What question did this study set out to answer?

To evaluate the specific roles of beta-1 versus nonselective beta-adrenergic receptors in modulating left ventricular performance and dimensions in response to epinephrine infusion.

May 1, 1988Clinical Pharmacology & Therapeutics

Epinephrine and left ventricular function in humans: Effects of beta-1 vs nonselective beta-blockade

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Why the study?

Does pretreatment with beta-1 selective versus nonselective beta-blockers alter the effects of epinephrine on left ventricular function in normotensive healthy subjects?

Population

Normotensive healthy subjects

Comparison

Pretreatment with atenolol or propranolol… vs Pretreatment with placebo followed by graded…

Design

Other

Authors

FLFrans H. H. LeenenPreventive Cardiology YCYvonne ChanSt. Michael's Hospital DSDonna L SmithUniversity of Minnesota

Discussion

Member takes

Implication

Findings in healthy subjects should not yet change practice; leaves open beta-receptor subtype roles in clinical epinephrine responses.

Key Points

To evaluate the specific roles of beta-1 versus nonselective beta-adrenergic receptors in modulating left ventricular performance and dimensions in response to epinephrine infusion.
Assessed cardiac performance via M-mode echocardiography during graded epinephrine infusions in normotensive healthy subjects.
Evaluated responses after pretreatment with placebo, the beta-1-selective blocker atenolol, or the nonselective beta-blocker propranolol.
Measured heart rate, left ventricular end-diastolic and end-systolic dimensions, fractional shortening, and the systolic blood pressure to end-systolic volume ratio.
Epinephrine alone increased heart rate, left ventricular end-diastolic dimension, fractional shortening, and the pressure-volume ratio while decreasing end-systolic dimension.
Atenolol did not significantly alter epinephrine-induced heart rate increases, but abolished left ventricular dimension and performance gains at lower infusion rates and blunted them at high rates.
Propranolol caused epinephrine to significantly decrease left ventricular end-diastolic dimension and ventricular emptying while leaving the pressure-volume ratio unchanged.

Structured PICO

Does pretreatment with beta-1 selective versus nonselective beta-blockers alter the effects of epinephrine on left ventricular function in normotensive healthy subjects?

Population

Normotensive healthy subjects

Intervention

Pretreatment with atenolol (beta 1-selective blocker) or propranolol (nonselective beta-blocker) followed by graded epinephrine infusion

Comparator

Pretreatment with placebo followed by graded epinephrine infusion

Outcome

Changes in cardiac performance assessed by M-mode echocardiography (including heart rate, left ventricular end diastolic dimension, left ventricular end systolic dimension, fractional shortening, and systolic blood pressure/end-systolic volume ratio)surrogate

Epinephrine's positive inotropic effect appears to be mediated primarily via beta-1 receptors, while beta-2 receptors play a major role in its chronotropic effects.

Cite This Study

Leenen et al. (1988) studied this question.

synapsesocial.com/papers/6a6f978e31a3df824327f08f https://doi.org/10.1038/clpt.1988.67

Topics

Echocardiography

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Epinephrine and left ventricular function in humans: Effects of beta-1 vs nonselective beta-blockade

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Topics

Epinephrine and left ventricular function in humans: Effects of beta-1 vs nonselective beta-blockade

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Topics

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