What question did this study set out to answer?

This research aims to assess how different pacing sites influence left ventricular contraction and pressure generation in canine hearts.

August 1, 1986AJP Heart and Circulatory Physiology

Influence of pacing site on canine left ventricular contraction

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Why the study?

Does pacing site influence left ventricular contraction and effective ventricular muscle mass in isolated canine hearts?

Key Points

This research aims to assess how different pacing sites influence left ventricular contraction and pressure generation in canine hearts.
Experiments conducted on isolated canine hearts constrained to contract isovolumically.
Pacing sites included atrium, left ventricular apex, left ventricular free wall, right ventricular free wall, and right ventricular endocardium at a rate of 130 beats/min.
Measurements of peak left ventricular pressure recorded and compared among different pacing sites.
Peak left ventricular pressure was highest with atrial pacing, averaging 26 +/- 10% greater than that from right ventricular free wall pacing.
There was a linear negative correlation (r = 0.971) between peak pressure changes and QRS complex duration changes with an average slope of -0.51 mmHg/ms.
End-systolic pressure-volume relation slope decreased with ventricular pacing compared to atrial pacing, while volume axis intercept remained constant.

Structured PICO

Does pacing site influence left ventricular contraction and effective ventricular muscle mass in isolated canine hearts?

Population

8 isolated supported canine hearts constrained to contract isovolumically

Intervention

Pacing from different sites (atrium, LV apex, LV free wall, right ventricular free wall, right ventricular endocardium) at 130 beats/min

Comparator

Atrial pacing (used as reference)

Outcome

Magnitude and time course of isovolumic LV pressure (P) generationsurrogate

Direct ventricular pacing, particularly from the right ventricular free wall, reduces peak left ventricular pressure and effective ventricular muscle mass compared to atrial pacing in isolated canine hearts.

Discussion

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Implication

RV pacing lowers peak LVP versus atrial pacing in isolated canine hearts; hypothesis-generating for dyssynchrony effects, requires in vivo confirmation.

Cite This Study

Burkhoff et al. (1986) studied this question.

synapsesocial.com/papers/69f3edd9dc238f81977994bf https://doi.org/10.1152/ajpheart.1986.251.2.h428

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Implication

RV pacing lowers peak LVP versus atrial pacing in isolated canine hearts; hypothesis-generating for dyssynchrony effects, requires in vivo confirmation.

Influence of pacing site on canine left ventricular contraction

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Influence of pacing site on canine left ventricular contraction

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Also Consider

Also Consider