Effect of Aortic Stenosis on Coronary Flow Dynamics: Studies in an In-Vitro Pulse Duplicating System

1982 ◽  
Vol 104 (3) ◽  
pp. 221-225 ◽  
Author(s):  
H. N. Sabbah ◽  
P. D. Stein
Keyword(s):  
Coronary Artery ◽  
Aortic Valve ◽  
Left Ventricle ◽  
Coronary Flow ◽  
Left Coronary Artery ◽  
Valvular Stenosis ◽  
Catheter Tip ◽  
Retrograde Coronary Flow

The dynamics of retrograde coronary flow in aortic valvular stenosis was investigated in an in-vitro pulse duplicating system which had the capability of simulating coronary flow. The ventricular chamber of the pulse duplicator consisted of an opaque elastic sac molded from rubber in the shape of a left ventricle. The aortic test section consisted of an acrylic mold of the root of the aorta of a calf, which included the sinuses of Valsalva and the entrance region of both the left and right coronary arteries. Flow in the left coronary artery was modeled to deliver both a systolic and a diastolic component of flow. Studies were performed with normal porcine valves in the aortic and mitral positions and were repeated with a human stenotic valve in the aortic position. Pressures were measured in the aorta, left ventricle, and at the ostium of the left coronary artery with catheter-tip micromanometers. In the presence of a normal aortic valve, total coronary flow was adjusted to 120 ml/min of which 21 percent of the flow occurred during systole. The phasic pattern of coronary flow was similar to that shown in vivo. In the presence of a stenotic aortic valve, a small amount of retrograde coronary flow (<1 percent of total coronary flow) was observed; and this occurred during the initial phase of systole. Retrograde coronary flow during systole appears to have resulted from compression of the collapsible segment of the simulated coronary artery. This was caused by the elevated simulated intramural pressure.

In Vitro Investigation of the Impact of Aortic Valve Stenosis Severity on Left Coronary Artery Flow

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
E. Gaillard ◽  
D. Garcia ◽  
L. Kadem ◽  
P. Pibarot ◽  
L.-G. Durand
Keyword(s):  
Coronary Artery ◽  
Angina Pectoris ◽  
Aortic Valve ◽  
Coronary Flow ◽  
Left Coronary Artery ◽  
In Vitro Model ◽  
Coronary Circulation ◽  
Physiological Conditions ◽  
Vitro Model

Patients with aortic valve stenosis (AS) may experience angina pectoris even if they have angiographically normal coronary arteries. Angina is associated with a marked increase in the risk of sudden death in AS patients. Only a few in vitro models describing the interaction between the left ventricular and aortic pressures, and the coronary circulation have been reported. These models were designed for specific research studies and they need to be improved or modified when other specific studies are required. Consequently, we have developed an in vitro model that is able to mimic the coronary circulation in presence of aortic stenosis. First, we have validated the model under physiological conditions. Then, we have examined and quantified the hemodynamic effects of different degrees of AS (from normal to severe AS) on the coronary flow using a model of the normal left coronary artery. In the coronary in vitro model without AS (normal valve), the amplitude and shape of coronary flow were similar to those observed in in vivo measurements obtained under physiological conditions, as described by Hozumi et al. (1998, “Noninvasive Assessment of Significant Left Anterior Descending Coronary Artery Stenosis by Coronary Flow Velocity Reserve With Transthoracic Color Doppler Echocardiography,” Circulation, 97, pp. 1557–1562). The presence of an AS induced an increase in the maximum and mean coronary flow rates (97% and 73%, respectively, for a very severe AS). Furthermore, when AS was very severe, a retrograde flow occurred during systole. This study allowed us to validate our coronary in vitro model under physiological conditions, both in the absence and presence of AS. These changes could explain the fact that even if patients have angiographically normal epicardial coronary arteries, we can observe the occurrence of angina pectoris in these patients in the presence of an AS.

