Persistent truncus arteriosus, also known as truncus arteriosus is a rare congenital heart disorder, part of the conotruncal abnormalities cluster, characterized by the fact that, during fetal life, the primitive arterial trunk fails to divide into the two great arteries: aorta and pulmonary. Therefore, a single artery that is large-sized supplies both systemic and pulmonary vascular beds. From this trunk arise the pulmonary arteries distally from the coronary arteries. A ventricular septal defect usually coexists, therefore this great arterial trunk will be filled from both ventricles, providing mixed (oxygenated and non-oxygenated) blood to distal territories.
Persistent truncus arteriosus should be diagnosed early during childhood, despite the fact that cyanosis may sometimes be mild, especially in newborns, that normally have increased pulmonary resistance. It is a cyanotic heart disease and clinician's attention should be first drawn by heart failure signs: diaphoresis, poor feeding, failure to thrive and tachypnea. These gradually appear, as the pulmonary blood flow and, consequently, myocardial work increase.
Clinical examination reveals a hyperdynamic precordium, an ejection click, and a single, loud second heart sound, due to the fact that a single truncal valve exists. If this valve is insufficient, the regurgitant flow causes a murmur that is characterized as high-pitched, decrescendo and diastolic. Some studies   find regurgitation to be an important risk factor for mortality, while others   fail to do so. The severity of the regurgitation is, however, clinically important because, if severe, it leads to more pronounced and earlier heart failure symptoms. Auscultation is completed by a mild or intense systolic murmur along the left sternal border. A mid-diastolic mitral flow murmur can also be noted. This is because of the high pulmonary blood flow. Pulmonary over-circulation, if present, prevents severe desaturation and cyanosis.
The presentation is usually much more dramatic if patients also have an interrupted aortic arch and patent ductus arteriosus that is about to close. In this case, the clinician will diagnose cardiogenic shock.
Entire Body System
- Congestive Heart Failure
All infants presented with symptoms of cyanosis and/or congestive heart failure within a few days to 2 months after birth and died shortly thereafter. [ncbi.nlm.nih.gov]
heart failure and cyanosis; the interventricular septum is usually patent. [medical-dictionary.thefreedictionary.com]
Because of the excessive amount of blood flow to the lungs with this anomaly, congestive heart failure (CHF) develops in the first week or two of life. [cincinnatichildrens.org]
Patients may present with signs and symptoms of cyanosis or congestive heart failure. There is a lack of normal separation of the embryological truncus arteriosus into a separate aorta and pulmonary trunk. [radiopaedia.org]
- Cyanotic Congenital Heart Disease
Juxtaposition of the atrial appendage is a sign of severe cyanotic congenital heart disease, and this is best diagnosed by a selective right atriogram or superior venacavogram. [ncbi.nlm.nih.gov]
With a clinical picture of cyanotic congenital heart disease, with high pulmonary blood flow, we proceeded with the definitive tests. [nigjcardiol.org]
Diagnosis and management of cyanotic congenital heart disease: part I. Indian J Pediatr. 2009 Jan. 76(1):57-70. [Medline]. [Guideline] Saxena A. Consensus on timing of intervention for common congenital heart disease. [emedicine.com]
Physiologic consequences of type I include mild cyanosis, heart failure (HF), and significant pulmonary overcirculation. [checkorphan.org]
The patient had mild cyanosis and developed heart failure soon after birth. Balloon septostomy was performed to enlarge the interatrial communication. [ncbi.nlm.nih.gov]
Persistent truncus arteriosus should be diagnosed early during childhood, despite the fact that cyanosis may sometimes be mild, especially in newborns, that normally have increased pulmonary resistance. [symptoma.com]
Physiologic consequences of truncus arteriosus include mild cyanosis, significant pulmonary overcirculation, and heart failure. [merckmanuals.com]
- Vascular Disease
Elective repair is recommended before the age of 2 years to minimize the risk of pulmonary vascular disease. [ncbi.nlm.nih.gov]
These findings suggested that late correction of TA should be undertaken prior to the development of pulmonary vascular disease. [cardiothoracicsurgery.biomedcentral.com]
Among the survivors, one developed severe pulmonary vascular disease and only two underwent late intracardiac repair. [heart.bmj.com]
- Single S2
Physical examination may detect a hyperdynamic precordium, increased pulse pressure, a loud and single S2, and an ejection click. A grade 2 to 4/6 holosystolic murmur is audible along the left sternal border. [checkorphan.org]
On physical examination, the S2 is loud and single (the aorta is anterior to the PA). A holosystolic murmur at the LLSB may indicate left AV valve (tricuspid) insufficiency. [utmb.edu]
Blood workup in persistent truncus arteriosus should include measurement of arterial blood gas, performed before and after a hyperoxia test if the diagnosis is uncertain. This test can also reveal acidosis if present. Electrolytes, especially total and ionized calcium should also be measured, due to the frequent association of truncus arteriosus with DiGeorge syndrome.
