Accurate preoperative diagnosis of pericardial constriction using cine computed tomography

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

Background

Diagnosis of constrictive pericarditis (CP) can be challenging. It can be nearly impossible to distinguish CP from other causes of right heart failure. Although various imaging modalities help in the diagnosis, no test is definitive. Several reviews have addressed the role of various imaging techniques in the diagnosis of CP but a systematic review has not yet been published.

Objective

Our intention was to study the ability of various non-invasive imaging modalities to diagnose CP in patients with surgically confirmed disease and to apply our findings to develop a clinically useful diagnostic algorithm.

Methods

A PubMed (NLM) search was performed with MeSH term “constrictive pericarditis”. Original articles that investigated the ability of various cardiovascular imaging modalities to noninvasively diagnose surgically confirmed CP were included in our review. Investigations that included any cases without surgical confirmation were excluded.

Results

The PubMed search yielded 3001 results with MeSH term “constrictive pericarditis” (January 8, 2016). We identified (40) studies on CP that matched our inclusion criteria. We summarized our results sorted by individual non-invasive CV imaging modalities – echocardiography, cardiac computed tomography (CT), and magnetic resonance imaging (MRI). Under each imaging modality, we grouped our discussion based on different parameters useful in CP diagnosis.

Conclusions

In conclusion, contemporary diagnosis of CP is based on clinical features and echocardiography. Cardiac MRI is recommended in patients where echocardiography is not diagnostic. Both cardiac MRI and CT can guide surgical planning but we prefer MRI as it provides both structural and functional information.

Diagnosis and Management of Pericardial Disease

The pericardium serves many important functions but is not essential for life. Pericardial heart disease comprises only pericarditis and its complications, tamponade and constriction, and congenital lesions. However, the pericardium is affected by virtually every category of disease. Thus the critical care physician is likely to encounter the patient with pericardial disease in a variety of settings, either as an isolated phenomenon or as a complication of a variety of systemic disorders, trauma, or certain drugs. Despite exhaustive etiological lists, the cause of pericardial heart disease is often never identified. This article reviews the diagnosis and management of acute and chronic pericarditis with an emphasis on those areas of greatest interest to the intensivist.

Korean guidelines for the appropriate use of cardiac CT

The development of cardiac CT has provided a non-invasive alternative to echocardiography, exercise electrocardiogram, and invasive angiography and cardiac CT continues to develop at an exponential speed even now. The appropriate use of cardiac CT may lead to improvements in the medical performances of physicians and can reduce medical costs which eventually contribute to better public health. However, until now, there has been no guideline regarding the appropriate use of cardiac CT in Korea. We intend to provide guidelines for the appropriate use of cardiac CT in heart diseases based on scientific data. The purpose of this guideline is to assist clinicians and other health professionals in the use of cardiac CT for diagnosis and treatment of heart diseases, especially in patients at high risk or suspected of heart disease.

Hiding in plain sight; constrictive pericarditis

We present a case of constrictive pericarditis that was especially difficult to diagnose. The patient presented with generalised oedema, dyspnoea and pleural effusions. History was significant for prior polysubstance abuse but was otherwise unremarkable. Physical examination revealed only jugular venous distention. CT demonstrated a normal pericardium with pleural effusions. Echocardiography showed mildly elevated right ventricular pressures with dyssynergic motion of the ventricular septum. No intervention was being carried out, but 1 month later further evaluation with a right and left heart catheterisation showed the classical square-root sign with equalisation of diastolic pressures in both ventricles as well as ventricular interdependence. Idiopathic constrictive pericarditis was thus diagnosed with a subsequent pericardial stripping which confirmed a thickened pericardium encasing the heart.

Noninvasive imaging techniques of constrictive pericarditis

Constrictive pericarditis (CP) is the result of scarring and loss of elasticity of the pericardial sac, resulting in external impedance of cardiac filling. It can occur after virtually any pericardial disease process. Patients typically present with signs and symptoms of right heart failure and/or low cardiac output. An important pathophysiological hallmark of CP is exaggerated ventricular interdependence and impaired diastolic filling. Echocardiography is the initial imaging modality for diagnosis of CP. Unfortunately, no echocardiographic sign or combination of signs is pathognomonic for CP. CT scan and cardiac MRI are other imaging techniques that can provide incremental diagnostic information. CT scan can easily detect pericardial thickening and calcification, while cardiac MRI provides a comprehensive evaluation of the pericardium, myocardium and cardiac physiology. Occasionally, a multimodality approach needs to be considered for the conclusive diagnosis of CP.

