Conventional pacing with either epicardial or endocardial systems for patients with univentricular physiology may be suboptimal owing to endovascular thrombosis risk and need for multiple redo procedures. Echocardiographic evaluation of univentricular physiology and. We report two cases of mechanical assistance in patients with sv physiology. Anatomy and physiology of the cardiovascular system. The use of mechanical cardiac assistance is well established as a bridge to orthotopic heart transplantation oht or to recovery for patients with congestive heart failure, however, the experience in single ventricle sv physiology is still limited. The concept of univentricular heart moved from hearts with only one ventricle connected with atria double inlet ventricle or absent atrioventricular av connection to hearts not amenable to biventricular repair, namely hearts with two ventricles unable to sustain separately pulmonary and systemic circulations in sequence. Although the anatomy and physiology of each reconstructive stage of palliation are unique, we will focus upon the pre and postoperative physiology as encountered in the neonate. In tricuspid atresia, the physiological effect of a restrictive asd is akin to systemic venous obstruction. Cardiovascular anatomy and physiology 1 anatomy of the major arteries and veins 3 anatomy of the heart, the pericardium and valves from cicm 3 coronary artery anatomy 3 anatomy of excitatory and conductive elements. Mechanical circulatory support in univentricular hearts. Specific injuries management in the postoperative of. Full text biomarkers of cardiac function and outcome in.
Blood can also enter the right atrium via the incompetent tricuspid valve. Rebeyka,a and holger buchholza failing singleventricle patients have now come into focus as the next cohort where improvement in outcomes for mechanical circulatory support can be realized. Changes in venous return parameters associated with. Unique in its complexity and scope, the univentricular heart has sparked intense debates about embryology and nomenclature, challenged our understanding of cardiovascular physiology and hemodynamics, and inspired some of the most. Right ventricular failure unresponsive to pharmacologic treatment occurs in approximately 20% to 30% of patients supported with a left ventricular assist device lvad. Frontiers decisionmaking for surgery in the management of. The univentricular heart encompasses a spectrum of rare and complex congenital cardiac malformations whereby both atria predominantly egress into one functionally single ventricular chamber, precluding biventricular repair. Without intervention in early life, survival to adult life is extremely. Perioperative management of univentricular hearts univentricular heart diseases have different physiology depending on stage of palliation in which they are table 1 and table 2. The physiology of this problem is not completely understood.
Basically, the concept is to place the pulmonary circulation in series with the systemic circulation rather than the parallel circulatory arrangement that is present. American journal of physiologyheart and circulatory. The patency of mitral or aortic valve does not change the physiology of the hypoplastic left heart, even though all its components are present. Hemodynamic interactions the right and left hearts have hemodynamic interactions. Pdf the new concept of univentricular heart researchgate.
Parallel advancements in surgical technique, preoperative and postoperative care, as well as a better understanding of physiology in patients with ductdependent pulmonary or systemic circulation and a functional single ventricle, have led to superb results in staged palliation of most complex congenital heart disease chd 1. Current management david horne,a jennifer conway,b ivan m. In each of these conditions there is a large pumping chamber ventricle which both collecting chambers atria empty their blood into. Natriuretic peptide, univentricular heart, congenital we appreciated this valuable study 1. Citeseerx orthotopic heart transplantation in patients.
Univentricular pathway is required in any congenital heart disease unsuitable for biventricular repair. The present report provides an overview of the nomenclature and classification of the univentricular heart, epidemiology and pathological subtypes, genetic factors, physiology, clinical features. Its four chambers and their valves make up two pumps. Direct left atrial pressure measurement with pressure sensing wires in complex univentricular heart disease. However, some patients with singleventricle defects do have health problems. Surgical management of lymphatic complications after univentricular heart repair christian kreutzer md head, pediatric and congenital heart surgery. We report the successful excision of a large left atrial rhabdomyoma producing complete obstruction of both inflow and outflow to the left ventricle. The excessive volume load on the right side of the heart and subsequent.
In short, optimal physiology of the univentricular heart requires good ventricular function with out av valve regurgitation, an unrestrictive asd. Although initially described for the palliation of tricuspid valve atresia, the fontan operation is now utilized for many other univentricular heart defects involving either hypoplastic right or left ventricles, and the number of babies who survive the surgery and the postsurgical hospitalization continues to grow. Followup studies on the somatic growth in children with a univentricular physiology are scarce and show inconsistent results. In each of these conditions there is a large pumping chamber ventricle which. Univentricular heart occurs in a number of congenital heart conditions a problem that a baby is born with. Research open access systemictopulmonary collateral flow in. Single ventricle heart defects childrens hospital of. A clear understanding of the associated physiology and possible complications is of paramount importance in. Cardiac cycle ventricular systole isovolumic contraction ejection ventricular diastole isovolumic relaxation rapid filling atrial contraction 4.
