is an independent risk factor for restenosis, so reducing insulin resistance is being studied as a new treatment approach. In this prospective study, we sought to clarify the factors associated with in-stent restenosis after percutaneous coronary intervention, and we evaluated the homeostasis model assessment of insulin resistance (HOMA-IR) index as a predictor of restenosis. We enrolled 136 consecutive patients who underwent elective percutaneous coronary intervention at our hospital from February 2010 through April 2013. All were implanted with a 2nd-generation drug-eluting stent. We distributed the patients in accordance with their HOMA-IR index values into insulin-resistant Group P (HOMA-IR, ≥2.5; n=77) and noninsulin-resistant Group N (HOMA-IR, <2.5; n=59). Before and immediately after stenting, we measured reference diameter, minimal lumen diameter, and percentage of stenosis, and after 8 months we measured the last 2 factors and late lumen loss, all by means of quantitative coronary angiography. After 8 months, the mean minimal lumen diameter was smaller in Group P than that in Group N (1.85 ± 1.02 vs 2.37 ± 0.66 mm; P=0.037), and the mean late lumen loss was larger (0.4 ± 0.48 vs 0.16 ± 0.21 mm; P=0.025). These results suggest that insulin resistance affects neointimal tissue proliferation after 2nd-generation drug-eluting stent implantation.

Impact of irbesartan, an angiotensin receptor blocker, on uric acid level and oxidative stress in high-risk hypertension patients

Hyperuricemia is a known cardiovascular risk factor. The angiotensin II receptor blocker (ARB) losartan is known to decrease serum uric acid (UA) level. A recent in vitro study demonstrated a strong interaction between irbesartan and UA transporters that exceeded that of losartan. The purpose of the present study was to evaluate the hypouricemic effect of irbesartan in a clinical setting. A total of 40 high-risk hypertensive outpatients with coronary artery disease, cerebrovascular disease and/or diabetes complications who were taking ARBs other than irbesartan and losartan were enrolled in this study. After a 4-week control period, the patients’ prescribed ARBs were exchanged for an equivalent dose of irbesartan. We assessed blood pressure, heart rate, serum UA level, parameters of lipid and glucose metabolism, cardiac and renal function and inflammatory and oxidative stress markers in blood samples taken immediately before the initiation of irbesartan treatment and again after 12 weeks of treatment. All 40 recruited patients were followed (31 men and 9 women, mean age: 68 years) without any dropouts. During the 12 weeks of irbesartan treatment, no significant changes in blood pressure, heart rate, parameters of lipid or glucose metabolism or other biomarkers of cardiac function, renal function, or inflammation were observed. However, UA level (5.9±1.6 to 5.5±1.6 mg ml−1, P=0.028) and the oxidative stress marker derivative reactive oxygen metabolites (dROMs) (354±83 to 310±65 U.CARR, P<0.001) were significantly lower at 12 weeks of treatment compared with before treatment. These results suggest that irbesartan has beneficial effects on hyperuricemia and oxidative stress.

Impact of catheter tip-tissue contact on three-dimensional left atrial geometries: Relationship between the external structures and anatomic distortion of 3D fast anatomical mapping and high contact force guided images.

BACKGROUND A high catheter tip-tissue contact force (CF) with the myocardium may cause 3-dimensional (3D) map distortion, however, the influence of external structures surrounding the left atrium (LA) on that distortion remains unknown. This study characterized the impact of high CF mapping on the local LA geometry distortion. METHODS Thirty AF patients underwent 3D-ultrasound merged with CT images (3D-Merge-CT). The LA area in contact with external structures was identified by enhanced CT. Fast-electroanatomical-mapping (FAM) geometries were created by two methods, point-by-point mapping with high (>10g) CFs (high-CF guided-FAM), followed by that with multielectrode-mapping catheters (conventional-FAM). The resulting geometries were compared with the 3D-Merge-CT images. RESULTS Three representative anatomical contact areas (ascending aorta-vs.-anterior wall, descending aorta-vs.-left pulmonary vein [PV], and vertebrae-vs.-posterior wall) were identified. The PV antrum distorted distance on the 3D-Merge-CT was significantly longer for high-CF guided-FAMs than conventional-FAMs (1.7[0-3.6] vs. 0[0-1.8]mm, P<0.0001). In high-CF maps, the distorted distance significantly differed between regions with and without contact areas in both the PV antrum (0[0-0.17] vs. 1.7[0-3.9]mm, P=0.0201) and LA body region (0[0-1.5] vs. 1.7[0.7-2.2]mm, P<0.005). The catheter tip-tissue CF did not correlate with the distorted distance (r=0.08, P=0.46), and a multivariate analysis revealed that the absence of anatomical contact areas was strongly associated with significant local distortion, independent of the CF. CONCLUSIONS High-CF guided mapping yields greater 3D-image anatomical distortion than conventional-FAM methods. That distortion was attenuated by regions with anatomical contact areas, suggesting that regional anatomic distortion is involved in the existence of external structures surrounding the LA.

