Radiologic-Pathologic Correlation of Cardiac Tumors: Updated 2021 WHO Tumor Classification

Cardiac tumors, although rare, carry high morbidity and mortality rates. They are commonly first identified either at echocardiography or incidentally at thoracoabdominal CT performed for noncardiac indications. Multimodality imaging often helps to determine the cause of these masses. Cardiac tumors comprise a distinct category in the World Health Organization (WHO) classification of tumors. The updated 2021 WHO classification of tumors of the heart incorporates new entities and reclassifies others. In the new classification system, papillary fibroelastoma is recognized as the most common primary cardiac neoplasm. Pseudotumors including thrombi and anatomic variants (eg, crista terminalis, accessory papillary muscles, or coumadin ridge) are the most common intracardiac masses identified at imaging. Cardiac metastases are substantially more common than primary cardiac tumors. Although echocardiography is usually the first examination, cardiac MRI is the modality of choice for the identification and characterization of cardiac masses. Cardiac CT serves as an alternative in patients who cannot tolerate MRI. PET performed with CT or MRI enables metabolic characterization of malignant cardiac masses. Imaging individualized to a particular tumor type and location is crucial for treatment planning. Tumor terminology changes as our understanding of tumor biology and behavior evolves. Familiarity with the updated classification system is important as a guide to radiologic investigation and medical or surgical management. ©RSNA, 2024 Supplemental material is available for this article.

Multimodality Imaging in Right Heart Tumors: Proposed Algorithm towards an Appropriate Diagnosis

A right heart tumor can be identified by transthoracic echocardiography during a routine examination or due to cardiac symptoms. The first step is the assessment by echocardiography, with its multiple techniques, and the obtained information must be judged in a clinical and biological context. The second step comprises one, sometimes even two, of the more complex modality imaging methods. The choice is driven not only by the advantages of each imaging technique but also by local expertise or the preferred imaging modality in the center. This step is followed by staging, follow-up, and/or imaging-guided excision or biopsy, which is performed in selected cases in order to obtain anatomopathological confirmation. In the presence of features suggestive of malignancy or causing hemodynamic impairment, a transvenous biopsy is essential before the more complex imaging modalities (which are still relevant in the staging process). Using a structured imaging approach, it is possible to reach an appropriate diagnosis without a biopsy. Frequently, these imaging techniques have a complementary role, so an integrated imaging approach is recommended. This proposed algorithm for appropriate diagnosis of right heart tumors could serve as a practical guide for clinicians (not only imaging specialists).

Cardiac Masses and Pseudomasses: An Overview about Diagnostic Imaging and Clinical Background

A cardiac lesion detected at ultrasonography might turn out to be a normal structure, a benign tumor or rarely a malignancy, and lesion characterization is very important to appropriately manage the lesion itself. The exact relationship of the mass with coronary arteries and the knowledge of possible concomitant coronary artery disease are necessary preoperative information. Moreover, the increasingly performed coronary CT angiography to evaluate non-invasively coronary artery disease leads to a rising number of incidental findings. Therefore, CT and MRI are frequently performed imaging modalities when echocardiography is deemed insufficient to evaluate a lesion. A brief comprehensive overview about diagnostic radiological imaging and the clinical background of cardiac masses and pseudomasses is reported.

What echocardiographic findings differentiate acute pulmonary embolism and chronic pulmonary hypertension?

BACKGROUND

Pulmonary embolism (PE) and pulmonary hypertension (PH) are potentially fatal disease states. Early diagnosis and goal-directed management improve outcomes and survival. Both conditions share several echocardiographic findings of right ventricular dysfunction. This can inadvertently lead to incorrect diagnosis, inappropriate and potentially harmful management, and delay in time-sensitive therapies. Fortunately, bedside echocardiography imparts a few critical distinctions.

