The features of the coronary blood flow in the right ventricle myocardial infarction

2017 ◽  
Vol 12 (13) ◽  
pp. 30-34
Author(s):  
V.Y. Tseluyko ◽  
◽  
T.A. Lozova ◽  
Keyword(s):  
Myocardial Infarction ◽  
Blood Flow ◽  
Right Ventricle ◽  
Coronary Blood Flow ◽  
The Right

Effect of hypoxemia and hypercapnia on regional distribution of myocardial blood flow

1965 ◽  
Vol 208 (6) ◽  
pp. 1211-1216 ◽  
Author(s):  
William D. Love ◽  
Myra D. Tyler
Keyword(s):  
Blood Flow ◽  
Left Ventricle ◽  
Right Ventricle ◽  
Coronary Blood Flow ◽  
Regional Distribution ◽  
Fick Principle ◽  
The Right ◽  
Isotope Content ◽  
Coronary Sinus Blood ◽  
Normal Difference

The effect of hypoxia and hypercapnia on regional coronary blood flow and vascular resistance (CVR) was studied in dogs without thoracotomy. Gas tensions were varied by ventilation at controlled rates with gas mixtures containing 4–100% O2 and 0–24% CO2. After 10 min intravenous infusion of Rb86, the animals were killed and the heart isotope content determined. Blood flow to the left ventricle was calculated by the Fick principle from the isotope uptake and the mean difference in radioactivity of arterial and coronary sinus blood. Patterns of flow elsewhere were estimated from the rates of regional Rb86 clearance. Myocardial Rb86 clearance in the right and left ventricles has been previously shown to be closely related to the rate of coronary blood flow. Hypoxemia and severe hypercapnia (pCO2 above 100 mm Hg) both produced a profound fall in CVR. With hypoxemia this decrease was more marked in the right ventricle. Elevation of pCO2 exaggerated the normal difference in Rb86 uptake between inner and outer thirds of the wall of the left ventricle, while hypoxemia reversed the normal gradients. Hypercapnia did not affect these gradients in the right ventricle, but hypoxemia significantly reduced them.

Mechanisms of Oxygen Demand/Supply Balance in the Right Ventricle

2005 ◽  
Vol 230 (8) ◽  
pp. 507-519 ◽  
Author(s):  
Pu Zong ◽  
Johnathan D. Tune ◽  
H. Fred Downey
Keyword(s):  
Blood Flow ◽  
Left Ventricle ◽  
Right Ventricle ◽  
Right Ventricular ◽  
Coronary Blood Flow ◽  
Oxygen Demand ◽  
Coronary Vasodilation ◽  
External Work ◽  
Coronary Conductance ◽  
The Right

Few studies have investigated factors responsible for the O2 demand/supply balance in the right ventricle. Resting right coronary blood flow is lower than left coronary blood flow, which Is consistent with the lesser work of the right ventricle. Because right and left coronary artery perfusion pressures are Identical, right coronary conductance is less than left coronary conductance, but the signal relating this conductance to the lower right ventricular O2 demand has not been defined. At rest, the left ventricle extracts ~75% of the O2 delivered by coronary blood flow, whereas right ventricular O2 extraction Is only ~50%. As a result, resting right coronary venous PO2 is ~30 mm Hg, whereas left coronary venous PO2 is ~20 mm Hg. Right coronary conductance does not sufficiently restrict flow to force the right ventricle to extract the same percentage of O2 as the left ventricle. Endogenous nitric oxide impacts the right ventricular O2 demand/supply balance by increasing the right coronary blood flow at rest and during acute pulmonary hypertension, systemic hypoxia, norepinephrine infusion, and coronary hypoperfusion. The substantial right ventricular O2 extraction reserve is used preferentially during exercise-induced increases in right ventricular myocardial O2 consumption. An augmented, sympathetic-mediated vasoconstrictor tone blunts metabolically mediated dilator mechanisms during exercise and forces the right ventricle to mobilize its O2 extraction reserve, but this tone does not limit resting right coronary flow. During exercise, right coronary vasodilation does not occur until right coronary venous PO2 decreases to ~20 mm Hg. The mechanism responsible for right coronary vasodilation at low PO2 has not been delineated. In the poorly autoregulating right coronary circulation, reduced coronary pressure unloads the coronary hydraulic skeleton and reduces right ventricular systolic stiffness. Thus, normal right ventricular external work and O2 demand/supply balance can be maintained during moderate coronary hypoperfusion.

scholarly journals CORONARY ARTERY PATHOLOGY IN RIGHT VENTRICULAR MYOCARDIAL INFARCTION

2013 ◽  
Vol 12 (4) ◽  
pp. 32-35
Author(s):  
G. G. Ayrapetyan ◽  
K. G. Adamyan
Keyword(s):  
Myocardial Infarction ◽  
Blood Flow ◽  
Coronary Artery ◽  
Coronary Blood Flow ◽  
Left Ventricular ◽  
Inferior Wall ◽  
Dominant Type ◽  
Right Ventricular Myocardial Infarction ◽  
Functional Features ◽  
The Right

