Atsushi Saito

Tachikawa Hospital, Edo, Tōkyō, Japan

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Publications (8)11.59 Total impact

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    ABSTRACT: Anticoagulation therapy is essential in atrial fibrillation (AF), and in Japan, less intense control is popular. To assess the efficacy and safety with a special reference to low intensity warfarin therapy. In 488 out of 508 patients with non-valvular AF, prothrombin time-international normalized ratio (PT-INR) was kept at 1.6-2.59, and they were followed for 49.5 months: 2098 person-years. The mean age was 73.7±9.9 years and 62% were male. The patients were divided by age: ≥70 years and <70 years, and by the intensity of warfarin therapy: PT-INR at 1.6-1.99 and at 2.0-2.59, respectively. The clinical data and event rates, ischemic stroke and major bleeding, were compared among the subgroups. Heart failure, previous stroke, and higher CHADS2 score were more often reported in patients ≥70 years while males were involved more often as younger patients. A total of 166 of 339 patients ≥70 years and 69 of 149 patients <70 years belonged to the low intensity group. Ischemic stroke and major bleeding occurred in 1.47%/year and 1.27%/year, respectively but there was no difference between the two age groups and between the two intensities of warfarin therapy. Time in therapeutic range was a predictor for ischemic stroke. A fall of PT-INR to <1.6 was found in 41.9% with ischemic stroke and a rise >2.61 in 40.0% with major bleeding at the time of the events. Blunt trauma and concomitant use of antiplatelets were risks for intracranial hemorrhage in the patients ≥70 years. The event rates were similar between the low- (1.6-1.99) and high- (2.0-2.59) intensity warfarin therapy groups in aged patients: <70 years and ≥70 years. Time in therapeutic range and a transient fall or rise in PT-INR were risks for clinical events. Blunt head trauma and concomitant use of antiplatelets were risks for intracranial hemorrhage.
    Journal of Cardiology 01/2014; 64(2). DOI:10.1016/j.jjcc.2013.11.015 · 2.57 Impact Factor
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    ABSTRACT: A 64-year-old woman underwent a coronary flow reserve evaluation using intracoronary-administered papaverine into the left anterior descending artery. Her baseline electrocardiogram (ECG) was normal, but toward the end of papaverine administration, the QTU intervals were excessively prolonged and torsade de pointes occurred, leading to ventricular fibrillation. Ten months previously, the patient's ECG showed mildly prolonged QTc (480 ms(1/2)), which normalized after the cessation of bepridil. This case report suggests that a history of drug-induced QT prolongation can be a risk factor for papaverine-induced fatal ventricular arrhythmia.
    Internal Medicine 01/2014; 53(15):1629-31. DOI:10.2169/internalmedicine.53.1828 · 0.97 Impact Factor
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    ABSTRACT: Controversies concerning the association between obesity and acute myocardial infarction (AMI) are still ongoing in Japan. We investigated the association between obesity defined by body mass index of 25 kg/m(2) or higher and AMI by a case-control study using data from 1199 AMI cases and 4056 apparently healthy controls. The analysis was performed in age- and sex-matched samples of 621 case-control pairs younger than 80 years and in crude samples aged 40-79 years divided into 10-year age groups. Prevalence of obesity, diabetes, current smoking, hypertension, and hypercholesterolemia were compared between cases and controls, and a multivariable odds ratio (OR) of AMI was calculated for each risk factor in various age groups. The OR (95 % confidence interval (CI)) of AMI for obesity was 1.63 (1.23-2.17), P = 0.0008 in men younger than 80 years; 2.65 (1.41-5.00), P = 0.0025 in women younger than 80 years; 2.23 (1.46-3.41), P = 0.0002 in men aged 59 years or younger; 1.34 (0.90-2.01), P = 0.1510 in men aged 60-79 years; and 2.98 (1.56-5.71), P = 0.0010 in women aged 60-79 years using paired samples. The OR (95 % CI) of AMI for obesity was 4.92 (2.53-9.58), P < 0.0001 in men aged 40-49 years; 1.54 (1.07-2.21), P = 0.0197 in men aged 50-59 years; 1.07 (0.69-1.66), P = 0.7717 in men aged 60-69 years; 2.24 (1.20-4.20), P = 0.0118 in men aged 70-79 years; 2.48 (1.12-5.48), P = 0.0245 in women aged 60-69 years; and 3.05 (1.46-6.37), P = 0.0029 in women aged 70-79 years using crude samples. The association between obesity and AMI was age- and gender-dependent in a Japanese population.
    Heart and Vessels 09/2012; 28(5). DOI:10.1007/s00380-012-0280-3 · 2.11 Impact Factor
