Cardiovascular pseudoneoplasms

The Spectrum of ECG Abnormalities in a Large Cohort of Cardiac Masses

BACKGROUND

Cardiac masses represent a heterogeneous clinical scenario. Potential electrocardiographic red flags of malignancy remain to be investigated.

OBJECTIVES

To describe the spectrum of electrocardiographic abnormalities in a large cohort of cardiac masses and to evaluate potential red flags suggestive of malignancy.

METHODS

Observational cohort study of 322 consecutive patients with a cardiac mass and available ECG at Bologna University Hospital. All masses were diagnosed by histological examination or, in the case of cardiac thrombi, by radiological resolution after proper anticoagulant therapy. Multivariable regression analysis was used to assess potential predictors of malignancy among electrocardiographic abnormalities. All-cause mortality at follow-up was evaluated.

RESULTS

Of 322 patients, 98 (30.4%) had malignant tumors. Compared with patients with benign masses, those with malignant tumors exhibited a higher heart rate, right axis deviation, greater depolarization, repolarization abnormalities and bradyarrhythmia at presentation. Regarding specific ECG features, a higher heart rate on admission (p=0.014), bradyarrhythmias (p=0.009), ischemic-like repolarization abnormalities (ST-segment deviation, both depression and elevation, and negative T-wave; p<0.001), low voltages (p=0.001) and right axial deviation (0.025) were identified as independent predictors of malignancy. Considering these specific ECG alterations, a malignancy-oriented ECG was associated with higher mortality at follow up (median time of 20.7 months).

CONCLUSION

ECG is frequently abnormal in case of malignant cardiac tumors. Some specific electrocardiographic changes are strongly suggestive for malignancy and type of infiltration.

Calcified amorphous tumor attached to the membranous septum: a rare clinical entity

We report a rare case of a pedunculated calcified amorphous tumor (CAT) of the left ventricle attached by a stalk to the membranous septum in a 74-year-old woman who presented with a cerebrovascular accident. We believe this is the first report of a CAT attached to the membranous septum.

Cardiac Magnetic Resonance to Predict Cardiac Mass Malignancy: The CMR Mass Score

BACKGROUND

Multimodality imaging is currently suggested for the noninvasive diagnosis of cardiac masses. The identification of cardiac masses' malignant nature is essential to guide proper treatment. We aimed to develop a cardiac magnetic resonance (CMR)-derived model including mass localization, morphology, and tissue characterization to predict malignancy (with histology as gold standard), to compare its accuracy versus the diagnostic echocardiographic mass score, and to evaluate its prognostic ability.

METHODS

Observational cohort study of 167 consecutive patients undergoing comprehensive echocardiogram and CMR within 1-month time interval for suspected cardiac mass. A definitive diagnosis was achieved by histological examination or, in the case of cardiac thrombi, by histology or radiological resolution after adequate anticoagulation treatment. Logistic regression was performed to assess CMR-derived independent predictors of malignancy, which were included in a predictive model to derive the CMR mass score. Kaplan-Meier curves and Cox regression were used to investigate the prognostic ability of predictors.

RESULTS

In CMR, mass morphological features (non-left localization, sessile, polylobate, inhomogeneity, infiltration, and pericardial effusion) and mass tissue characterization features (first-pass perfusion and heterogeneity enhancement) were independent predictors of malignancy. The CMR mass score (range, 0-8 and cutoff, ≥5), including sessile appearance, polylobate shape, infiltration, pericardial effusion, first-pass contrast perfusion, and heterogeneity enhancement, showed excellent accuracy in predicting malignancy (areas under the curve, 0.976 [95% CI, 0.96-0.99]), significantly higher than diagnostic echocardiographic mass score (areas under the curve, 0.932; P=0.040). The agreement between the diagnostic echocardiographic mass and CMR mass scores was good (κ=0.66). A CMR mass score of ≥5 predicted a higher risk of all-cause death (P<0.001; hazard ratio, 5.70) at follow-up.

CONCLUSIONS

A CMR-derived model, including mass morphology and tissue characterization, showed excellent accuracy, superior to echocardiography, in predicting cardiac masses malignancy, with prognostic implications.

Sex-Related Disparities in Cardiac Masses: Clinical Features and Outcomes

BACKGROUND

Cardiac masses (CM) represent a heterogeneous clinical scenario, and sex-related differences of these patients remain to be established.

