Significant incidental cardiac disease on thoracic CT: what the general radiologist needs to know
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Incidental cardiac findings are often found on chest CT studies, some of which may be clinically significant. The objective of this pictorial review is to illustrate and describe the appearances and management of the most frequently encountered significant cardiac findings on non-electrocardiographically gated thoracic CT. Most radiologists will interpret multidetector chest CT and should be aware of the imaging appearances, significance, and the appropriate next management steps, when incidental significant cardiac disease is encountered on thoracic CT.
This article reviews significant incidental cardiac findings which may be encountered on chest CT studies. After completing this review, the reader should not only be familiar with recognizing clinically significant cardiac findings seen on thoracic CT examinations but also have the confidence to direct their further management.
KeywordsCardiac disease Incidental finding Significant Chest computed tomography (CT) Management
Arrhythmogenic right ventricular cardiomyopathy/dysplasia
Atrial septal defects
Bicuspid aortic valve
Coronary artery fistula
Congenital heart disease
- ECG gated
Left anterior descending
Left ventricular enlargement
Left ventricular hypertrophy
Left ventricular outflow tract
Multi-detector row CT
Magnetic resonance imaging
Patent ductus arteriosus
Right ventricular outflow tract
Systolic anterior wall motion
Sinus of Valsalva aneurysm
Superior vena cava
Ventricular septal defects
With the continued rise in advanced imaging, particularly multidetector row computed tomography (CT), radiologists who interpret trauma or inpatient body CT will diagnose incidental cardiac disease on chest CT, which may require swift action or further management.
In sick patients and inpatients, thoracic and cardiac comorbidities frequently occur and therefore radiologists should be aware of the appearances of significant cardiac findings on chest CT so that they can direct further appropriate management.
Chest (thoracic and cardiovascular) computed tomography (CT) is commonly performed for a variety of acute and routine clinical indications and is the third most common CT procedure performed after abdominal pelvic and brain CT . The numbers of CT’s performed are also rising, with an average increase of 7.8% annually between 1996 and 2010 . The incidence and prevalence of chest symptoms and disorders in the general adult population is common, and it may be higher in ill in-patients, with many indications generating chest CT examinations. In addition, patients undergoing CT are often middle aged and older and may have existing heart and lung comorbidities, some of which will manifest on thoracic CT. Given that thoracic and cardiac disease etiological factors and disease processes overlap, radiologists who interpret body CT will frequently encounter cardiac findings on chest CT .
Most hospitals and outpatient medical centers now utilize multi-detector row CT (MDCT) which allows better spatial resolution and for more efficient throughput and increased numbers of patients scanned . With this increase in CT imaging, body or chest radiologists are encountering more and more incidental findings and the challenge is to determine which findings are significant and will require further action or management. Previous studies of patients undergoing CT (including CT to evaluate for pulmonary embolism) have reported cardiac abnormalities, in 61 to 78% of cases [5, 6]. Similarly, many radiologists will frequently interpret non-cardiac or non-electrocardiographically (ECG) gated thoracic CT and will likely come across cardiac disease and findings, some of which will require further management or specific action to be taken [7, 8, 9, 10]. The high volume of thoracic CT examinations without ECG gating (including pulmonary embolism CT) represents an opportunity for radiologists to comprehensively evaluate and comment on the presence or absence of cardiac disease, which may influence future clinical decisions .
Some of these cardiac entities will be significant, requiring further management, which may include referral for other imaging, referral to another specialty, intervention, or imaging follow up. Therefore, radiologists should not only be familiar with the appearances of the more commonly occurring significant cardiac findings encountered on thoracic CT but also be able to confidently direct their further management.
Incidental significant cardiac findings that might be encountered on thoracic CT will include shunts (both intracardiac and extracardiac), valvular anomalies and diseases, coronary anomalies and disease, chamber and wall masses, and myocardial and pericardial disease.
