Fumito Miyoshi

Prolonged Paced QRS Duration as a Predictor for Congestive Heart Failure in Patients with Right Ventricular Apical Pacing

Background: The recent studies showed that right ventricular (RV) pacing was associated with worsening of heart failure. The aim of this study is to clarify the clinical significance of paced QRS duration during RV pacing to predict congestive heart failure (CHF) patients.

Candesartan decreases type III procollagen-N-peptide levels and inflammatory marker levels and maintains sinus rhythm in patients with atrial fibrillation.

This study has evaluated whether candesartans prevent the recurrence of atrial fibrillation (AF) and decrease type III procollagen-N-peptide (PIIINP) levels. A total of 153 patients with AF were enrolled in this study. Three groups of patients were compared; candesartan group was treated with candesartan plus bepridil (n = 52); and carvedilol group with carvedilol plus bepridil (n = 51); and bepridil group with bepridil alone (n = 50). The primary end point was length of time to the recurrence of AF and all patients were ultimately followed-up for 730 days. Serum levels of the biomarkers were measured at baseline and after 24 months. Maintenance of sinus rhythm was achieved in 25 (50%) patients in bepridil group, 37 (73%) in candesartan group, and 34 (67%) in carvedilol group, giving a bepridil group/candesartan group hazard ratio of 0.36 (95% confidence interval 0.21-0.63; P = 0.03). Candesartan significantly decreased PIIINP levels at 24 months than at baseline in sinus rhythm group (0.57 ± 0.02 vs. 0.64 ± 0.05 U/mL, P = 0.04) and did not decrease PIIINP levels in the recurrence group. In conclusions, PIIINP might be related to the possibility of the atrial fibrosis for AF. However, further studies are needed to clarify the relationship between PIIINP and AF.

Recurrence of atrial fibrillation within three months after pulmonary vein isolation for patients with paroxysmal atrial fibrillation: Analysis using external loop recorder with auto-trigger function

Pulmonary vein isolation (PVI) via catheter ablation has been shown to be a highly effective treatment option for patients with symptomatic paroxysmal atrial fibrillation (AF). The recurrence of AF within 3 months after PVI is not considered to be the result of ablation procedure failure, because early recurrence of AF is not always associated with late recurrence. We examined the usefulness of an external loop recorder with an auto‐trigger function (ELR‐AUTO) for the detection of atrial fibrillation following PVI to characterize early recurrence and to determine the implications of AF occurrence within 3 months after PVI.

Increase in Tpeak-Tend interval induced by cardiac resynchronization therapy is a predictor of ventricular tachyarrhythmia

The impact of cardiac resynchronization therapy (CRT) on dispersion of repolarization is controversial. This study aimed to determine whether CRT alters the QT interval and Tpeak–Tend interval (Tpeak–end) and whether such changes relate to the risk of developing a major arrhythmic event (MAE).

Long-term effectiveness of right septal pacing vs. right apical pacing in patients with atrioventricular block

Long‐term right ventricular apical (RVA) pacing increases the risk of heart failure (HF) by inducing ventricular dyssynchronization. Although recent studies suggest that right ventricular septal (RVS) pacing results in improved short‐term outcomes, its long‐term effectiveness remains unclear.

Characteristics of head-up tilt testing with additional adenosine compared with head-up tilt testing with isoproterenol and isosorbide dinitrate

Head‐up tilt (HUT) testing is used to establish the diagnosis of neurally mediated syncope (NMS). Adenosine administration during HUT testing is useful for inducing NMS. However, no comparison between adenosine HUT testing and HUT testing using other drugs has been reported. The purpose of this study was to investigate the clinical usefulness of adenosine compared with isoproterenol (ISP) and isosorbide (ISDN) during HUT testing.

Suppression of Torsades de Pointes by Biventricular Pacing in a Patient with Long QT Syndrome

This report describes a case of a patient with long QT syndrome (LQTS) with recurrent episodes of torsades de pointes (TdP). Use of biventricular pacing (BiVP) resulted in a shorter QT interval and a shorter T‐peak‐end interval and prevented further episodes of TdP. These findings suggest that BiVP may be helpful in patients with LQTS and refractory TdP.

Management of Patients Receiving Warfarin during Invasive Procedures and the Adverse Effects of Warfarin

Aim: The aim of this study was to assess the frequency and characteristics of complications in patients on anticoagulant therapy who were to undergo invasive procedure.

The Effects of Nicorandil and Nifekalant, Which Were Injected into the Pericardial Space, for Transmural Dispersion of Repolarization in the Pig

Introduction: Some studies have reported that transmural dispersion of repolarization (TDR) is involved in the onset of ventricular arrhythmia. We investigated the effects of nicorandil (NIC) and nifekalant (NIF) injected into the pericardial space, on TDR and T waves in the pig. Methods and Results: We injected NIC 4 or 8 mg and NIF 50 or 100 mg at intervals into the pericardial space for eleven pigs. The effects of these drugs were investigated on the effective refractory period (ERP) between the endocardial and epicardial myocardial cells, as well as on QT time, QT peak‐end (QTcpe) as an index of TDR, and T waveforms, respectively. QTcpe increased from 91 ± 21 to 116 ± 19 msec, 2.8 min after injection of NIC (p < 0.01), although corrected QT (QTc) interval did not changed. But 5.5 min after injection, QTc decreased while QTcpe recovered. T wave amplitude significantly increased, and epicardium ERP decreased. When NIF was injected, TDR decreased from 55 ± 10 msec to 44 ± 8 msec (p < 0.01) although QTc did not change. In a later phase, QTc increased (p < 0.01) and QTcpe recovered. T wave amplitude rapidly decreased and became negative. Conclusion: Injected into the pericardial space, NIC and NIF brought about certain changes in ERP, QT and T waveform. Furthermore, NIC increased TDR while NIF decreased TDR.

Electrical Remodeling in Persistent Atrial Fibrillation May Be Mediated by Changes in the IKATP Channel

The goal of this study was to measure the effective refractory period (ERP), the conduction velocity (CV) and the wavelength (WL) after cardioversion in patients with persistent atria] fibrillation (AF) and to determine the effects of the adenosine triphosphate sensitive potassium channel (KATP) opening agent, nicorandil, on those parameters in patients with persistent AF.