Comprehensive review of pericardial diseases using different imaging modalities

Congenital Absence of Pericardium: The Swinging Heart

Congenital absence of the pericardium (CAP) is an unusual condition discovered, in most cases, incidentally but can potentially lead to fatal complications, including severe arrhythmias and sudden death. Recently, the use of modern imaging technologies has increased the diagnosis of CAP, providing important findings for risk stratification. Nevertheless, there is not yet consensus regarding therapeutic decisions, and the management of patients with CAP remains challenging. In this paper, we discuss the pathophysiological implication of CAP, review the current literature and explain the role of multimodality imaging tools for its diagnosis, management and treatment.

Cardiac tamponade

Cardiac tamponade is a medical emergency caused by the progressive accumulation of pericardial fluid (effusion), blood, pus or air in the pericardium, compressing the heart chambers and leading to haemodynamic compromise, circulatory shock, cardiac arrest and death. Pericardial diseases of any aetiology as well as complications of interventional and surgical procedures or chest trauma can cause cardiac tamponade. Tamponade can be precipitated in patients with pericardial effusion by dehydration or exposure to certain medications, particularly vasodilators or intravenous diuretics. Key clinical findings in patients with cardiac tamponade are hypotension, increased jugular venous pressure and distant heart sounds (Beck triad). Dyspnoea can progress to orthopnoea (with no rales on lung auscultation) accompanied by weakness, fatigue, tachycardia and oliguria. In tamponade caused by acute pericarditis, the patient can experience fever and typical chest pain increasing on inspiration and radiating to the trapezius ridge. Generally, cardiac tamponade is a clinical diagnosis that can be confirmed using various imaging modalities, principally echocardiography. Cardiac tamponade is preferably resolved by echocardiography-guided pericardiocentesis. In patients who have recently undergone cardiac surgery and in those with neoplastic infiltration, effusive-constrictive pericarditis, or loculated effusions, fluoroscopic guidance can increase the feasibility and safety of the procedure. Surgical management is indicated in patients with aortic dissection, chest trauma, bleeding or purulent infection that cannot be controlled percutaneously. After pericardiocentesis or pericardiotomy, NSAIDs and colchicine can be considered to prevent recurrence and effusive-constrictive pericarditis.

Agreement on Interpretation of Point-of-Care Ultrasonography for Cardiac Tamponade Among Emergency Physicians

STUDY OBJECTIVE

Cardiac tamponade is an impending calamitous disorder that emergency physicians need to consider and diagnose rapidly. A pericardial effusion with right atrial systolic collapse (earliest sign) or right ventricular diastolic collapse (most specific sign) and a plethoric inferior vena cava are indicators of cardiac tamponade physiology and may be identified with point-of-care ultrasonography (POCUS). The goal of this study is to assess the agreement among emergency physicians with varying levels of sonographic training and expertise in interpreting echocardiographic signs of cardiac tamponade in adult patients.  Methods: Emergency physicians at different levels of training as sonographers were surveyed at didactic conferences at three major academic medical centers in northern New Jersey. Two cardiologists were also included in the study for comparison. Survey respondents were shown 15, 20-second video clips of patients who had presented to the emergency department (ED) with or without significant pericardial effusions and were asked to rate whether tamponade physiology was present or not. Data were collected anonymously on Google Forms (Google LLC, Mountain View, CA) and included self-reported levels of POCUS expertise and level of training. Data were analyzed using Fleiss' kappa (k). All patients had an echocardiogram performed by the department of cardiology within 24 hours of the POCUS, and the results are presented in the paper.  Results: There were 97 participant raters, including attendings, fellows, and resident physicians specializing in adult emergency medicine and two cardiologists. There was a fair degree of inter-rater agreement among all participants in interpreting whether tamponade physiology was present or not. This low level of agreement persisted across self-reported training levels and self-reported POCUS expertise, even at the expert level in both emergency medicine and cardiology specialties.

