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.
Geometry of the Aortic Valve
Mano Thubrikar in The Aortic Valve, 2018
The heart has four chambers (right atrium, right ventricle, left atrium, and left ventricle) and four valves (tricuspid, pulmonary, mitral, and aortic valves) (Figure 1). The tricuspid valve is located between the right atrium and the right ventricle, the pulmonary valve between the right ventricle and the pulmonary artery, the mitral valve between the left atrium and the left ventricle, and the aortic valve between the left ventricle and the aorta. The tricuspid and mitral valves are called atrioventricular valves since they are between the atrium and the ventricle, and the pulmonary and aortic valves are called arterioventricular valves since they are between the artery and the ventricle. The aortic and pulmonary valves are also called semilunar valves because their leaflets have the shape of a half moon. Atrioventricular valves are attached to the heart muscle (myocardium) by means of papillary muscles and fibrous cords and are considered to be active structures responding to myocardial contractions. Semilunar valves, on the other hand, do not have direct attachment of the mobile part of the leaflet to the myocardium, and therefore have been considered in the past to function passively in response to blood flow. It will be shown that parts of the aortic valve are active.
The patient with acute cardiovascular problems
Peate Ian, Dutton Helen in Acute Nursing Care, 2020
Central venous pressure monitoring (CVP) is helpful for those who have complex fluid management requirements, as they help evaluate fluid status and right ventricular function. The pressure measures right atrial pressure, but also reflects right ventricular end diastolic pressure, as the AV valves open in diastole. Fluid challenges described earlier in this chapter may be repeated if the CVP is low or normal with a reduced BP to ensure circulating volume is adequate. Central venous pressure is normally between 3–8mmHg, but in clinical practice it may be maintained up to 12mmHg to ensure optimum ventricular preload. Those who do not respond to fluid challenge may require inotropic support of the circulation. Factors that may cause a rise in CVP include: Heart failure.Cardiac tamponade.Tension pneumothorax.Vasoconstriction (caused by drugs such as adrenaline or as part of the sympathetic response to poor cardiac output).COPD.Tricuspid valve problems.
Design and evaluation of the crimping of a hooked self-expandable caval valve stent for the treatment of tricuspid regurgitation
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Gideon Praveen Kumar, Hwa Liang Leo, Fangsen Cui
The tricuspid valve consists of three leaflets that separates the right atrium from the right ventricle and maintains unidirectional blood flow. In addition to these, the leaflets, chordae tendinae, papillary muscles, fibrous annulus, the right atrial and ventricular myocardium make up the entire valvular complex (Séguéla et al. 2011). A disturbance of any of these structures may lead to tricuspid regurgitation (TR). With an increased volume of TR, cardiac output (CO) decreases and patients tend to develop symptoms of right heart failure with possible congestive hepatosplenomegaly, peripheral oedema and associated ascites (Filsoufi et al. 2005). Surgical correction with tricuspid valve repair or replacement which is the only corrective therapy available currently, carries an operative mortality of up to 22% in these patients, and is therefore not routinely offered (Lauten et al. 2010; Zhu et al. 2016). TR is more prevalent among the elderly which is also a concern as the patients are deemed high-risk for open heart valve replacement (Nkomo et al. 2006; Campelo-Parada et al. 2017). Thus, transcatheter tricuspid valve replacement offers a better prognosis for patients affected by TR (Muller et al. 2017). In this minimally invasive procedure, the transcatheter heart valve is crimped and inserted into the femoral vein via a small incision. The crimped valve is then moved to the heart using a delivery system. At the deployment site, which is the diseased tricuspid valve, the crimped valve re-expands to its pre-set diameter and become fully functional (Ismail et al. 2017).
First Trimester Prenatal Diagnosis of a Conotruncal Anomaly Using Spatiotemporal Image Correlation Imaging Confirmed by Conventional Autopsy
Published in Fetal and Pediatric Pathology, 2022
Balaganesh Karmegaraj, Vani Udhayakumar, Gigi Selvan
External examination of the fetus showed no obvious congenital anomalies. The heart was dissected using the approach described by Erickson [4] and described according to the sequential segmental analysis proposed by Anderson et al. [5] There was usual arrangement of the abdominal and thoracic organs. The heart was in the left hemithorax (Figure 2A). The inferior caval vein was intact and drained into the right sided atrium. There were bilateral superior caval veins with no bridging vein, right sided aortic arch with mirror image branching and normal thymus gland (Figure 2B-D) The pulmonary veins drained normally into the left sided atrium. The right sided atrial appendage was larger and more pyramidal (Figure 2A). The left sided atrial appendage was finger like (Figure 2B). The right atrium opened into the anterior ventricle through a morphologically normal tricuspid valve. The left atrioventricular connection was normal. There was a large subaortic VSD (Figure 2D) and great arteries disproportion [main pulmonary artery (MPA) < Ascending Aorta (AO)] (Figure 2B). The MPA arose from the left side of the ascending aorta with confluent branch pulmonary arteries and the ductus arteriosus was absent confirming the diagnosis of Type I Truncus arteriosus. (Figure 3 (E-G)). Retrospective rendering of the stored STIC movies confirmed the origin of MPA from the left side of AO (Figure 1 E&F).
Heart failure in congenital heart disease: management options and clinical challenges
Published in Expert Review of Cardiovascular Therapy, 2020
Elsbeth M. Leusveld, Robert M. Kauling, Laurie W. Geenen, Jolien W. Roos-Hesselink
Congenital conditions with a predominantly right-sided phenotype and heart failure often exhibit signs of systemic venous congestion, such as peripheral edema (ankles, lower legs, and abdomen), raised jugular venous pressure, hepatic and splenic enlargement, and pleural effusion. Conditions associated with right-sided congestion include left-to-right shunts (e.g. atrial septal defects), Ebstein’s anomaly with severe tricuspid valve regurgitation and Tetralogy of Fallot (ToF) with abnormalities of the pulmonary valve, arteries, and the right ventricular outflow tract. Importantly, patients with predominantly right-sided abnormalities such as ToF may also develop left ventricular dysfunction, which may in turn cause symptoms [32]. Signs of left-sided causes of heart failure include crackles on lung auscultation, third heart sound, and a displaced apex beat. It is important to realize that failure of the right ventricle and tricuspid valve in systemic right ventricles (e.g. ccTGA or after atrial switch surgery) leads to symptoms and signs of pulmonary congestion. In patients after Fontan procedure with a univentricular heart systemic congestion often predominates, related to elevated pressures in the Fontan circulation.
Related Knowledge Centers
- Papillary Muscle
- Blood
- Systole
- Chordae Tendineae
- Heart
- Atrium
- Diastole
- Ventricle
- Regurgitation
- Heart Valve