The thoracic radiograph shows raised pulmonary vascular markings due to pulmonary over-circulation along with cardiomegaly. A right aortic arch may coexist and be seen with this method . The pulmonary arteries originate high from the common trunk.
The electrocardiogram usually shows both right and left ventricular hypertrophy. A left atrial enlargement may be present if pulmonary over-circulation is marked. Axis may slightly deviate to the right.
Echocardiography is used to establish the diagnosis. Subcostal and parasternal long axis views are key when aiming to demonstrate the single trunk arising from both ventricles and the existence of a ventricular septal defect. The trunk may override the interventricular septum in variable degrees, therefore originating more from the left or from the right ventricle. It is also important to characterize the truncal valve in terms of anatomy and function (stenosis or regurgitation) and this can be performed by doppler color imaging. The subcostal view is also used to observe the origins of the pulmonary and coronary arteries.
Prenatal echocardiography can raise disease suspicion, but differential diagnosis with similar malformations may prove difficult . Four-dimensional fetal echocardiography may improve accuracy .
Cardiac catheterization is only used when coronary artery origin and anatomy cannot be properly characterized using echocardiography, in a preoperative setting .
- Right Axis Deviation
ECG shows right axis deviation, right ventricular hypertrophy, and occasionally right atrial enlargement. [merck.com]
- Left Axis Deviation
Cardiomegaly and increased pulmonary vascular markings on the chest x-ray film and left axis deviation with left ventricular hypertrophy on the ECG are usually present. [ncbi.nlm.nih.gov]
- Biventricular Hypertrophy
hypertrophy Cardiomegaly Increased pulmonary vascularity Hypocalcemia (if associated with DiGeorge syndrome) Classification A well-known classification is the fourfold system developed by Collett and Edwards in 1949. Collett/Edwards Types I, [en.wikipedia.org]
hypertrophy Cardiomegaly Increased pulmonary vascularity Hypocalcemia (if associated with DiGeorge syndrome ) Treatment Treatment is with neonatal surgical repair, with the objective of restoring a normal pattern of blood flow.  The surgery is open [ipfs.io]
Electrocardiogram showed features of biventricular hypertrophy. Chest X-ray showed features of cardiomegaly and right aortic arch. [annals.in]
Making the Diagnosis EKG may show biventricular hypertrophy. CXR shows increased pulmonary vascular markings and prominent ascending aorta. It may also be suggestive of right aortic arch (25% of cases). [utmb.edu]
Biventricular hypertrophy is frequently seen. The left atrium may be dilated. A right-sided aortic arch is frequently present. Interruption of the aortic arch is occasionally present. Coronary artery anatomy can be assessed. [ejca.eg.net]
- Left Atrial Hypertrophy
ECG commonly shows combined ventricular hypertrophy. Substantial pulmonary overcirculation may produce evidence of left atrial hypertrophy. Prognosis - Persistent truncus arteriosus Not supplied. [checkorphan.org]
Between September 2006 and 2016, 105 patients with persistent truncus arteriosus (PTA) received surgical treatment at Shanghai Children's Medical Center. [ncbi.nlm.nih.gov]
Medical treatment is used before surgery to allow the infant to stabilize and be a better candidate for surgery. [msdmanuals.com]
Medical treatment for heart failure is typically followed by surgical repair. Endocarditis prophylaxis is recommended. Persistent truncus arteriosus accounts for 1 to 2% of congenital heart anomalies. [checkorphan.org]
It has an extremely poor prognosis and carries a high mortality rate during the early years of life unless surgically repaired. [ncbi.nlm.nih.gov]
Treatment and prognosis Due to parallel fetal circulation, truncus arteriosus does not cause any hemodynamic problem in utero. [radiopaedia.org]
Prognosis - Persistent truncus arteriosus Not supplied. [checkorphan.org]
(Outcomes/Resolutions) With proper diagnosis, treatment, and medications, the prognosis for Patent Ductus Arteriosus is excellent. [dovemed.com]
Figure 3: Postrepair mid-esophageal ascending aortic short axis colour flow Doppler showing right ventricle to pulmonary artery conduit Click here to view Truncus arteriosus, also known as common arterial trunk is a rare CHD (  Etiology is mostly genetic [annals.in]