Aim. To study anatomical and functional features of coronary blood flow in myocardial infarction (MI) of left ventricular (LV) inferior wall with the involvement of right ventriculum (RV).Material and methods. The study included 120 patients who suffered MI of LV inferior wall with (Group 2 – LVMI; n=58) or without (Group 1 – RVMI; n=62) RV involvement.Results. One coronary artery (CA) was affected in 65,0% of the participants. Right CA (RCA) pathology was registered in 97,4% (n=76), while circumflex CA (CxCA) pathology was observed only in 2,6% (n=2). Involvement of two and three or more CA was observed in 26,7% and 8,3% of the patients, respectively. Single CA pathology was at least 1,3 times more common in the RVMI group (p<0,05), while three or more CA were affected at least 8 times more often in the LVMI group (p<0,05). The right dominant, co-dominant, and left dominant types of coronary flow were registered in 76,7%, 15,0%, and 8,3% of the patients, respectively, all of whom were from the LVMI group. In 85% and 15% of the cases, the infarct-related artery (IRA) was RCA and CxCA, respectively. Among LVMI patients, RCA was the IRA almost three times more often than CxCA; among RVMI patients, this difference was 18-fold (p<0,001 for both comparisons). All LVMI patients (n=47) had distal occlusion of RCA, while all RVMI patients (n=55) had its proximal occlusion.Conclusion. Over two-thirds of the cases оf ST elevation MI of LV inferior wall with RV involvement occur in patients with the right dominant type of coronary blood flow. RVMI typically occurs in patients with right dominant type of coronary blood flow and PCA pathology. MI of LV inferior wall with RV involvement is characterised by proximal RCA occlusion.

Moderate Systemic Hypotension During Reperfusion Reduces the Coronary Blood Flow and Increases the Size of Myocardial Infarction in Pigs

CHEST Journal ◽  
2004 ◽  
Vol 125 (4) ◽  
pp. 1492-1499 ◽  
Author(s):  
John N. Nanas ◽  
Elias Tsolakis ◽  
John V. Terrovitis ◽  
Ageliki Eleftheriou ◽  
Stavros G. Drakos ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Blood Flow ◽  
Coronary Blood Flow ◽  
Systemic Hypotension

scholarly journals The study of systemic hemodynamic disorders of patients with varicose and post-thrombotic diseases

2020 ◽  
Vol 19 (2) ◽  
pp. 32-37
Author(s):  
I. N. Shanaev
Keyword(s):  
Blood Flow ◽  
Right Ventricle ◽  
Right Atrium ◽  
Ultrasound Examination ◽  
Anterior Wall ◽  
Right Heart ◽  
Normal Limits ◽  
Flow Through ◽  
The Right ◽  
Restrictive Type

Aim. Study of heart function in the patients with CVD. Materials and methods. 46 patients with varicosity (VD) and 34 patients with post-thrombotic disease (PTD) were examined; the control group was represented by 15 healthy volunteers. The diagnosis was established using the CEAP basic classification. The study did not include patients with a diagnosed arterial hypertension, diabetes mellitus, chronic lung disease, significant hemodynamic heart defects, coronary heart disease. Ultrasound examination of the heart and veins of the lower extremities was performed on a Saote My Lab Alpha, Acuson Sequoia 512 apparatus. In addition to the standard protocol of heart ultrasound examination, the parameters of the right heart were calculated: sizes of the right ventricle (RV), right atrium, thickness of the anterior wall of the pancreas; to assess the ejection fraction (EF) of the pancreas the mobility of the lateral edge of the tricuspid ring was calculated, and the pressure on the tricuspid valve (TV) was measured. Diastolic ventricular function was studied by spectrograms of tricuspid and mitral blood flow. Results. Most of the indicators of cardiac activity in patients with VD were within normal limits, but a tendency to increase increasing of the right heart size was noted. In addition, the thickness of the interventricular septum and the right ventricle (RV) anterior wall was found to increase from 0.8 to 1.1 cm and from 0.3 to 0.5 cm, respectively, according clinical classes from C2 to C6 (CEAP). Eject fraction (EF) of both the RV and the left ventricle (LV) were also within normal limits, but with a tendency to decrease (67.8 % – C2, to 62 % – C6). The growth of the clinical class is followed by the increasing of percentage of non-restrictive blood flow through the tricuspid valve (TV). The restrictive type of blood flow in patients with VD had not been identified. Patients with PTD also showed a tendency to increase the right heart. However, whereas the size of the RV, as a rule, did not exceed 3.0 cm, the size of the right atrium was slightly higher than normal one in the clinical class C4 and C5.6. All the patients had EF of LV within normal limits, but it slightly decreased by the growth of class. Only patient classes C3 and C4 had EF of RV within the normal range. The 18 % of patient class C5.6 had EF lower than normal with value 48%. Diastolic dysfunction (DD) of the RV was detected in 73.3% of patients with class C3 and 100% with classes C4 and C5.6. Moreover, a restrictive type of blood flow through TV appeared from class C4 and the percentage increased up to 27.2% (class C5,6). Conclusions. DD of the RV was the main hemodynamic disorder.

