scholarly journals Arterial-venous relationships in the human left ventricular myocardium: anatomic basis for countercurrent regulation of blood flow.

Circulation ◽  
1986 ◽  
Vol 74 (6) ◽  
pp. 1195-1202 ◽  
Author(s):  
G M Hutchins ◽  
G W Moore ◽  
E V Hatton
Keyword(s):  
Blood Flow ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Anatomic Basis

Cardiac microdialysis to estimate interstitial adenosine and coronary blood flow

1990 ◽  
Vol 258 (6) ◽  
pp. H1642-H1649 ◽  
Author(s):  
D. G. Van Wylen ◽  
J. Willis ◽  
J. Sodhi ◽  
R. J. Weiss ◽  
R. D. Lasley ◽  
...  
Keyword(s):  
Blood Flow ◽  
Myocardial Ischemia ◽  
Coronary Blood Flow ◽  
Fold Increase ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Simultaneous Estimation ◽  
Microdialysis Probe ◽  
Regional Myocardial Ischemia

The purpose of this study was twofold: 1) to investigate the feasibility and usefulness of cardiac microdialysis for the simultaneous estimation of regional cardiac interstitial fluid (ISF) adenosine (ADO) concentration and coronary blood flow (CBF); and 2) to determine the changes in the ISF levels of ADO and CBF during cardiac stimulation or regional myocardial ischemia. Cardiac microdialysis probes were implanted in the left ventricular myocardium of chloralose-urethan-anesthetized dogs and perfused with Krebs-Henseleit buffer. The concentration of ADO in the effluent dialysate was used as an index of intramyocardial ISF ADO concentration while local CBF was measured by H2 clearance via a platinum wire within the dialysis fiber. Dialysate ADO was elevated immediately after insertion of the microdialysis probe, declined rapidly in the first 20 min, stabilized by 60 min, and remained constant for 2 h. Based on the relationship in vitro and in vivo between microdialysis probe perfusion rate and dialysate ADO concentration, ISF ADO concentration within the left ventricular myocardium was estimated to be 0.9-1.3 microM. Dobutamine (10 micrograms.kg-1.min-1) infusion resulted in a 36% increase in CBF and a 2.5-fold increase in dialysate ADO (n = 9; P less than 0.05). Regional myocardial ischemia, induced by occlusion of the left anterior descending artery (LAD), caused a 13-fold increase in dialysate ADO in the LAD perfused myocardium (n = 9; P less than 0.05). These results are consistent with the ADO hypothesis and suggest that cardiac microdialysis provides a reliable technique for the sampling of regional intramyocardial ISF.

Variability of heart rhythm in patients with viral cirrhosis depending on types of portal blood flow

2019 ◽  
Vol 1 (8) ◽  
pp. 26-29
Author(s):  
S. V. Peshkova ◽  
M. V. Chistyakova ◽  
V. S. Barcan
Keyword(s):  
Blood Flow ◽  
Portal Vein ◽  
Heart Rhythm ◽  
Portal Blood Flow ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Linear Velocity ◽  
Portal Blood ◽  
Control Group ◽  
Left Ventricular Myocardium

The paper analyzes the results of examinations of 24 patients with viral cirrhosis of classes B and C according to Child-Pugh criteria. The control group consisted of 16 healthy patients. Patients with viral cirrhosis were divided into 2 groups: 1 group consisted of 14 patients with pseudonormokinetic type of portal blood flow; Group 2-10 patients with hyperkinetic type of portal blood flow with predominant acceleration of the linear velocity in the portal vein. The average age of patients was 35.2 ± 7.4 years. Left ventricular myocardium mass and left ventricular myocardium mass index were determined in all the patients; the diameter and the maximum linear velocity in the main portal vein were measured using an Artida pro Toshiba apparatus, Japan. Heart rate variability was studied at rest and in active orfhostasis using the «Neuro-Soth)program, Ivanovo. it was found that in patients with liver cirrhosis the sympathetic effects of the autonomic nervous system predominated, which coincided with the literature data. It was also shown that in patients with the pseudonormokinetic type of portal blood flow these effects were more pronounced. The relationship between HRV indices and the formation of left ventricular hypertrophy in patients with pseudo-normokinetic type of portal blood flow was revealed.

scholarly journals Ultrasound study of layer-specific strain and perfusion of left ventricular myocardium in patients with dilated cardiomyopathy

2021 ◽  
Author(s):  
Sha Tang ◽  
Lina Guan ◽  
Yuming Mu
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Dilated Cardiomyopathy ◽  
Correlation Coefficients ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Volume Index ◽  
Control Group ◽  
Left Ventricular Myocardium ◽  
Myocardial Microcirculation