Advances in cardiovascular CT imaging: CT clinical imaging

Recent advances in cardiovascular CT imaging have dramatically changed the way we evaluate cardiac and great vessel disease. The superb spatial and faster temporal resolutions of the newer scanners, have allowed CT to gain acceptance not only in defining cardiac and great vessel anatomy but also has allowed its entry into the field of functional and perfusion imaging. This paper reviews the current status of CT in clinical imaging of the heart and great vessels.

The hemodynamic signs of constrictive pericarditis can be mimicked by tricuspid regurgitation

A case with clinical and hemodynamic findings consistent with constrictive pericarditis is reported. At surgery, the pericardium was not thickened or adherent to the epicardial wall. As suggested by echocardiography, a diagnosis of severe tricuspid regurgitation was confirmed. This case illustrates that invasive hemodynamic findings consistent with a picture of pericardial constriction can be produced by processes other than constrictive pericarditis.

Constrictive pericarditis in 26 patients with histologically normal pericardial thickness

BACKGROUND

Traditionally, increased pericardial thickness has been considered an essential diagnostic feature of constrictive pericarditis. Although constriction with a normal-thickness pericardium has been demonstrated clinically by noninvasive imaging, the details of clinicopathological correlates have not been described.

METHODS AND RESULTS

A total of 143 patients with proven constriction underwent pericardiectomy at Mayo Clinic between 1993 and 1999. Their baseline characteristics, operative data, and pathological specimens were reviewed retrospectively. The pericardium was of normal thickness (< or =2 mm) in 26 patients (18%; group 1) and was thickened (>2 mm) in 117 (82%; group 2). The most common causes of constriction in group 1 included previous cardiac surgery, chest irradiation, previous infarction, and idiopathic disease. There was little difference in symptoms and findings on physical examination between the 2 groups. Microscopically, no patient had an entirely normal pericardium. Histopathological abnormalities in group 1 were mild and focal, including fibrosis, inflammation, calcification, fibrin deposition, and focal noncaseating granulomas. Pericardiectomy was equally effective in relieving symptoms regardless of the presence or absence of increased thickness.

CONCLUSIONS

Pericardial thickness was not increased in 18% of patients with surgically proven constrictive pericarditis, although the histopathological appearance was focally abnormal in all cases. When clinical, echocardiographic, or invasive hemodynamic features indicate constriction in patients with heart failure, pericardiectomy should not be denied on the basis of normal thickness as demonstrated by noninvasive imaging.

Imaging of the pericardium

Computed tomography (CT) and magnetic resonance imaging (MRI) are modalities well suited for imaging of the pericardium and pericardial disease. Both offer excellent resolution with a wide field of view. Both have advantages and disadvantages when compared with each other and with echocardiography. Establishing the diagnosis of constrictive pericarditis is a common indication for CT or MRI of the pericardium. Pericarditis, neoplasms, effusions, and congenital anomalies are additional conditions involving the pericardium that can be diagnosed with CT and MRI.

Contemporary cardiac imaging: an overview

Comprehensive cardiac assessment embraces virtually every imaging modality and includes information about coronary vascular anatomy as well as cardiac morphology, function, perfusion, metabolism, and tissue characterization. Through sophisticated computer processing and image analysis, newer imaging technologies such as computed tomography (CT), magnetic resonance (MR), MR spectroscopy, and positron emission tomography now provide quantitative information that may obviate more invasive angiographic assessment. Currently, no single imaging technology realizes all questions relating to cardiac form and function, and many of the technologies overlap in the content and quality of information they provide. This overview seeks to provide a broad perspective on current cardiac imaging, articulating the benefits of various technologies and their limitations.