CONCLUSION

According to the results of our study, there appears to be a low level of agreement in the interpretation of cardiac tamponade in adult patients. The lack of agreement persisted across specialties, self-reported training levels, and self-reported ultrasonographic expertise. This low level of agreement seen among both specialists indicates that emergency physicians are not limited in their ability to determine cardiac tamponade on POCUS. This highlights the technical nature of POCUS clips and strengthens the importance of physical exam findings when diagnosing cardiac tamponade in emergency department patients. Further research utilizing POCUS for the diagnosis of tamponade is warranted.

Severely Calcified Pericardium Causing Constrictive Pericarditis

Constrictive pericarditis (CP) is a type of diastolic heart failure caused by an inelastic pericardium that impairs cardiac filling. Diagnosing CP can be challenging, and a variety of imaging techniques may be necessary. We present a unique case of severely calcified pericardium leading to CP.

A difficult-to-diagnose pericardial fistula

Pericardial fistula is a rare complication. Generally, the diagnosis can be confirmed by imaging examination, but our patient was an exception. We present a 71-year-old female patient that complained of remnant gastric cancer for five months and dyspnea for seven days; the dyspnea became aggravated during the last two days. After admission, emergency thoracic computed tomography and echocardiography showed pericardial effusion, and pericardiocentesis was performed. After conventional treatment, the pericardial effusion was unchanged and no cancer cells were found in the pericardial drainage. However, the color changed from turbid to golden yellow and, finally, to green. After 20 days of repeated laboratory, imaging, and gastrointestinal contrast examinations, no cause was found. Moreover, a clinical diagnosis could not be obtained following numerous comprehensive clinical analyses. Given the color change of the pericardial drainage, we strongly suspected pericardial fistula, but the imaging examinations were negative. Finally, a methylene blue test confirmed the existence of a pericardial fistula. When the color of the pericardial effusion changes, the existence of a pericardial fistula must be considered in advance, and other methods should be evaluated if imaging cannot assist in the diagnosis.

Autoimmune Pericarditis: Multimodality Imaging

PURPOSE OF THE REVIEW

The purpose of this review is to understand the underlying mechanism that leads to pericarditis in systemic autoimmune and autoinflammatory diseases. The underlying mechanism plays a vital role in the appropriate management of patients. In addition, we will review the current landscape of available cardiac imaging modalities with emphasis on pericardial conditions as well as proposed treatment and management tailored toward pericardial autoimmune and autoinflammatory processes.

RECENT FINDINGS

Approximately 22% of all cases of pericarditis with a known etiology are caused by systemic autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, and vasculitis. In recent years, there have been advancements of imaging modalities including cardiac MRI, cardiac CT scan, and PET scan and their respective nuances in regard to contrast use, technique, and views which clinicians may utilize to better understand the extent of a patient's pericardial pathology and the trajectory of his or her disease process. In this review, we will discuss systemic autoimmune and autoinflammatory diseases that involve the pericardium. We will also review different imaging modalities that are currently used to further characterize such conditions. Having a deeper understanding of such techniques will improve patient outcomes by helping clinicians tailor treatment plans according to the unique underlying condition.

Recent advances in pericarditis

Pericardial diseases are an heterogeneous group of entities, ranging from acute pericarditis to asymptomatic pericardial effusions. New advances in understanding the processes underlying them have been made. In 2020 a prospective study defined the reference intervals of the component of normal pericardial fluid, that was found to be rich in nucleated cells, proteins, albumin and LDH, at levels compatible with the inflammatory exudates of other biological fluids such as pleural or peritoneal fluid; Light's criteria should not be used to evaluate it. Recently we also analyzed systematically large chronic idiopathic non-inflammatory pericardial effusions, observing that a non-invasive wait-and-see approach may be the best choice in clinical practice in oligosymptomatic cases. Concerning acute recurrent pericarditis (RP), an innovative interaction between cardiologists, internists and pediatric rheumatologists led to the intuition of a pivotal role of IL-1 in recurrent pericarditis characterized by an evident inflammatory recurrent phenotype, and recent data have shown the striking efficacy of anakinra and rilonacept in these patients. The proper selection of the patient is important; the ideal candidate for anti-IL-1 therapy is the patient with RP with high levels of serum C-reactive protein, high fever, neutrophil leukocitosis, pleuropulmonary involvement, frequent exacerbations and resistant to conventional therapy. On the contrary, anti-IL-1 drugs are not indicated in patients with pericardial effusion whose cause is not attributable to inflammatory phenomena. Finally, many patients with RP are women of childbearing age, and the possibility for these women to become pregnant must be addressed by multidisciplinary teams.

