Interatrial shunt detected in coronary computed tomography angiography: differential features of a patent foramen ovale and an atrial septal defect

Natural History of Secundum ASD in Preterm and Term Neonates: A Comparative Study

Atrial septal defects (ASDs) are common in neonates. Although past studies suggest ASDs  ≥ 3 mm in term neonates (TNs) are less likely to close, there is paucity of data regarding the natural history in preterm neonates (PNs), information that would inform surveillance. We sought to compare spontaneous closure rates and need for intervention for ASDs in TNs/near term (≥ 36 weeks) versus PNs (< 36 weeks). We included all TNs and PNs who underwent echocardiography at ≤ 1 month between 2010 and 2018 in our institution with an ASD ≥ 3 mm, without major congenital heart disease, and with repeat echocardiogram(s). Spontaneous resolution was defined as size diminution to < 3 mm or closure. We included 156 TNs (mean gestational age at birth 38.6 ± 1.4 weeks) and 156 PNs (29.6 ± 3.7 weeks) with a mean age at follow-up of 16 ± 19 and 15 ± 21 months, respectively (p = 0.76). Based on maximum color Doppler diameter, in TNs, ASD resolution occurred in 95% of small (3-5 mm), 87% of moderate (5.1-8 mm), and 60% of large (> 8 mm) defects; whereas, in PNs, resolution occurred in 79% of small, 76% of moderate, and 33% of large ASDs. There was a significant association between size and ASD resolution in TNs (p = 0.003), but not PNs (p = 0.17). Overall, ASD resolution rate was higher in TNs (89%) versus PNs (78%) (p = 0.009), and fewer TNs (1%) compared to PNs (7%) required ASD intervention (p = 0.02). Most ASDs identified in TNs and PNs spontaneously resolve. PNs, however, demonstrate lower ASD resolution and higher intervention rates within all size groups. These data should inform follow-up of affected neonates.

CT evaluation of unrepaired/incidental congenital cardiovascular diseases in adults

Congenital heart disease (CHD) affects approximately one million people in the USA with the number increasing by 5% each year. Patients are usually both diagnosed and treated in infancy, however many of them may have subclinical CHD that remains undiagnosed until late adulthood. Patients with complex CHD tend to be symptomatic and are diagnosed at a younger age than those with a single defect. CHDs can be divided into three categories, including cardiac, great vessels and coronary artery anomalies. Recent advances in computed tomography (CT) technology with faster acquisition time and improved spatial resolution allow for detailed evaluation of cardiac morphology and function. The concomitant increased utilization of CT has simultaneously led to more sensitive detection and more thorough diagnosis of CHD. Recognition of and understanding the imaging attributes specific to each anomaly is important for radiologists in order to make a correct and definite diagnosis. This article reviews the spectrum of CHDs, which persist into adulthood that may be encountered by radiologists on CT.

Prevalence of left atrial abnormalities in atrial fibrillation versus normal sinus patients

Background

Atrial fibrillation (AF) may be the cause or sequela of left atrial abnormalities and variants.

Purpose

To determine the prevalence of left atrial (LA) abnormalities in AF patients compared to normal sinus rhythm (NSR) patients.

Material and Methods

We retrospectively reviewed 281 cardiac CT examinations from 2010 to 2012, excluding patients with prior pulmonary vein ablation, known coronary artery disease, prior coronary stent placement, or coronary artery bypass grafts. The first group consisted of 159 AF patients undergoing cardiac CT prior to pulmonary vein ablation and the second group consisted of 122 NSR patients evaluated with coronary CT angiography. Demographic data were collected. LA abnormalities were analyzed. Left atrial diameter was measured on an axial view.

Results

A total of 281 patients were included. The male gender has significantly higher prevalence of AF than female gender, P value <0.001. Patients with AF were significantly older (mean age, 57.4 years; standard deviation [SD], 11.8 years) than NSR patients (mean age, 53.4 years; SD, 13.6 years), P value, 0.01. The left atrial diameter was greater in the AF patients (mean diameter, 4.3 cm; SD, 0.82 cm) versus the NSR patients (3.4 cm; SD, 0.58 cm), P value, <0.0001. LA diverticulum was the most prevalent variant, occurring in 28.4% of the entire patient population followed by LA pouch, occurring in 24%. There was no significant between group differences in the prevalence of these or the remainder of the LA variants.

Conclusion

AF patients differed significantly from NSR patients in LA size, gender, and mean age. There was no statistical significance between the two groups with regard to the LA morphologic abnormalities other than size.

Interatrial shunt: diagnosis of patent foramen ovale and atrial septal defect with 64-row coronary computed tomography angiography

PURPOSE

The aim of this study was to investigate the frequency with which interatrial shunts are found during routine coronary computed tomography (CT) angiography and to describe imaging characterizations of patent foramen ovale (PFO), atrial septal defect (ASD), and atrial septal aneurysm (ASA).