Coronary atherosclerosis and its effect on cardiac structure and function: evaluation by electron beam computed tomography

Coronary artery disease affects millions of Americans annually. In evaluating coronary artery disease, it is important to develop diagnostic methodology that can screen patients before the onset of symptoms or cardiac events and, in addition, evaluate the functional aspects of coronary artery disease, including any residual effects on the heart after events have occurred. Electron beam computed tomography allows the identification of coronary calcium, which is a marker for coronary atherosclerotic disease, and also allows the quantification of cardiac function, which may be altered from coronary atherosclerosis or the occurrence of a cardiac event. Thus, electron beam computed tomographic imaging is having a major impact on the diagnosis and follow-up on coronary artery disease.

Phasic coronary flow characteristics in patients with constrictive pericarditis: comparison with restrictive cardiomyopathy

BACKGROUND

Phasic coronary flow characteristics have been reported in patients with aortic valve disease and hypertrophic cardiomyopathy. The purpose of this study was to assess the differences in coronary flow characteristics between patients with constrictive pericarditis and those with restrictive cardiomyopathy.

METHODS AND RESULTS

The study populations consisted of 7 case patients with constrictive pericarditis, 8 with restrictive cardiomyopathy, and 11 control subjects with chest pain and normal coronary arteries. Five minutes after injection of 3 mg of isosorbide dinitrate, phasic coronary flow velocity patterns were analyzed in the proximal segment of the angiographically normal left anterior descending coronary artery at rest using a 0.014-in, 15-MHz Doppler guidewire. Coronary flow reserve was obtained from the ratio of adenosine-induced (0.14 mg x kg(-1) x min(-1) I.V.) hyperemic/baseline time-averaged peak velocity. Although in case patients with constrictive pericarditis and restrictive cardiomyopathy maximal hyperemic time-averaged peak velocity (21+/-8 and 31+/-17 versus 60+/-19 cm/s, respectively; P<.001) and coronary flow reserve (1.3+/-0.4 and 1.6+/-0.6 versus 3.6+/-0.4, respectively, P<.001) were significantly lower than in control subjects, there were no significant differences in these indexes between the two groups of case patients. Velocity half-time of diastolic flow velocity corrected by square root(RR), which indicates deceleration of diastolic flow, in the groups of case patients with constrictive pericarditis and restrictive cardiomyopathy was significantly less than that in control subjects (6.2+/-2.6 and 10.6+/-1.5 versus 16.9+/-2.7, respectively; P<.001); this was also significantly smaller in constrictive pericarditis than restrictive cardiomyopathy (P<.001). This index <9.5 could distinguish constrictive pericarditis from restrictive cardiomyopathy with a sensitivity of 86% and a specificity of 88%. Furthermore, time from the beginning of diastole to diastolic peak velocity corrected by square root(RR) indicating acceleration of diastolic flow velocity in constrictive pericarditis was significantly less than that in restrictive cardiomyopathy and control subjects (2.8+/-1.2 versus 4.8+/-0.8 and 4.4+/-0.6, respectively; P<.001).

CONCLUSIONS

Although coronary flow reserve is limited in both constrictive pericarditis and restrictive cardiomyopathy because of restriction of hyperemic response, rapid acceleration and more rapid deceleration of diastolic flow velocity are more characteristic in constrictive pericarditis than in restrictive cardiomyopathy.

Pericardial thickness measured with transesophageal echocardiography: feasibility and potential clinical usefulness

OBJECTIVES

This study assessed the reliability of transesophageal echocardiographic measurements of pericardial thickness and the potential diagnostic usefulness of this technique.

BACKGROUND

Transthoracic echocardiography cannot reliably detect thickened pericardium. The superior resolution achieved with transesophageal echocardiography should allow better pericardial definition.

METHODS

Pericardial thickness measured at 26 locations in 11 patients with constrictive pericarditis who underwent intraoperative transesophageal echocardiography was compared with pericardial thickness measured with electron beam computed tomography. Intraobserver and interobserver variabilities were determined. Pericardial thickness was then measured in 21 normal subjects. With these values as a guide, two observers reviewed 37 transesophageal echocardiographic studies to determine whether echocardiographic measurement of pericardial thickness could be used to distinguish diseased from normal pericardium.

RESULTS

The correlation between echocardiographic and computed tomographic measurements (r > or = 0.95, SE < or = 0.06 mm, p < 0.0001) was excellent. The +/-2 SD limits of agreement were +/-1.0 mm or less for pericardial thickness < 5.5 mm and +/-2.0 mm or less for the entire range of thicknesses. Intraobserver and interobserver agreements were good. Mean normal pericardial thickness was 1.2 +/- 0.8 mm (+/-2 SD) and did not exceed 2.5 mm. Pericardial thickness > or = 3 mm on transesophageal echocardiography was 95% sensitive and 86% specific for the detection of thickened pericardium.

CONCLUSIONS

Measurement of pericardial thickness with transesophageal echocardiography is reproducible and should be a valuable adjunct in assessing constrictive pericarditis.

Differentiation of constrictive pericarditis from restrictive cardiomyopathy: assessment of left ventricular diastolic velocities in longitudinal axis by Doppler tissue imaging

OBJECTIVES

We sought to determine the utility of left ventricular expansion velocities in differentiating constrictive pericarditis from restrictive cardiomyopathy.

BACKGROUND

Several studies have shown that left ventricular diastolic expansion is influenced by the elastic recoil forces of the myocardium. These forces are affected by intrinsic myocardial disease but should be preserved when diastole is impaired as a result of extrinsic causes.

METHODS

Using Doppler tissue imaging, we measured peak early velocity of longitudinal axis expansion (Ea) in 8 patients with constrictive pericarditis, 7 patients with restriction and 15 normal volunteers. Transmitral early (E) and late (A) Doppler flow velocities, left ventricular systolic and diastolic volumes, ejection fraction and mitral annular M-mode displacement were also compared between the groups.

RESULTS

The Ea value was significantly higher in normal subjects (14.5 +/- 4.7 cm/s [mean +/- SD]) and in patients with constriction (14.8 +/- 4.8 cm/s) than in those with restriction (5.1 +/- 1.4 cm/s, p < 0.001 constriction vs. restriction). There was weak correlation between Ea and the extent of annular displacement (r = 0.55, p = 0.004) and the E/A ratio (r = 0.44, p = 0.03). There was no correlation between Ea and E (r = 0.33, p = 0.07) or ejection fraction (r = 0.21, p = 0.26). By multivariate analysis, Ea was the best variable for differentiating constriction from restriction.

CONCLUSIONS

Our study indicates that longitudinal axis expansion velocities are markedly reduced in patients with restrictive cardiomyopathy. The poor correlation found with transvalvular flow velocities suggests that Ea may be relatively preload independent. The measurement of longitudinal axis expansion velocities provides a clinically useful distinction between constrictive pericarditis and restrictive cardiomyopathy and may prove to be valuable in the study of diastolic function.

Constrictive pericarditis: its history and current status

The diagnosis of constrictive pericarditis remains a challenge because it is often mimicked by restrictive cardiomyopathy. The last few years have seen numerous advances in our ability to differentiate between these two conditions which often have similar physical findings and hemodynamics. This review begins with a brief history of constrictive pericarditis; this is followed by an extensive discussion of newer etiologies, and then the classical clinical history and physical examination findings are described. Radiologic, electrocardiographic, and angiographic findings are discussed. The hemodynamics of constrictive pericarditis are reviewed. Recent results of echocardiographic and echo-Doppler investigations are presented. Emphasis is placed upon the limitations of M-mode echocardiography in the diagnosis of constrictive pericarditis. The value of echocardiographic Doppler studies of mitral and tricuspid flow velocity patterns, as well as of those in the pulmonary veins and hepatic veins, is described. Nuclear ventriculograms and angiocardiograms tend to show more rapid ventricular filling in constrictive pericarditis than in restrictive cardiomyopathy. Although only a small number of patients has been studied, these evaluations seem to have merit in separating restrictive cardiomyopathy from constrictive pericarditis. The role of computed tomography scanning and magnetic resonance imaging studies of pericardial thickness in confirming the presence of constrictive pericarditis is discussed. Abnormal pericardial thickening (> 3 mm) confirms the diagnosis of constrictive pericarditis, but only if the characteristic hemodynamic pattern is present. The usefulness of endomyocardial biopsy in recognizing specific varieties of restrictive cardiomyopathy is presented.(ABSTRACT TRUNCATED AT 250 WORDS)