Thrombosis in an Internal Jugular Vein and an Upper Limb Deep Vein Treated with Edoxaban

A 45-year-old man complained of swelling of the left side of his neck and left upper limb. Ultrasonography and enhanced computed tomography (CT) revealed thrombosis of the left internal jugular, subclavian, and brachiocephalic vein. Based on various examinations, the patient was diagnosed with idiopathic venous thrombosis early in his clinical course. There were no findings to suggest malignancy or abnormal coagulability. However, two months after the start of treatment, the patient was diagnosed with gastric cancer. Despite the presence of Trousseau syndrome, treatment with edoxaban (an oral anticoagulant), reduced the swelling dramatically without any bleeding complications.

Eicosapentaenoic Acid Added to Strong Statin Therapy

this study are consistent with the findings of the previous study. In terms of inflammatory markers, coronary sinus levels of pentraxin (PTX) 3 and monocyte chemoattractant protein (MCP)-1 were reduced by treatment with EPA. These 2 markers are known to be associated with the mechanism of many inflammatory diseases. In particular, the PTX3 level might reflect atherosclerotic activity, local inflammatory status, and plaque instability at the coronary culprit site more directly than other biomarkers.7 In addition to the changes in plaque components, coronary vessel volumes were reduced in the EPA group more than in the control group, which also reflected the anti-inflammatory effect of EPA. Regarding the anti-inflammatory effects of EPA, Niki et al explain that its mechanisms were associated with prostaglandins, leukotrienes, nuclear factor κ-B, and peroxisome proliferator activated receptor γ.3 PTX3 and MCP-1 levels were reduced in coronary sinus samples after EPA treatment, but not in femoral vein samples. These results suggest that EPA could improve the inflammation of coronary artery plaques. Recent studies have documented the efficacy of EPA in diseases other than coronary artery disease through improvement of inflammation. EPA prevented abdominal aortic aneurysm Beneficial Effects of EPA Statin monotherapy is widely prescribed to treat elevated levels of low-density lipoprotein (LDL) cholesterol and the beneficial effects on clinical outcomes in patients with cardiovascular diseases are recognized worldwide. However, patients have a residual risk despite highly effective statin therapy. A number of studies have been conducted over 10 years to explore the effects of adding other treatments to statins, called ‘Beyond Statin’, such as niacin, cholesteryl ester transfer protein inhibitors, ezetimibe, and eicosapentaenoic acid (EPA).

Insulin Resistance as a Predictor of the Late Catch-up Phenomenon After Drug-Eluting Stent Implantation

BACKGROUND Percutaneous coronary intervention (PCI) is an effective treatment for patients with ischemic heart disease. In particular, restenosis is suppressed after drug-eluting stent (DES) implantation. However, several problems remain. Previously, we reported neointimal proliferation after DES implantation, which was associated with insulin resistance (IR). The aim of the present study was to clarify whether IR is associated with mortality and major adverse cardiac and cerebrovascular events (MACCE) after 1st-generation DES implantation. METHODSANDRESULTS We researched the clinical records of 109 patients who had undergone elective PCI and DES implantation between May 2007 and December 2010. We segregated these patients according to the value of the homeostasis model assessment of IR (HOMA-IR) into Group P (n=63; HOMA-IR ≥2.5, positive) and Group N (n=46; HOMA-IR <2.5, negative), and examined the relationship between HOMA-IR and MACCE. The observation period was 7.4±1.6 years. There were no differences between the 2 groups in the occurrence of all-cause death, cardiac death, restenosis, myocardial infarction, stroke, heart failure, or stent thrombosis. However, the late catch-up phenomenon was significantly more common in Group P than in Group N (12.7% vs. 2.2% P=0.048). CONCLUSIONS IR is a useful predictor of the late catch-up phenomenon after DES implantation, and improvement of IR may help to prevent the phenomenon. (Circ J 2016; 80: 657-662).

Influence of the left atrial contact areas on fixed low-voltage zones during atrial fibrillation and sinus rhythm in persistent atrial fibrillation: NAKAHARA et al .

Atrial low‐voltage zones (LVZ) are suggested as important factors for maintaining persistent atrial fibrillation (PsAF). The relationship between LVZs and left atrial (LA) contact areas (CoAs) is still unclear.

Coved-type ST-elevation during ablation of ischemic ventricular tachycardia

A coved‐type electrocardiogram (ECG) change in Brugada syndrome is suggested to be the result of abnormally delayed depolarization over the right ventricular outflow tract; however, ischemia of the conus branch of the right coronary artery presents the same ECG change. A 63‐year‐old man with a history of myocardial infarction demonstrated a transient coved‐type ECG change during catheter ablation of ventricular tachycardia. The ECG change appeared during left ventricular mapping without any chest symptoms, and recovered spontaneously. A pilsicainide test was negative and a coved‐type ECG did not appear during the perioperative or follow‐up period.

Percutaneous Removal of Inferior Vena Cava Filter after Migration to Pulmonary Artery using an 8-Fr Multipurpose Catheter

An inferior vena cava filter migrated to the left pulmonary artery during removal. The legs of the filter were not open adequately due to thrombus accumulating around the legs and resulted in the filter floating up and migrating to the pulmonary artery through the right atrium and ventricle. The hook for retrieval placed at the top of the filter faced proximal in the pulmonary artery and the legs of filter remained closed, consequently the filter could be removed safely from the pulmonary artery. An 8-Fr multipurpose catheter with its flexibility was useful to retrieve the filter from the pulmonary artery.