Total Anomalous Pulmonary Venous Return (TAPVR)

Overview

Definition

Total anomalous pulmonary venous return (TAPVR) is a cyanotic congenital heart defect that results in the drainage of the 4 pulmonary veins Pulmonary veins The veins that return the oxygenated blood from the lungs to the left atrium of the heart. Lungs: Anatomy into the systemic venous circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment, rather than into the left atrium, resulting in mixing of oxygenated and deoxygenated blood. An interatrial defect ( ASD ASD Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by poor social skills, restricted interests/social interactions, and repetitive/stereotyped behaviors. The condition is termed a “spectrum” because of the wide variability in the severity of symptoms exhibited. Autism Spectrum Disorder, PFO PFO A patent foramen ovale (PFO) is an abnormal communication between the atria that persists after birth. The condition results from incomplete closure of the foramen ovale. Small, isolated, and asymptomatic pfos are a common incidental finding on echocardiography and require no treatment. Patent Foramen Ovale, or PDA PDA The ductus arteriosus (DA) allows blood to bypass pulmonary circulation. After birth, the DA remains open for up to 72 hours and then constricts and involutes, becoming the ligamentum arteriosum. Failure of this process to occur results in patent ductus arteriosus (PDA), a condition that causes up to 10% of congenital heart defects. Patent Ductus Arteriosus (PDA)) must be present to allow mixed blood to shunt to the left side of the heart and the systemic arterial circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment.

Classification

• Based on where pulmonary veins Pulmonary veins The veins that return the oxygenated blood from the lungs to the left atrium of the heart. Lungs: Anatomy drain:
  • Supracardiac (50% of cases): into superior vena cava Superior vena cava The venous trunk which returns blood from the head, neck, upper extremities and chest. Mediastinum and Great Vessels: Anatomy (SVC)
  • Infracardiac (20%): into inferior vena cava Inferior vena cava The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels: Anatomy ( IVC IVC The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels: Anatomy)
  • Cardiac (20%): into right atrium (RA)
  • Mixed (10%): combination of above forms
• Obstructed TAPVR: Pulmonary vein is narrowed, resulting in impedance to blood flowing out of pulmonary circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment.

Epidemiology

• Rare condition: 0.7%–1.5% of all CHD
• Prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency: 1 per 7,800 births in the United States

Embryology

This condition arises due to the failure of the left atrium to merge with the pulmonary venous plexus during fetal development.

• 1st month of gestation: Primitive cardinal and umbilicovitelline vessels drain systemic circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment into fetal heart.
• 27–29 days from conception:
  • Pulmonary venous plexus arises from splanchnic plexus.
  • Embryonal left atrium (LA) gives rise to common pulmonary vein (CPV).
  • CPV merges with venous plexus.
  • CPV splits into 4 and is incorporated into wall of LA.
• Failure of common pulmonary vein to merge with venous plexus resulting in TAPVR:
  • Connection with primitive cardinal venous system (draining into RA or SVC) and umbilicovitelline system ( IVC IVC The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels: Anatomy, hepatic, or portal vein Portal vein A short thick vein formed by union of the superior mesenteric vein and the splenic vein. Liver: Anatomy)

Pathophysiology and Clinical Presentation

Pathophysiology

• In non-obstructed TAPVR:
  • Oxygenated blood from pulmonary venous plexus flows into deoxygenated blood found in RA, IVC IVC The venous trunk which receives blood from the lower extremities and from the pelvic and abdominal organs. Mediastinum and Great Vessels: Anatomy, or SVC → venous mixing 
  • Mixed blood is shunted right to left through intra-atrial shunt ( ASD ASD Autism spectrum disorder (ASD) is a neurodevelopmental disorder marked by poor social skills, restricted interests/social interactions, and repetitive/stereotyped behaviors. The condition is termed a “spectrum” because of the wide variability in the severity of symptoms exhibited. Autism Spectrum Disorder) into systemic circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment → causing cyanosis Cyanosis A bluish or purplish discoloration of the skin and mucous membranes due to an increase in the amount of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule. Pulmonary Examination
  • RA and RV dilate to accommodate extra volume → right-sided heart failure Right-Sided Heart Failure Ebstein’s Anomaly 
• In moderate obstruction to pulmonary return: increased pressure in pulmonary vein → increased pressure in pulmonary artery Pulmonary artery The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs. Lungs: Anatomy → pulmonary hypertension Pulmonary Hypertension Pulmonary hypertension (PH) or pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary arterial pressure, which can lead to chronic progressive right heart failure. Pulmonary hypertension is grouped into 5 categories based on etiology, which include primary PAH, and PH due to cardiac disease, lung or hypoxic disease, chronic thromboembolic disease, and multifactorial or unclear etiologies. Pulmonary Hypertension → RVH → right-sided heart failure Right-Sided Heart Failure Ebstein’s Anomaly

Clinical presentation

The degree of obstruction of pulmonary veins Pulmonary veins The veins that return the oxygenated blood from the lungs to the left atrium of the heart. Lungs: Anatomy determines the age of presentation:

• Obstructed:
  • At birth
  • Cyanosis Cyanosis A bluish or purplish discoloration of the skin and mucous membranes due to an increase in the amount of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule. Pulmonary Examination 
  • Signs of shock Shock Shock is a life-threatening condition associated with impaired circulation that results in tissue hypoxia. The different types of shock are based on the underlying cause: distributive (↑ cardiac output (CO), ↓ systemic vascular resistance (SVR)), cardiogenic (↓ CO, ↑ SVR), hypovolemic (↓ CO, ↑ SVR), obstructive (↓ CO), and mixed. Types of Shock
  • Difficult to arouse
  • Severe shortness of breath Shortness of breath Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea or apnea
• Unobstructed:
  • 30 + days of age
  • Subtle cyanosis Cyanosis A bluish or purplish discoloration of the skin and mucous membranes due to an increase in the amount of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule. Pulmonary Examination
  • Poor feeding
  • Labored breathing

Diagnosis

Physical examination

• Cyanosis Cyanosis A bluish or purplish discoloration of the skin and mucous membranes due to an increase in the amount of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule. Pulmonary Examination: 
  • Pulse oximetry: ↓ Sp0₂
• Failure to thrive Failure to Thrive Failure to thrive (FTT), or faltering growth, describes suboptimal weight gain and growth in children. The majority of cases are due to inadequate caloric intake; however, genetic, infectious, and oncological etiologies are also common. Failure to Thrive
• Heart sounds Heart sounds Heart sounds are brief, transient sounds produced by valve opening and closure and by movement of blood in the heart. They are divided into systolic and diastolic sounds. In most cases, only the first (S1) and second (S2) heart sounds are heard. These are high-frequency sounds and arise from aortic and pulmonary valve closure (S1), as well as mitral and tricuspid valve closure (S2). Heart Sounds:
  • Fixed, split, loud S2 S2 Heart Sounds
  • Continuous murmur at site of obstruction
  • Pulmonary valve Pulmonary valve A valve situated at the entrance to the pulmonary trunk from the right ventricle. Heart: Anatomy → systolic ejection murmur
  • Tricuspid valve Tricuspid valve The valve consisting of three cusps situated between the right atrium and right ventricle of the heart. Heart: Anatomy → diastolic rumble Diastolic Rumble Ventricular Septal Defect (VSD)
• Signs of respiratory failure Respiratory failure Respiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure:
  • Tachypnea Tachypnea Increased respiratory rate. Pulmonary Examination
  • Grunting Grunting Physical Examination of the Newborn 
  • Nasal flaring
• Signs of heart failure:
  • Hepatomegaly
  • Tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children
  • Hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension
  • Cool extremities
  • Weak pulses
• Asplenia Asplenia Asplenia is the absence of splenic tissue or function and can stem from several factors ranging from congenital to iatrogenic. There is a distinction between anatomic asplenia, which is due to the surgical removal of the spleen, and functional asplenia, which is due to a condition that leads to splenic atrophy, infarct, congestion, or infiltrative disease. Asplenia (seen in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with heterotaxy syndromes)