scholarly journals Evaluation of the Right Ventricle Function Conducted in Patients after Acute Myocardial Infarction, Using Threedimensional Echocardiography and Myocardial Strain Analysis. Summary of the Doctoral Thesis

2021 ◽  
Author(s):  
◽  
Žanna Pičkure ◽  
Keyword(s):  
Myocardial Infarction ◽  
Ejection Fraction ◽  
Right Ventricle ◽  
Longitudinal Strain ◽  
Myocardial Strain ◽  
St Elevation Myocardial Infarction ◽  
Right Ventricle Function ◽  
St Elevation ◽  
The Right ◽  
Ventricle Function

It is well known that dysfunction of the right ventricle in ST segment elevation myocardial infarction causes such complications as rhythm disturbances, cardiogenic shock and others. Its presence is an independent prognostic indicator of all-cause mortality, cardiovascular mortality and development of heart failure. However, in clinical practice still too little attention is paid to the evaluation of the right ventricle function, despite the new echocardiographic methods available, which are capable of providing an accurate diagnostics of the right ventricle disfunction. The purpose of this work is to evaluate changes in the systolic function of the right ventricle in patients with proven acute ST elevation myocardial infarction by threedimensional echocardiography and myocardial strain techniques, and to select the most informative echocardiographic parameters for the size and function of the right ventricle for use in everyday practice. Based on the data gained during this study, the algorithm for the evaluation of the right ventricle function in patients with acute ST elevation myocardial infarction will be developed. A healthy individuals control group and a group of patients with ST elevation myocardial infarction were formed within the study. Each participant was examined according to standart echocardiography protocol. In each case new echocardiographic right venricle function evaluation methods also were applied – a three-dimensional echocardiography with following right ventricle reconstruction, volume and ejection fraction determination, as well as myocardial longitudinal strain measurements. Based on these methods, by comparing the data to the control group results, it was possible to etermine the pathology threshold for the right ventricular ejection fraction and longitudinal strain to detect right ventricle disfunction in the case of acute myocardial infarction. Three-dimensional echocardiography and evaluation of myocardial strain are new, relatively simple, sufficiently sensitive and specific methods for the diagnosis of right ventricular dysfunction in patients with ST elevation myocardial infarction. The methods are to be introduced for use in everyday clinical practice along with the standard ehocardiography parameters, which also change in ST elevation myocardial infarction: fractional area change, tricuspid annular plane systolic excursion, and visual evaluation of segmental systolic function of the right ventricle. Among new parameters ejection fraction of the right ventricle and right ventricle free wall longitudinal strain have to be determined. When evaluating the right chamber, it should be remembered that its function deterioration can be observed in case of myocardial infarction of any localization.

CLINICAL CONFERENCE

PEDIATRICS ◽  
1957 ◽  
Vol 19 (6) ◽  
pp. 1139-1147
Author(s):  
Mary Allen Engle
Keyword(s):  
Blood Flow ◽  
Right Ventricle ◽  
Right Ventricular ◽  
Pulmonary Blood Flow ◽  
Ventricular Hypertrophy ◽  
Pulmonary Valve ◽  
Muscular Tissue ◽  
Pulmonic Stenosis ◽  
Infundibular Stenosis ◽  
The Right

Dr. Engle: When pulmonic stenosis occurs as an isolated congenital malformation of the heart, it usually is due to fusion of the valve cusps into a dome with a small hole in the center. In Figure 1 the pulmonary artery has been laid open so that one can see the three leaflets of the pulmonary valve are completely fused, and that there is only a small, central, pinpoint opening which permits blood to leave the right ventricle and enter the pulmonary circulation. Valvular pulmonic stenosis is much more common than subvalvular or infundibular stenosis, where the obstruction to pulmonary blood flow lies within the substance of the right ventricle. There it may be due to a diaphragm of tissue which obstructs the outflow of the right ventricle, or to an elongated narrow tunnel lined with thickened endocardium, or to a ridge of fibrous or muscular tissue just beneath the pulmonary valve. The changes in the cardiovascular system which result from obstructed pulmonary blood flow are so characteristic that they permit the ready recognition of this condition. Proximal to the constriction, these changes manifest the burden placed on the right ventricle, which enlarges and hypertrophies. On physical examination this is demonstrated by the precordial bulge and tapping impulse just to the left of the sternum, where the rib cage overlies the anterior (right) ventricle. Radiographically, both by fluoroscopy and in roentgenograms in the frontal and both oblique views, right ventricular enlargement is seen. In the electrocardiogram, the precordial leads show a pattern of right ventricular hypertrophy.

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