Electrophysiology
A. Bakiya, K. Kamalanand, R. L. J. De Britto in Mechano-Electric Correlations in the Human Physiological System, 2021
The cardiopulmonary system consists of blood vessels that carry nutrients and oxygen to the tissues and removes carbon dioxide from the tissues in the human body (Humphrey & McCulloch, 2003; Alberts et al., 1994). Blood is transported from the heart through the arteries and the veins transport blood back to the heart. The heart consists of two chambers on the top (right ventricle and left ventricle) and two chambers on the bottom (right atrium and left atrium). The atrioventricular valves separates the atria from the ventricles. Tricuspid valve separates the right atrium from the right ventricle, mitral valve separates the left atrium from the left ventricle, pulmonary valve situates between right ventricle and pulmonary artery, which carries blood to the lung and aortic valve situated between the left ventricle and the aorta which carries blood to the body (Bronzino, 2000). Figure 3.9 shows the schematic diagram of heart circulation and there are two components of blood circulation in the system, namely, pulmonary and systemic circulation (Humphrey, 2002; Opie, 1998; Milnor, 1990). In pulmonary circulation, pulmonary artery transports blood from heart to the lungs. The blood picks up oxygen and releases carbon dioxide at the lungs. The blood returns to the heart through the pulmonary vein. In the systemic circulation, aorta carries oxygenated blood from the heart to the other parts of the body through capillaries. The vena cava transports deoxygenated blood from other parts of the body to the heart.
Bioelectric and Biomagnetic Signal Analysis
Arvind Kumar Bansal, Javed Iqbal Khan, S. Kaisar Alam in Introduction to Computational Health Informatics, 2019
Heart consists of two types of chambers: atria and ventricles. Atria are further divided into left-atrium and right-atrium. Ventricles are further divided into left-ventricle and right-ventricle. Oxygenated blood comes from lungs to the left-atrium. The deoxygenated blood comes from the body to the right-atrium. The oxygenated blood flows from the left-ventricle to the body during the contraction of ventricles. Deoxygenated blood flows out from the right-ventricle to lungs during the compaction of ventricles. Proper contraction of atria and ventricles is essential for the continuous and sufficient flow of the blood within the heart–lung–body complex. Insufficient contraction of atria will result into blood-clots that may travel through the ventricles to any part of the body choking the blood-flow. A blood-clot in a brain causes that part of the brain-cells to die causing a stroke. Improper contractions of ventricles reduce the supply of the oxygenated blood to the body causing fatigue and cell-death. Improper contraction in ventricles also causes sudden cardiac death.
The history of circulation
Dinker B. Rai in Mechanical Function of the Atrial Diastole, 2022
The anatomical structure of the heart was defined by Aristotle and the rest of the stalwarts who followed him continued his teachings. Aristotle defined the heart as hard flesh not easily injured and composed of hard and tense muscular fibers. That definition surpassed all the others. Definitely only two chambers of the heart, the right and left ventricles, corresponded to that description of the heart with the exception of the auricle of the atrium, which appears to be an appendage of the ventricle. The remainder of the atrium did not even come close to it and was never considered to be a functional part of the heart. Sir William Harvey did not devote any importance to the atrial chambers in his theory of the explanation of the motion of blood in the body. He concentrated his efforts solely on the ventricular chambers. He thought of the atria as a storage house for blood. Up to the end of Galen's era, all anatomists believed that the arteries and veins were end vessels and diffused into the tissues.
Mathematical modeling of the Fontan blood circulation supported with pediatric ventricular assist device
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Ekaterina Rubtsova, Aleksandr Markov, Sergey Selishchev, Jamshid H. Karimov, Dmitry Telyshev
Comparison of Fontan circulation and normal circulation shows that vena cava pressure in Fontan circulation is significantly higher than the normal pressure, which entails systemic veins stretching. Moreover, due to absence of the pulmonary ventricle, venous return decreases which, according to the Frank-Starling mechanism, leads to a decrease in the cardiac output and eventually to circulatory failure (Table 2). The model of single-ventricular circulation consists of the ventricle, systemic and pulmonary vessels, and also includes two heart valves. The model is based on a biventricular circulation model of a pediatric patient. This means that all changes made to the model correspond to the Fontan procedure, and parameters that are not related to the pulmonary ventricle remain unchanged.
Update on shunt closure in neonates and infants
Published in Expert Review of Cardiovascular Therapy, 2021
Karim A. Diab, Younes Boujemline, Ziyad M. Hijazi
The ductus arteriosus is a normal vascular structure in the fetus that connects the main pulmonary artery with the descending aorta or subclavian artery. It allows the right ventricle to pump the blood into the aorta, bypassing the pulmonary circulation. It typically closes within the first 2–3 weeks of life and is considered an abnormal shunt if it remains patent beyond that period. The Patent Ductus Arteriosus (PDA) occurs at an incidence of 1 in 2,000 live births in children born at term [1]. It is even more common in preterm neonates and those with Down syndrome and is actually the most common shunting lesion in premature newborns [77]. It can result in significant heart failure and increased morbidity including increased risk of intraventricular hemorrhage, necrotizing enterocolitis and chronic lung disease and prolongation of ventilator support, particularly in those high-risk infants [78–84]. Medical therapy with anti-inflammatory medications is commonly used for achieving closure of the PDA in these infants. However, this carries some risk such as renal injury, intracranial hemorrhage and intestinal perforation and can be contraindicated in some patients [85]. Surgical ligation has been commonly used when medical therapy fails. However, it is also not without risks including among other morbidities systemic hypotension, significant worsening of the patient’s pulmonary status, vocal cord paralysis, scoliosis and phrenic nerve palsy [86].
In vitro testing of an intra-ventricular assist device
Published in Computer Assisted Surgery, 2019
Shidong Zhu, Lin Luo, Bibo Yang, Xinghui Li, Kai Ni, Qian Zhou, Xiaohao Wang
Left ventricular assist device (LVAD) is widely used to implant in heart failure (HF) patients. It helps the failing ventricle pumping blood from ventricle to the aorta. LVADs play an important role in the treatment of HF patients. In recent years, the permanent implantation (destination therapy) has become an option for this device [1]. Currently, pulsatile and non-pulsatile pump are available for clinical treatment, namely, continuous flow LVAD (CF-LVAD) and pulsatile flow LVAD (PF-LVAD). CF-LVADs generally provide non-pulsatile flow that has less pulsatility compared to the physiological flow. In most cases, CF-LVADs own much smaller size and lighter and be implanted intracorporeally. Therefore, they have better performance in terms of preventing infection arise from the smaller size [2,3]. However, they still have some significant issues, for example, the decreasing pulsatility and non-physiologically high levels of shear stress, the patients will suffer long-term complication such as gastro-intestinal bleeding and aortic valve insufficiency [4]. On the other hand, in several studies, they believed that pulsatile flow is necessary. Variable speed mode of CF-LVAD increase the pulsatile pressure synchronized with ventricular beats, however, the pulsatility remained limited [5,6]. Additional, to prevent backflow, CF-LVADs should continue working. Although the old pulsatile pumps are larger size and heavier, they generate pulsating flow likes physiological flow. Last several years, some new pulsatile pumps have been studied, such as LibraHeart pulsatile LVAD. Therefore, the study of pulsatile pump is meaningful.
Related Knowledge Centers
- Aorta
- Blood Pressure
- Interventricular Septum
- Pulmonary Circulation
- Atrium
- Lung
- Circulatory System
- Heart
- Blood
- Intraventricular Block