Diverential Diagnosis of Restrictive Cardiomyopathy and Constrictive

Heart 2001;86:343–349

Varieties of constrictive pericarditis CARDIOMYOPATHY Heart: first published as 10.1136/heart.86.3.343 on 1 September 2001. Downloaded from x Typical forms DiVerential diagnosis of restrictive –chronic (calciﬁc, rigid shell) cardiomyopathy and constrictive –subacute (non-calciﬁc, elastic) pericarditis x EVusive-constrictive 343 x Localised E William Hancock x Occult Stanford University School of Medicine, Stanford, California, USA

predominant clinical feature of ascites, simulat- he diVerentiation of restrictive cardio- ing liver disease, were notable in White’s series. myopathy and constrictive pericarditis Haemodynamic features delineated in the Thas been a perennial problem in clinical 1940s and ’50s included the narrow pulse pres- cardiology. Constrictive pericarditis requires sure in the right ventricle with normal systolic surgical treatment and is usually curable, while pressure and greatly increased diastolic pres- restrictive cardiomyopathy, short of cardiac sure, a prominent early diastolic dip and later transplantation, is treatable only by medical diastolic plateau in right ventricular pressure means and often responds unsatisfactorily. The waveforms, and an additional prominent systo- opinion has often been expressed that there are lic dip in the right atrial waveform, giving a “W” diYcult cases in which only an exploratory atrial waveform. Comments on the difficulty of operation will allow the two conditions to be distinguishing constrictive pericarditis from distinguished. However, such cases were rela- restrictive cardiomyopathy began to appear in tively rare in the past and should be extremely the medical literature only after the pressure so in the present era. Many diVerences exist recordings from cardiac catheterisation began between the two conditions, even though no to be used in the diagnosis of constrictive peri- one diagnostic method can be relied upon to carditis. One may suspect that cardiac catheteri- make the distinction by itself. sation data in the two conditions were more similar than the clinical features. Constrictive pericarditis Since 1960 the clinical profile of constrictive pericarditis has changed greatly. Tuberculous aetiology has become rare in developed coun- Constrictive pericarditis was recognised in the tries, while new aetiologies have appeared. Two 19th century and its surgical treatment was of them, previous cardiac surgery and previous developed early in the 20th century. Paul Wood radiotherapy, are now responsible for up to one noted in 1961 that only details had been added third of cases in some centres.3 The term http://heart.bmj.com/ to the picture presented to the English speaking “chronic” is often no longer included in the title, world by Paul Dudley White in his 1935 St because so many cases are now more appropri- 12 Cyres lecture. White described a “chronic ately considered to be acute or subacute. fibrous or callous thickening of the wall of the Subacute constrictive pericarditis diVers in sev- Correspondence to: pericardial sac that is so contracted that the eral respects from the chronic cases, as Paul E William Hancock normal diastolic filling of the heart is pre- Wood noted in his delineation of the diVerences MD, Stanford vented . . . There may or may not be calcifica- University Medical between active and inactive tuberculous con-

Center, Division of tion ...Parietal pericardium or epicardium strictive pericarditis. A distinction between elas- on October 2, 2021 by guest. Protected copyright. Cardiovascular may be preponderantly involved . . . one area tic (subacute) and rigid shell (chronic) constric- Medicine, H-2157, 300 may be involved, other areas free . . . associated tion has been proposed to help to rationalise Avenue Louis Pasteur, heart disease is extremely rare . . . insidious these diVerences4 (table 1). Other additions to Stanford, CA evolution makes diagnosis more diYcult than the clinical profile include the recognition of 94305-5233, USA 5 whancock@cvmed. that of active constrictive pericarditis”. A eVusive–constrictive pericarditis, occult con- stanford.edu history of several years duration and a striction,6 localised constriction,7 and reversible constriction.8 These variant forms of constric- Table 1 Comparison of certain features in subacute (elastic) and chronic (rigid shell) constrictive pericarditis tive pericarditis each have some features that diVer from the classic chronic constrictive Subacute (elastic) Chronic (rigid shell) pericarditis of the past (table 2). Paradoxical pulse usually present, other signs of Paradoxical pulse usually minimal or absent, interdependence usually prominent other signs of interdependence less prominent Restrictive cardiomyopathy Usually an XY waveform (“M” or “W” waveform) Y is predominant, X sometimes minimal Dip–plateau pattern less conspicuous, because Dip–plateau usually conspicuous, because early diastolic nadir may not approach zero early diastolic nadir often reaches zero As the haemodynamics of constrictive pericarditis became known in the 1940s and ’50s it Calcification usually absent Calcification often present quickly became apparent that amyloid and Pericardial eVusion sometimes present, Pericardial eVusion absent. The two layers of other forms of myocardial or endocardial generalised or loculated. Constriction is by pericardium are fused, and jointly constrict disease could have similar haemodynamic fea- the visceral pericardium the heart tures. At the same time, the concept of P waves usually normal P waves often wide, notched and low in amplitude idiopathic cardiomyopathy was evolving, lead- ing to Goodwin’s 1961 classification into three Atrial fibrillation or flutter rare Atrial fibrillation or flutter common types.9 The hypertrophic and dilated forms

