What does this research mean for the field?

The stroke volume response to elevated aortic blood pressure is determined by a balance between the stroke-volume-increasing effect of increased end-diastolic myocardial fiber length and the stroke-volume-reducing effect of reduced myocardial shortening, which shifts toward increased stroke volume under high adrenergic activity. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

To identify the physiological mechanisms regulating ventricular stroke volume and myocardial contractility during acute elevations in aortic blood pressure under diverse adrenergic conditions.

January 1, 1972Scandinavian Journal of Clinical and Laboratory Investigation

Cardiac Mechanisms for Regulating Stroke Volume during Elevation of Aortic Blood Pressure in Dogs

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Why the study?

Does high adrenergic activity alter the stroke volume response to elevated aortic blood pressure in dogs?

Population

Open-chest and conscious dogs

Comparison

Elevation of aortic blood pressure at high… vs Elevation of aortic blood pressure in control…

Design

Preclinical

Authors

BBB Bugge-AsperheimOslo University Hospital FKFredrik KiilOslo University Hospital

Discussion

Member takes

Implication

High adrenergic activity may preserve stroke volume during afterload rise in dogs; extends Frank-Starling insights but leaves open human translation.

Key Points

To identify the physiological mechanisms regulating ventricular stroke volume and myocardial contractility during acute elevations in aortic blood pressure under diverse adrenergic conditions.
Evaluated conscious and open-chest canine models during induced aortic blood pressure elevation under baseline conditions, beta-adrenergic blockade with propranolol, and enhanced adrenergic stimulation via isoproterenol infusion or left stellate ganglion stimulation.
Measured myocardial segment dimensions using ultrasonic gauges and determined ventricular volumes using thermodilution techniques, with selective manipulation of coronary blood flow.
Aortic blood pressure elevation consistently increased left ventricular end-diastolic volume across all experimental states.
Stroke volume and myocardial shortening decreased upon aortic pressure elevation in control and beta-blocked states, but increased significantly under high adrenergic stimulation.
Myocardial shortening enhancement during high adrenergic tone persisted despite reducing coronary blood flow to control levels, ruling out accelerated catecholamine delivery as the primary driver.

Structured PICO

Does high adrenergic activity alter the stroke volume response to elevated aortic blood pressure in dogs?

Population

Open-chest and conscious dogs

Intervention

Elevation of aortic blood pressure at high adrenergic activity (constant isoproterenol infusion or stimulation of left stellate ganglion)

Comparator

Elevation of aortic blood pressure in control conditions and after propranolol administration

Outcome

Stroke volume and cardiac outputsurrogate

The study demonstrates that high adrenergic activity shifts the balance of the Frank-Starling mechanism and myocardial shortening to increase stroke volume during elevated aortic pressure.

Cite This Study

Bugge-Asperheim et al. (1972) studied this question.

synapsesocial.com/papers/6a199a254b45427442ea75b2 https://doi.org/10.3109/00365517209081086

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Implication

High adrenergic activity may preserve stroke volume during afterload rise in dogs; extends Frank-Starling insights but leaves open human translation.

Cardiac Mechanisms for Regulating Stroke Volume during Elevation of Aortic Blood Pressure in Dogs

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Cardiac Mechanisms for Regulating Stroke Volume during Elevation of Aortic Blood Pressure in Dogs

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider