114
edits
mNo edit summary |
No edit summary |
||
Line 2: | Line 2: | ||
[[Image:ventrfascreflex.jpg|thumb| Ventriculophasic reflex during second degree AV block type I. The PP interval that follow upon the blocked sinus beat is prolonged.<cite>Rosenbaum</cite>]] | [[Image:ventrfascreflex.jpg|thumb| Ventriculophasic reflex during second degree AV block type I. The PP interval that follow upon the blocked sinus beat is prolonged.<cite>Rosenbaum</cite>]] | ||
Ventriculophasic reflex is a phenomenon that can be seen during AV block or during ventricular extrasystoles in bigemini. It describes the sinus arrhythmia that exists during a irregular rhythm. The phenomenon has been described by Erlanger and Blackman in 1910 <cite>Erlanger</cite>. Different theories have been postulated to explain the phenomenon (a.o. by Wenkebach), but the theory | Ventriculophasic reflex is a phenomenon that can be seen during AV block or during ventricular extrasystoles in bigemini. It describes the sinus arrhythmia that exists during a irregular rhythm. The phenomenon has been described by Erlanger and Blackman in 1910 <cite>Erlanger</cite>. Different theories have been postulated to explain the phenomenon (a.o. by Wenkebach), but the theory published by Rosenbaum and Lepeschkin in 1955 <cite>Rosenbaum</cite> is the most accepted. | ||
A positive chronotropic (accelerating) effect on the ventricular contraction is probably caused by stretch on the right atrium by contraction of the ventricles. A negative chronotropic effect ( | A positive chronotropic (accelerating) effect on the ventricular contraction is probably caused by stretch on the right atrium by contraction of the ventricles. A negative chronotropic effect (slow down) is probably caused by a vagal reflex caused by stimulation of the carotid arterial baroreceptors by the pressure wave. The result of these two effects determines whether the P-P interval that surrounds the extra beat is shorter or longer than the P-P interval that surrounds the missing beat. | ||
The baroreflex influences both the | The baroreflex influences both the sinus node and the AV node and thus both sinus rate and atrioventricular conduction can be influenced. | ||
{{clr}} | {{clr}} | ||
== References == | == References == |
edits