PURPOSE

To evaluate sex-related disparities in CMs regarding clinical presentation and outcomes.

MATERIAL AND METHODS

The study cohort included 321 consecutive patients with CM enrolled in our Centre between 2004 and 2022. A definitive diagnosis was achieved by histological examination or, in the case of cardiac thrombi, with radiological evidence of thrombus resolution after anticoagulant treatment. All-cause mortality at follow-up was evaluated. Multivariable regression analysis assessed the potential prognostic disparities between men and women.

RESULTS

Out of 321 patients with CM, 172 (54%) were female. Women were more frequently younger (p = 0.02) than men. Regarding CM histotypes, females were affected by benign masses more frequently (with cardiac myxoma above all), while metastatic tumours were more common in men (p < 0.001). At presentation, peripheral embolism occurred predominantly in women (p = 0.03). Echocardiographic features such as greater dimension, irregular margin, infiltration, sessile mass and immobility were far more common in men. Despite a better overall survival in women, no sex-related differences were observed in the prognosis of benign or malignant masses. In fact, in multivariate analyses, sex was not independently associated with all-cause death. Conversely, age, smoking habit, malignant tumours and peripheral embolism were independent predictors of mortality.

CONCLUSIONS

In a large cohort of cardiac masses, a significant sex-related difference in histotype prevalence was found: Benign CMs affected female patients more frequently, while malignant tumours affected predominantly men. Despite better overall survival in women, sex did not influence prognosis in benign and malignant masses.

Echocardiographic Markers in the Diagnosis of Cardiac Masses

BACKGROUND

The echocardiographic parameters required for a comprehensive assessment of cardiac masses (CMs) are still largely unknown. The aim of this study was to identify and integrate the echocardiographic features of CMs that can accurately predict malignancy.

METHODS

An observational cohort study was conducted among 286 consecutive patients who underwent standard echocardiographic assessment for suspected CM at Bologna University Hospital between 2004 and 2022. A definitive diagnosis was achieved by histologic examination or, in the case of cardiac thrombi, with radiologic evidence of thrombus resolution after appropriate anticoagulant treatment. Logistic and multivariable regression analysis was performed to confirm the ability of six echocardiographic parameters to discriminate malignant from benign masses. The unweighted count of these parameters was used as a numeric score, ranging from 0 to 6, with a cutoff of ≥3 balancing sensitivity and specificity with respect to the histologic diagnosis of malignancy. Classification tree analysis was used to determine the ability of echocardiographic parameters to discriminate subgroups of patients with differential risk for malignancy.

RESULTS

Benign masses were more frequently pedunculated, mobile, and adherent to the interatrial septum (P < .001). Malignant masses showed a greater diameter and exhibited a higher frequency of irregular margins, an inhomogeneous appearance, sessile implantation, polylobate shape, and pericardial effusion (P < .001). Infiltration, moderate to severe pericardial effusion, nonleft localization, sessile implantation, polylobate shape, and inhomogeneity were confirmed to be independent predictors of malignancy in both univariate and multivariable models. The predictive ability of the unweighted score of ≥3 was very high (>0.90) and similar to that of the previously published weighted score. Classification tree analysis generated an algorithm in which infiltration was the best discriminator of malignancy, followed by nonleft localization and sessile implantation. The percentage correctly classified by classification tree analysis as malignant was 87.5%. Agreement between observer readings and CM histology ranged between 85.1% and 91.5%. The presence of at least three echocardiographic parameters was associated with lower survival.

CONCLUSIONS

In the approach to CMs, some echocardiographic parameters can serve as markers to accurately predict malignancy, thereby informing the need for second-level investigations and minimizing the diagnostic delay in such a complex clinical scenario.

Cardiac Calcified Amorphous Tumor in the Left Atrium: A Case Report

A cardiac calcified amorphous tumor (CAT) is a rare non-neoplastic mass of the heart with histological characteristics comprising calcification and amorphous fibrous material. Little is known regarding the incidence, symptoms, and therapeutic strategies for CAT. Echocardiography and computed tomography were performed on a 48-year-old man who had a cardiac mass that was accidentally discovered on admission to a local hospital for a fracture related to a trauma that occurred 1 month prior. After surgery, a histological examination resulted in the diagnosis of a cardiac CAT. The patient was discharged without postoperative complications on the 12th day after surgery.