The purpose of this pictorial review is to demonstrate the more common and significant cardiac findings seen on non-cardiac, non-ECG gated chest CT (thoracic CT) examinations; discuss their incidence and prevalence when known; describe and illustrate their CT imaging features; generate an appropriate differential diagnosis; and finally, to outline the appropriate next management steps.
Atrial septal defect
About 60% of atrial septal defects (ASDs) are secundum defects, found in the region of the fossa ovalis, and over two-thirds of patients with secundum defects are female [12, 13]. Although, isolated small patent foramen ovale or ostium secundum ASDs have an estimated prevalence of up to 24% in MDCT and coronary CT patients and up to 25–35% in autopsy studies, most are not visualized [14, 15]. Associations include mitral valve prolapse.
Less common ASDs include the ostium primum ASD in the lowermost atrial septum (about 35% of ASDs), associated with Downs syndrome and endocardial cushion defects and presenting early in life [12, 13]. More rare ASDs include the superior sinus venosus defect in the superior atrial septum, usually associated with partial anomalous pulmonary venous return and the inferior sinus venosus defect in the inferior portion of the right atrium at the junction of the inferior vena cava with the right atrium and the coronary sinus ASD, a deficiency of the wall between the coronary sinus and the left atrium .
Tiny shunts < 0.5 cm in diameter are usually not of hemodynamic significance with larger shunts > 2 cm being associated with hemodynamic disturbance . Some ASDs will not be diagnosed until the fourth and fifth decades of life and most frequently present with progressive dyspnea on exertion. Atrial septal defects get progressively larger with age due to hypertrophy of the left ventricle with decreased compliance.
Management involves the use of closure devices, which are nowadays inserted percutaneously, although shunts greater than 3.8 cm (in late systole) are generally not amenable to closure with devices . In general, elective closure is advised for all ASDs with evidence of right ventricular overload or with a clinically significant shunt (pulmonary flow [Qp]-to-systemic flow [Qs] ratio > 1.5) . According to the latest American Heart Association and the British Society for Antimicrobial Chemotherapy guidelines, patients with ASDs no longer require antibiotic prophylaxis before medical and dental procedures [19, 20].
Patent ductus arteriosus
The incidence of patent ductus arteriosus (PDA) is estimated to be as high as 1 in 500 and it is twice as common in females . Most cases are sporadic and risk factors include prematurity, with other associations including Rubella infection in early pregnancy, fetal valproate syndrome, and genetic disorders such as Trisomy 21, Holt Oram, and Carpenters Syndrome . Familial cases with an autosomal recessive inheritance have been reported.
There is a wide variability in size and configuration, which determines the degree of shunt and other effects. Patent ductus arteriosus is classified as silent, small, moderate, or large. Some small and moderate-sized PDAs may not present until adulthood, typically after the onset of hypertension, which increases flow through the PDA due to a rise in systemic arterial resistance . Complications in severe cases include pulmonary hypertension and Eisenmengers syndrome. Aneurysms of the ductus arteriosus may also occur as a complication. Associations include ASD and ventricular septal defects (VSD).
Echocardiography is recommended as the first step to diagnose and characterize the PDA. Nowadays, closure for symptomatic shunts is indicated unless there is fixed high pulmonary vascular resistance. This is usually performed with transcatheter closure techniques, including coil insertion as well as occluder devices. For asymptomatic shunts, closure is indicated if there is left atrial enlargement resulting from the left-to-right shunting. According to the latest society guidelines, patients with PDA’s no longer require antibiotic prophylaxis before medical and dental procedures [19, 20].
Sinus of Valsalva aneurysm
Sinus of Valsalva aneurysms (SOVA) are rare with an incidence of about 0.09% of the general population . The exact incidence is unknown, however, as these lesions are frequently silent. They account for 0.1–3.5% of all congenital heart defects and can also be acquired with connective tissue disorders and trauma [24, 25]. In SOVA, there is a weakness in the elastic lamina at the junction of the aortic media and the annulus fibrosus, which in congenital cases, is associated with Marfan’s syndrome, Ehlers-Danlos syndrome, or bicuspid aortic valve. In acquired SOVA, secondary degeneration of the elastic connective tissue can occur due to connective tissue disease, atherosclerosis, infection (e.g., bacterial endocarditis, syphilis, and TB), or trauma (including iatrogenic). There is a 4:1 male predominance and the reported incidence is higher in Asian people.
