Hirokazu Hayakawa

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Recently, we developed a transgenic mouse with cardiac-specific Gs a overexpression (TG mouse), which exhibits enhanced postsynaptic b-adrenergic receptor signaling, ultimately developing a cardiomyopathy. The goal of the present study was to determine whether cardiac Gs a overexpression alters autonomic cardiovascular control, which could shed light on the(More)
BACKGROUND The Tranilast Restenosis Following Angioplasty Trial showed that oral administration of 600 mg/day of tranilast for 3 months markedly reduced the restenosis rate after percutaneous transluminal coronary angioplasty (PTCA) for de novo lesions. METHODS We conducted the second multicenter, randomized, double-blinded placebo-controlled trial. A(More)
BACKGROUND Anthracyclines are effective anticancer drugs for childhood cancer with dose-limiting cardiotoxicity. Children who have received anthracyclines thus need periodical cardiac evaluation. The plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) have been shown to increase in proportion to severity of cardiac(More)
Objective: The aim of this study was to examine the hypothesis that long-term treatment with antipsychotic drugs in conventional doses prolongs QTc dispersion and increases ventricular tachyarrhythmias in patients with schizophrenia in the absence of cardiac disease. Methods: We measured QTc and QTc dispersion and ventricular tachyarrhythmias in 64 patients(More)
OBJECTIVES We sought to determine the prevalence of right bundle branch block (RBBB) and ST segment elevation in the working Japanese population, as well as the event rate during a three-year prospective follow-up period. BACKGROUND A poor prognosis of RBBB and ST segment elevation has been reported in Europe and South America, even in asymptomatic(More)
The efficacy of nitroglycerin ointment was determined by treadmill exercise testing through a randomized, double-bling crossover trial with placebo in 22 patients with chronic stable exertional angina. On different days, 3 cm of nitroglycerin ointment (NGO, 18 mg) and placebo ointment were applied over the epigastric region, followed by the exercise lest 1(More)
BACKGROUND A wide QRS complex is not a rare electrocardiographic phenomenon at the termination of paroxysmal supraventricular tachycardia (PSVT), but no plausible underlying mechanism has yet been proposed. The purpose of the present study was to elucidate the frequency and the underlying mechanism of the wide QRS complexes at the termination of PSVT. (More)
Cilostazol, a novel cyclic adenosine monophosphate phosphodiesterase type III inhibitor, has been developed as an antiplatelet drug with a vasodilating action on peripheral arteries. The present study was designed to test, in humans, whether cilostazol can dilate the epicardial coronary arteries and what are its hemodynamic effects. Eight patients with(More)
The differential diagnosis of wide QRS premature contractions is often inaccurate in most ECG machines with automatic computer-assisted diagnosis. The purpose of the present study was to improve the accuracy of the automated differential diagnosis between premature ventricular contractions (PVC) and supraventricular contractions with aberrant conduction(More)
The mechanism by which insulin can alter the heart-rate and blood pressure of diabetics has been studied. Insulin decreased the plasma volume of 16 diabetics without complications by an average of 190 ml, a 6% change. Nine diabetics with severe autonomic neuropathy had no significant change in plasma volume after insulin. The basal plasma volume of(More)