Endocardial catheter mapping was performed in 18 patients with left bundle branch block (LBBB). Four patients had no organic heart disease (group I), six had cardiomyopathy (group II), and eight had coronary artery disease and previous infarction (group III). Twelve patients had one septal site of left ventricular endocardial breakthrough, while six had two left ventricular endocardial breakthr...

Classical conditioning of the rabbit nictitating membrane response was accomplished by presenting a 100-msec tone conditioned stimulus at intervals of 0, 100, 200, 400, and 800 msec before the presentation of a 100-msec shock unconditioned stimulus. In addition, tone-alone and shock-alone trials were interspersed during conditioning. On the first day of conditioning, during which there was no e...

BACKGROUND The purpose of this study was to examine retinal recovery processes to pographically by the application of three flash sequences with specific interstimulus intervals. METHODS Twelve healthy subjects underwent multifocal electroretinography with a light-emitting diode stimulator. Every flash sequence consisted of three flashes with 25 msec between the first and the second flash and...

Staphylococcal enterotoxin C (SEC), a bacterial superantigenic exotoxin, is commonly produced by invasive Staphylococcus aureus isolates, especially methicillin-resistant strains and isolates from animal diseases. We constructed and expressed a nontoxic mutant SEC (mSEC) and investigated whether immunization with mSEC, which is devoid of superantigenic activity, can protect against S. aureus in...

INTRODUCTION Studies of the electrical dynamics of cardiac tissue are important for understanding the mechanisms of arrhythmias. This study uses high-frequency pacing to investigate the dynamics of sheep atria. METHODS AND RESULTS A 504-electrode mapping plaque was affixed to the right atrium in six sheep. Cathodal pacing stimuli were delivered to the center of the plaque. Pacing period (Tp) ...

How do visual luminance, shape, motion, and depth bind together in the brain to represent the coherent percept of a 3-D object within hundreds of milliseconds (msec)? We provide evidence from simultaneous magnetoencephalographic (MEG) and electroencephalographic (EEG) data that perception of 3-D objects defined by luminance or motion elicits sequential activity in human visual cortices within 5...

Background: Early risk stratification of patients with myocardial infarction is critical to determine optimum treatment strategies and enhance outcomes. The present study was therefore undertaken the relationship between QRS duration (QRSd) on admission ECG left ventricular ejection fraction (LVEF) as a measure function in non-ST elevated (NSTEMI) patients. Methods: This observational carried o...

BACKGROUND Intraventricular conduction in hypertrophic cardiomyopathy (HCM) has been characterized to test the hypothesis that myofibrillar disarray will cause dispersion of activation throughout the ventricular myocardium. METHODS AND RESULTS Of 37 patients with HCM, four had spontaneous ventricular fibrillation (VF), five had nonsustained ventricular tachycardia (VT), 13 had no risk factors...

BACKGROUND Transcatheter aortic valve implantation (TAVI) has been established as a treatment option for inoperable patients with symptomatic aortic valve stenosis. However, patients suffer frequently from conduction disturbances after TAVI. METHODS Baseline, procedural as well as surface and intracardiac ECG parameters were evaluated for patients treated with TAVI and a comparison between pa...

Seventeen patients with first-degree or Mobitz I atrioventricular (AV) block and narrow QRS complexes underwent electrophysiologic drug testing before and after i.v. administration of disopyramide. Disopyramide did not significantly change the mean sinus cycle length (895 +/- 131 vs 877 +/- 119 msec), mean maximal sinus node recovery time (1134 +/- 160 vs 1133 +/- 13 msec), mean atrial effectiv...