Since the surgical palliation of a univentricular congenital heart defect was first described in the early. The prevalence of patients with this type of physiology continues to increase due to improved surgical palliative procedures. Our hypothesis is that the rudimentary ventricle should be taken into account in calculations regarding contractility and wall stress in cases of univentricular physiology. Echocardiographic evaluation of univentricular physiology. Physiology in unpalliated univentricular chd, cyanosis occurs because of mixing of saturated and unsaturated blood in the heart. American journal of physiology heart and circulatory physiology dec 2019 h1173h90.
Improvement in echocardiographically derived myocardial performance index and the product of dominant outflow tract velocity time integral and heart rate as a surrogate measure of cardiac output were seen after administration of oral sildenafil in a cohort of patients with fontan physiology. Systemic ventricular implantation of a leadless pacemaker. Increased venous return produced by an lvad can affect right ventricular function by increasing preload. Below is a description of the heart condition and possible treatments offered. Ventricular assist device in univentricular heart physiology. The effect of the assistance on right ventricular function is highly controversial. State of the art of the fontan strategy for treatment of. Rudimentary ventricle in univentricular physiology european. Frontiers the new concept of univentricular heart pediatrics. Guyton and hall textbook of medical physiology th edition pdf is the bestselling book in physiology and it has continued this tradition since its very first publication. The heart fills passively, rather than by actively sucking. Advances in proper patient selection, staging of the fontan palliation, and modifications of the surgical technique resulted in continuous improvement of the surgical results during the past two decades.
Extubation failure in infants with shuntdependent pulmonary blood flow and univentricular physiology volume 24 issue 1 punkaj gupta, rachel mcdonald, sunali goyal, jeffrey m. All patients had congenital heart disase with univentricular physiology, underwent total cavopulmonary anastomosis and showed signs of arterial oxygen desaturation in the mediumterm followup. The berlin heart excor pediatric ventricular assist device is the only fdaapproved device with high success rates and gives new hope for children with advanced heart failure. Pdf the concept of univentricular heart moved from hearts with only one ventricle connected. Incidence numbers of scd in this group as a whole are unknown. This audit is a retrospective study aiming to evaluate the nutritional status of these infants. Physiology of the univentricular heart depends on such key determinants as obstruction to outflow, inflow, andor flow across the atrial septum. Even though the types of defects are different, the treatments are similar. Direct left atrial pressure measurement with pressure. The effect of the assistance on the right ven tricular function is highly controversial table 1. Thomas hospitals in london, united kingdom 12 bcpc, 8 fontan or at the german heart institute in berlin, germany 2 bcpc, 7. Heart single ventricle an overview sciencedirect topics. Systemictopulmonary collateral flow spcf, figure 1 often develops in patients with univentricular heart physiology after bidirectional cavopulmonary connection bcpc or fontantype palliation although little is known about their true prevalence.
Following the procedures that are performed, either systemicpulmonary shunt or pulmonary artery. Background growth impairment in infants with univentricular congenital heart disease is well documented. The population of adults with congenital heart disease chd continues to grow in size but also evolves in anatomic and complexity case composition. Neonatal physiology of the functionally univentricular heart. Patients with such functionally univentricular physiology often respond to common interventions, such as supplemental oxygen, mechanical ventilation, and vasoactive drugs, differently than patients with conventional circulations.
In unpalliated univentricular chd, cyanosis occurs because of mixing of saturated and unsaturated blood in the heart. A univentricular circulation describes a congenital heart defect where a biventricular repair is not possible, typically associated with hypoplasia of one of the ventricles andor atrioventricular valves, and often with other associated features. In most hearts with doubleinlet connection it is not the ventricles that are univentricular. In this context, appropriate decisionmaking relies on a thorough understanding of the anatomy and physiology of the univentricular heart at each stage of palliation, as well as a comprehensive knowledge of the advantages and disadvantages of the various management strategies. Surgical management of lymphatic complications after. In the next manuscript we will describe the three stages of univentricular palliation, i.
The final stage is the creation of a total cavopulmonary univentricular circulation. It was first described by francois marie fontan for repair of triscupid atresia. The cardiovascular system, therefore, consists of a closed circuit. A univentricular fontan repair can be considered in cardiac malformations with a single functional ventricle, usually because of the absence of an adequate atrioventricular valve or pumping chamberfor example, tricuspid atresia, pulmonary atresia with intact ventricular septum, double inlet ventricle, hypoplastic left heart syndrome fig 2. In the latter definition, even hearts with one hypoplastic ventricle. The term univentricular heart uh defines complex congenital heart disease that lacks a pulmonic ventricular chamber either in the original anatomy or the final palliation. Basically, the concept is to place the pulmonary circulation in series with the systemic circulation rather than the parallel circulatory arrangement that is present before repair 8, 30. Current treatment and prognosis in children with functionally. Considering the peculiar pathophysiology with difficult balance between systemic and pulmonary blood flow, often these patients require a period. In fontan physiology, lymphatic circulation drains to high pressure site. Babies with hypoplastic left heart physiology undergo staged norwood repair resulting in an eventual total cavopulmonary connection with the rv functioning. Singleventricle defects are among the most complex congenital heart problems. The left pump left side of the heart helps move blood through the systemic circulation and the right pump right side of the heart helps move blood through the pulmonary. Obstructive rhabdomyoma and univentricular physiology.
