Regular heart rhythm restoration after a period of asystole: modeling in experimental cardiology

Abstract

Abstract Funding Acknowledgements Type of funding sources: None. Regular heart rhythm restoration after a period of asystole: modeling in experimental cardiology Purpose To study the arterial hemodynamics during the regular heart rhythm restoration after a period of asystole using the original device for modeling of intra-arterial circulation. Materials and methods We used the device for modeling of intra-arterial circulation made by us (Document of invention № RU 202780 U1). The main part of the device is rotameter glass tube - a prototype of human arterial vessel. Electric pump with various modes of work was connected into the closed system with rotameter by flexible silicone tubes. Inside the closed system we introduced an aqueous solution of glycerin diluted to have the same viscosity as the human blood. As indicators for studying the intra-arterial hemodynamics we used intravascular piezoelectric crystal pressure sensor connected to an oscilloscope, 5 mm long silk thread alternately installed inside the tube, and a dye - clerical ink. Results With the electric pump work modes, we were able to imitate the regular heart rhythm (RR) restoration after a period of asystole inside the device for modeling of intra-arterial circulation. We observed the speed of fluid increased in comparison with the RR with the pendency: if longer pause of asystole was than more speed increased. We observed the appearance of reflected, stand waves on the walls of rotameter during the spread of the pulse wave after the long asystole pause. We alternatively put the plastic diaphragm inside the rotameter with internal lumen stenosis of 70% with symmetrical and asymmetrical hole. The speed with a RR was 3.24 m/s, after the pause of asystole 1 s speed was 4.08 m/s, after the pause 2 s speed was 7.36 m/s, after the pause 3 s speed was 9.22 m/s. The pressure measured by piezoelectrical probe increased proportionally to the speed. Conclusion Intense mechanical effect of the pressure waves after the long period of asystole can cause the additional trauma of intima of arterial vessels that can lead to non-stability of atherosclerotic plaques, stimulating of endothelial dysfunction and as a result of atherosclerosis progression with further complications. Changes in hemodynamics we characterized by proposed concept of "hydraulic shock".