Sinus of Valsalva aneurysms occur mainly in the right coronary sinus (75–90%), less often in the non-coronary sinus (10–25%), and least often in the left coronary sinus (and are frequently acquired in this location).
The upper limits of normal for sinus diameter in men is 4 cm and in women, 3.5 cm, with slight variations, when adjusted for body surface area . Depending on the location of the aneurysm, there may be compression of other structures by the aneurysm. Aortic regurgitation is a complication. Surgery is indicated for ruptured cases, and for cases with associated aortic regurgitation. Management of un-ruptured SOVA is controversial, but elective intervention is recommended for large lesions, to prevent rupture later. Intervention is also indicated where there is compression of the right ventricular outflow tract, or if the lesion is complicated by arrhythmia or infection.
Bicuspid aortic valve
Anatomically tricuspid but functionally bicuspid valves (secondary bicuspid valves) are more common than congenital bicuspid valves and can be difficult to distinguish from each other on imaging. Double oblique reformatted images (on a dedicated 3D workstation) can be viewed to see the valve in plane, but for definitive differentiation and evaluation for the need for operative intervention, functional information will be required, which can be obtained using ECHO or MRI.
On imaging, the cusps of the bicuspid valve are usually of unequal size (as one of them is two cusps fused with or without a raphe). Calcification may be seen at the base of the cusps or at the raphe. Ascending aortic dilatation occurs mostly due to cystic medial necrosis (bicuspid aortopathy) rather than secondary to valve stenosis (post stenotic dilatation) (Fig. 4). Patients with BAV and aortic root or ascending aortic diameters greater than 4 cm should undergo serial evaluation with MRI or CT, and yearly evaluation when the aortic diameter exceeds 4.5 cm . Operative intervention is recommended when the aortic root or ascending aortic diameter is greater than 5.5 cm or if the rate of increase is more than 0.5 cm per year [29, 30].
Coronary arterial disorders
Coronary artery disease
Coronary arterial calcification (CAC) is a marker of the burden of coronary artery atherosclerosis but its relationship to plaque instability is less predictable. Coronary arterial calcification can be an early indicator of coronary artery disease in asymptomatic individuals being worked up for surgery or other suspected chest pathology. Coronary artery disease was the most frequent cardiac finding on chest CT in prior studies with the left anterior descending coronary artery being the most frequently involved . The same authors note that the presence of coronary arterial calcification was often not mentioned in chest CT reports . Coronary arterial calcification can be easily seen even on non-ECG gated unenhanced CT. Radiologists interpreting chest CT should not only evaluate the anatomic origin of the coronary arteries but also evaluate for the extent and severity of coronary arterial disease. Patients with coronary arterial calcification have increased risk for cardiac events, including ischemia, arrhythmia, hypotension, myocardial infarction, coronary arterial intervention or surgery, and death. For each standard deviation increase in CAC scores on non-ECG gated CT, the odds ratio for death increased by 50%, when adjusted for traditional cardiovascular disease risk factors . Detection of coronary arterial calcification might enable the patient to undergo primary preventative measures such as dietary changes, exercise, aspirin, or statin treatment. Coronary arterial calcification has a high specificity and negative predictive value . In patients who are undergoing CT prior to surgery, it is important for the surgeon and anesthetist to know about the coronary arterial calcification burden, as the patient may need functional imaging or cardiology consultation first or a different surgical approach or anesthetic plan.