OBJECTIVE

This narrative review describes eight physiologically interdependent echocardiographic parameters that help distinguish acute PE and chronic PH. The manuscript details each finding along with associated pathophysiology and summarization of the literature evaluating diagnostic utility. This guide then provides pearls and pitfalls with high-quality media for the bedside evaluation.

DISCUSSION

The echocardiographic parameters suggesting acute or chronic right ventricular dysfunction (best used in combination) are: 1. Right heart thrombus (acute PE) 2. Right ventricular free wall thickness (acute ≤ 5 mm, chronic > 5 mm) 3. Tricuspid regurgitation pressure gradient (acute ≤ 46 mmHg, chronic > 46 mmHg, corresponding to tricuspid regurgitation maximal velocity ≤ 3.4 m/sec and > 3.4 m/sec, respectively) 4. Pulmonary artery acceleration time (acute ≤ 60-80 msec, chronic < 105 msec) 5. 60/60 sign (acute) 6. Pulmonary artery early-systolic notching (proximally-located, higher-risk PE) 7. McConnell's sign (acute) 8. Right atrial enlargement (equal to left atrial size suggests acute, greater than left atrial size suggests chronic).

CONCLUSIONS

Emergency physicians must appreciate the echocardiographic findings and associated pathophysiology that help distinguish acute and chronic right ventricular dysfunction. In the proper clinical context, these findings can point towards PE or PH, thereby leading to earlier goal-directed management.

An Unusual Cause of Right Heart Dysfunction and High Output Heart Failure in a Young Woman

A 35-year-old female presented to our emergency department with clinical signs of acute heart failure. Clinical workup identified severe right heart (RH) dilation and dysfunction with a crossing membrane structure in the right atrium. Right heart catheterization confirmed high output heart failure (HOHF), pulmonary hypertension (PH), and left-to-right blood shunting followed by the documentation of multiple liver and pulmonary arteriovenous malformations (AVMs). Hereditary Hemorrhagic Telangiectasia (HHT) diagnosis was made according to clinical criteria and was established as the cause of HOHF because of chronic volume overload from systemic to pulmonary shunts. With this illustrative case, we aim to discuss the broad spectrum of clinical manifestations of HHT and the unusual phenotype of HOHF secondary to HHT. This case also highlights the broad diagnosis of atrial echocardiographic abnormalities and cardiac structural distortion secondary to high output that can be misleading at imaging evaluation.

A rare congenital anomaly: Anomalous fibromuscular cord of the left atrium

BACKGROUND

Left atrial anomalous fibromuscular cord is a rare congenital anomaly, which exists in a small proportion of the general population. Although its clinical significance remains largely unknown, it is generally considered a benign entity. We report a case of incidental finding of left atrial fibromuscular cord without structural cardiac abnormalities or hemodynamic obstruction.

METHODS AND RESULTS

A-39-year-old female presented with palpitations for more than 10 years. Electrocardiogram and laboratory tests showed no unremarkable. Transthoracic echocardiography revealed an abnormal linear structure connecting the interatrial septum and the left atrial free wall, color Doppler flow imaging did not show hemodynamic obstruction. Cardiac contrast-enhanced computed tomography images showed the string-like structure associated with calcification, connecting the interatrial septum and the ridge around the orifice of the left inferior pulmonary vein. Sagittal multiplanar reconstructed image showed a dot-like structure located in the left atrial cavity.

DISCUSSION

Left atrial anomalous fibromuscular cord is a rare congenital anomaly, which is also known as left atrial anomalous fibromuscular cord, left atrial false tendon, accessory chordae tendineae, or left atrial aberrant band. The clinical significance is unclear. Some cases have been reported that the fibromuscular cord, which do not have pathological significance. It has also been reported that it may be associated with supraventricular arrhythmias, patent foramen ovale, and Chiai's network. In some patients, attachment to the mitral chord can lead to mitral valve insufficiency and murmur. Nevertheless, a detailed understanding the anomalous anatomical characteristics of the anomalous cord may help us to better predict an unexpected difficulty in catheter manipulation, and potential arrhythmogenicity.