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    ABSTRACT: AIMS: The prevalence, clinical significance, and pathogenesis of J-waves were studied in the patients with an ST-elevation myocardial infarction (MI) after percutaneous coronary intervention (PCI).METHODS AND RESULTS: One hundred and fifty-two consecutive patients with an acute ST-elevation MI were included. The mean age was 68.6 ± 13.5 years, and 78.3% of the patients were male. Following successful PCI, 12-lead electrocardiograms (ECGs) were monitored, and J-waves were measured 1 week after the MI and analysed in relation to the location of the MI and arrhythmias. Clinical and ECG parameters were compared between the groups with and without J-waves. The rate dependency of the J-wave amplitude was analysed in the conducted atrial premature beats (APBs). J-waves were present in 60.5% (≥0.1 mV) or 48.9% (≥0.2 mV) of the 152 patients. The J-waves were more often located in the inferior leads and more frequently in an inferior MI. The presence of J-waves was associated with ventricular arrhythmias, including ventricular fibrillation. The J-wave amplitude increased in the conducted APB, mechanistically suggesting a phase 3 block.CONCLUSION: Many patients in the early recovery phase after an acute MI had J-waves. This ECG phenomenon was associated with an increased incidence of ventricular arrhythmias. The tachycardia-dependent augmentation of the J-wave amplitude suggested a mechanistic role of conduction delay.
    Europace 08/2012; 15(1). DOI:10.1093/europace/eus259 · 3.05 Impact Factor
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    ABSTRACT: Papaverine is used for the evaluation of functional status of the coronary arteries but it may provoke severe ventricular tachyarrhythmias (VTAs). This study compared the clinical and ECG characteristic of patients with papaverine-induced VTAs. The study involved 25 patients who underwent a fractional flow reserve (FFR) study. FFR was determined as the ratio of blood pressure at the distal and the proximal site of stenosis after intracoronary papaverine administration at 12 mg into the left and 8 mg into the right coronary artery. The QT and QTU intervals were measured manually in the limb leads and in the precordial leads, respectively and corrected by the R-R interval to obtain QTc and QTUc. The clinical and ECG data were compared between the patient groups with and without VTAs. After papaverine administration into the left (20), right (3) or both coronary arteries (2), the RR interval shortened, but non-significantly however, the QT interval (and QTc) and the QTU interval (and QTUc) were significantly prolonged. VTAs developed in four women: torsade de pointes in 3 followed by ventricular fibrillation and ventricular premature beats in 1 patient. After papaverine administration, QTU and QTUc were more prolonged in women than men and in patients with VTAs compared to those without. Just prior to VTAs, giant T-U waves were observed. Intracoronary papaverine was used to determine FFR which may induce VTAs. VTAs developed only in women and they were closely related to prolongation of the QTU intervals with prominent T-U waves.
    Internal Medicine 01/2012; 51(4):351-6. DOI:10.2169/internalmedicine.51.6567 · 0.97 Impact Factor
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    ABSTRACT: We encountered two consecutive cases with spontaneous ST elevation due to right coronary spasms and subsequent ventricular fibrillation (VF). Their 12-lead ECGs on anterior chest pain showed elevation of ST-segments in the inferior leads, but coronary angiography (CAG) revealed no significant stenosis. Both cases showed dramatically evolving J waves in the inferior leads during the right CAG, but it was not observed during angiography of the left CAG. Neither Brugada-type ECG nor long-QT was evident. In summary, J waves can be produced without ST-segment elevation, and contrast media-induced J waves might be related to the arrhythmogenesis of subsequent VF evoked by right coronary spasms.
    Internal Medicine 01/2012; 51(2):185-8. DOI:10.2169/internalmedicine.51.6343 · 0.97 Impact Factor
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    ABSTRACT: J wave or early repolarization has been associated with the risk of ventricular tachyarrhythmias, and its risk stratification is to be established. Case 1: A 51-year-old man without structural heart disease was admitted because of near syncope due to repeated episodes of very rapid non-sustained monomorphic VT (∼240 bpm). His ECG showed J waves in the inferior and lateral leads, and J waves persisted after the administration and were not affected by pilsicainide or epinephrine. VT was mapped to the free wall of right ventricular outflow tract. Case 2: A 74 year-old man developed ventricular fibrillation after successful coronary artery bypass graft surgery. His preoperative ECG showed small J waves in the inferior and lateral leads. During the stay in ICU, J waves were dramatically augmented and led to VF. After the restoration of sinus rhythm by a DC shock, they decreased. The dynamicity and relation of the influence to J wave on the ventricular arrhythmias may be different.
    Journal of Arrhythmia 01/2011; 27(Supplement):PJ3_065. DOI:10.4020/jhrs.27.PJ3_065
  • Internal Medicine 02/2008; 47(6):563-4. DOI:10.2169/internalmedicine.47.0854 · 0.97 Impact Factor

Publication Stats

15 Citations
11.59 Total Impact Points

Institutions

  • 2008–2014
    • Tachikawa Hospital
      Edo, Tōkyō, Japan