Coronary artery ectasia and aneurysm
Coronary artery aneurysms are commonly defined as a 50% or greater localized increase in diameter of the affected vessel compared with the adjacent arterial segment . Giant coronary artery aneurysms can reach several cm in diameter . Coronary artery ectasia is defined as diffuse coronary artery dilation with less than 50% increase in diameter . Coronary artery aneurysms are most commonly caused by atherosclerosis in adults or by Kawasaki disease in children . Other etiologies include trauma (including iatrogenic), arteritis (granulomatosis with polyangitis, polyarteritis nodosa, systemic lupus arteriosus), infection (syphilis, staphylococcus), dissection, connective tissue disorders (Marfan’s, Ehlers-Danlos), and cocaine abuse .
Further evaluation can be carried out non-invasively with electrocardiographically (ECG) gated cardiac CT or cardiac magnetic resonance imaging (CMR). Management is unclear with some advocating surgical or endovascular repair (usually to treat any areas of stenosis in cases of atherosclerosis) and others taking a more conservative approach, including anti platelet agents and anticoagulation .
Coronary artery fistula
A coronary artery fistula (CAF) is defined as a single or multiple direct precapillary connections between a branch of a coronary artery and the lumen of a cardiac chamber (coronary cameral fistula), or an arterial/venous structure including the coronary sinus, superior vena cava, pulmonary artery, pulmonary vein, or bronchial vein (coronary arteriovenous fistula) [39, 40]. Coronary artery fistulas are rare, representing 0.2 to 0.4% of all congenital heart disease (CHD), 14% of all coronary anomalies, and often incidentally found on angiographic imaging [41, 42]. The majority of CAF are congenital, but some are acquired secondary to trauma, infection, neoplasms, or iatrogenic injury. They can also occur as a result of intracardiac congenital heart operations, transcutaneous techniques used for myocardial biopsy or coronary angioplasty, or as a complication of Kawasaki disease [41, 43]. As more cardiac transplants are performed and patients undergo myocardial biopsies, the incidence of acquired CAF in this patient population is increasing.
Fistulas most commonly arise from the RCA (50 to 60% of cases), the left anterior descending coronary artery (25 to 42%), the circumflex (18%), or both coronary arteries (5%) [33, 45]. Single fistulas are more common (74 to 90%) than multiple (10 to 16%) . The most common (60 to 90%) site of drainage is the right side of the heart [44, 45, 46]. The remaining 10% may be connected to the pulmonary artery, coronary sinus, superior vena cava (SVC), pulmonary vein, left atrium (LA), left ventricle (LV), or have multiple connections . Termination into a cardiac chamber or vascular structure with lower pressure may lead to enlargement and tortuosity of the artery . The clinical presentation of CAFs depends on the severity of the left-to-right shunt, with the majority detected in adult patients being usually asymptomatic. Coronary angiography can reliably demonstrate the proximal part of the CAF and allow evaluation of the size and number of fistulas present. However, coronary fistulas draining into low-pressure chambers of the heart may not be well-visualized by conventional angiography because of significant dilution of the contrast medium. Electrocardiographically gated MDCT is useful to image CAF and provide a road map for treatment planning .
Anomalous coronary artery origin
Coronary arteries can have anomalous origins from a contralateral sinus of Valsalva, the pulmonary artery, or another coronary artery or its branches [48, 49, 50]. The most serious anomaly occurs when a left or right coronary artery arises from the contralateral sinus of Valsalva and courses between the aorta and pulmonary trunk (intra-arterial or “malignant” course). Other high-risk anatomic features include a slit-like orifice, an intramural course (through the aortic wall), and an acute take off angle . Death is thought to be caused by ischemia resulting from ostial occlusion due to angulation or kinking at the coronary orifice or compression within the aortic wall or between the aorta and the pulmonary artery during diastole .
Abnormalities of the cardiac walls
Left ventricular aneurysm, pseudoaneurysm, and diverticulum
It can be difficult to distinguish true left ventricular aneurysms from pseudoaneurysms or congenital diverticula, but correct differentiation is crucial since pseudoaneurysms have a high risk of rupture and surgical repair is recommended, while true aneurysms and diverticula can often be managed medically. Two features which may help distinguish these entities include location and ostial (neck) diameter.