Near-fatal neonatal coronary ischaemia associated with intermittent aortic regurgitation: successful surgical treatment

2015 ◽  
Vol 25 (8) ◽  
pp. 1531-1535 ◽  
Author(s):  
Maggie L. Likes ◽  
Norman H. Silverman ◽  
Erin L. Albers ◽  
Raylene Choy ◽  
Aarti Bhat ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Surgical Treatment ◽  
Cardiac Function ◽  
Aortic Regurgitation ◽  
Coronary Arteries ◽  
Coronary Flow ◽  
Left Coronary Artery ◽  
Anomalous Left Coronary Artery ◽  
Retrograde Coronary Flow ◽  
Anomalous Left Coronary

AbstractAn infant presented with features suggestive of an anomalous left coronary artery was found to have normal origins of both coronary arteries. Echocardiography during episodes of ischaemia showed marked aortic regurgitation with retrograde coronary flow. The left coronary leaflet was mildly hypoplastic. Surgical re-suspension of this leaflet prevented aortic regurgitation and the patient had no further symptoms and recovered cardiac function.

Scintigraphic Detection of Experimental Myocardial Infarction with 99mTc-Heparin in the Dog

1985 ◽  
Vol 24 (03) ◽  
pp. 111-114 ◽  
Author(s):  
P. Kafka ◽  
J. Kubíček ◽  
J. Vižda ◽  
Y. Mazurová ◽  
F. Duška
Keyword(s):  
Myocardial Infarction ◽  
Coronary Artery ◽  
Left Coronary Artery ◽  
Background Activity ◽  
Experimental Myocardial Infarction ◽  
The Other ◽  
Tissue Samples ◽  
Ramus Interventricularis Anterior

SummaryExperimental infarctions were produced in 12 dogs by ligation of the Ramus interventricularis anterior of the left coronary artery, and their uptake of 99mTc-heparin was measured 7, 24 and 48 h as well as 7 days thereafter by recording an in vivo chest scintigram 4 h after intravenous injection of the compound. The dogs were subsequently killed, the heart removed and an in vitro scintigram obtained. Finally, the uptake of the compound was measured in tissue samples. The results indicate that 99mTc-heparin is accumulated in lesions which are not older than 24 h. At the other points in time uptake is low but even 24-h old lesions cannot be demonstrated reliably. The results are impaired by the high blood activity on the cardiac chambers and by the background activity of the lungs. In general, 99mTc-heparin has less useful properties than the more frequently employed 99mTc-pyrophosphate so that a change of procedure is not to be recommended.

Dynamic Capacitance of Epicardial Coronary Arteries In Vivo

1985 ◽  
Vol 107 (1) ◽  
pp. 29-33 ◽  
Author(s):  
R. S. Reneman ◽  
T. Arts
Keyword(s):  
Coronary Artery ◽  
Coronary Arteries ◽  
Left Coronary Artery ◽  
Pressure Pulse ◽  
Front Velocity ◽  
Arterial System ◽  
The Right ◽  
Dynamic Capacitance

The dynamic capacitance of epicardial coronary arteries (i.d. ≥ 0.4 mm) in vivo was assessed from the volume stiffness and volume of these arteries. The volume stiffness was derived from the pressure wave front velocity as determined in dogs by measuring the delay time between the pressure pulses recorded proximal and distal to a segment of the anterior descending branch of the left coronary artery. The pressure pulse was generated elsewhere in the arterial system during diastole. The volume of the epicardial coronary arteries was calculated from the lengths and diameters as measured in araldite casts, making corrections for in-vitro/in-vivo differences in dimensions. The dynamic capacitance of the right coronary artery, and the anterior descending and circumflex branches of the left coronary artery at an arterial pressure of 13.3 kPa and a frequency between 7 and 30 Hz was found to be 0.0024 ± 0.0013, 0.0062 ± 0.0028 and 0.0079 ± 0.0035 mL/kPa (mean ± SD), respectively. The total capacitance of the epicardial coronary arteries was calculated to be (0.007 mL/kPa)/100 g, which is small as compared to the total capacitance of the coronary vasculature, including the intramyocardial compartment, which is in the order of (0.5 mL/kPa)/100g [1].

scholarly journals Prognostic value of non-invasive coronary artery flow velocity assessment in elderly patients