Abstract Purpose To investigate the changes in deformation and myocardial microcirculation perfusion of left ventricular three-layer myocardium in patients with dilated cardiomyopathy (DCM) by using speckle tracking imaging (STI) and myocardial contrast echocardiography (MCE). Methods Twenty-four patients with DCM and 19 healthy controls were selected. Two-dimensional and MCE dynamic images of apical four-chamber, two-chamber, and three-chamber sections and left ventricular mitral valve, papillary muscle and apex sections were collected. The peak values of longitudinal strain (LS), circumferential strain (CS), cross-sectional area of a microvessel (A) and average myocardial microvascular lesion (β) were obtained by Qlab 10.8 workstation values, and myocardial blood flow (MBF) was calculated with A × β to evaluate the deformation and coronary microvascular perfusion of left ventricular three-layer myocardium. Results The brain natriuretic peptide (BNP), left ventricular mass index (LVMI), left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVEDS), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), left atrial volume index (LAVI), E peak in early diastolic period/A peak velocity in late diastolic period (E/A) and average E/e' in the DCM group were higher than those in the control group (P < 0.05); left ventricular ejection fraction (LVEF), left ventricular fractional shortening (FS) rate, stroke volume (SV), cardiac output (CO), cardiac index (CI), A peak, and the e' and a' velocities of both the lateral wall and interventricular septum were smaller than those in the control group (P < 0.05). The LS, CS, A, β, and A × β of the DCM group were all lower than those of the control group, The time to peak and the cardiac cycle required to reach the peak were longer than those in the control group (P < 0.05). The pattern of myocardial strain and perfusion among myocardial layers was subendocardial > middle > subepicardial. The correlation coefficients of LS with A, β, and A × β were − 0.500, -0.279 and − 0.190, respectively, and the correlation coefficients of CS with A, β, and A × β were − 0.383, -0.255 and − 0.208, respectively. Conclusions The deformation of the three-layer myocardium and coronary microcirculation perfusion in DCM patients were diffusely damaged from the endocardium to the epicardium, layer by layer. The longitudinal function of the left ventricular myocardium was closely related to changes in myocardial microcirculation perfusion. Echocardiography is helpful to evaluate myocardial blood flow and myocardial ischemia in patients with DCM.

Acute effects of amrinone on regional myocardial and systemic blood flow distribution in the dog

1982 ◽  
Vol 60 (6) ◽  
pp. 811-818 ◽  
Author(s):  
Stanley Einzig ◽  
Gundu H. R. Rao ◽  
Mary Ella Pierpont ◽  
James G. White
Keyword(s):  
Central Nervous System ◽  
Blood Flow ◽  
Nervous System ◽  
Caudate Nucleus ◽  
Cervical Spinal Cord ◽  
Flow Distribution ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Blood Flow Distribution

The effect of bolus intravenous injections of amrinone (1–2 mg/kg) on abdominal organ, central nervous system, and myocardial blood flow distribution was examined in 15 anesthetized dogs. Blood flows were measured during control conditions and 5 and 60 min following drug administration using left atrial injection of 15-μm radionuclide-labeled spheres. Analysis of variance revealed that blood flow changes were similar in dogs receiving either drug dose (P > 0.10). Five minutes following injection, blood flow was increased (all P < 0.05) in the renal cortex (+20.4%), spleen (+40.4%), and liver (+47.1%); flow was unchanged in other abdominal organs (pancreas, gallbladder, small and large intestine, and fundic and antral gastric mucosa) and the central nervous system (cervical spinal cord, pons, medulla, dorsal thalamus, cerebellum, caudate nucleus, and cerebral cortical gray and white matter); and flow was reduced in the triceps muscle (−23.7%). At this time, left ventricular flow was increased (+25.0%) and the left ventricular subendocardial/subepicardial (Endo/Epi) flow ratio was reduced (1.09 ± 0.02 (SE) vs. 0.90 ± 0.02, P < 0.001). Sixty minutes following injection, renal and hepatic flows had returned to control values while splenic flow remained increased (+61.6%); intestinal, gastric mucosal, gallbladder, and triceps flows were reduced by values ranging from 26.7 to 38.9% and central nervous system perfusion was reduced by values ranging from 11.8 to 19.4% in all regions except the caudate nucleus. Although left ventricular flow had returned to control values, the Endo/Epi ratio (1.02 ± 0.02) remained minimally reduced at this time (P < 0.001). These results suggest that vascular responsiveness to intravenous amrinone is not uniform in different circulatory beds and that relative subendocardial under-perfusion of the left ventricular myocardium occurs following bolus intravenous amrinone injections in the dog.