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Table 2 Features of variant forms of constrictive pericarditis Major forms of restrictive cardiomyopathy EVusive–constrictive pericarditis Pericardial eVusion is present, sometimes loculated, with Heart: first published as 10.1136/heart.86.3.343 on 1 September 2001. Downloaded from x Amyloid constriction by the visceral pericardium Occult constrictive pericarditis Haemodynamics are normal at rest, but assume the x Other inﬁltrative diseases features of constriction after an acute volume load Localised constrictive pericarditis Constriction limited to the right or left ventricle. x Endomyocardial ﬁbrosis Ventricular interdependence reduced or absent 344 Transient constrictive pericarditis During the resolution of acute pericarditis with eVusion, constriction develops, but then resolves spontaneously over x Idiopathic restrictive cardiomyopathy a few weeks

11 quickly became well known, but the third type, years. When the definition is broadened to “constrictive cardiomyopathy” (later renamed permit what is considered to be a lesser degree “restrictive cardiomyopathy”), defined as con- of systolic dysfunction associated with pre- gestive heart failure with neither hypertrophy dominant diastolic dysfunction, diastolic heart nor dilatation, was less common and received failure becomes very common, and perhaps less attention. The definition of restrictive car- includes about one half of all cases of diomyopathy has varied considerably, and the congestive heart failure. It is particularly com- term has usually been used in a broad sense, to mon in elderly patients. Such patients may be include such entities as amyloidosis, tropical referred to as having restrictive cardiomyopa- endomyocardial fibrosis, endocardial fibroelas- thy, even though it appears likely that hyper- tosis, haemochromatosis, and eosinophilic en- tension and increased arterial stiVness are 12 domyocardial disease, as well as the idiopathic background factors in many of them. cases. Idiopathic restrictive cardiomyopathy, Whatever definition of restrictive cardiomy- strictly defined to include normal ventricular opathy is used, it is clear that patients who wall motion as well as normal wall thickness simulate constrictive pericarditis are relatively and ventricular chamber dimensions, proved to rare, and that cardiac amyloidosis is the most be relatively rare. Such a strict definition can be frequent diagnosis among them. The others carried a step further by defining restrictive have miscellaneous diagnoses, with a small cardiomyopathy as those patients who cannot number representing an idiopathic restrictive be diVerentiated from constrictive pericarditis cardiomyopathy. by means of physical examination, chest radiograph, and cardiac catheterisation.10 No large Differentiating features series of patients with such a condition have been described. On the other hand, the concept of diastolic Table 3 lists 17 features, obtained by eight dif- heart failure, or diastolic dysfunction, has ferent clinical methods, that provide useful received a great deal of attention in the past 20 clues in diVerentiating constrictive pericarditis http://heart.bmj.com/ Table 3 Features useful in diVerentiating constrictive pericarditis from restrictive cardiomyopathy

