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V Pavlov

Publications and source records attributed to V Pavlov.

31 records · Page 2Linked to original sources
PubMed1979

Influence of temperature on the atrioventricular conduction time for spontaneous and imposed rhythms.

In the present work data are obtained about the changes in the atrioventricular conduction time under the effect of two parameters: temperature and frequency of the sinus node. The experiments are carried out on preparations from the right atrium of rabbit heart. Temperature changes are obtained by regulation of the temperature of the nutrient medium in the 23--36 degrees C range. The excitation frequency of the sinus node was changed by imposition of artificial (external) rhythms. Data are obtained about the presence of frequency- and temperature-dependent components of the atrioventricular (AV) delay. Upon cooling the preparation the influence of the temperature factor is predominant and parallel with this the capacity for assimilating a higher imposed rhythm decreases. Considerations are expressed about the behaviour of the AV-conduction system at different temperatures under conditions of saccadic changes in the imposed rhythm.

Animals↗
PubMed1979

On the effect of preceding atrial- atrial and His-atrial intervals on the atrioventricular nodal conduction time in rabbit heart.

The study of conduction in the atrioventricular node is often associated with two characteristic time intervals. The first of these intervals reflects the time between two successive atrial excitatory complexes. The second interval reflects the time from the moment of the appearance of the excitation at the output of the atrioventricular node to the next atrial complex. In different publications the value of the conduction time is associated predominantly either with one (atrial-atrial) or with the other (His-atrial) preceding intervals. The present paper makes an attempt at comparative estimation of the effect of preceding atrial-atrial and His-atrial intervals on current conduction time. The experiments are carried out on rabbit heart preparation, using micro- and macroelectrode technique. Stimulation programmes guaranteeing the imposition of rhythm with fixed atrial-atrial and His-atrial intervals are used. It is concluded that there is no strictly determined connection between the value of any of the above intervals and atrioventricular conduction time.

Animals↗
PubMed1979

On the changes in the atrioventricular conduction time under the effect of acetylcholine.

The aim of the present investigation is to study the effect of acetylcholine on the atrioventricular (AV) conduction time in preparation from rabbit heart right atrium. The artrial electrogram and the action potentials of the His-cells are recorded by means of bipolar electrodes and microelectrodes. The effect of acetylcholine is assessed by the simultaneous changes in the period of the atrial complexes and in the atrioventricular conduction time. The significance of the prolonged period of the atrial complexes for the compensation of the acetylcholine effect on the node area of the conduction system is pointed out. A considerable increase in the refractory periods of the atrioventricular node is found.

Acetylcholine↗
PubMedDate not supplied

[Study on the causes for some characteristic damages of diamond instruments for dental practice].

An attempt has been made for investigation and classification of the causes for diamond instruments for dental practice resource decrease. The overheating of the instruments is considered to be the main cause and the plastic materials smudges and unstable fixing of the diamond grains--as accompanying causes. Taking in consideration the above mentioned factors could contribute to a more rational use of the diamond instruments for dental practice.

Carbon↗