Arrhythmogenic potential of myocardial disarray in hypertrophic cardiomyopathy: genetic basis, functional consequences and relation to sudden cardiac death

Myocardial disarray is defined as disorganized cardiomyocyte spatial distribution, with loss of physiological fibre alignment and orientation. Since the first pathological descriptions of hypertrophic cardiomyopathy (HCM), disarray appeared as a typical feature of this condition and sparked vivid debate regarding its specificity to the disease and clinical significance as a diagnostic marker and a risk factor for sudden death. Although much of the controversy surrounding its diagnostic value in HCM persists, it is increasingly recognized that myocardial disarray may be found in physiological contexts and in cardiac conditions different from HCM, raising the possibility that central focus should be placed on its quantity and distribution, rather than a mere presence. While further studies are needed to establish what amount of disarray should be considered as a hallmark of the disease, novel experimental approaches and emerging imaging techniques for the first time allow ex vivo and in vivo characterization of the myocardium to a molecular level. Such advances hold the promise of filling major gaps in our understanding of the functional consequences of myocardial disarray in HCM and specifically on arrhythmogenic propensity and as a risk factor for sudden death. Ultimately, these studies will clarify whether disarray represents a major determinant of the HCM clinical profile, and a potential therapeutic target, as opposed to an intriguing but largely innocent bystander.

An MRI Image Analysis of Primary Cardiac Neoplasms

Objective

This study aimed to examine the magnetic resonance imaging (MRI) characteristics of primary cardiac neoplastic lesions.

Methods

A retrospective investigation was conducted on 24 cases of primary cardiac neoplastic lesions as confirmed by surgery and pathology results. All the cases in this study received MRI multi-sequence and multi-dimension scanning, including the cardiac long-axis and short-axis cine sequences, parameter sequences of the cardiac long axis and short axis (T1WI, T2WI), first-pass perfusion sequence, and delayed enhancement sequence of the cardiac long axis and short axis. The age and gender of the patients and the location, size, signal characteristics, and relationship with the neighboring tissues of all the lesions were examined.

Results

Twenty-four cases of primary neoplastic lesions were examined in this study, the onset age was 11–72 years old, the median age was 53 years old, and the mean age was 46 years old. Among these cases, there were 8 cases including males and 16 cases including females, 19 cases were benign lesions; including 11 cases of myxoma, 4 cases of hemangioma, 1 case of paraganglioma, 1 case of PEcoma, 1 case of hamartoma, and 1 case of lipoma. The malignant lesions included 3 sarcomas and 2 lymphomas in 5 patients.

Conclusion

MRI imaging provides a great value in the preoperative classification of primary cardiac neoplastic lesions.

Diagnostic Accuracy of Cardiac Computed Tomography and 18-F Fluorodeoxyglucose Positron Emission Tomography in Cardiac Masses

OBJECTIVES

This study sought to assess the diagnostic accuracy of cardiac computed tomography (CT) and ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) with positron emission tomography/computed tomography (PET/CT) in defining the nature of cardiac masses.

BACKGROUND

The diagnostic accuracy of cardiac CT and ¹⁸F-FDG PET/CT in identifying the nature of cardiac masses has been analyzed to date only in small samples.

METHODS

Of 223 patients with echocardiographically diagnosed cardiac masses, a cohort of 60 cases who underwent cardiac CT and ¹⁸F-FDG PET/CT was selected. All masses had histological confirmation, except for a minority of thrombotic formations. For each mass, 8 morphological CT signs, standardized uptake value (SUV_max, SUV_mean), metabolic tumor volume, and total lesion glycolysis in ¹⁸F-FDG PET were used as diagnostic markers.

RESULTS

Irregular tumor margins, pericardial effusion, invasion, solid nature, mass diameter, CT contrast uptake, and pre-contrast characteristics were strongly associated with the malignant nature of masses. The coexistence of at least 5 CT signs perfectly identified malignant masses, whereas the detection of 3 or 4 CT signs did not accurately discriminate the masses' nature. The mean SUV_max, SUV_mean, metabolic tumor volume, and total lesion glycolysis values were significantly higher in malignant than in benign masses. The diagnostic accuracy of SUV, metabolic tumor volume, and total lesion glycolysis ¹⁸F-FDG PET/CT parameters was excellent in detecting malignant masses. Among patients with 3 or 4 pathological CT signs, the presence of at least 1 abnormal ¹⁸F-FDG PET/CT parameter significantly increased the identification of malignancies.