Feature Constrictive pericarditis Restrictive cardiomyopathy Past medical history Previous pericarditis, cardiac surgery, trauma, radiotherapy, These items rare connective tissue disease Jugular venous waveform X and Y dips brief and “flicking”, not conspicuous positive X and Y dips less brief, may have conspicuous A wave or V waves wave Extra sounds in diastole Early S3, high pitched “pericardial knock”. No S4 Later S3, low pitched, “triple rhythm”. S4 in some cases on October 2, 2021 by guest. Protected copyright. Mitral or tricuspid regurgitation Usually absent Often present ECG P waves reflect intra-atrial conduction delay. Atrioventricular P waves reflect right or left atrial hypertrophy or overload. or intraventricular conduction defects rare Atrioventricular or intraventricular conduction defects not unusual Plain chest radiograph Pericardial calcification in 20–30% Pericardial calcification rare Ventricular septal movement in diastole Abrupt septal movement (“notch”) in early diastole in most Abrupt septal movement in early diastole seen only cases occasionally Ventricular septal movement with Notable movement toward left ventricle in inspiration usually Relatively little movement toward left ventricle in most cases respiration seen Atrial enlargement Slight or moderate in most cases Pronounced in most cases Respiratory variation in mitral and Greater than 25% in most cases Less than 15% in most cases tricuspid flow velocity Equilibration of diastolic pressures in Within 5 mm Hg in nearly all cases, often essentially the same Within 5 mm Hg in a small proportion of cases all cardiac chambers Dip–plateau waveform in the right End diastolic pressure more than one third of systolic End diastolic pressure often less than one third of systolic ventricular pressure waveform pressure in many cases pressure Peak right ventricular systolic pressure Nearly always less than 60 mm Hg, often less than 40 mm Hg Frequently more than 40 and occasionally more than 60 mm Hg Discordant respiratory variation of Right and left ventricular peak systolic pressure variations are Right and left ventricular peak systolic pressure variations are ventricular peak systolic pressures out-of-phase in-phase Paradoxical pulse Often present to a moderate degree Rarely present MR/CT imaging Shows thick pericardium in most cases Shows thick pericardium only rarely Endomyocardial biopsy Normal, or non-specific abnormalities Shows amyloid in some cases, rarely other specific infiltrative disease

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and restrictive cardiomyopathy. The length of sound occurs, usually 0.06–0.12 s after S2, and the list indicates that no one or two of the fea- somewhat high pitched and “snapping” in Heart: first published as 10.1136/heart.86.3.343 on 1 September 2001. Downloaded from tures have suYcient sensitivity and specificity character. The auscultatory impression tends to be decisive in all cases. More items could be to be that of a widely split S2 or a mitral open- included, but the list would then become even ing snap. The term “pericardial knock,” more unwieldy. The items listed have been although commonly used, is not particularly selected for having reasonable sensitivity and appropriate. The sound does not resemble a specificity, and for the most part of being read- knock on a door, and is not caused by the cal- 345 ily and reliably ascertained. cified heart knocking against the chest wall, as students sometimes misconceive. Past medical history Although many cases of constrictive pericardi- Late diastolic sounds tis are idiopathic, some have a history of Some patients with restrictive cardiomyopathy definite or possible acute pericarditis in the have S4, resulting from a powerful atrial past. Factors such as previous cardiac surgery, contraction in response to the increased resist- radiotherapy, connective tissue disease, and ance to ventricular filling. S4 does not occur in thoracic trauma may be the background for the constrictive pericarditis, despite similar degrees development of constrictive pericarditis, and of resistance to filling, probably because the none of these factors are expected in the past fibrotic constricting process impairs the atrial medical history of patients with restrictive contraction. cardiomyopathy. Mitral/tricuspid regurgitation Jugular venous waveform The physical examination is also helpful when The typical jugular venous pulse in constrictive it indicates pronounced mitral or tricuspid pericarditis has two dips per cardiac cycle: the regurgitation. Echo Doppler and cardiac cath- outward movements are less conspicuous. The eterisation are part of this assessment. Mitral two dips are the X and Y troughs, in systole and and tricuspid regurgitation are rarely promi- early diastole, respectively. Y is sometimes nent in constrictive pericarditis, but are often more prominent than X, especially in chronic prominent in restrictive cardiomyopathy. (rigid shell) cases, many of whom have atrial fibrillation, a factor that minimises the systolic Electrocardiogram descent. These features are also common in The P waves in constrictive pericarditis tend to restrictive cardiomyopathy. What distinguishes be wide and notched, but low in amplitude, constrictive pericarditis is the brief duration of reflecting intra-atrial conduction delay. This is Y, giving a “flicking” appearance in an seen in chronic cases more often than in the otherwise continuously distended vein. This is subacute cases. In restrictive cardiomyopathy the essential feature of Friedreich’s sign, the P waves may be wide, but have a particular considered by Paul Wood to be the most char- tendency to be increased in amplitude, reflect- acteristic physical sign of constrictive pericardi- ing left atrial overload or hypertrophy, as in http://heart.bmj.com/ tis. Subacute (elastic) cases are more likely to hypertension or aortic valve disease. The have comparable X and Y dips, giving a “W” or diVerence probably reflects the invasion of “M” contour, or even a dominant X descent, as atrial myocardium by fibrosis in constrictive in cardiac tamponade. Patients with restrictive pericarditis. Also, the raised atrial and ventricu- cardiomyopathy sometimes have waveforms lar diastolic pressure causes less stretch of atrial with conspicuous outward pulsations, caused myofibrils in constrictive pericarditis than in by large A waves, or obvious tricuspid regurgi- restrictive cardiomyopathy, because of the

