What question did this study set out to answer?

Determine the reflex vascular effects of isolated mechanical stretch of the right and left ventricles on systemic, skeletal muscle, and cutaneous resistance.

September 1, 1977Cardiovascular Research

Effects of isolated right and left ventricular stretch on regional arteriolar resistance

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Why the study?

Does isolated right and left ventricular stretch affect regional arteriolar resistance in dogs?

Population

12 dogs placed on total cardiopulmonary bypass

Comparison

Isolated left ventricular stretch and right… vs Baseline/un-stretched state

Design

Preclinical

Authors

RZR. ZelisPennsylvania State University MLM. LotyshPennsylvania State University MBM BraisUniversity of Ottawa

Discussion

Member takes

Implication

May reduce muscle vascular resistance via ventricular reflexes in dogs; leaves open human relevance in postural or ischemic states.

Key Points

Determine the reflex vascular effects of isolated mechanical stretch of the right and left ventricles on systemic, skeletal muscle, and cutaneous resistance.
Placed 12 dogs on total cardiopulmonary bypass and inserted compliant balloons into the right and left ventricles to selectively stretch each chamber.
Inflated the left ventricle from 1.33 to 7.32 kPa (10 to 55 mmHg) for 15 seconds and the right ventricle from 0.67 to 4.00 kPa (5 to 30 mmHg) for 30 seconds.
Monitored perfusion pressures across the systemic circulation, gracilis muscle, and cutaneous paw vascular beds under constant-flow conditions.
Both left and right ventricular stretch induced significant drops in systemic perfusion pressure (-4.92 kPa [-37 mmHg], -36%) and gracilis muscle perfusion pressure (-5.59 kPa [-42 mmHg], -30%), but had minimal effect on cutaneous resistance (-0.80 kPa [-6 mmHg], -4%).
The reflex response operated with low activation thresholds (a 0.67 kPa [5 mmHg] rise in the left ventricle and 1.33 kPa [10 mmHg] in the right ventricle) through vagal afferent pathways and a sympathetic alpha-adrenergic efferent limb.

Structured PICO

Does isolated right and left ventricular stretch affect regional arteriolar resistance in dogs?

Population

12 dogs placed on total cardiopulmonary bypass

Intervention

Isolated left ventricular stretch (balloon inflation from 1.33 kPa to 7.32 kPa for 15s) and right ventricular stretch (balloon inflation from 0.67 to 4.00 kPa for 30s)

Comparator

Baseline/un-stretched state

Outcome

Changes in systemic, gracilis muscle, and paw perfusion pressure at a constant flowsurrogate

Isolated right and left ventricular stretch in dogs induces a vagally mediated reflex that significantly decreases systemic and muscle vascular resistance, which may play a physiological role in postural changes and pathological conditions like valvular stenosis or myocardial infarction.

Cite This Study

Zelis et al. (1977) studied this question.

synapsesocial.com/papers/6a843fb98658c07e42f79537 https://doi.org/10.1093/cvr/11.5.419

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Effects of isolated right and left ventricular stretch on regional arteriolar resistance

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Effects of isolated right and left ventricular stretch on regional arteriolar resistance

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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