CONCLUSIONS

Cardiac CT is a powerful tool to diagnose cardiac masses as the number of abnormal signs was found to correlate with the lesions' nature. Similarly, ¹⁸F-FDG PET/CT accurately identified malignant masses and contributed with additional valuable information in diagnostic uncertainties after cardiac CT. These imaging tools should be performed in specific clinical settings such as involvement of great vessels or for disease-staging purposes.

Cardiac Masses in Echocardiography: A Pragmatic Review

Transthoracic echocardiography is a useful diagnostic technique for the identification of intracardiac and extracardiac masses, which can evaluate morphologic properties of the masses such as their location, attachment, shape, size, mobility, and possible hemodynamic-related implications. Apart from physiological variants and structural normal mimickers, echocardiography can detect principal intracardiac masses such as neoplasms, thrombi, vegetation, and extracardiac masses such as metastatic lesions. Moreover, transesophageal echocardiography can provide further details and provide higher accuracy in case a deeper examination of the mass is needed. This review will focus on the systematic evaluation of intra-/extracardiac masses including epidemiology and morphological and echocardiographic features, providing practical and technical tips to health-care professionals to achieve correct identification of the masses. General data on cardiac masses were extracted via PubMed/MEDLINE search engine from indexed reviews, original studies, and clinical case reports. The echocardiographic features of cardiac masses were reviewed according to the most relevant international cardiology and echocardiography scientific societies' position statements.

Evaluation of Mitral Apparatus Blood Cyst: A Case Report and Review of Literature

Intracardiac blood cysts (ICBC) are cardiac pseudoneoplasm commonly seen in infants below two months of age. ICBC typically resolve spontaneously; however, they can sometimes persist in adults and can cause detrimental consequences. A 47-year-old female presented to our facility with complaints of chest pain and was found to have an incidental subvalvular chordal mitral apparatus echolucent mass on transthoracic echocardiogram (TTE). A stress echocardiography was performed, which revealed transient left ventricle outflow tract (LVOT) obstruction in the absence of anginal symptoms. A cardiac magnetic resonance imaging (MRI) showed no evidence of increased mass enhancement confirming the diagnosis of a benign blood cyst of mitral apparatus. The cyst was treated conservatively with carvedilol to prevent worsening of exertional LVOT obstruction. A follow-up study done at six months showed stable exertional hemodynamics. There is no general consensus while managing ICBC. In asymptomatic, non-surgical patients stress echocardiography can offer valuable information by assessing the hemodynamic implications resulting from the cyst.

Cardiac Calcified Amorphous Tumors in a Patient with Hemodialysis for Diabetic Nephropathy

Calcified amorphous tumor (CAT) is a rare, non-neoplastic tumor involving calcium deposition in amorphous materials. Although its etiology is unknown, cases have frequently been reported in patients with hemodialysis for chronic kidney disease. We herein describe a case of cardiac CAT in a 64-year-old woman who had been on hemodialysis for diabetic nephropathy for 20 years, and the findings of the present patient, in association with the findings of previous case reports, suggest that end-stage renal disease seems to play an important role in the onset of CAT, especially in CAT formation at the mitral annulus, which appears to differ from CAT occurring at other sites.

Surgical treatment of a calcified, amorphous tumor of the right ventricle complicated with thrombosis of the right pulmonary artery in an adult male: a case report

BACKGROUND

A calcified amorphous tumor of the heart is an extremely rare cardiac mass.

CASE PRESENTATION

A 32-year-old Albanian man presented to our hospital with fatigue, shortness of breath, progressive dyspnea, and right congestive heart failure. Echocardiography and chest computed tomography revealed a giant, calcified right ventricular mass that originated between the papillary muscles and the trabeculae and extended to the pulmonary valve. The patient underwent surgery with excision of the mass, replacement of the pulmonary valve with a biological one, and repair of the tricuspid valve. His histopathological examination revealed that the mass was a calcified, amorphous tumor. His postoperative course was uneventful.