tation, patterns not seen in constrictive pericar- external compression by the pericardium. on October 2, 2021 by guest. Protected copyright. ditis. Conduction defects, both atrioventricular Examination of the jugular venous pulse is and intraventricular, are more often features of not completely superseded by recording the restrictive cardiomyopathy than they are of atrial pressure waveforms at cardiac catheteri- constrictive pericarditis. Bundle branch block sation. The jugular veins exhibit dynamic occurs in perhaps 20–30% of patients with volume changes, which can be more conspicu- restrictive cardiomyopathy and is rare in ous than pressure changes in the relatively low constrictive pericarditis. Low voltage is not pressure atrial–venous system. critically helpful; it is less common in constrictive pericarditis than it is in cardiac tamponade, Early diastolic sounds and it does occur in some instances of restric- Extra heart sounds in the early diastolic filling tive cardiomyopathy, especially those with period occur in both constrictive pericarditis amyloid. Left ventricular hypertrophy, how- and in restrictive cardiomyopathy, but can be ever, would be an important factor favouring suspected of being one or the other of two types restrictive cardiomyopathy. Amyloid is notable by the practised auscultator. In restrictive for showing Q waves simulating infarct in some cardiomyopathy, especially when tricuspid re- cases, but this can also occur in constrictive gurgitation is prominent, an S3 frequently pericarditis, probably on the basis of fibrosis occurs, falling approximately 0.12–0.18 s after invading the myocardium. S2, and demonstrating a “thudding” low pitched character. Such sounds result in a “tri- Plain chest radiograph ple rhythm” eVect, that needs deciphering as to Pericardial calcification seen in the plain chest which members of the trio are S1, S2, and S3. radiograph is highly specific for constrictive In constrictive pericarditis an earlier filling pericarditis, in the context of a diVerential

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diagnosis between constrictive pericarditis and elevation of atrial pressure is present, but it is restrictive cardiomyopathy. Calcification is rare to see the major enlargement that is char- Heart: first published as 10.1136/heart.86.3.343 on 1 September 2001. Downloaded from usually absent in subacute constrictive pericar- acteristic of restrictive cardiomyopathy. Pres- ditis, and is therefore less frequent overall than ence of the constricting process around the it was in the past. However, it still occurs in atria appears to account for this diVerence. approximately a quarter of cases.13 It is unclear Thickening of the pericardium in the whether more sensitive methods, such as elec- echocardiogram is a second line feature in dif- 346 tron beam computed tomography (CT) or cine ferentiating constrictive pericarditis and re- fluoroscopy will show pericardial calcification strictive cardiomyopathy. The limited resolu- in a higher proportion of patients with tion of echocardiography lowers the specificity constrictive pericarditis, while retaining a simi- of this finding, although it is sometimes notable larly high specificity. in patients with constrictive pericarditis. Trans- oesophageal echocardiography gives better Echocardiographic imaging resolution than the conventional transthoracic Echocardiography will have been carried out study, but chest CT or magnetic resonance by the time that a diVerential diagnosis imaging (MRI) have better specificity. between constrictive pericarditis and restrictive cardiomyopathy is formulated, because the Doppler ultrasound studies problem applies only to patients who show Doppler ultrasonic studies for diVerentiating normal ventricular chamber dimensions and constrictive pericarditis and restrictive cardio- systolic wall motion. Three further clues from myopathy were introduced in the late 1980s standard echocardiography are particularly and have proven considerably valuable.14 15 In important. constrictive pericarditis there is an exaggerated variation in the velocity of early diastolic filling The septal notch of the two ventricles with respiration. The vari- In constrictive pericarditis the rate of filling is ation is reciprocal, the tricuspid velocity rapid in early diastole, and the rate of change in increasing in inspiration and the mitral velocity ventricular pressure at this time in the cycle is decreasing. The reciprocal ventricular variation particularly rapid. Slight asymmetry of right reflects ventricular interdependence, and oc- and left ventricular filling rate can result in curs to a much lesser degree in restrictive car- rapid changes in the pressure diVerential diomyopathy. It is usually prominent in sub- between the two sides of the ventricular acute constriction and less prominent or absent septum. The septum may therefore shift in in chronic (rigid shell) cases. It appears that in position very abruptly, responding to such the chronic (rigid shell) cases the variations in rapid changes in pressure. The abnormal septal intrathoracic pressure are not transmitted to motion may take several forms, and does not the interior of the heart. necessarily fit the definition of a “notch”. Further Doppler methods have been added, including the assessment of respiratory varia- Ventricular septal shift with respiration tion in pulmonary venous flow velocity, and the http://heart.bmj.com/ Reciprocal changes in left and right ventricular study of mitral annular movement (“tissue volumes with respiration are one aspect of the Doppler”).16 The place of the newer Doppler increased degree of ventricular interdepend- methods in diVerential diagnosis remains to be ence that is characteristic of constrictive determined. pericarditis. Because the heart is enclosed The sensitivity and specificity of the Doppler within a relatively fixed volume, enlargement of respiratory method may be as high as 85–90% one ventricle tends to be associated with a cor- in expert hands. However, the studies are diY-