CONCLUSION

Transthoracic echocardiography and cardiac computed tomography angiography have an important imaging value for the diagnosis of the left atrial anomalous fibromuscular cord, including its origin, course, or whether associated with other cardiovascular malformations.

A Rare Complication During Transcatheter Closure of Double Atrial Septal Defects With Incomplete Cor Triatriatum Dexter: A Case Report

The cor triatiatum dexter is an embryologic remnant derived from the right atrium and totally separate from the right atrium. An incomplete cor triatiatum dexter (iCTD) means a partially obstructive remnant at the right atrium. It is usually formed by a remnant of the Eustachian valve (EV), Thebesian valve (ThV), or Chiari network (CN). This anatomic variant is usually asymptomatic but is often associated with other heart abnormalities including atrial septal defects (ASDs), and has the potential to hamper percutaneous heart procedures such as electrophysiological study or ASD closure. Herein, we report a rare complication, transient heart ischemia, in transcatheter closure of double ASDs in a 55-year-old woman with EV. This rare complication was thought to be caused by coronary sinus obstruction during device placement. The ischemic change was resolved spontaneously after we withdrew the device. For a second attempt, we adjusted the position of the device to avoid coronary sinus obstruction under transesophageal echocardiogram guidance and the device was smoothly deployed in a good position with a minimal residual shunt. This case suggests that anatomy details in percutaneous heart procedures are important, and this rare and dangerous complication, heart ischemia, should be identified immediately during the procedure.

Prominent crista terminalis mimicking a right atrial mass: A case report and brief review of the literature

The crista terminalis is a normal anatomical structure, characterized by a smooth muscular ridge along the superior aspect of the right atrium. It is derived from resorption of the right valve of the sinus venosus and it divides the right atrium into smooth posteromedial and trabeculated anterolateral portions. Crista terminalis is not normally detected in the standard views of transthoracic echocardiogram and non-gated CT of the chest. In rare circumstances, the crista terminalis may be prominent and could lead to misdiagnosis as a malignant process, such as in our case. A comprehensive understanding of the crista terminalis anatomy, and its characteristic appearance on transthoracic echocardiogram, CT and PET/CT will minimize the risk of misdiagnosis and will avoid patient anxiety with more extensive examinations. Here, we present a case of a 78-year-old male with newly diagnosed high-grade invasive urinary bladder urothelial carcinoma. Pre-operative transthoracic echocardiogram reported as 2 cm right atrial mass concerning a metastasis lesion. Subsequent evaluation with MRI cardiac morphology confirmed the diagnosis of benign prominent crista terminalis, a normal anatomical structure.

The morphometric study of the moderator band in Thais

A moderator band, also known as the septomarginal trabecula, is a group of muscle bundles located in the ventricle of almost all human hearts. The morphology of the moderator band has various forms and several studies have focused mostly on its structure. Thus, in the present study, we sought to study the morphology and morphometry of the moderator band and tried to rearrange the criteria based on the previous studies to classify the moderator band in Thais. The study investigated 67 formalin-fixed human hearts of both sexes obtained from Thai donors aged 24-101 years with mean age at death 69.92 years. The moderator band was evident in 66 of the 67 specimens (98.51%). The moderator band had the mean or median of overall length, thickness, distance to the base of the tricuspid valve, distance to the base of the pulmonary valve, distance to the apex of the right ventricle, the angle at the septal connection, and angle of the papillary, which were 18.9 ± 6.4 mm, 3.17 (2.04-4.55) mm, 33.0 ± 7.97 mm, 38.8 ± 9.62 mm, 56.4 ± 8.09 mm, 50 (30-105)°, 73.9 ± 30.1°, respectively. The mean distance originating point from the supraventricular crest to the anterior papillary muscle was 0.396 ± 0.07 of the distance from the base of the tricuspid valve to the apex of the right ventricle. Our present classification found that crest-like and thick moderator band with complex secondary branching at high origin (type IVc), and low origin (type IVd) were the most common subtypes. This study provided both anatomical and clinical information that should be useful in cardiac surgery, radiology, and cardiac electrophysiological interventions.

