Rhythmic structures and atherosclerosis in the aorta.

The presence of so-called rhythmic structures (RS) or 'wave-lines' was studied in aortic specimens from 380 males and 201 females of ages between 10 and 39 years, from Malmö, Sweden, Prague, CSSR, and Yalta, Ukraine. RS were found in 56% of the males and 54% of the females, but with some sex differences between cities: in Malmö they were more frequent in males, in Yalta in females, but in Prague no sex difference was found. RS were significantly more common in the abdominal than in the thoracic part (68% and 32%, respectively).

Magnetic resonance imaging of cardiac hypertrophy in malignant arterial hypertension.

The major target organs that become damaged as a consequence of long-standing arterial hypertension are the kidneys, heart, and brain. Left ventricular hypertrophy (LVH) cannot be considered only as an adaptive process to elevated blood pressure (BP), and the heart is also a major target organ in malignant arterial hypertension (MH). Magnetic resonance (MR) was used as a method for visualization of the heart in 68 patients with MH including 18 with essential hypertension, 16 with chronic glomerulonephritis, 13 with chronic pyelonephritis, 16 with renovascular hypertension, eight with adrenal tumors, and in 20 healthy volunteers (as a comparison group).

Patterns of serological markers for cellular immune activation in patients with dilated cardiomyopathy and chronic myocarditis.

We determined serum concentrations of neopterin and beta 2-microglobulin, soluble markers of cellular immune activation, in 27 patients with either dilated cardiomyopathy (DCM) or chronic myocarditis. Neopterin and beta 2-microglobulin concentrations were respectively increased in 2 and 5 of 11 patients with DCM and in 11 and 9 of 16 patients with chronic myocarditis. A higher cardiac functional class (according to the New York Heart Association) was associated with greater neopterin and beta 2-microglobulin concentrations.

Some medical aspects of an 8-month's space flight.

In 1984 a 237-day space flight was performed on board the orbital complex Salyut-7-Soyuz-T with the crew members Leonid D. Kizim (Commander), Vladimnir A. Solovyov (Flight-Engineer), and Oleg Yu.

Giant aneurysm of the coronary artery.

A case of a patient presenting a giant size mass compressing the SVC and IVC is presented. Chest X-ray, substernal echo-scanning, magnetic resonance tomography, etc. led to the hypothesis of a benign cardiac tumor or cardiac echinococcosis.

Effects of ryanodine on ouabain-induced spontaneous mechanical and electrical oscillations in guinea-pig heart.

The effects of ryanodine on ventricular arrhythmias in guinea-pigs in vivo, on delayed after potentials and after contractions, and on spontaneous oscillations of the membrane potential (SOP) and of resting tension (SOT) of guinea-pig papillary muscle under ouabain intoxication were studied. After addition of ouabain (1 microM) the after potentials, after contractions, and SOP and SOT amplitude were significantly increased. The power spectra of SOT and SOP under these conditions had a resonance harmonic with the frequency of about 5 Hz.

Influence of ionic modification on electrical activity of Purkinje fibers obtained from dogs with 1-day-old myocardial infarction.

A stable sustained rhythmic activity (SRA) occurred in 62 of 192 specimens isolated from the infarcted subendocardium of 48 dogs 24 h after a left descending coronary artery occlusion. Changes in [Na+]o and/or [Ca2+]o of the superfusate allowed us to distinguish two types of responses, suggestive of two different mechanisms for SRA. In type 1 responses at constant [Na+]o, the rate of SRA decreased when [Ca2+]o was increased and increased when [Ca2+]o was decreased.

Vagally induced depression of impulse propagation as a cause of atrial tachycardia.

It is known that parasympathetic influence favors induction of re-entrant atrial tachycardias (ATs). This effect is usually interpreted as a result of inhomogeneous shortening of atrial refractoriness leading to increased probability of circus movement following a premature impulse. However, early microelectrode studies showed that in spontaneously beating isolated frog atria, intensive vagal stimulation (VS) induced paroxysms of rapid AT in the absence of myocardial extrastimulation.