Pseudoaneurysms are usually located posteroinferiorly and may be caused by ischemia, infarction, or trauma (Fig. 8) . A pseudoaneurysm occurs when rupture of the free LV wall in myocardial infarction is contained by overlying adherent pericardium or not contained. Left ventricular pseudoanerysms usually rupture, resulting in immediate death, and as a result are not commonly seen by imaging. If the patient survives, pseudoaneurysms may cause congestive heart failure with embolic events as the cavity is noncontractile or dyskinetic, due to slow flow of blood and thrombosis . Left ventricular aneurysms tend to have wide, more evident openings in contrast to the narrow ostium of pseudoaneurysms or diverticula which can be difficult to visualize [55, 56].
Diverticula are rare congenital anomalies and typically include endocardium, full thickness myocardium and pericardium, arising near the apex, except for the isolated fibrous variety, found at the heart base or in the subvalvular area (Fig. 8) [56, 57]. Muscular diverticula are often associated with midline defects involving the abdominal wall (omphalocoele), sternum, diaphragm, and heart (ASD) (Cantrell syndrome) . Left heart catheterization (ventriculography) was the gold standard to visualize muscular diverticula contracting in systole, in contrast to pseudoaneurysms which do not contract. Nowadays, dynamic imaging with ECG gated MDCT or functional cine MRI can demonstrate the form and function less invasively. The presence of myocardium surrounding the aneurysmal cavity suggests a true aneurysm (thinned myocardium) or diverticulum (full thickness myocardium) and myocardial discontinuity suggests pseudoaneurysm.
Finally, true aneurysms in any location within the left ventricle are much more common than pseudoaneurysms or diverticula; therefore, location is not an adequate criterion for clinical decision making. The more posterior the outpouching, the more difficult it is to detect .
Left ventricular hypertrophy
LVH is usually diagnosed by electrocardiogram or on echocardiography (ECHO) and if suspected on non-ECG gated CT, further evaluation should be recommended using these modalities and by cardiac MRI .
Asymmetric septal wall hypertrophy causes obstruction of the left ventricular outflow tract (LVOT) in up to a third of cases. The mitral valve may be affected secondary to left ventricular outflow tract obstruction with systolic anterior wall motion (SAM), or because of a primary abnormality in the valve itself. Anatomic narrowing of the LVOT during systole and SAM contribute to cause dynamic subaortic obstruction [64, 65]. On axial CT images, narrowing may be seen at the level of the left ventricular outflow tract, in association with thickening of the mid ventricular septum, and non-invasive assessment of the anatomic and functional changes with MRI can be recommended [60, 64, 65]. In older patients, a sigmoid shape to the interventricular septum may be seen but is not usually associated with hemodynamic changes .
Metastatic calcification is associated with elevated serum calcium and is most commonly reported in chronic renal failure patients on hemodialysis . Globular, diffuse, amorphous, or patchy metastatic calcifications are found in many locations including the ventricular walls (Fig. 12). Metastatic calcification can also be seen with primary, secondary, and tertiary hyperparathyroidism.
The prevalence, etiology, and mechanisms of idiopathic myocardial calcifications are unknown, but some believe these to be dystrophic or metastatic, and secondary to a clinically occult myocardial abnormality .
Left ventricular myocardial fat
Right ventricular myocardial fat
Finding right ventricular myocardial fat on CT is only one of many diagnostic features of ARVC/D, and CT has not been included in the diagnosis task force criteria used in the of ARVC/D, but there may be a role for dynamic, 4-D cine cardiac CT in the future . Arrhythmogenic right ventricular dysplasia also occurs in a younger (and symptomatic) patient population and there is often associated right ventricular wall dilatation . The diagnosis of ARVC/D is challenging, due to the absence of unique diagnostic criteria, incomplete penetrance, and variable disease expression. In addition, diagnostic tests are not sensitive enough, findings are non-specific, and the diagnostic criteria used are subjective . Therefore, if ARVC/D is suspected, referral to a cardiologist for complete assessment of diagnostic task force criteria for ARVC/D (which include features on cardiac MRI) is recommended.