Imaging

• Echocardiogram Echocardiogram Transposition of the Great Arteries:
  • Confirms diagnosis
  • Can be performed prenatally
  • Evaluates:
    • Type of TAPVR
    • Degree of obstruction
    • Right-to-left shunt
    • RV dilation
    • With doppler Doppler Ultrasonography applying the doppler effect, with frequency-shifted ultrasound reflections produced by moving targets (usually red blood cells) in the bloodstream along the ultrasound axis in direct proportion to the velocity of movement of the targets, to determine both direction and velocity of blood flow. Ultrasound (Sonography) → pulmonary vascular pressure
• Chest X-ray X-ray Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard x-rays are the higher energy, shorter wavelength x-rays. Soft x-rays or grenz rays are less energetic and longer in wavelength. The short wavelength end of the x-ray spectrum overlaps the gamma rays wavelength range. The distinction between gamma rays and x-rays is based on their radiation source. Pulmonary Function Tests:
  • Classic “snowman” sign seen in supra-cardiac TAPVR
  • Pulmonary venous congestion
  • Right heart enlargement
• ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG):
  • Right axis deviation
  • Right ventricle hypertrophy Hypertrophy General increase in bulk of a part or organ due to cell enlargement and accumulation of fluids and secretions, not due to tumor formation, nor to an increase in the number of cells (hyperplasia). Cellular Adaptation
• CTA CTA A non-invasive method that uses a ct scanner for capturing images of blood vessels and tissues. A contrast material is injected, which helps produce detailed images that aid in diagnosing vascular diseases. Pulmonary Function Tests (Computed Tomography Angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery) and MRA MRA Imaging of the Heart and Great Vessels (Magnetic Resonance Angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery):
  • Used when echocardiography Echocardiography Ultrasonic recording of the size, motion, and composition of the heart and surrounding tissues. The standard approach is transthoracic. Tricuspid Valve Atresia (TVA) is inconclusive
  • Provide detailed visualization of pulmonary pathways and connections
  • CTA CTA A non-invasive method that uses a ct scanner for capturing images of blood vessels and tissues. A contrast material is injected, which helps produce detailed images that aid in diagnosing vascular diseases. Pulmonary Function Tests is better for lung parenchyma but involves radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma.
  • MRA MRA Imaging of the Heart and Great Vessels avoids radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma but has lower spatial resolution and longer imaging time.
  • Both require intravenous contrast.

Management

• Surgery required in all patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship
• Medical management required to stabilize patient and bridge to surgery:
  • Supplemental 0₂
  • Inotropes Inotropes Hypoplastic Left Heart Syndrome (HLHS)
  • Prostaglandin E1 Prostaglandin E1 Coarctation of the Aorta IV to keep ductus arteriosus Ductus arteriosus A fetal blood vessel connecting the pulmonary artery with the descending aorta. Patent Ductus Arteriosus (PDA) open (if that is the only intra-atrial connection)
  • Ventilator support
• Surgical management:
  • Definitive therapy aiming to redirect drainage of pulmonary veins Pulmonary veins The veins that return the oxygenated blood from the lungs to the left atrium of the heart. Lungs: Anatomy into LA 
  • Palliative surgery in severely obstructed TAPVR (sick newborns) includes:
    • Atrial septostomy Atrial Septostomy Tricuspid Valve Atresia (TVA)
    • Placement of stent

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

• If untreated, neonate Neonate An infant during the first 28 days after birth. Physical Examination of the Newborn usually dies within 1st month of life.
• Surgical repair has very low mortality Mortality All deaths reported in a given population. Measures of Health Status rate and excellent long-term outcome.