The Validity of the Total Myocardial Blood Flow Determination by Means of 113Xe in Regional Ischemia

1976 ◽  
Vol 15 (03) ◽  
pp. 115-118 ◽  
Author(s):  
J. Kasalický
Keyword(s):  
Blood Flow ◽  
Coronary Artery ◽  
Left Coronary Artery ◽  
Ventricular Myocardium ◽  
Total Radioactivity ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
The Difference ◽  
133Xe Washout

SummaryRegional MBF in the ischemic and healthy left ventricular myocardium was measured in 21 mongrel dogs by means of locally injected 133Xe and its washout one week after ligation of the left anterior descending coronary. Simultaneously the total MBF was calculated from the precordial washout determination of 133Xe injected into the left coronary artery. The 133Xe measurements were compared with the regional 86Rb uptake. The values of total MBF determination after left coronary artery injection did not diminish adequately to the size of the ischemic area; these values were usually higher as compared with the calculated mean MBF evaluated from the regional left ventricular blood flow and did not agree with regional MBF in the intact left ventricular myocardium. The difference of perfusion between the necrotic and the healthy left ventricular myocardium determined from the local 133Xe washout was higher in comparison to 86Rb uptake. The method of total MBF determination by means of precordially determined 133Xe washout injected into the coronary artery yields artificially higher values in cases with greater ischemic areas. This may be accounted for by a low initial radioactivity of the hypoperfused areas and their negligible contribution to the total radioactivity changes produced predominantly by the well perfused areas. The relatively low 86Rb uptake difference in the healthy and the necrotic left ventricular myocardium may be caused by affected extraction coefficients of 86Rb in the necrotic tissue.

Effects of coronary sinus pressure elevation on coronary blood flow distribution in dogs with normal preload

1985 ◽  
Vol 63 (7) ◽  
pp. 787-797 ◽  
Author(s):  
Jacques R. Rouleau ◽  
Michel White
Keyword(s):  
Blood Flow ◽  
Coronary Sinus ◽  
Flow Distribution ◽  
Ventricular Myocardium ◽  
Anterior Wall ◽  
Left Ventricular ◽  
Left Ventricular Myocardium ◽  
Blood Flow Distribution ◽  
Tissue Pressure ◽  
Sinus Pressure

Coronary sinus pressure (Pcs) elevation shifts the diastolic coronary pressure–flow relation (PFR) of the entire left ventricular myocardium to a higher pressure intercept. This finding suggests that Pcs is one determinant of zero-flow pressure (Fzf) and challenges the existence of a vascular waterfall mechanism in the coronary circulation. To determine whether coronary sinus or tissue pressure is the effective coronary back pressure in different layers of the left ventricular myocardium, the effect of increasing Pcs was studied while left ventricular preload was low. PFRs were determined experimentally by graded constriction of the circumflex coronary artery while measuring flow using a flowmeter. Transmural myocardial blood flow distribution was studied (15-μm radioactive spheres) at steady state, during maximal coronary artery vasodilatation at three points on the linear portion of the circumflex PFR both at low and high diastolic Pcs (7 ± 3 vs. 22 ± 5 mmHg; p < 0.0001) (1 mmHg = 133.322 Pa). In the uninstrumented anterior wall the blood flow measurements were obtained in triplicate at the two Pcs levels. From low to high Pcs, mean aortic (98 ± 23 mmHg) and left atrial (5 ± 3 mmHg) pressure, percent diastolic time (49 ± 7%), percent left ventricular wall thickening (32 ± 4%), and percent myocardial lactate extraction (15 ± 12%) were not significantly changed. Increasing Pcs did not alter the slope of the PFR; however, the Pzf, increased in the subepicardial layer (p < 0.0001), whereas in the subendocardial layer Pzf did not change significantly. Similar slopes and Pzf were observed for the PFR of both total myocardial mass and subepicardial region at low and high Pcs. Subendocardial: subepicardial blood flow ratios increased for each set of measurements when Pcs was elevated (p < 0.0001), owing to a reduction of subepicardial blood flow; however, subendocardial blood flow remained unchanged, while starting in the subepicardium toward mid-myocardium blood flow decreased at high Pcs. This pattern was similar for the uninstrumented anterior wall as well as in the posterior wall. Thus as Pcs increases it becomes the effective coronary back pressure with decreasing magnitude from the subepicardium toward the subendocardium of the left ventricle. Assuming that elevating Pcs results in transmural elevation in coronary venous pressure, these findings support the hypothesis of a differential intramyocardial waterfall mechanism with greater subendo- than subepi- cardial tissue pressure.

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