Pathomorphology of myocardial circulation: Comparative study in increased left or right ventricle afterload

Abstract

Comparative study of pathomorphology of myocardial circulation under conditions of increased afterload of the left or right ventricles showed similar changes. All compartments of the coronary bed were plethoric, capillary blood stasis and perivascular edema, more pronounced in arterial vessels, were detected in both cases. These changes equally involved both ventricles and the ventricular septum. Significant differences consisted in local increase in the density of functioning capillaries. The increase was the maximum in hemodynamically overloaded ventricle and ventricular septum, presumably due to increase of their contractile activity. The density of functioning capillaries in the intact (vs. pressure overloaded) ventricle also increased, but to a lesser degree, which could be due to systemic neurohumoral effects. If increased afterload was complicated by the development of heart failure, circulatory disorders in the myocardium progressed. Significant increase in the density of functioning capillaries in all cardiac compartments indicated decreased vascular tone and exhaustion of coronary reserve. This was paralleled by a sharp arterial plethora in case of increased afterload of the left ventricle and sharp blood stasis in the microcirculatory bed in case of increased right ventricle afterload. Reduction of effective perfusion pressure in the presence of coronary dystonia can cause coronary insufficiency and myocardial ischemia in case of increased right ventricle afterload.

Up-Regulation of mRNA Ventricular PRNP Prion Protein Gene Expression in Air Pollution Highly Exposed Young Urbanites: Endoplasmic Reticulum Stress, Glucose Regulated Protein 78, and Nanosized Particles

“…Apoptosis is not a welcome response in myocardial tissues, particularly because there is significant ventricular inflammation and inflammasome activation in highly exposed young MCMA residents [13]. It is plausible that the significant left vs. right ventricular PrP C up-regulation is indeed a protective mechanism to a critical pump ventricular chamber with marked differences in morphologic and contractile properties and in myocardial microcirculation vs. the right chamber [52,53]. Pro-inflammatory mediators, including TNF-α and IL-1β have been implicated in the pathogenesis of myocardial dysfunction and cardiomyocyte death in ischemia-reperfusion injury, sepsis, chronic heart failure, viral myocarditis, and cardiac allograft rejection [54–57].…”

“…The fact that the left ventricle exhibited striking ER and mitochondrial abnormalities likely relates to the left morphologic and contractile properties [52] and differences in myocardial circulation [53]. These contractile and microcirculatory changes might contribute to the sharp differences between ventricular gene expression in subjects exposed to high levels of pollution.…”

Intra-city Differences in Cardiac Expression of Inflammatory Genes and Inflammasomes in Young Urbanites: A Pilot Study

“…Indeed, the right ventricle expression of the target genes was significantly different for all selected genes, while the left ventricle differences between cohorts were only significant for TNF-α and IL-10. Cardiac chambers differ in their morphologic and contractile properties 25 and in myocardial circulation 26 . In a heart with increased afterload there is a sharp arterial plethora of the left ventricle and sharp blood stasis in the microcirculatory bed in case of increased right ventricle afterload 26 .…”

“…Cardiac chambers differ in their morphologic and contractile properties 25 and in myocardial circulation 26 . In a heart with increased afterload there is a sharp arterial plethora of the left ventricle and sharp blood stasis in the microcirculatory bed in case of increased right ventricle afterload 26 . These contractile and microcirculatory changes might contribute to the sharp differences between ventricular gene expression in subjects exposed to high levels of pollution.…”

Echocardiography for patients undergoing extracorporeal cardiopulmonary resuscitation: a primer for intensive care physicians

“…Theoretically, the increases in afterload may impair LV distention, ensuing subendocardial ischemia. These are risk factors for delayed recovery of cardiac function [ 70 – 72 ]. However, their clinical utility has been well established in extracorporeal membrane oxygenation setting, and further studies are warranted to clarify their association.…”