[Peripheral vascular reflexes during ventricular overdriving and cardiac ischemia. An experimental study].
The aim of this paper is to analyze the behaviour of the muscular arteries during ventricular tachycardia in normal and in ischemic hearts. In 19/30 anaesthetized dogs in which a resistance vessel (gracilis muscle artery) was isolated (while innervation and venous backflow remained intact), we performed transient (20 min) coronary artery occlusions and ventricular overdriving (30 sec). A systolic left ventricular pressure decrease (144.2 +/- 18.2 mmHg vs 114 +/- 16.1) (p < 0.001) was produced with the coronary circumflex obstruction. Changes in the end-diastolic left ventricular pressure and muscular artery pressure were not significant. A new systolic left ventricular pressure decrease (114 +/- 16.1 mmHg vs 64.8 +/- 27) (p < 0.001) was induced when the ventricular overdriving (272.2 +/- 46.1 bpm) was added to the coronary circumflex obstruction. The end-diastolic left ventricular pressure increased (6.8 +/- 10.1 mmHg vs 18.3 +/- 4.8) (p < 0.001) and the muscular artery pressure increased (121 +/- 27.3 mmHg vs 158.1 +/- 21.3) (p < 0.01) in these circumstances. When the ventricular overdriving (275 +/- 70.7 bpm) was added to the left descendent anterior coronary occlusion a significative decrease of left systolic ventricular pressure (141 +/- 23 mmHg vs 84.4 +/- 28.4) (p < 0.01) and an increase of the muscular artery pressure (124.3 +/- 25 mmHg vs 149 +/- 25.1) (p < 0.01) was produced. Ventricular overdriving-induced hypotension produced an isolated muscular artery response with clear vasoconstrictor predominance, which indicates that there is a natural compensatory capacity with predominance of efferent sympathetic activity.(ABSTRACT TRUNCATED AT 250 WORDS)
Seguí Bonnin
J
J
Centro de Investigación, Hospital La Fe, Valencia.
Cosín Aguilar
J
J
García Civera
R
R
Andrés Conejos
F
F
Hernándiz Martínez
A
A
Solaz Mínguez
J
J
Graullera Sanz
B
B
D000208:Acute Disease; D000818:Animals; D006328:Cardiac Catheterization; D004285:Dogs; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006352:Heart Ventricles / Q000503:physiopathology; D006439:Hemodynamics; D008297:Male; D017202:Myocardial Ischemia / Q000503:physiopathology*; D012018:Reflex / Q000502:physiology*; D013610:Tachycardia / Q000503:physiopathology; D014655:Vascular Resistance / Q000502:physiology; D014666:Vasomotor System / Q000503:physiopathology*; D016277:Ventricular Function, Left / Q000502:physiology
Reflejos vasculares periféricos durante sobreestimulación ventricular e isquemia cardíaca. Estudio experimental.