responding decrease in volume of the other cult to carry out and to interpret. They should on October 2, 2021 by guest. Protected copyright. ventricle. This contrasts with the non- ideally incorporate a simultaneous graphic constricted heart, in which enlargement of one record of the phases of respiration. Irregular ventricle can be associated with a correspond- patterns of breathing, irregular cardiac rhythm, ing increase in volume of the two ventricles and short diastolic periods resulting from rapid combined. The volume of the right ventricle heart rate cause diYculty in interpretation. increases in inspiration, both normally and in Falsely positive results can be seen when constrictive pericarditis, as a result of lowered intrathoracic pressure variations are exagger- intrathoracic pressure drawing in a greater ated, as in asthma or chronic obstructive airway venous return. This aspect of ventricular inter- disease; in such conditions the flow velocity in dependence is best seen in the two dimensional the superior vena cava should be recorded, echocardiogram as a movement of the ven- because the superior vena cava has much larger tricular septum toward the left ventricle with respiratory variation in flow velocity with respi- inspiration and toward the right ventricle in ration in pulmonary disease than it does in expiration. either constrictive pericarditis or restrictive cardiomyopathy. Atrial enlargement Major enlargement of the right and left atrium Cardiac catheterisation is a hallmark of restrictive cardiomyopathy. Cardiac catheterisation studies have perhaps This occurs in response to pronounced chronic received too much emphasis in the diVerential elevation of atrial pressure, and is enhanced by diagnosis between constrictive pericarditis and mitral and tricuspid regurgitation. Some en- restrictive cardiomyopathy.17 Indeed, the diag- largement of the atria often occurs in constric- nostic dilemma may almost be defined as exist- tive pericarditis, in which the same sustained ing when the cardiac catheterisation results do

