The effects of diphenylbydantoin (DPH) were studied on isolated, perfused Purkinje fibers over a range of concentrations from lCh to 10 M. The time course of repolarization of the transmembrane action potential shortened due to abbreviation of all phases of repolarization. The effective refractory period also shortened during exposure to DPH, but to a lesser extent than the action potential. As...

PurposeTo analyze differences in systolic and diastolic left ventricular (LV) as well atrial (LA) function parameters obtained from identical cardiac magnetic resonance (MR) imaging techniques during inspiratory breath-holding breathing (breath-hold to differences).Method56 subjects without signs of heart failure (23/33 male/female, age 58 ± 14 years) underwent 3 T MR cine real-time transmitral...

The kinetic energy (KE) of intracardiac blood may play an important role in cardiac function. The aims of the present study were to 1) quantify and investigate the determinants of KE, 2) compare the KE expenditure of intracardiac blood between athletes and control subjects, and 3) quantify the amount of KE inside and outside the diastolic vortex. Fourteen athletes and fourteen volunteers underw...

Diastolic waves of Ca(2+) release have been shown to activate delayed afterdepolarizations as well as some cardiac arrhythmias. The aim of this study was to investigate whether increasing ryanodine receptor open probability alone or in the presence of beta-adrenergic stimulation produces diastolic Ca release from the sarcoplasmic reticulum (SR). When voltage-clamped rat ventricular myocytes wer...

BACKGROUND Type 2 diabetes aggravates the postprandial metabolic effects of food, which increase cardiovascular risk. We investigated the acute effects of fast food on postprandial left ventricular (LV) function and the potential effects of pre-exercise in type 2 diabetes individuals. METHODS We used a cross-over study including 10 type 2 diabetes individuals (7 male and 3 females; 53.4 ± 8.1...

Impaired shortening deactivation of cardiac myocytes could sustain myocardial contraction, preserving ejection fraction at the expense of diastolic dysfunction. We examined the relationship between first-phase ejection fraction (EF1), the fraction of left ventricular volume ejected from the start of systole to the time of the first peak in left ventricular pressure (corresponding to the time of...

The "Comparative Study of Antihypertensive Treatments"-CSA T is a placebo-controlled, randomized, double-blind clinical trial, with the primary objective of comparing the efficacy of different pharmacological treatments of hypertension. Drug side-effects, patient compliance, and alterations in the patients' quality of life are also compared. Subjects with mild to moderate diastolic hyperte...

Electrograms from the bundle of His were recorded in two patients with acute myocardial infarction during paroxysmal atrioventricular block induced by carotid sinus massage. From the viewpoint of the surface electrocardiogram this arrhythmia was considered as a form of Type II (Mobitz) Ulo:k, the onset of which was related to a decrease in atrial rate. In the first patient, the conduction distu...