What question did this study set out to answer?

To examine the roles of the sympathetic nervous system and the renin-angiotensin system in regulating regional blood flow distribution during progressive cardiac tamponade.

January 1, 1987Circulation ResearchOpen Access

Influences on the distribution of blood flow during cardiac tamponade in the conscious dog.

Q: What is the clinical evidence from this study?

Study design: Other. Population: Cardiac tamponade (n=6). Intervention: Alpha-adrenergic, beta-adrenergic, or angiotensin-converting enzyme blockade vs. Absence of blockade (control). Primary outcome: Distribution of blood flow (aortic, renal, coronary, and mesenteric artery blood flows).

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Key result

During progressive cardiac tamponade in conscious dogs, coronary artery blood flow decline was partly mediated by alpha-adrenergic mechanisms, while renal artery blood flow was well maintained.

Why the study?

Does pharmacological blockade of the sympathetic or renin-angiotensin systems alter the distribution of blood flow during progressive cardiac tamponade in conscious dogs?

Population

6 chronically instrumented conscious dogs undergoing 51 episodes of acute cardiac tamponade induced to…

Comparison

Alpha-adrenergic blockade, beta-adrenergic… vs Absence of blockade (control)

Design

Preclinical

Authors

GBG A BernathAtrium Health Wake Forest Baptist TCT L CogswellAtrium Health Wake Forest Baptist RHRichard G. HoffmanUniversity of Minnesota

Discussion

Member takes

Implication

No immediate clinical implications; extends mechanistic insight into regional flow in conscious canine tamponade.

Key Points

To examine the roles of the sympathetic nervous system and the renin-angiotensin system in regulating regional blood flow distribution during progressive cardiac tamponade.
Induced 51 episodes of acute cardiac tamponade to decompensation (aortic pressure reduced to 70% of baseline) via intrapericardial saline infusion in 6 chronically instrumented conscious dogs.
Measured cardiac output, intrapericardial and vascular pressures, and Doppler blood flows in aortic, coronary, renal, and mesenteric beds under control conditions and during pharmacological blockades (phenoxybenzamine, propranolol, or captopril).
Aortic and mesenteric blood flows declined progressively during tamponade regardless of alpha-, beta-, or angiotensin-converting enzyme blockade.
Coronary artery blood flow was maintained without significant change during alpha-adrenergic blockade, demonstrating that tamponade-induced coronary vasoconstriction is partly alpha-receptor mediated.
Renal artery blood flow remained well preserved across all pharmacological blockade conditions, confirming robust intrinsic renal autoregulation during progressive cardiac tamponade.

Structured PICO

Does pharmacological blockade of the sympathetic or renin-angiotensin systems alter the distribution of blood flow during progressive cardiac tamponade in conscious dogs?

Population

6 chronically instrumented conscious dogs undergoing 51 episodes of acute cardiac tamponade induced to decompensation.

Intervention

Alpha-adrenergic blockade (phenoxybenzamine), beta-adrenergic blockade (propranolol), or angiotensin-converting enzyme blockade (captopril)

Comparator

Absence of blockade (control)

Outcome

Changes in cardiac output, intrapericardial pressure, aortic and right atrial blood pressures, and renal, coronary, and mesenteric artery blood flowssurrogate

Alpha-adrenergic mechanisms contribute to the decline in coronary blood flow during cardiac tamponade, whereas renal blood flow is maintained by autoregulation regardless of sympathetic or renin-angiotensin blockade.

Cite This Study

Bernath et al. (1987) studied Cardiac tamponade (n=6). Alpha-adrenergic, beta-adrenergic, or angiotensin-converting enzyme blockade vs. Absence of blockade (control) was evaluated on Distribution of blood flow (aortic, renal, coronary, and mesenteric artery blood flows). During progressive cardiac tamponade in conscious dogs, coronary artery blood flow decline was partly mediated by alpha-adrenergic mechanisms, while renal artery blood flow was well maintained.

synapsesocial.com/papers/6a93be630d47ea57beb85c21 https://doi.org/10.1161/01.res.60.1.72

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Influences on the distribution of blood flow during cardiac tamponade in the conscious dog.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Influences on the distribution of blood flow during cardiac tamponade in the conscious dog.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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