Modulating intraventricular conduction through competition of two class 1 antiarrhythmic agents: experience with ethacizin and lidocaine in canine heart.

The frequency-dependent effects on the intraventricular conduction through the dog heart in situ produced by two class 1 antiarrhythmic drugs, ethacizin and lidocaine, with different kinetic properties were investigated. Conduction delay was measured using stimulation of the His-bundle after pharmacologically induced atrioventricular (AV) block. Electrical events were derived from local epicardial bipolar electrograms at the base of the right ventricle.

Modulation of cardiac sodium channel gating by lysophosphatidylcholine.

The effects of lysophosphatidylcholine (LPC) on Na channels have been investigated in inside-out patches of adult rat ventricular cells using the patch-clamp technique. Applying LPC (9-25 microM) to the inner side of the membrane reduced peak Na current (INa) and prolonged the time course of INa inactivation. Both effects increased with duration of LPC exposure.

Effects of barium on spontaneous mechanical and electrical oscillations in rat papillary muscle.

In experiments on isolated rat papillary muscles the effects of Ba2+ (0.2-1 mM) on spontaneous resting tension oscillations (RTO) and membrane potential oscillations (MPO) were investigated. In normal Tyrode's solution the muscles were not spontaneously active, however, the addition of barium (1 mM) after a delay of 3-5 min induced the spontaneous excitations of the preparations.

A biochemical approach to essential hypertension.

Using multivariate statistical analysis, an attempt has been made to select hypertensive and normotensive sub-groups of subjects on the basis of certain parameters of their blood serum, such as the inhibition of purified Na,K-ATPase by serum and the content of two proteins with molecular masses of 12 and 15 kDa. An analysis of 20 human beings (10 hypertensive and 10 normotensive individuals) revealed that the best division into sub-groups is achieved only through the use of a combination of these three parameters.

2-Deoxy-D-glucose-induced central glycopenia differentially influences renal and adrenal nerve activity in awake SHR rats.

2-deoxy-D-glucose (2-DG) evokes an increase in the efferent discharge rate of the adrenal nerve in narcotized rats and rabbits. The study reported here was undertaken to determine the sympathetic nerves and blood pressure responses to i.v.

Clinical, electrophysiologic and antiarrhythmic efficacy of moricizine HCl.

The electrophysiologic effects and antiarrhythmic efficacy of moricizine HCl (1.5 to 2.0 mg/kg intravenously, and 600 to 800 mg orally/24 hours) were studied using electrophysiologic testing, ambulatory electrocardiographic monitoring, exercise stress testing and transesophageal stimulation of the left atrium.

Electrophysiologic aspects of moricizine HCl.

Moricizine HCl, a phenothiazine derivative, is a new antiarrhythmic drug that has quinidine-like effects on the myocardium. Moricizine HCl, 1 X 10(-7) g/ml, significantly decreases Vmax of the transmembrane action potential of canine Purkinje fibers and reduces the duration of the action potential at 50% and 90% of repolarization, whereas resting potential is unchanged. The drug decreases the fast inward sodium current (lNa), as measured by the double sucrose gap technique in frog atrium trabeculae; the processes of activation, inactivation and reactivation of current did not change even when a high concentration of drug (5 X 10(-6) g/ml) was used.

End-tidal carbon dioxide as a noninvasive monitor of circulatory status during cardiopulmonary resuscitation: a preliminary clinical study.

In four postoperative cardiac patients during controlled ventilation, acute circulatory failure was associated with decreases in end-tidal CO2 (PetCO2) and cardiac index. Closed cardiac compression caused an increase in both PetCO2 and cardiac index, with complete restoration to baseline values after successful CPR. Our data indicate that PetCO2 measurements during controlled ventilation in acute circulatory failure patients may be used as an indirect noninvasive tool to monitor the patient's hemodynamic status during CPR.