Differential Diagnosis

• Tetralogy of Fallot Tetralogy of Fallot Tetralogy of Fallot is the most common cyanotic congenital heart disease. The disease is the confluence of 4 pathologic cardiac features: overriding aorta, ventricular septal defect, right ventricular outflow obstruction, and right ventricular hypertrophy. Tetralogy of Fallot (TOF): congenital heart disease characterized by occurrence of 4 key cardinal features: overriding aorta Overriding Aorta Tetralogy of Fallot, ventricular septal defect Ventricular Septal Defect Tetralogy of Fallot, right ventricular outlet obstruction, and right ventricular hypertrophy Right Ventricular Hypertrophy Tetralogy of Fallot. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship present with cyanosis Cyanosis A bluish or purplish discoloration of the skin and mucous membranes due to an increase in the amount of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule. Pulmonary Examination and history of “ tet spells Tet Spells Tetralogy of Fallot” (fainting while crying). Diagnosis is confirmed by echocardiogram Echocardiogram Transposition of the Great Arteries and patient is surgically managed.
• Tricuspid valve Tricuspid valve The valve consisting of three cusps situated between the right atrium and right ventricle of the heart. Heart: Anatomy atresia Atresia Hypoplastic Left Heart Syndrome (HLHS) (TVA): congenital heart disease characterized by lack of development of tricuspid valve Tricuspid valve The valve consisting of three cusps situated between the right atrium and right ventricle of the heart. Heart: Anatomy. Presents with cyanosis Cyanosis A bluish or purplish discoloration of the skin and mucous membranes due to an increase in the amount of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule. Pulmonary Examination, labored breathing, and hypoxic spells. Holosystolic murmur Holosystolic Murmur Tricuspid Valve Atresia (TVA) and single S2 S2 Heart Sounds are present on exam. Diagnosis made by echocardiogram Echocardiogram Transposition of the Great Arteries. Ultimate treatment is surgical.
• Transposition of the great vessels Transposition of the Great Vessels Transposition of the great vessels (TGV) is a cyanotic congenital heart disease characterized by “switching” of the great arteries. There are 2 presentations: the dextro (D)- and levo (L)-looped forms. The L-looped form is rare and congenitally corrected, as the ventricles are also switched. Transposition of the Great Arteries (TGV): congenital heart defect characterized by switching of great vessels, so aorta Aorta The main trunk of the systemic arteries. Mediastinum and Great Vessels: Anatomy originates from right ventricle and pulmonary artery Pulmonary artery The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs. Lungs: Anatomy from left. Presents with cyanosis Cyanosis A bluish or purplish discoloration of the skin and mucous membranes due to an increase in the amount of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule. Pulmonary Examination, tachypnea Tachypnea Increased respiratory rate. Pulmonary Examination, heart failure, hypoxemia Hypoxemia Neonatal Respiratory Distress Syndrome, and lack of response to supplemental oxygen Supplemental Oxygen Respiratory Failure. Ultimate treatment is surgical.
• Truncus arteriosus Truncus arteriosus Truncus arteriosus (TA) is a congenital heart defect characterized by the persistence of a common cardiac arterial trunk tract that fails to divide into the pulmonary artery and aorta during embryonic development. Truncus arteriosus is a rare congenital malformation with a high mortality rate within the 1st 5 weeks of life if not managed promptly. Truncus Arteriosus ( TA TA Thyrotoxicosis and Hyperthyroidism): emergence of aorta Aorta The main trunk of the systemic arteries. Mediastinum and Great Vessels: Anatomy and pulmonary artery Pulmonary artery The short wide vessel arising from the conus arteriosus of the right ventricle and conveying unaerated blood to the lungs. Lungs: Anatomy from common trunk overriding ventricular septal defect Ventricular Septal Defect Tetralogy of Fallot (VSD). Symptomatic from 1st days of life, including cyanosis Cyanosis A bluish or purplish discoloration of the skin and mucous membranes due to an increase in the amount of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule. Pulmonary Examination, respiratory distress, heart failure, poor feeding, and excessive sweating. Diagnosed by echocardiogram Echocardiogram Transposition of the Great Arteries. Ultimate treatment is surgical.
• Ebstein anomaly (EA): congenital heart defect in which there is downward displacement Displacement The process by which an emotional or behavioral response that is appropriate for one situation appears in another situation for which it is inappropriate. Defense Mechanisms of tricuspid valve Tricuspid valve The valve consisting of three cusps situated between the right atrium and right ventricle of the heart. Heart: Anatomy leaflets causing right ventricular outflow tract tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children (RVOT) obstruction. Presents with cyanosis Cyanosis A bluish or purplish discoloration of the skin and mucous membranes due to an increase in the amount of deoxygenated hemoglobin in the blood or a structural defect in the hemoglobin molecule. Pulmonary Examination, arrhythmias, and failure to thrive Failure to Thrive Failure to thrive (FTT), or faltering growth, describes suboptimal weight gain and growth in children. The majority of cases are due to inadequate caloric intake; however, genetic, infectious, and oncological etiologies are also common. Failure to Thrive. Diagnosed by echocardiogram Echocardiogram Transposition of the Great Arteries. Ultimate treatment is surgical.