February 1, 1994CirculationOpen Access

Dependence of Gorlin formula and continuity equation valve areas on transvalvular volume flow rate in valvular aortic stenosis.

Q: What is the clinical evidence from this study?

Study design: Other. Population: Chronic valvular aortic stenosis (n=8). Intervention: Saline or dobutamine infusion to alter transvalvular volume flow rate vs. Minimum vs maximum mean volume flow rates. Primary outcome: Aortic valve areas calculated using the Gorlin formula and the continuity equation (p=<.0001).

Q: What question did this study set out to answer?

Investigate the effects of altering transvalvular volume flow rate on aortic valve areas calculated using the Gorlin formula and the Doppler-echocardiographic continuity equation in chronic aortic stenosis.

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Why the study?

Does altering transvalvular volume flow rate affect aortic valve areas calculated by Gorlin formula and continuity equation in a canine model of chronic valvular aortic stenosis?

Population

Canine model of chronic valvular aortic stenosis (n=8)

Comparison

Alteration of transvalvular volume flow rates… vs Different flow rates within the same subjects

Design

Preclinical

Follow-up

3 studies at 2-week intervals

Key result

Altering transvalvular volume flow rates significantly changed calculated aortic valve areas using both the Gorlin formula (0.54 to 0.68 cm2) and continuity equation (0.57 to 0.70 cm2) (P<0.0001).

Authors

IBIan G. Burwash DTDavid D. Thomas MSMitsuaki Sadahiro

Discussion

Member takes

Overview

Flow dependence of calculated AVA persists in chronic AS; leaves open need for flow-adjusted interpretation in patients.

Key Points

Investigate the effects of altering transvalvular volume flow rate on aortic valve areas calculated using the Gorlin formula and the Doppler-echocardiographic continuity equation in chronic aortic stenosis.
Evaluated a canine model of chronic valvular aortic stenosis (n = 8) across 24 total catheterization sessions performed at 2-week intervals.
Manipulated transvalvular volume flow rates across a broad hemodynamic range using saline or dobutamine infusions (mean, 10.3 ± 5.1 flow rates per study).
Simultaneously collected invasive micromanometer hemodynamics, transit-time flowmeter volume flow rates, and Doppler echocardiographic velocity profiles.
Transit-time transvalvular volume flow rates ranged from 80 ± 33 to 153 ± 49 mL/min across studies (P < .0001).
Gorlin valve area increased from 0.54 ± 0.22 cm² at minimum flow to 0.68 ± 0.21 cm² at maximum flow (P < .0001), showing a strong linear relation with flow rate (median r = .88).
Continuity equation valve area increased from 0.57 ± 0.18 cm² at minimum flow to 0.70 ± 0.20 cm² at maximum flow (P < .0001), displaying a moderate linear relation with flow rate (median r = .51).

Structured PICO

Does altering transvalvular volume flow rate affect aortic valve areas calculated by Gorlin formula and continuity equation in a canine model of chronic valvular aortic stenosis?

Population

Canine model of chronic valvular aortic stenosis (n=8)

Intervention

Alteration of transvalvular volume flow rates with saline or dobutamine infusion

Comparator

Different flow rates within the same subjects (minimum vs maximum mean volume flow rates)

Outcome

Aortic valve areas calculated using the Gorlin formula and the continuity equationsurrogate

Main Result

p-value: p=<.0001

In a canine model of aortic stenosis, both Gorlin and continuity equation valve areas were flow-dependent, indicating that changes in transvalvular volume flow should be considered when assessing hemodynamic severity.

Cite This Study

Burwash et al. (1994) studied Chronic valvular aortic stenosis (n=8). Saline or dobutamine infusion to alter transvalvular volume flow rate vs. Minimum vs maximum mean volume flow rates was evaluated on Aortic valve areas calculated using the Gorlin formula and the continuity equation (p=<.0001). Altering transvalvular volume flow rates significantly changed calculated aortic valve areas using both the Gorlin formula (0.54 to 0.68 cm2) and continuity equation (0.57 to 0.70 cm2) (P<0.0001).

synapsesocial.com/papers/6a08ac82ad370a6b44de42eb https://doi.org/10.1161/01.cir.89.2.827

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February 1, 1994CirculationOpen Access

Dependence of Gorlin formula and continuity equation valve areas on transvalvular volume flow rate in valvular aortic stenosis.

View Full Paper

Ask AI

Bookmark

Why the study?

Does altering transvalvular volume flow rate affect aortic valve areas calculated by Gorlin formula and continuity equation in a canine model of chronic valvular aortic stenosis?

Population

Canine model of chronic valvular aortic stenosis (n=8)

Comparison

Alteration of transvalvular volume flow rates… vs Different flow rates within the same subjects

Design

Preclinical

Follow-up

3 studies at 2-week intervals

Key result

Altering transvalvular volume flow rates significantly changed calculated aortic valve areas using both the Gorlin formula (0.54 to 0.68 cm2) and continuity equation (0.57 to 0.70 cm2) (P<0.0001).

Authors

IBIan G. Burwash DTDavid D. Thomas MSMitsuaki Sadahiro

Discussion

Member takes

Overview

Flow dependence of calculated AVA persists in chronic AS; leaves open need for flow-adjusted interpretation in patients.

Key Points

Investigate the effects of altering transvalvular volume flow rate on aortic valve areas calculated using the Gorlin formula and the Doppler-echocardiographic continuity equation in chronic aortic stenosis.
Evaluated a canine model of chronic valvular aortic stenosis (n = 8) across 24 total catheterization sessions performed at 2-week intervals.
Manipulated transvalvular volume flow rates across a broad hemodynamic range using saline or dobutamine infusions (mean, 10.3 ± 5.1 flow rates per study).
Simultaneously collected invasive micromanometer hemodynamics, transit-time flowmeter volume flow rates, and Doppler echocardiographic velocity profiles.
Transit-time transvalvular volume flow rates ranged from 80 ± 33 to 153 ± 49 mL/min across studies (P < .0001).
Gorlin valve area increased from 0.54 ± 0.22 cm² at minimum flow to 0.68 ± 0.21 cm² at maximum flow (P < .0001), showing a strong linear relation with flow rate (median r = .88).
Continuity equation valve area increased from 0.57 ± 0.18 cm² at minimum flow to 0.70 ± 0.20 cm² at maximum flow (P < .0001), displaying a moderate linear relation with flow rate (median r = .51).

Structured PICO

Does altering transvalvular volume flow rate affect aortic valve areas calculated by Gorlin formula and continuity equation in a canine model of chronic valvular aortic stenosis?

Population

Canine model of chronic valvular aortic stenosis (n=8)

Intervention

Alteration of transvalvular volume flow rates with saline or dobutamine infusion

Comparator

Different flow rates within the same subjects (minimum vs maximum mean volume flow rates)

Outcome

Aortic valve areas calculated using the Gorlin formula and the continuity equationsurrogate

Main Result

p-value: p=<.0001

Cite This Study

synapsesocial.com/papers/6a08ac82ad370a6b44de42eb https://doi.org/10.1161/01.cir.89.2.827

Also Consider

Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context:

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