2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
E Kalinina ◽  
A Zagatina ◽  
N Zhuravskaya ◽  
D Shmatov
Keyword(s):  
Myocardial Infarction ◽  
Coronary Artery ◽  
Elderly Patients ◽  
Flow Velocity ◽  
Coronary Arteries ◽  
Coronary Flow ◽  
Prognostic Value ◽  
Area Under Curve ◽  
Left Coronary Artery ◽  
Maximal Velocity

Abstract Funding Acknowledgements Type of funding sources: None. Background There is a high prevalence of coronary artery disease (CAD) in the elderly population. However, symptoms of CAD are often non-specific. Dyspnoe, non-anginal pains are among the main symptoms in older patients. Exercise tests are of limited feasibility in these patients, due to neuro-muscular weakness, physical deconditioning, and orthopaedic limitations. Pharmacological tests often are contraindicated in a substantial percentage of elderly patients. Some recent studies indicate using local flow acceleration during routine echocardiography has prognostic potential for coronary artery assessments without stress testing. The aim of the study was to define the prognostic value of coronary artery ultrasound assessment in patients ≥75 years old. Methods This is a prospective cohort study. Patients ≥ 75 years old who underwent routine echocardiography with additional scans for coronary arteries over a period of 24 months were included in the study. The study group consisted of 80 patients aged 75-90 years (56 women; mean age 79 ± 4). Initial exams were performed for other reasons, primarily for arterial hypertension. Fifteen patients had known CAD. Death, non-fatal myocardial infarction (MI), and revascularization were defined as major adverse cardiac events (MACE). All patients were followed up with at a median of 32 months. Results There were 34 patients with high local velocities in the left coronary artery. Eight deaths, two non-fatal myocardial infarctions occurred, and 13 revascularizations were performed. With a ROC analysis, a coronary flow velocity &gt;110 cm/s was the best predictor for risk of death (area under curve 0.84 [95% CI 0.74–0.92]; sensitivity 75%; specificity 88%). Only the maximal velocity in proximal left-sided coronary arteries was independently associated with death (HR 1.03, 95% CI 1.01; 1.05; p &lt; 0.002), or death/MI (HR 1.03, 95% CI 1.01; 1.04; p &lt; 0.0001). The cut-off value of 66 cm/s was a predictor of all MACE (area under curve 0.87 [95% CI 0.77–0.94]; sensitivity 80%; specificity 86%). Any causes of death or MI occurred more frequently in patients with velocities of &gt;66 cm/s (27% vs. 2%; p &lt; 0.002). The rates of MACE were 58.0% vs. 2%; p &lt; 0.0000001, respectively. Conclusion The analysis of coronary flow in the left coronary artery during echocardiography can be used as a predictor of outcomes in elderly patients. Maximal velocities in proximal left-sided coronary arteries is independently associated with further death or myocardial infarction.

scholarly journals A RARE CASE OF LARGE DIFFUSE BILATERAL RIGHT AND LEFT CORONARY ARTERY FISTULAS TERMINATING IN THE LEFT VENTRICLE

2021 ◽  
Vol 77 (18) ◽  
pp. 2434
Author(s):  
Iyad Farouji ◽  
Omar Alradaideh ◽  
Hossam Abed ◽  
Zaid Amin ◽  
Dilesha Kumanayaka ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Left Ventricle ◽  
Rare Case ◽  
Left Coronary Artery ◽  
Coronary Artery Fistulas

Right and left coronary artery to left ventricle fistula detected by color Doppler flow mapping

1987 ◽  
Vol 114 (4) ◽  
pp. 890-894 ◽  
Author(s):  
Toshio Nishikimi ◽  
Hisao Oku ◽  
Kazuyoshi Hirota ◽  
Kayoko Murai ◽  
Takahiko Kawarabayashi ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Left Ventricle ◽  
Left Coronary Artery ◽  
Color Doppler ◽  
Flow Mapping ◽  
Doppler Flow ◽  
Color Doppler Flow
Sign in / Sign up

Export Citation Format

Share Document