Echocardiographic evaluation of univentricular physiology and cavopulmonary shunts. References 1 brancaccio g, gandolfo f, carotti a, amodeo a. Research open access systemictopulmonary collateral. Challenges of univentricular physiology in heterotaxy marshall l. Challenges of univentricular physiology in heterotaxy. The fontan operation places the systemic and pulmonary circulations in series, driven by a singleventricular chamber. The univentricular heart comprises a highly heterogeneous group of malformations that include hypoplastic right and left heart syndromes, extreme forms of ebstein anomaly, and rarely true univentricular hearts. Meeting nutritional requirements in the early phase of infancy can be particularly challenging as these infants undergo complex surgical palliation within the first few days of life. Gossett, michiaki imamura, amit agarwal, warwick butt, adnan t. For more than 30 years fontantype procedures have been performed for surgical treatment in patients with functionally univentricular hearts. Single ventricle defects american heart association. Direct left atrial pressure measurement with pressure sensing. Univentricular heart management is needed for all cardiac anomalies where successful biventricular repair is not possible.
May 29, 2014 the term univentricular heart uh defines complex congenital heart disease that lacks a pulmonic ventricular chamber either in the original anatomy or the final palliation. The heart as a pump in chapter 18 we discussed the functional anatomy of the heart. The development of this operation was the result of bench and clinical research. Systemictopulmonary collateral flow in patients with. And for those who do not know, guyton physiology pdf is the worlds first trusted textbook on medical physiology. The concept of a univentricular av connection, then, appropriately groups hearts with doubleinlet along with those having absence of one av connection. There has been ongoing innovation and improvement of surgical and percutaneous. Univentricular heart double inlet or outlet ventricle. The resultant univentricular physiology was initially managed medically, with spontaneous tumor regression contemplated as a means of possible longterm cure.
Physiology of univentricular versus biventricular support. Babies with hypoplastic left heart physiology undergo staged norwood repair resulting in an eventual total cavopulmonary connection with the rv functioning as. If you have this defect, youll need regular checkups by cardiologists with expertise in adult congenital heart disease as well as ongoing care all your life. Request pdf ventricular assist device in univentricular heart physiology the use of mechanical cardiac assistance is well established as a bridge to orthotopic heart transplantation oht or. Guyton and hall textbook of medical physiology pdf free. Most patients with significant chd are nowadays diagnosed prenatally, what often enables safe delivery and even occasionally intrautero therapy. Early perinatal management of patients with univentricular heart is focused on identification of the anatomy which may constitute an immediate risk to the patient after birth and on stabilization with the usual measures to control the volume and pressure load to the ventricle while enabling adequate systemic delivery of oxygen. View enhanced pdf access article on wiley online library html view download pdf for offline. The optimal timing of the fontan staging for a univentricular heart and its impact on growth remains debateable. Physiology shunting occurs at the atrial and ventricular levels in a lefttoright direction. Patients with congenital heart disease and rhythm disturbances are a challenging patient group owing to their complex anatomy and embolic risk.
Decisionmaking for surgery in the management of patients. Systemic perfusion was dependent on anterograde ductual flow. The right atrium also receives blood from the left ventricle via the insufficient mitral valve and asd. Classification of the functionally univentricular heart. Systemic ventricular implantation of a leadless pacemaker in.
Jacobs, md and constantine mavroudis, md world journal for pediatric and congenital heart surgery 2011 2. A summary of management of patients with a univentricular heart will be provided. The various types of single ventricle heart defects are very different. Thomas hospitals in london, united kingdom 12 bcpc, 8 fontan or at the german heart institute in berlin, germany 2 bcpc, 7 fontan between march 2010 and february 2011. Hemodynamically, spcf may result in competitive pulmonary perfusion and power loss in the fontan pathway by transferring kinetic energy. The right and left ventricles, which pump into the same system that they pump out of, are in series with two interposed vascular beds systemic and pulmonary.
Univentricular physiology and cavopulmonary shunts. For instance, in hypoplastic left heart syndrome hlhs, the left side of the heart doesnt work correctly. In the few patients in whom surgery has not been performed, there is cyanosis lower oxygen levels, causing blueness, lower energy and a higher risk of infections such as brain abscess or endocarditis infection of the heart. As early as 1699, chemineau described a heart composed of 2 auricles but only 1 ventricle.
1108 1645 1124 673 529 1075 1518 545 1474 1022 410 281 1570 500 1073 1111 1383 1154 1327 1435 202 255 1277 557 463 1525 1501 304 866 978 1129 940 1066 1448 506 1145 13 1425 526 927