Publications by authors named "Tomokazu Iguchi"

Subcutaneous implantable cardioverter-defibrillator implantation is known to be a safe procedure. However, inappropriate lead insertion can lead to serious complications. We present a case where an inappropriate lead placement resulted in puncturing the lung parenchyma, and successful management of the lead-related pneumothorax through thoracoscopic lead removal and partial lung resection.

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Background And Aims: Eicosapentaenoic acid (EPA) has been reported to reduce cardiovascular risk in patients with hypertriglyceridemia. Although several mechanisms underlying the effects of EPA have been demonstrated, those responsible for its beneficial role in patients with hypertriglyceridemia without evidence of coronary artery disease (CAD) have not been fully elucidated. We sought to clarify the main factors associated with EPA administration that led to improved endothelial function.

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We report a case of multiple coronary spasms leading to life-threatening ventricular arrhythmia, during left atrium (LA) ablation. Coronary artery spasm is a rare complication during radiofrequency catheter ablation of atrial fibrillation (AF). Previous reports mention that autonomic imbalance leads to coronary artery spasm and ST-segment elevation in the inferior leads, during trans-septal LA catheterization and AF ablation procedures.

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Although recent optical coherence tomography (OCT) studies have focused on spotty calcification, whether there were any characteristics in the concomitant existence of calcification and plaque rupture remains unknown. The aim of the present study was to investigate the characteristics of spotty calcification in acute coronary syndrome (ACS) patients with or without plaque rupture, using OCT. This study enrolled 98 consecutive patients with ACS.

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Background: Varenicline has been reported to achieve high rates of smoking cessation. It remains undetermined whether varenicline therapy improves vascular function in smokers.

Methods: Consecutive Seventy-two smokers (age 57 ± 12 years) who succeeded in complete smoking cessation and 46 normal healthy volunteers (age 24 ± 3 years) with no cardiovascular risk factors were enrolled into this study.

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Although obesity and chest-wall thickness influence the Sokolow-Lyon electrocardiographic (ECG) voltage criteria and strain pattern, these factors have not been taken into account in previous studies that evaluate the relationship between the ECG criteria and anatomic left ventricular hypertrophy (LVH). The introduction of multislice computed tomography (MSCT) has enabled assessment of not only coronary artery stenoses but also left ventricular volume and mass, left atrial volume, and chest-wall thickness. We hypothesized that evaluating the relation between the ECG voltage criteria or strain pattern and the aforementioned factors using MSCT would be highly valuable.

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Aims: Previous studies have reported that insulin resistance plays an important role in the progression of atherosclerosis. However, the relationship between insulin resistance and coronary plaque instability is not well established. The purpose of this study was to assess the relationship between insulin resistance and coronary plaque characteristics identified by optical coherence tomography (OCT).

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A low ratio of eicosapentaenoic acid to arachidonic acid (EPA/AA) has been demonstrated to be associated with a higher risk of cardiovascular events. Optical coherence tomography (OCT) is useful for the assessment of coronary plaque vulnerability. The purpose of this study was to evaluate the association between EPA/AA ratio and coronary plaque vulnerability.

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Many investigators have speculated that hyperintense plaques (HIPs) of the carotid artery on noncontrast T1-weighted imaging (T1WI) in cardiovascular magnetic resonance indicate the presence of mural or intraplaque hemorrhage containing methemoglobin. However, coronary plaque imaging with T1WI is challenging, and the clinical significance of coronary HIPs on T1WI remains unknown. Incidentally, it is very rare to find an intracoronary thrombus at the culprit lesion site in patients in stable condition.

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The accuracy of measurements of the intima-media thickness (IMT) and flow-mediated dilatation (FMD) of the brachial artery made using a new semiautomated ultrasound system and the relationships among those parameters and the Framingham Risk Score (FRS) as a predictor of coronary heart disease (CHD) are unknown. We enrolled 70 subjects, including 47 patients with cardiovascular risk factors and 23 normal healthy volunteers. IMT and FMD were simultaneously measured using a new semiautomated ultrasound system, and the measurements were compared with those obtained manually as a reference standard (study 1).

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Background: Myocardial fractional flow reserve (FFR) is useful in the evaluation of coronary lesion ischemia. However, the impact of lesion length on FFR has not been adequately assessed.

Hypothesis: We hypothesized that lesion length would influence functional significance in intermediate coronary lesions.

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Several coronary angiographic studies have reported that enlarged and tortuous epicardial coronary arteries are characteristic of patients with left ventricular concentric hypertrophy (LVCH). Recently, we showed that small volumes opacified by contrast medium can be accurately measured by 64-multislice computed tomography (MSCT) and that there is a direct relationship between the coronary artery volume and left ventricular (LV) mass. However, the relationship of coronary artery volume with LV mass in patients with dilated cardiomyopathy (DCM) is unknown.

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Aims: Many investigators have speculated that hyperintense plaques (HIPs) of the carotid artery on non-contrast T1-weighted imaging (T1WI) in magnetic resonance indicate the presence of mural or intraplaque haemorrhage containing methemoglobin. Coronary plaque imaging with T1WI is challenging, and the clinical significance of coronary HIP on T1WI remains unknown. The aim of this study was to compare HIPs on T1WI with coronary plaque morphology assessed by optical coherence tomography (OCT), which allows us to identify not only plaque rupture, but also fibrous cap thickness and intracoronary thrombus in vivo, in patients with angina pectoris.

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Late adverse events including late stent thrombosis and late catch-up phenomenon after percutaneous coronary intervention have been a serious clinical problem in the drug-eluting stent era. Recently, peri-stent contrast staining, namely extension of incomplete stent apposition was reported following drug-eluting stent implantation. Here, we report a case of late incomplete stent apposition with late stent restenosis 3 years after sirolimus-eluting stent implantation.

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