What is the clinical evidence from this study?

Study design: Other. Intervention: Tachycardia (heart rate >150/min) vs. Heart rate <150/min. Primary outcome: Coronary blood supply to the right and left ventricles.

What question did this study set out to answer?

To evaluate how changes in heart rate influence coronary blood flow distribution between the right and left ventricles.

January 22, 1981Quarterly Journal of Experimental PhysiologyOpen Access

Dynamic Redistribution of Coronary Blood Flow in the Dog as Measured by a Thermistor Technique

Q: What are the key findings of this study?

Tachycardia (>150 beats/min) caused coronary blood flow to be dynamically redistributed in favor of the right ventricle, while left ventricular perfusion increased less or declined.

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Key result

Tachycardia (>150 beats/min) caused coronary blood flow to be dynamically redistributed in favor of the right ventricle, while left ventricular perfusion increased less or declined.

Why the study?

Does elevation of heart rate affect the distribution of coronary blood flow to the right and left ventricles in dogs?

Population

Anaesthetized, open-chest dogs

Comparison

Elevation of heart rate (tachycardia) vs Lower heart rates (less than about 150/min)

Design

Preclinical

Authors

JKJ. KedemRutgers, The State University of New Jersey BAB. A. AcadJohnson University JSJudith SonnBar-Ilan University

Discussion

Member takes

Implication

Does not support changing heart rate targets in patients; leaves open whether tachycardia redistributes coronary flow similarly in humans.

Key Points

To evaluate how changes in heart rate influence coronary blood flow distribution between the right and left ventricles.
Assessed coronary blood perfusion in anaesthetized, open-chest dogs using thermistors placed locally on the surface or within the ventricular wall.
Validated the thermistor technique both in vivo and in an in vitro model, alongside electromagnetic flowmeters measuring flow through the anterior descending and circumflex arteries, coronary sinus, and Thebesian drainage.
At heart rates below approximately 150 beats per minute, coronary blood flow increased equally to both ventricles as rate rose.
At heart rates exceeding 150 beats per minute, perfusion to the right ventricle continued to increase linearly, whereas left ventricular perfusion increased substantially less or declined.

Structured PICO

Does elevation of heart rate affect the distribution of coronary blood flow to the right and left ventricles in dogs?

Population

Anaesthetized, open-chest dogs evaluated for the effect of heart rate on coronary blood supply.

Exposure

Elevation of heart rate (tachycardia)

Comparator

Lower heart rates (less than about 150/min)

Outcome

Coronary blood supply/perfusion to the right and left ventricles measured by thermistors and electromagnetic flowmeterssurrogate

Tachycardia causes a dynamic redistribution of coronary blood flow in favor of the right ventricle in a canine model.

Cite This Study

Kedem et al. (1981) studied this question. Tachycardia (heart rate >150/min) vs. Heart rate <150/min was evaluated on Coronary blood supply to the right and left ventricles. Tachycardia (>150 beats/min) caused coronary blood flow to be dynamically redistributed in favor of the right ventricle, while left ventricular perfusion increased less or declined.

synapsesocial.com/papers/6a970f01c00de92d9bfbe0fe https://doi.org/10.1113/expphysiol.1981.sp002526

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Implication

Does not support changing heart rate targets in patients; leaves open whether tachycardia redistributes coronary flow similarly in humans.

Dynamic Redistribution of Coronary Blood Flow in the Dog as Measured by a Thermistor Technique

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Dynamic Redistribution of Coronary Blood Flow in the Dog as Measured by a Thermistor Technique

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider