Systematic review of non-invasive cardiovascular imaging in the diagnosis of constrictive pericarditis

Constrictive Pericarditis: An Update on Noninvasive Multimodal Diagnosis

Constrictive pericarditis (CP) is a rare condition that can affect the pericardium after every pericardial disease process and has been described even after SARS-CoV-2 infection or vaccine. In CP, the affected pericardium, usually the inner layer, is noncompliant, constraining the heart to a fixed maximum volume and impairing the diastolic function. This leads to several clinical features, that, however, can be pleomorphic. In its difficult diagnostic workup, noninvasive multimodal imaging plays a central role, providing important morphological and functional data, like the enhanced ventricular interdependence and the dissociation between intrathoracic and intracardiac pressures. An early and proper diagnosis is crucial to set an appropriate therapy, changing the prognosis of patients affected by CP. In this review, we cover in detail the main elements of each imaging technique, after a reminder of pathophysiology useful for understanding the diagnostic findings.

Echocardiographic Criteria to Differentiate Constrictive Pericarditis From Restrictive Cardiomyopathy: A Meta-analysis

Background

To assess the diagnostic accuracy of the Mayo Clinic echocardiographic criteria for differentiating between constrictive pericarditis and restrictive cardiomyopathy.

Methods

We searched electronic databases for the date range from their inception to July 1, 2022. The index tests were the Mayo Clinic echocardiographic criteria. We performed a bivariate random-effects model to estimate the pooled sensitivity and specificity, each with 95% confidence interval (CI). The area under the curve of the summary receiver operator characteristic curves, with 95% CI, was also calculated.

Results

We included 17 case-control studies involving 889 patients. The pooled sensitivity and specificity (95% CI), respectively, were as follows: ventricular septal shift, 82% (60%-94%) and 78% (65%-87%); respiratory variation in mitral inflow ≥ 14.6%, 71% (51%-85%) and 82% (66%-91%); septal e' velocity ≥ 8 cm/s, 83% (80%-87%) and 90% (83%-95%); septal e' velocity/lateral e' velocity ≥ 0.88, 74% (64%-82%) and 81% (70%-88%); and hepatic vein ratio in expiration ≥ 0.79, 73% (65%-81%) and 71% (19%-96%). The area under the curve of the summary receiver operator characteristic curves varied from 0.75 to 0.85, with overlapping CIs across index tests.

Conclusions

Our meta-analysis suggests that all echocardiographic parameters from the Mayo Clinic criteria have good diagnostic accuracy for differentiating between constrictive pericarditis and restrictive cardiomyopathy.

Transverse and longitudinal right ventricular fractional parameters derived from four-chamber cine MRI are associated with right ventricular dysfunction etiology

Studies of the usefulness of transverse right ventricular (RV) shortening are limited. We retrospectively analyzed the CMR images of 67 patients (age: 50.8 ± 19.0 years; men: 53.7%; Control: n = 20, Overloaded RV (atrial septal defect): n = 15, Constricted RV (pericarditis): n = 17, Degenerated RV (arrhythmogenic right ventricular cardiomyopathy): n = 15) (all enrolled consecutively for each disease) in a single center. We defined RV longitudinal (fractional longitudinal change: FLC) and transverse (fractional transverse change: FTC) contraction parameters. We assessed the FTC/FLC (T/L) ratio on four-chamber cine CMR views and compared the four groups regarding the fractional parameters. FTC had a stronger correlation (R² = 0.650; p < 0.001) with RV ejection fraction than that with FLC (R² = 0.211; p < 0.001) in the linear regression analysis. Both FLC and FTC were significantly lower in the Degenerated RV and Constricted RV groups compared with those in the Control and Overloaded RV groups. The T/L ratio was significantly lower in the Degenerated RV group (p = 0.008), while the Overloaded RV (p = 0.986) and Constricted RV (p = 0.582) groups had preserved T/L ratios, compared with the Control group. Transverse shortening contributes to RV function more significantly compared with longitudinal contraction. Impaired T/L ratios may reflect RV myocardial degeneration. RV fractional parameters may help precisely understand RV dysfunction.

Echocardiographic Differentiation of Pericardial Constriction and Left Ventricular Restriction

PURPOSE OF REVIEW

Overlapping hemodynamics in constrictive pericarditis (CP) and restrictive cardiomyopathy (RCM) often pose difficulties in establishing accurate diagnosis. Echocardiography is the first-line imaging modality used for this purpose, but no single echocardiographic parameter is sufficiently robust for distinguishing between the two conditions. The newer developments may improve the diagnostic accuracy of echocardiography in this setting.

RECENT FINDINGS

Recent studies have validated multiparametric algorithms, based on conventional echocardiographic parameters, which enable high sensitivity and specificity for distinguishing between CP and RCM. In addition, myocardial deformation analysis using speckle-tracking echocardiography has revealed distinct pattern of abnormalities in the two conditions. CP is characterized by impaired left ventricular apical rotation with relatively preserved longitudinal strain, esp. of ventricular and atrial septum. In contrast, RCM results in global and marked impairment of left ventricular longitudinal strain with initially preserved circumferential mechanics. Combining multiple echocardiographic parameters into step-wise algorithms and incorporation of myocardial deformation analysis help improve the diagnostic accuracy of echocardiography for distinguishing between CP and RCM. The use of machine-learning may allow easy integration of a wide range of echocardiographic and clinical parameters to permit accurate, automated diagnosis, with less dependence on the user expertise.

A Systematic Review of COVID-19 and Pericarditis

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first identified in Wuhan, China in December 2019. Since then, the disease has spread globally, leading to the ongoing pandemic. It can cause severe respiratory illness; however, many cases of pericarditis have also been reported. This systematic review aims to recognize the clinical features of pericarditis and myopericarditis in COVID-19 patients.

Google Scholar, Medline/PubMed, CINAHL, Cochrane Central, and Web of Science databases were searched for studies reporting “Coronavirus” or “COVID” and “Peri-myocarditis,” “heart,” or “retrospective.” Case reports and retrospective studies published from May 2020 to February 2021 were reviewed.

In total, 33 studies on pericarditis, myopericarditis, and pericardial infusion were included in this review. COVID-19 pericarditis affected adult patients at any age. The incidence is more common in males, with a male-to-female ratio of 2:1. Chest pain (60%), fever (51%), and shortness of breath (51%) were the most reported symptoms, followed by cough (39%), fatigue (15%), myalgia (12%), and diarrhea (12%). Laboratory tests revealed leukocytosis with neutrophil predominance, elevated D-dimer, erythrocyte rate, and C-reactive protein. Cardiac markers including troponin-1, troponin-T, and brain natriuretic peptide were elevated in most cases. Radiographic imaging of the chest were mostly normal, and only 31% of chest X-rays showed cardiomegaly and or bilateral infiltration. Electrocardiography (ECG) demonstrated normal sinus rhythm with around 59% ST elevation and rarely PR depression or T wave inversion, while the predominant echocardiographic feature was pericardial effusion. Management with colchicine was favored in most cases, followed by non-steroidal anti-inflammatory drugs (NSAIDs), and interventional therapy was only needed when patient developed cardiac tamponade. The majority of the reviewed studies reported either recovery or no continued clinical deterioration.

The prevalence of COVID-19-related cardiac diseases is high, and pericarditis is a known extrapulmonary manifestation. However, pericardial effusion and cardiac tamponade are less prevalent and may require urgent intervention to prevent mortality. Pericarditis should be considered in patients with chest pain, ST elevation on ECG, a normal coronary angiogram, and COVID-19. We emphasize the importance of clinical examination, ECG, and echocardiogram for decision-making, and NSAIDs, colchicine, and corticosteroids are considered to be safe in the treatment of pericarditis/myopericarditis associated with COVID-19.

Transthoracic Echocardiography: Beginner's Guide with Emphasis on Blind Spots as Identified with CT and MRI

Transthoracic echocardiography (TTE) is the primary initial imaging modality in cardiac imaging. Advantages include portability, safety, availability, and ability to assess the morphology and physiology of the heart in a noninvasive manner. Because of this, many patients who undergo advanced imaging with CT or MRI will have undergone prior TTE, particularly when cardiac CT angiography or cardiac MRI is performed. In the modern era, the increasing interconnectivity of picture archiving and communication systems (PACS) has made these images more available for comparison. Therefore, radiologists who interpret chest imaging studies should have a basic understanding of TTE, including its strengths and limitations, to make accurate comparisons and assist in rendering a diagnosis or avoiding a misdiagnosis. The authors present the standard TTE views along with multiplanar reformatted CT images for correlation. This is followed by examples of limitations of TTE, focusing on potential blind spots, which have been placed in seven categories on the basis of the structures involved: (a) pericardium (thickening, calcification, effusions, cysts, masses), (b) aorta (dissection, intramural hematoma, penetrating atherosclerotic ulcer), (c) left ventricular apex (infarcts, aneurysms, thrombus, apical hypertrophic cardiomyopathy), (d) cardiac valves (complications of native and prosthetic valves), (e) left atrial appendage (thrombus), (f) coronary arteries (origins, calcifications, fistulas, aneurysms), and (g) extracardiac structures (primary and metastatic masses). Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article . ^©RSNA, 2021.