Left ventricular false tendons

Left ventricular false tendons (LVFTs) are fibromuscular structures, connecting the left ventricular free wall or papillary muscle and the ventricular septum.

There is some discussion about safety issues during intense exercise in athletes with LVFTs, as these bands have been associated with ventricular arrhythmias and abnormal cardiac remodelling. However, presence of LVFTs appears to be much more common than previously noted as imaging techniques have improved and the association between LVFTs and abnormal remodelling could very well be explained by better visibility in a dilated left ventricular lumen.

Although LVFTs may result in electrocardiographic abnormalities and could form a substrate for ventricular arrhythmias, it should be considered as a normal anatomic variant. Persons with LVFTs do not appear to have increased risk for ventricular arrhythmias or sudden cardiac death.

Pre- and Postprocedural CT of Transcatheter Left Atrial Appendage Closure Devices

Transcatheter left atrial appendage (LAA) closure is an alternative to long-term anticoagulation therapy in selected patients with nonvalvular atrial fibrillation who have an increased risk for stroke. LAA closure devices can be implanted by means of either an endocardial or a combined endocardial and epicardial approach. Preprocedural imaging is key to identifying contraindications, accurately sizing the device, and minimizing complications. Transesophageal echocardiography (TEE) has been the reference standard imaging modality to assess the anatomy for LAA closure and to provide intraprocedural guidance. However, CT has emerged as a less-invasive alternative to TEE for pre- and postprocedural imaging. CT is comparable to TEE for exclusion of thrombus but is superior to TEE for the delineation of complex LAA anatomy, measurement for device sizing, and evaluation of pulmonary venous and extracardiac structures. CT provides accurate measurements of the LAA ostial diameter, landing zone diameter, and LAA length, which are vital for accurate sizing of the device. CT allows evaluation of the relationship with the pulmonary veins and other adjacent structures that can be injured during the procedure. CT also simulates procedural fluoroscopic angles and provides evaluation of the interatrial septum, which is punctured during LAA closure. CT also provides a more convenient method for the evaluation of postprocedural complications such as incomplete closure, peridevice leaking, device-related thrombus, and device dislodgement. Online supplemental material is available for this article. ^©RSNA, 2021.

Two cases of six-chambered hearts

Double-chambered right ventricles (DCRV) and left ventricles are rare entities on their own. We present two cases with an unusual combination of double-chambered right as well as left ventricles. One was discovered in a 28-year-old female, while the other was found at birth in a female child. The differing nature of both the patient demographics as well as the presentation with a common morphological background is shown on both computed tomography and magnetic resonance imaging. The oldest description of an obstructive muscular band within the right ventricle was given in 1867. In the literature, there is ample description of the long-term prognosis and management guidelines for DCRV, but no inheritance patterns or risk factors have been identified except for associations with septal defects, tetralogy of Fallot and transposition of the great arteries. A combination of both double-sided left as well as right ventricles has been published in literature a few times with little details about management and prognosis. SIMILAR CASES PUBLISHED: Although many cases of DCRV and DCLV have been published, to our knowledge only 3 cases of combined DCRV and DCLV have been published in literature.

Masses in right side of the heart: spectrum of imaging findings

Primary heart tumors are rare, benign tumors represent the majority of these. If a cardiac mass is found, the probability that it is a metastasis or a so-called “pseudo-mass” is extremely higher than a primary tumor. The detection of a heart mass during a transthoracic echocardiography (TE) is often unexpected. The TE assessment can be difficult, particularly if the mass is located at the level of the right chambers. Cardiac Computed Tomography (CCT) can be useful in anatomical evaluation and Cardiac Magnetic Resonance (CMR) for masses characterization as well. We provide an overview of right cardiac masses and their imaging futures. (www.actabiomedica.it)