Left atrial enlargement
Left atrial enlargement can be caused by mitral valvular disease (stenosis and regurgitation), atrial fibrillation, left to right shunts, left ventricular hypertrophy (LVH), left ventricular failure, dilated cardiomyopathy, and ischemic heart disease. A search should be made for thrombus in the left atrium or its appendage. In addition, evaluation of the mitral valve for calcification or thickening can be made, as well as checking the other chamber sizes and wall thicknesses, and looking for coronary arterial calcification. Left atrial anteroposterior measurements should ideally be made on a three-chamber view (aortic outflow tract, left atrium, and left ventricle) at the end of left ventricular systole . Measurements of the largest anteroposterior left atrial diameter (made at the level of the aortic valve), greater than 4.5 cm on axial non-ECG gated CT, had 94% specificity (53% sensitivity) for left atrial dilatation . Normalized reference range volume measurements for the left atrium and other cardiac chambers have been established using dynamic magnetic resonance imaging by Maceira and colleagues .
Right atrial enlargement
Right atrial enlargement can be caused by pulmonary arterial hypertension, tricuspid valvular disease (stenosis and regurgitation), atrial fibrillation, left to right shunts, left ventricular hypertrophy (LVH), and ischemic heart disease. There are no accepted standardized measurements for right atrial sizes. Normalized reference range volume measurements for the right atrium and other cardiac chambers have been established using dynamic magnetic resonance imaging .
Left ventricular enlargement
Left ventricular enlargement (LVE) can be indicative of many pathological entities, including cardiomyopathies, ischemic heart disease and valvular dysfunction.
Non-ECG gated CT images likely will not be obtained in end-diastole and so the ventricular cavity size may be underestimated. A recent study suggested that left ventricular chamber measurements greater than 5.6 cm (made half way between the apex and the valve, from inner wall to inner wall) on axial non-ECG gated CT had a 100% specificity (78% sensitivity) and negative predictive value of 93% (positive predictive value of 80%) . Therefore, dimensional thresholds are best used to provide specific detection (rule in) and to suggest for chamber enlargement, rather than being able to exclude it. Normalized reference range volume measurements for the left ventricle and other cardiac chambers are well established by dynamic magnetic resonance imaging .
Right ventricular enlargement
Right ventricular enlargement is difficult to assess, due to its complex shape and variability and lack of specific landmarks that can be used as reference points. Right ventricular enlargement is found with pulmonary hypertension, pulmonary valve stenosis or regurgitation, left to right shunts (ventricular septal defect), and cardiomyopathy. Normalized reference range volume measurements for the right ventricle and other cardiac chambers have been established using dynamic magnetic resonance imaging .
Filling defects in the cardiac chambers
Malignant cardiac masses
Primary cardiac tumors
Rhabdomyosarcoma is the most common primary cardiac tumor in infants and children, with a slight male predominance. Rhabdomyosarcomas can be multiple, are more likely to occur on the valves, and can occur in all chambers, with variable presentation. They tend to involve the myocardium and can invade the pericardium with nodular masses, rather than diffuse sheet-like thickening. The other sarcomas (undifferentiated, leiomyosarcoma, fibrosacroma, and osteosarcoma) typically involve the left heart chambers and cause left heart failure . Low attenuation components in a mass arising typically from the posterior wall of the left atrium may be seen with leiomyosarcomas, while chondroid or osteoid elements may be seen with osteosarcomas. Unfortunately, delayed diagnosis leads to a poor prognosis with an average survival of 1 year. Cardiac lymphoma is defined as one that is mostly confined to the heart or pericardium (to distinguish it from invasive non-Hodgkin’s lymphoma) and almost all primary cardiac lymphomas are aggressive B cell lymphomas. Unlike other primary cardiac malignancies, primary cardiac lymphoma has a favorable response to chemotherapy. They are more frequent in the right atrium and pericardial effusion is a common feature, and sometimes the only finding visible on imaging. Findings of primary cardiac lymphoma on CT are non-specific.