Multimodality imaging of constrictive pericarditis in H syndrome

This is the first report of constrictive pericarditis (CP) in a 16-year-old boy with H syndrome with pericardial involvement predominantly over the right ventricle with favorable response to anti-inflammatory treatment. H syndrome, first reported in 2008, is a new auto-inflammatory syndrome with multiorgan involvement due to mutation in the SLC29A3 gene. We described the echocardiographic characteristics of asymmetric pericardial involvement and presented the cardiac computed tomography angiographic and magnetic resonance imaging findings. We reviewed the echocardiographic signs of CP, introduced tricuspid E/A respiratory alternans as a novel echocardiographic sign of right ventricular dominant CP, and explained the underlying mechanism.

Experimental Research on the Evaluation of Left Ventricular Function by Layered Speckle Tracking in a Constrictive Pericarditis Rat Model

OBJECTIVES

In animal models with constrictive pericarditis (CP), detecting the function of cardiac systole by conventional noninvasive ultrasound is a challenge. We aimed to detect cardiac dysfunction in rat models with CP in the early stage by layered speckle tracking.

METHODS

We compared a rat CP model (n = 23, injected with a solution of 1-mg/mL lipopolysaccharides [0.5 mL] and a 10% talc suspension [0.5 mL]) with a control group (n = 20, no injection). After 8 weeks, conventional echocardiography and layered speckle tracking were used to assess the left ventricular structures and functions in the groups.

RESULTS

The global circumferential strain (CS) and longitudinal strain (LS) were decreased in the CP group (P < .05). The CS of the epicardial and middle layers in the CP group was decreased (P < .05), but the endocardial layer was not statistically different. The LS of the epicardial layer was decreased (P < .05), but the middle and endocardial layers were not statistically different. The global free-wall and septal-wall CS of the CP group was decreased (P < .05), mainly due to the decrease of CS of the epicardial and middle layers. The global free-wall LS of the CP group was decreased (P < .05), mainly due to the decrease of LS of the epicardial and middle layers. There were no significant differences between the groups in global LS of the septal wall.

CONCLUSIONS

In the early stage of CP, subepicardial myocardial damage precedes that of the subendocardial myocardium, and free-wall damage precedes that of the septal wall.

Misdiagnosis of constrictive pericarditis presenting with haemorrhagic pericardial effusion: a case report

BACKGROUND

The symptoms and signs of constrictive pericarditis (CP) are often elusive at onset, with a long symptom-free period that may take weeks to decades to develop after an episode of CP or pericardial injury, leading to a misdiagnosis.

CASE SUMMARY

In this case, a 58-year-old man complained of lower extremity fatigue, intermittent chest tightness, and shortness of breath. He was first misdiagnosed as neuropathy, later unsuccessfully treated as ischaemic heart disease though severe stenosis of the diagonal branch of left anterior descending artery was confirmed by computer tomography angiography. He was finally diagnosed as CP after carefully reading the initial computed tomography. The gross pathology of heart in situ originally observed at the time of pericardectomy indicated fibrinous pericarditis, massive haemorrhagic pericardial effusion (300 mL), and thickened pericardium (maximum thickness more than 6 mm). Following pericardial tissue biopsy, the histopathology showed chronic fibrinous pericarditis, without a clear aetiology. His symptoms gradually disappeared after surgical pericardectomy. At the 1-year follow-up visit, the patient complained of no discomfort.

DISCUSSION

Constrictive pericarditis is one of the serious diseases commonly misdiagnosed. Computed tomography and echocardiography show the important diagnostic role in patients with CP, and surgical pericardectomy shows the potential in treating this disease, in some of which the mechanism underlying large haemorrhagic pericardial effusion remains unclear.

A New High-Performance Gadonanotube-Polymer Hybrid Material for Stem Cell Labeling and Tracking by MRI

A gentle, rapid method has been developed to introduce a polyacrylic acid (PAA) polymer coating on the surface of gadonanotubes (GNTs) which significantly increases their dispersibility in water without the need of a surfactant. As a result, the polymer, with its many carboxylic acid groups, coats the surface of the GNTs to form a new GNT-polymer hybrid material (PAA-GNT) which can be highly dispersed in water (ca. 20 mg·mL⁻¹) at physiological pH. When dispersed in water, the new PAA-GNT material is a powerful MRI contrast agent with an extremely short water proton spin-lattice relaxation time (T₁) which results in a T₁-weighted relaxivity of 150 mM⁻¹·s⁻¹ per Gd³⁺ ion at 1.5 T. Furthermore, the PAA-GNTs have been used to safely label porcine bone-marrow-derived mesenchymal stem cells for magnetic resonance imaging. The labeled cells display excellent image contrast in phantom imaging experiments, and transmission electron microscopy images of the labeled cells reveal the presence of highly dispersed PAA-GNTs within the cytoplasm with 10¹⁴ Gd³⁺ ions per cell.