Cardioprotective effects of sarcolemmal and mitochondrial K-ATP channel openers in an experimental model of autoimmune myocarditis. Role of the reduction in calcium overload during acute heart failure.

It has been reported that K-ATP channel openers have a cardioprotective effect in acute ischemia as a pharmacological preconditioning effect. In the present study, the chronic effects of clinical K-ATP channel openers, ie, nicorandil (Nic) and mexiletine (Mex), on cardiac function were evaluated in a rat model of experimental autoimmune myocarditis (EAM). Nicorandil (3 or 10 mg/kg/day) or Mex (10 or 25 mg/kg/day) was administered to the EAM rats, and the effects were compared with those in untreated EAM rats (control EAM) and sham rats without EAM on day 21 (acute phase) or day 60 (chronic phase).

N-acetylcysteine suppresses the progression of ventricular remodeling in acute myocarditis: studies in an experimental autoimmune myocarditis (EAM) model.

Background: Electrical and structural remodeling, characterized by prolonged action potential duration (APD), Kv4.2 downregulation and cellular infiltration were studied in rat experimental autoimmune myocarditis (EAM). Because the reactive oxygen species (ROS) has been speculated to play a role in the promotion of such remodeling, the effect of N-acetylcysteine (NAC) on the progression of ventricular remodeling was evaluated.

Clinical usefulness of electrophysiologic study (EPS)-guided risk stratification for life-threatening arrhythmia in patients with heart failure.

Background: Ventricular tachyarrhythmia is one of the most important factors determining the prognosis of patients with heart failure and sudden death can be observed even during stable therapy controlling clinical heart failure. In this study, the usefulness of electrophysiologic study (EPS) for the prediction of a future arrhythmic event was evaluated in patients with heart failure.

Methods And Results: The patient population consisted of 474 patients with a history of clinical heart failure but without an episode of spontaneous sustained ventricular tachycardia or fibrillation (VT/VF).

Predictive impact of the inducibility of ventricular fibrillation in patients with Brugada-type ECG.

The natural history of asymptomatic individuals with a Brugada-type electrocardiogram (ECG) is still controversial. In this study, we evaluated ventricular fibrillation (VF) inducibility in Brugada-type ECG patients and compared it with other risk factors to clarify the significance of these data on their prognosis. The study population consisted of 38 patients who presented with a typical ST-segment elevation in the precordial leads and underwent an electrophysiological study (EPS).

Bepridil inhibits sub-acute phase of atrial electrical remodeling in canine rapid atrial stimulation model.

Background The effect of bepridil, a multichannel blocker, on atrial electrical remodeling was evaluated in a canine rapid atrial stimulation model. Methods and Results In 10 beagle dogs, the right atrial appendage (RAA) was paced at 400 beats/min for 2 weeks. The atrial electrophysiological parameters, including effective refractory period (AERP), were evaluated at three atrial sites: RAA, the right atrium close to the inferior vena cava (IVC) and the left atrium (LA), during the time course of rapid pacing.

Long-term follow-up of changes in fibrillation waves in patients with persistent atrial fibrillation: spectral analysis of surface ECG.

Background: Little is known about the shortening of atrial refractoriness as a result of electrical remodeling in atrial fibrillation (AF) in clinical cases, especially in terms of long-term follow-up, because of a lack of noninvasive testing methods.

Methods And Results: The present study population comprised 38 consecutive patients with persistent AF (PAF, >1 month). Before and after the follow-up period of 1-14 months, surface ECGs were recorded for analysis.