What question did this study set out to answer?

To evaluate the interactive effects of vagal and sympathetic cardiac nerve stimulation on left ventricular contraction and relaxation.

May 1, 1990AJP Heart and Circulatory Physiology

Vagal stimulation attenuates sympathetic enhancement of left ventricular function

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Why the study?

Does vagal nerve stimulation attenuate the sympathetic enhancement of left ventricular function in anesthetized dogs?

Population

16 anesthetized dogs with ventricles paced at a fixed rate of 120 beats/min and constant systemic arterial…

Comparison

Vagal nerve stimulation combined with… vs Control level and sympathetic nerve stimulation…

Design

Preclinical

Authors

RHRobert J. HenningLouisiana State University Health Sciences Center Shreveport IKIrene KhalilMount Sinai Hospital MLMatthew N. LevyTechnion – Israel Institute of Technology

Discussion

Member takes

Implication

May attenuate sympathetic LV effects in dogs; leaves open translation to human autonomic therapies.

Key Points

To evaluate the interactive effects of vagal and sympathetic cardiac nerve stimulation on left ventricular contraction and relaxation.
Evaluated 16 anesthetized dogs with ventricular pacing fixed at 120 beats/min and systemic arterial pressure maintained at a constant level.
Measured left ventricular pressure rise (dP/dtmax) and fall (dP/dtmin) under sympathetic stimulation (6 Hz) and vagal stimulation (5 Hz), evaluated before and after propranolol administration (1.5 mg/kg).
Sympathetic nerve stimulation at 6 Hz alone elevated dP/dtmax by 802 mmHg/s and dP/dtmin by 847 mmHg/s above control values.
Vagal nerve stimulation at 5 Hz decreased dP/dtmax by 187 mmHg/s and dP/dtmin by 199 mmHg/s in the absence of sympathetic drive, but decreased dP/dtmax by 513 mmHg/s and dP/dtmin by 709 mmHg/s during concurrent 6 Hz sympathetic stimulation.
Pretreatment with propranolol (1.5 mg/kg) completely abolished vagal-induced reductions in both ventricular contraction and relaxation.

Structured PICO

Does vagal nerve stimulation attenuate the sympathetic enhancement of left ventricular function in anesthetized dogs?

Population

16 anesthetized dogs with ventricles paced at a fixed rate of 120 beats/min and constant systemic arterial pressure

Intervention

Vagal nerve stimulation (5 Hz) combined with sympathetic nerve stimulation (6 Hz)

Comparator

Control level (no stimulation) and sympathetic nerve stimulation alone (6 Hz)

Outcome

Maximum rates of left ventricular pressure rise (dP/dtmax) and fall (dP/dtmin)surrogate

Vagal stimulation significantly attenuates the sympathetic enhancement of left ventricular contraction and relaxation through a substantial antagonistic interaction.

Cite This Study

Henning et al. (1990) studied this question.

synapsesocial.com/papers/6a922cf65ab1441fe3c8019f https://doi.org/10.1152/ajpheart.1990.258.5.h1470

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Vagal stimulation attenuates sympathetic enhancement of left ventricular function

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Vagal stimulation attenuates sympathetic enhancement of left ventricular function

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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