What question did this study set out to answer?

To evaluate the direct, continuous effects of intravenous and sublingual nitroglycerin on systemic, coronary, and regional hemodynamics, left ventricular dimensions, and myocardial contractility.

March 1, 1978AJP Heart and Circulatory Physiology

Effects of nitroglycerin on cardiac function and regional blood flow distribution in conscious dogs

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Why the study?

Does nitroglycerin alter cardiac function and regional blood flow distribution in conscious dogs?

Population

Conscious dogs (including deafferented dogs)

Comparison

Intravenous infusion of nitroglycerin 8 and 32… vs Baseline/control measurements

Design

Preclinical

Follow-up

Acute (minutes)

Authors

SVStephen F. VatnerHeart Failure & Transplant MPM. PaganiUniversity of Milan JRJennifer RutherfordCharles River Laboratories (Netherlands)

Discussion

Member takes

Implication

Biphasic NTG response in dogs warrants caution against clinical extrapolation; leaves open mechanisms and human relevance for nitrate therapy.

Key Points

To evaluate the direct, continuous effects of intravenous and sublingual nitroglycerin on systemic, coronary, and regional hemodynamics, left ventricular dimensions, and myocardial contractility.
Administered intravenous nitroglycerin infusions (8 and 32 µg/kg·min for 7 minutes), sublingual nitroglycerin (1.2 mg), and direct iliac intra-arterial infusions (1 µg/kg·min) in conscious dogs.
Continuously recorded left ventricular pressures, dimensions, dP/dt, and blood flows across coronary, mesenteric, renal, and iliac vascular beds in intact and deafferented states.
Nitroglycerin initially induced transient increases in heart rate, dP/dt, cardiac output, and regional blood flows, accompanied by reduced mean arterial pressure and vascular resistances.
A secondary phase followed where cardiac output, cardiac work, and mesenteric and iliac flows fell significantly below baseline, with marked systemic, mesenteric, iliac, and coronary vasoconstriction while left ventricular end-diastolic dimensions remained reduced.
Late peripheral vasoconstriction was absent during local intra-arterial infusion or in deafferented dogs, confirming secondary reflex mediation.

Structured PICO

Does nitroglycerin alter cardiac function and regional blood flow distribution in conscious dogs?

Population

Conscious dogs (including deafferented dogs)

Intervention

Intravenous infusion of nitroglycerin (NTG) 8 and 32 microgram/kg.min for 7 min, sublingual NTG 1.2 mg, and intra-arterial NTG 1 microgram/kg.min

Comparator

Baseline/control measurements

Outcome

Systemic, coronary, and regional hemodynamics, left ventricular (LV) dimensions, pressures, and myocardial contractilitysurrogate

Systemic nitroglycerin induces a biphasic hemodynamic response in conscious dogs, characterized by initial vasodilation followed by reflex vasoconstriction.

Cite This Study

Vatner et al. (1978) studied this question.

synapsesocial.com/papers/6a873736bb0787ff27ca1ff1 https://doi.org/10.1152/ajpheart.1978.234.3.h244

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Implication

Biphasic NTG response in dogs warrants caution against clinical extrapolation; leaves open mechanisms and human relevance for nitrate therapy.

Effects of nitroglycerin on cardiac function and regional blood flow distribution in conscious dogs

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Effects of nitroglycerin on cardiac function and regional blood flow distribution in conscious dogs

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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