What is the clinical evidence from this study?

Study design: Other. Population: Left ventricular compliance under sympathetic stimulation (n=10). Intervention: Intracisternal veratrine injection vs. Baseline / Stellectomy / Blood infusion. Primary outcome: Left ventricular end-diastolic compliance (LVEDC/LVEDP ratio).

January 1, 1976Open Access

Sympathetic Influence on Ventricular Compliance

Key Result

Extreme sympathetic stimulation via intracisternal veratrine injection significantly decreased left ventricular diastolic compliance in anesthetized dogs, an effect reversed by bilateral stellectomy.

Structured PICO

Does extreme sympathetic stimulation via intracisternal veratrine alter left ventricular diastolic compliance in anesthetized dogs?

Population

10 anesthetized mongrel dogs were used to study the effects of extreme sympathetic stimulation via intracisternal veratrine on left ventricular diastolic compliance.

Intervention

Intracisternal injections of veratrine (to induce extreme sympathetic stimulation) followed by bilateral stellectomy

Comparator

Volume expansion with whole blood (transfusion)

Outcome

Left ventricular diastolic compliance (assessed via left ventricular end-diastolic pressure [LVEDP] and left ventricular end-diastolic circumferential [LVEDC] segment length)surrogate

Extreme sympathetic stimulation reduces left ventricular diastolic compliance in a canine model, an effect that is reversible by bilateral stellectomy.

Limitations

Animal model (dogs)
LVEDC gauge was not calibrated, so values are relative rather than absolute
Heart rate was allowed to increase without restriction
Afterload was not controlled

Abstract

Intracisternal injections of veratrine in the anesthetized dog were used to study the effects of extreme sympathetic stimulation on left ventricular diastolic compliance. The results obtained were compared with those seen during volume expansion with whole blood, and after removal of both stellate ganglia. The injection of veratrine into the cisterna magna caused an increase in left ventricular end-diastolic pressure (LVEDP) which was considerably larger than that which occurred in left ventricular end-diastolic circumferential (LVEDC) segment length suggesting a reduction in diastolic compliance. There were also increases in left ventricular systolic pressure (LVSP) as well as its first derivative (LV dp/dt). Bilateral stellectomy during the veratrine response abruptly reduced LVEDP with a lesser decrease in LVEDC. Thus, the left ventricular compliance change was reversed. Both LVSP and LV dp/dt were decreased by stellectomy but remained above control levels. During transfusion, the pressure-length curve of the ventricle was located downward and to the right in comparison with the curve observed with intracisternal veratrine.

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