Role of non-invasive multimodality imaging in autoimmune pericarditis

Systemic autoimmune diseases are an important cause of pericardial involvement and contribute to up to ∼22% cases of pericarditis with a known aetiology. The underlying mechanism for pericardial involvement varies with each systemic disease and leads to a poor understanding of its management. Multimodality imaging establishes the diagnosis and determines the type and extent of pericardial involvement. In this review, we elaborate upon various pericardial syndromes associated with different systemic autoimmune and autoinflammatory diseases and the multitude of imaging modalities that can be used to further characterize autoimmune pericardial involvement. Lastly, these forms of pericarditis have a greater likelihood of recurrence, and clinicians need to understand their unique treatment approaches to improve patient outcomes.

Associated Pleural and Pericardial Effusions: An Extensive Differential Explored

Concurrent pleural and pericardial effusions are not an unusual finding, but their differential diagnosis remains uncertain. Medline-based review identified an extensive list of infectious, inflammatory, neoplastic, iatrogenic, and myriad other etiologies. A single retrospective study had addressed this presentation. Several principles of a diagnostic workup are suggested, acknowledging that a significant minority of patients may not require a comprehensive workup and remain 'idiopathic'.

Recurrent pericarditis: an update on diagnosis and management

Acute pericarditis is a disease of the pericardium characterized by inflammation. Around 16-38% of patients develop recurrent events after the first episode. Recurrent pericarditis (RP) seems to be caused by a pathologic immune response. An inadequate treatment in terms of drug choice, dose, duration of therapy or tapering, has been shown to increase the risk of recurrences. Symptoms, physical signs and electrocardiographic signs are usually less severe during a recurrent event as compared to the first episode, thus favoring imaging as a tool to confirm the diagnosis of RP. Cardiac magnetic resonance is becoming the technique of choice because of its ability to detect active pericardial inflammation. Inflammatory biomarkers can be used to assess the risk of recurrences and to guide the tapering of treatments. First-line treatment is based on non-steroidal anti-inflammatory drugs (NSAIDs) and colchicine. NSAIDs are useful for pain control, and colchicine has shown to reduce the risk of further recurrences. Glucocorticoids are often used as second-line drugs, but they are associated with a high rate of recurrent events. Interleukin-1 inhibitors, such as anakinra and rilonacept, significantly reduce the risk of recurrences in patients with RP while on treatment.

Echocardiographic assessment in cardiogenic shock

Echocardiography is the most helpful diagnostic modality in cardiogenic shock, the management of which still remains challenging despite advances in therapeutic options. The presence of cardiogenic shock portends high mortality rates. Therefore, rapid recognition, identification of the underlying cause, and evaluation of the severity of hemodynamic dysfunction are vital for correct management. Whether the cause of shock is unknown, suspected, or established, echocardiography is utilized in its diagnosis and management as well as to monitor progress. It is recommended as the modality of first choice. No other investigative bedside tool can offer comparable diagnostic capability, allowing for exact targeting of the underlying cardiac and hemodynamic problems. Echocardiography can promptly provide an impression of the etiology of shock and the potential line of treatment. Normal left ventricular and right ventricular systolic function, normal cardiac chamber dimensions, absence of any significant valvular pathology, and absence of any pericardial effusion virtually rule out a cardiac cause of shock. This review discusses the role of echocardiography as a decision-making tool in the evaluation and management of cardiogenic shock.