CT provides good soft tissue detail and can depict calcification, ossification or fat, or make a tissue diagnosis in the case of lipomas. However, cardiac MR imaging has the added advantage of providing functional information and utilizes multiple planes which can help pre-therapy planning [95, 96].
Cardiac disease and pathology are commonly seen on thoracic CT performed for other indications. Relatively common and significant entities include filling defects due to thrombus or myxoma. Other not uncommonly encountered entities include small left to right shunts, the sequelae of prior MI (such as ventricular fat or calcium deposition), or pericardial constriction. Rarer but significant entities described include coronary artery fistula or aneurysm, anomalous coronary artery course, left ventricular aneurysm, or pseudoaneurysm and malignant cardiac tumors (metastases). Radiologists should be aware of the imaging features of these cardiac diseases encountered on thoracic CT, as some will require specific further referral or diagnostic testing. After completing this article, the reader should be familiar with clinically significant cardiac findings seen on chest CT examinations and be confident to direct the next management steps.
MK and AK carried out the initial manuscript drafting and imaging collection. PC provided some images later. MK and AK participated in the design of the study and performed the literature reviews. AK and MK conceived of the study and participated in its design and coordination. All authors read and approved the final manuscript.
The authors declare that they have no competing interests.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
- 1.National Council on Radiation Protection and Measurements. Report No. 160, Ionizing Radiation Exposure of the Population of the United States. Available at: http://ncrponline.org/publications/reports/ncrp-report-160/. Accessed on 23 Jan 2019
- 7.Bruzzi JF, Rémy-Jardin M, Delhaye D, Teisseire A, Khalil C, Rémy J (2006) When, why, and how to examine the heart during thoracic CT: part 1, basic principles. AJR Am J Roentgenol 186:324–332Google Scholar
- 19.Wilson W, Taubert KA, Gewitz M et al (2007) Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association rheumatic fever, endocarditis, and Kawasaki disease committee, council on cardiovascular disease in the Young, and the council on clinical cardiology, council on cardiovascular surgery and anesthesia, and the quality of care and outcomes research interdisciplinary working group. Circulation 116:1736–1754PubMedCrossRefGoogle Scholar
- 22.Krichenko A, Benson LN, Burrows P, Möes CA, McLaughlin P, Freedom RM (1989) Angiographic classification of the isolated, persistently patent ductus arteriosus and implications for percutaneous catheter occlusion. Am J Cardiol 63:877–880Google Scholar
- 29.Nishimura RA, Otto CM, Bonow RO et al (2014) 2014 AHA/ACC Guideline for the Management of Patients with Valvular Heart Disease: executive summary: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 129:2440–2492 Erratum in: Circulation 129:e650PubMedCrossRefGoogle Scholar
- 30.Vahanian A, Alfieri O, Andreotti F et al (2012) Guidelines on the management of valvular heart disease (version 2012): the Joint Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS). Eur J Cardiothorac Surg 42:S1–S44PubMedCrossRefGoogle Scholar
- 48.Komatsu S, Sato Y, Ichikawa M et al (2008) Anomalous coronary arteries in adults detected by multislice computed tomography: presentation of cases from multicenter registry and review of the literature. Heart Vessels 23:26–34Google Scholar
- 53.Vadivelu R, Bagga S (2013) Is endovascular therapy the right choice for treatment of functional compression of anomalous right coronary artery arising from left coronary sinus with interarterial course? BMJ Case Rep https://casereports.bmj.com/content/casereports/2013/bcr-2012-007856.full.pdf. Accessed on 23 Jan 2019
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