CONCLUSIONS

The clinical presentation of the calcified amorphous tumor is similar to that of other cardiac tumors, so surgical excision is mandatory. Histopathological examination remains the gold standard for an accurate diagnosis.

A rare case of regressively changed lipomatous hypertrophy of the interatrial septum presenting with anemia and recurrent fever

Lipomatous hypertrophy of the interatrial septum (LHIS) is characterized by excessive accumulation of adipose tissue within some segments of the interatrial septum. Only one published case so far describes fever as a presenting feature of LHIS. On the other hand, systemic symptoms including anemia and fever are well-known clinical presentations of cardiac myxomas. We report an unusual case of a 79-year-old woman who was thoroughly but unsuccessfully investigated for recurrent fever and anemia in several specialized departments over the course of 4 years. Computed tomography scan showed a pathological mass localized in the interatrial septum and spreading to ascending aorta. Histological analysis of the biopsy samples from surgery revealed the unexpected diagnosis of regressively changed LHIS. We discuss the clinical and pathologic features of this lesion suggesting that its regressive changes may be associated with inflammation and can cause systemic symptoms such as fever and anemia.

Cardiac calcified amorphous tumor: A systematic review of the literature

BACKGROUND

Calcified amorphous tumor (CAT) of the heart is a rare non-neoplastic intracavitary cardiac mass. Several case reports have been published but large series are lacking.

OBJECTIVE

To determine clinical features, current management and outcomes of this rare disease.

DESIGN

A systematic review of all articles reporting cases of CAT in order to perform a pooled analysis of its clinical features, management and outcomes.

DATA SOURCES

An electronic search of all English articles using PUBMED was performed. Further studies were identified by cross-referencing from relevant papers.

INCLUSION CRITERIA

We restricted inclusion to articles reporting cases of CAT in the English language literature published up to July 2014.

DATA EXTRACTION

One author performed data extraction using predefined data fields.

RESULTS

A total of 27 articles, reporting 42 cases of CAT were found and included in this review.

CONCLUSION

In this review, the most frequent presenting symptoms were dyspnea and embolic events. Mitral valve and annulus were the most frequent location of CAT. Surgery was most of the time required to confirm diagnosis, and was relatively safe. Overall outcome after surgical resection was good.

Unresectable cardiac pseudoneoplasms causing ventricular tachycardia

Cardiac pseudoneoplasms are rare and benign. According to World Health Organization, they are classified as tumor-like lesions. We report two patients with recurrent ventricular tachycardia (VT) in whom magnetic resonance imaging revealed a pathological mass occupying a large part of the left ventricle. The localization of both tumors precluded the possibility of resection; thus, only surgical biopsy was performed. After deducting the prospect of malignancy of the tumors, we treated both patients with amiodarone and implantation of a cardioverter-defibrillator [implanted cardioverter/defibrillator (ICD)]. VT is one of many probable symptoms indicating a tumor within the heart; therefore, treatment with an ICD should only be considered after a more thorough diagnosis.

Pericoronary pseudotumor caused by helicobacter cinaedi

Cardiac tumors and tumor-like lesions are uncommon; most are true neoplasms. We here report a case of a pericoronary tumor-like lesion surrounding the right coronary artery in a 39-year-old man who presented with fever and chest pain. Although clarithromycin was administered for 1 week, his fever persisted. Helicobacter cinaedi (H. cinaedi) was isolated from blood cultures and found to be sensitive to ceftriaxone. A computed tomography scan showed a tumor-like lesion with no (18)F-fl uorodeoxyglucose uptake surrounding the right coronary artery. After administration of ceftriaxone, the tumor-like lesion diminished in size according to meticulous computed tomography examinations. We therefore concluded that it was caused by H. cinaedi infection. The patient has been followed up closely for 1 year and remains asymptomatic.