(Etiology) Patent Ductus Arteriosus (PDA) could be idiopathic (occurring without any identifiable cause), or secondary to some other medical condition PDA can be associated with other congenital heart abnormalities, or it may arise on its own. [dovemed.com]
Irrespective of the etiology, right heart failure will result in inadequate systemic perfusion, exacerbating the original problem. [ejca.eg.net]
Epidemiology Truncus arteriosus is a rare cyanotic cardiac malformation with an incidence of 0.07 per 1000 live births (1.1 percent of all cardiac anomalies), with 40 percent of patients disclosing 22q11 deletion on genetic testing. [accesssurgery.mhmedical.com]
A number of these cases have survived well into adulthood. Epidemiology Persistent truncus arteriosus is a rare cardiac abnormality that has a prevalence of less than 1%. Additional images See also Truncus arteriosus (embryology [en.wikipedia.org]
A number of these cases have survived well into adulthood.  Epidemiology Persistent truncus arteriosus is a rare cardiac abnormality that has a prevalence of less than 1%.   Additional images See also Truncus arteriosus (embryology) Patent [ipfs.io]
Epidemiology TA is responsible for 0.21%-0.34 % of congenital heart defects Incidence has been found to be 0.03-0.05/1,000 live births. [pedclerk.bsd.uchicago.edu]
Epidemiology Frequency United States Truncus arteriosus represents 1-2% of congenital heart defects in liveborn infants. [emedicine.com]
Truncus Arteriosus Background, Pathophysiology, All students in the School of Health Professions are required to follow and abide by policies stated in the KU School of Health Professions student handbook as well as those defined in the handbook of the [ucsfcme.com]
(Click picture to show/hide bloodflows) Pathophysiology The result of intracardiac mixing of the systemic and pulmonary venous return is systemic desaturation. [vhlab.umn.edu]
Kay PH, Brass T, Lincoln C (1989) The pathophysiology of atypical tamponade in infants undergoing cardiac surgery. Eur J Cardiothorac Surg 3: 255–261 PubMed CrossRef Google Scholar 12. [link.springer.com]
Grasp the full scope of the pathophysiology of CHD with well-organized, expert guidance. Quickly search the contents online, download images in JPG or PPT format, and view 70 echocardiogram videos at expertconsult.com. [books.google.ro]
Pathophysiology Typically, there is intracardiac mixing (atrial and/or ventricular septal defect) with pulmonary over-circulation and, if interrupted aortic arch (IAA) is present, features of duct-dependent distal aortic perfusion. [accesssurgery.mhmedical.com]
Early operation may prevent pulmonary vasculopathy. However, the results in complex PTA remain poor. [ncbi.nlm.nih.gov]
Prevention In most cases, congenital heart disease, such as truncus arteriosus can not be prevented. [resultmed.com]
There is no known prevention. Early treatment can often prevent serious complications. Fraser CD, Kane LC. Congenital heart disease. In: Townsend CM Jr, Beauchamp RD, Evers BM, Mattox KL, eds. [nlm.nih.gov]
What about preventing endocarditis? For patients with uncorrected or partially corrected truncus arteriosus, antibiotics are recommended before certain dental procedures to prevent endocarditis. See the section on Endocarditis for more information. [heart.org]
Pulmonary over-circulation, if present, prevents severe desaturation and cyanosis. The presentation is usually much more dramatic if patients also have an interrupted aortic arch and patent ductus arteriosus that is about to close. [symptoma.com]
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- Hanley F, Heinemann M, Jonas R, et al. Repair of truncus arteriosus in the neonate. J Thorac Cardiovasc Surg. 1993;105:1047–1056.
- Brown J, Ruzmetov M, Okada Y, et al. Truncus arteriosus repair : Outcomes, risk factors, reoperation and management. Eur J Cardiothorac Surg. 2001;20:221–227.
- Kaza A, Burch P, Pinto N, et al. Durability of truncal valve repair. Ann Thorac Surg. 2010;90:1307–1312.
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- Swanson T, Selamet E, Tworetzky W, et al. Truncus arteriosus: diagnostic accuracy, outcomes, and impact of prenatal diagnosis. Pediatr Cardiol. 2009;30(3):256-261.
- Turan S, Turan OM, Desai A, et al. First-trimester fetal cardiac examination using spatiotemporal image correlation, tomographic ultrasound and color Doppler imaging for the diagnosis of complex congenital heart disease in high-risk patients. Ultrasound Obstet Gynecol. 2014;44(5):562-567.
- Rao PS. Diagnosis and management of cyanotic congenital heart disease: part I. Indian J Pediatr. 2009;76(1):57-70.