MATERIALS AND METHODS

A total of 1081 adult patients were evaluated retrospectively for interatrial shunting; 77 were excluded from the study. CT diagnosis of PFO was defined as (1) a channel-like appearance of the interatrial septum (IAS) and (2) a contrast agent jet flow from the left atrium (LA) to the right atrium (RA). ASD was defined as (1) the IAS resembling a membrane with a hole and (2) a contrast jet flow between the two atria. ASA was identified by detecting a minimum 10-mm protrusion of the LA beyond the IAS into the RA.

RESULTS

Among 1004 patients, 86 patients (8.6%) were diagnosed to have PFO. Another 23 patients (2.3%) had a hole in the IAS and were diagnosed as having ASD: 21 with an ostium secundum-type ASD and 2 with the sinus venosus type. ASA accompanied ASD in three patients.

CONCLUSION

Electrocardiography-gated CT using the saline-chaser contrast injection technique that is routinely used for coronary arterial imaging can be used to detect interatrial shunts. The technique can also serve as a method for differentiating PFO, ASD, and ASA.

Potential role of three-dimensional rotational angiography and C-arm CT for valvular repair and implantation

Imaging modalities utilized in the interventional cardiology suite have seen an impressive evolution and expansion recently, particularly with regard to the recent interest in three-dimensional (3D) imaging. Despite this, the backbone of visualization in the catheterization laboratory remains two-dimensional (2D) X-ray fluoroscopy and cine-angiography. New imaging techniques under development, referred to as three-dimensional rotational angiography (RA) and C-arm CT, hold great promise for improving current device implantation and understanding of cardiovascular anatomy. This paper reviews the evolution of rotational angiography and advanced 3D X-ray imaging applications to interventional cardiology.

Haemodynamic findings on cardiac CT in children with congenital heart disease

In patients with congenital heart disease, haemodynamic findings demonstrated on cardiac CT might provide useful hints for understanding the haemodynamics of cardiac defects. In contrast to morphological features depicted on cardiac CT, such haemodynamic findings on cardiac CT have not been comprehensively reviewed in patients with congenital heart disease. This article describes normal haemodynamic phenomena of cardiovascular structures and various abnormal haemodynamic findings with their mechanisms and clinical significance on cardiac CT in patients with congenital heart disease.

Amplatzer septal occluder closure of atrial septal defect: evaluation of transthoracic echocardiography, cardiac CT, and transesophageal echocardiography

OBJECTIVE

The purpose of this study was to compare transthoracic echocardiography (TTE), cardiac CT, and transesophageal echocardiography (TEE) in the evaluation of secundum atrial septal defect (ASD) for closure with an Amplatzer septal occluder in pediatric patients.

SUBJECTS AND METHODS

The cases of 28 children with ASD initially diagnosed with TTE who were scheduled for cardiac CT for evaluation for insertion of an Amplatzer septal occluder under TEE guidance were reviewed. The patients were divided into a group with small ASD (long axis < 1.5 cm) and a group with large ASD (long axis > or = 1.5 cm). Measurements of the ASD obtained at TTE, cardiac CT, and TEE were compared. Kappa statistics were used to correlate the diagnostic value of cardiac CT assessed by two independent reviewers.

RESULTS

After cardiac CT, six patients were excluded from occluder implantation; therefore, 22 patients (seven boys, 15 girls; mean age, 4.95 years; range, 2-11 years) were included in the study. There were no significant differences in the ages and sexes of the patients in the two groups, but pulmonary-to-systemic blood flow ratio in the large-ASD group was significantly greater than that in the small-ASD group (3.54 +/- 1.43 vs 1.89 +/- 0.36; p = 0.001). With respect to long- and short-axis lengths of the ASD, interatrial septum, and four rims and to detection of rim deficiency, neither group had a significant difference between cardiac CT findings at ventricular end-systole and TEE findings. The long axis of the ASD in the large-ASD group measured at cardiac CT at end-systole and TEE was significantly longer than the long axis measured at TTE (p = 0.012). A high diagnostic score with good interobserver correlation (kappa = 0.674-0.750) validated the feasibility of cardiac CT in the assessment of ASD for closure with an Amplatzer septal occluder.

CONCLUSION

The long axis of a large ASD can be underestimated at TTE. Cardiac CT seems comparable with TEE in the assessment of ASD and is helpful in noninvasive evaluation for Amplatzer septal occluder implantation, especially for large ASD.

MDCT features of cardiothoracic sources of stroke

Multidetector computed tomography (MDCT) is widely used in the assessment of cardiothoracic disease and provides high-resolution images of the heart, great vessels, and lungs. A range of cardiothoracic conditions can precipitate stroke, including intracardiac thrombus, right-to-left shunts, and diseases of the thoracic aorta. Many of these conditions may be identified on non-electrocardiogram (ECG)-gated studies, but the advent of high temporal resolution ECG-gated MDCT provides superior anatomical delineation. Radiologists should be familiar with the pathogenesis and CT features of cardiothoracic conditions that can precipitate stroke as their early identification to enables appropriate management and prognostic decisions.