Benign lipomatous masses of the heart: a comprehensive series of 47 cases with cytogenetic evaluation

Benign lipomatous lesions of the heart encompass an apparently etiologically diverse group of entities including neoplastic, congenital, and reparative phenomena. Among these, lipomas and lipomatous hypertrophy of the atrial septum (LHAS) represent 2 commonly encountered mass lesions. To date, no study has systematically and comparatively evaluated the morphologic and genetic characteristics of these lesions. Tissue registry archives of Mayo Clinic were queried for cases of cardiac lipoma and LHAS (1994-2011). Clinical, imaging, and pathologic findings were reviewed. Representative cases in each cohort were evaluated by fluorescence in situ hybridization (FISH) for HMGA1 and HMGA2 loci rearrangement and for MDM2/CPM locus amplification. Five cases of cardiac lipoma were identified (mean age, 67 years; range, 48-101; 3 men): 4 right atrial and 1 left ventricular. Forty-two cases of LHAS were identified (mean age, 75.6 years; range 45-95; 20 men), 39 of which were autopsy derived. The median size was 3.4 cm for lipomas and 2.8 cm for LHAS (n = 14). A single case each of cardiac lipoma and LHAS were found to harbor HMGA2 rearrangement, whereas no case showed cytogenetic abnormality of HMGA1 or CPM. This represents the largest series of histopathologically confirmed cardiac lipomas from a single institution. In addition, it is the first to evaluate cardiac lipomas and LHAS for genetic alterations associated with extracardiac lipomatous lesions. The genetic and morphologic similarities found provide evidence in support of the neoplastic classification of cardiac lipomas. A single case of LHAS contained an HMGA2 rearrangement, challenging the currently accepted hypothesis of pathogenesis for this lesion.

Inflammatory myofibroblastic tumor of the aortic valves causing sudden cardiac death: a case report and review of the literature

Cardiac inflammatory myofibroblastic tumor (IMT) is a rare entity affecting predominantly infants, children, and young adults. Although most tumors have a benign clinical course after complete surgical resection, some have significant clinical effects. We report the case of a 9-year-old girl who had sudden cardiac death as a result of occlusion of the left circumflex coronary artery. A review of 57 cases of cardiac IMTs reported in the literature in terms of epidemiology, clinical presentation, histologic and immunohistologic features, and outcome is presented. Recognition of this rare abnormality is important in order to initiate prompt surgical intervention.

IgG4 related cardiac disease

IgG4-related systemic disease is an inflammatory disorder that can affect many organs. This case report describes a patient who in 2004 was found to have an inflammatory pseudotumor with IgG4 pathology. Over the next 3 years, visual symptoms responded well to recurrent courses of prednisone. In 2009, the patient developed chest pain and bradycardia with subsequent third-degree heart block, necessitating placement of a pacemaker. A subsequent PET scan showed extensive involvement of multiple organs as described in IgG4 disease as well as involvement of the myocardium and SA node. Pseudotumors involving the heart have been reported but have not been shown to be related to IgG4 disease. Although there was no pathology confirmation of heart involvement, the nature and extent of the organ involvement led us to conclude that it was due to IgG4-related disease. The use of the PET scan may help identify involvement of the myocardium.

Clinical classification of cardiovascular tumors and tumor-like lesions, and its incidences

Tumors of the heart and the great vessels are very rare disease, and there are many disorders such as tumors originated from the heart and great vessels, metastatic tumors, and tumor-like lesions which do not fit into the usual concept of tumor or neoplasm; thus, it is very difficult to classify these tumors. We proposed a new classification of cardiovascular tumors for clinical use based on the accumulated biological analyses and clinical data of the reported literatures and our own study as benign tumors, malignant tumors, ectopic hyperplasia/ectopic tumors/others, and tumors of great vessels, with reference to the series of Atlas of tumor pathology of the Armed Forces Institute of Pathology and the recent World Health Organization classification of cardiac tumors issued in 2004. More than 50 disorders have been reported as tumors originated from the cardiovascular system, and various metastatic tumors from nearby organs, distant lesions, and intravascular extension tumors to the heart were reported. Based on the new classification, we reviewed epidemiology and incidence of cardiovascular tumors. Metastatic tumors are more frequent than tumors originated from the heart and great vessels, and cardiac myxoma is the most frequent tumors in all cardiac tumors.

Multimodality imaging in the evaluation of cardiovascular manifestations of malignancy

Up to one third of the population will die as a direct result of cancer. Accurate and timely diagnosis of disease often requires multiple different approaches including the use of modern imaging techniques. Prompt recognition of adverse consequences of some anti-cancer therapies also requires a knowledge of the optimum imaging strategy for the problem at hand. The purpose of this article is to review not only some of the commoner cardiovascular manifestations of malignancy but also to discuss the strengths, weaknesses and appropriate use of cardiovascular imaging modalities.