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not distinguish the two. However, a carefully systolic peaks above the top of the scale. Such conducted haemodynamic study is likely to recordings must minimise artefacts to be accu- Heart: first published as 10.1136/heart.86.3.343 on 1 September 2001. Downloaded from yield important clues. rately interpreted, and a graphic recording of respiration is also useful. Equilibration of diastolic pressures Nearly equal levels of diastolic pressure in all Paradoxical pulse chambers of the heart are a hallmark of Paradoxical pulse is not often mentioned as a constrictive pericarditis, and reflect the usually distinguishing feature between constrictive 347 symmetrical pathological process around the pericarditis and restrictive cardiomyopathy. entire heart. Somewhat greater elevation of Indeed, some authors state that paradoxical pressure on the left side than the right is more pulse is not a feature of uncomplicated characteristic of restrictive cardiomyopathy. constrictive pericarditis, and some state that it Comparison of instantaneous end diastolic does occur in restrictive cardiomyopathy. Both pressure in the two ventricles is perhaps the statements are doubtful. Paradoxical pulse is most critical way to evaluate this, but in indeed minimal or absent in the classic chronic practice a comparison of the mean pressures in (rigid shell) constrictive pericarditis that typi- the right atrium and the left atrium (or the pul- fied the condition in years past. In the subacute monary artery wedge position) may be more (elastic) cases that are more often seen reliable, because such recordings are less currently, a moderate paradoxical pulse is often subject to troublesome artefacts. A discrepancy present. This may occur with or without the of more than 5 mm Hg is very unusual in con- presence of some pericardial eVusion. The res- strictive pericarditis, but can be seen when the piratory variation is readily seen in direct arte- constriction is relatively or totally localised. rial pressure recordings during cardiac cath- The discrepancy is more than 5 mm Hg in eterisation, although it is not as pronounced as many cases with restrictive cardiomyopathy that typically seen in cardiac tamponade and is that otherwise resemble constrictive pericardi- often not readily detected by bedside examina- tis rather closely. tion. The respiratory variation in restrictive cardiomyopathy is rarely enough to raise a sus- Dip–plateau waveform picion of constrictive pericarditis, particularly The dip–plateau, or square root-like, waveform if cases of cor pulmonale are correctly recog- in the right ventricular pressure waveform is a nised. Since paradoxical pulse is an exagger- classic hallmark of constrictive pericarditis, but ated degree of a normal phenomenon, its defi- is also the feature of restrictive cardiomyopathy nition is arbitrary, and it should be treated as a that most commonly simulates constriction. continuous variable, not a categorical one. The dip–plateau is most prominent in chronic (rigid shell) cases, where there is initially no Magnetic resonance and computed limitation of filling and the ventricular diastolic tomographic imaging pressure approaches zero before beginning its CT and MRI of the thorax have been used rapid rise to the elevated plateau level. In the since the early 1980s as an improved method of http://heart.bmj.com/ subacute (elastic) constrictive cases, now more evaluating abnormal thickening of the pericar- common, there is some limitation of filling even dium. Most cases of constrictive pericarditis do in beginning diastole, and the nadir does not indeed show an apparent pericardial thickness approach zero. of 3 mm or more, at least in some areas.19 CT Commonly used catheters that are soft, small and MRI often appear to show only focal areas in calibre, and connected to the transducers by of pericardial thickening in cases where the long, fluid filled connectors produce distorted constriction is present around the entire heart.

waveforms in right ventricular pressure record- Surgeons often note variable degrees of peri- on October 2, 2021 by guest. Protected copyright. ings that obscure the diVerences in the cardial thickness in diVerent areas, that do not dip–plateau waveform that occur in constric- necessarily correspond to diVerences in the tive pericarditis and restrictive cardiomyopa- degree of constriction. It is perhaps insuY- thy. ciently realised, however, that some patients have constriction with relatively small degrees Discordant peak systolic pressure variation of thickening. The normal pericardium is less Another aspect of ventricular interdependence, than 1.0 mm thick; a considerable increase characteristic of constrictive pericarditis in may not exceed the threshold of abnormality in contrast to restrictive cardiomyopathy, is the a CT or MRI. Indeed, the constricting pericar- discordant variation of right and left ventricu- dium can be visually unimpressive, or even lar peak systolic pressure levels with respira- appear normal at ﬁrst glance to the surgeon at tion.18 In restrictive cardiomyopathy the two the time of operation. Some cases of occult pressures vary together, while in constrictive constriction appear to have anatomically nor- pericarditis they vary out-of-phase with one mal visceral and parietal pericardium. Thus, another. Right ventricular peak systolic pres- the principal limitation of CT and MRI is the sure rises with the onset of inspiration, while occurrence of falsely negative studies. In addi- the peak pressure falls in the left ventricle. This tion, the ﬁnding of thickened pericardium does is a simple observation to make during cardiac not necessarily indicate that constriction is catheterisation, but it may not be looked for, present. most frequently because there is an emphasis CT and MRI have approximately equal on assessing the similarity of diastolic pressures value in demonstrating thickening of the in the two ventricles and the pressure recorder pericardium. CT is therefore preferable in is set at a sensitive calibration that leaves the most cases, with MRI usually reserved for

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the use of speciﬁc technologies. A broad clini- Points frequently helpful in favouring cal viewpoint, in which the results of many Heart: first published as 10.1136/heart.86.3.343 on 1 September 2001. Downloaded from constrictive pericarditis over restrictive diagnostic methods are synthesised, is neces- cardiomyopathy sary to achieve the optimal diVerential diagnosis. x History—active pericarditis

Examination—Freidreich’s sign, 1. White PD. Chronic constrictive pericarditis (Pick’s 348 x disease) treated by pericardial resection. Lancet paradoxical pulse 1935;ii:539–48, 597–603. • St Cyres lecture, National Heart Hospital, London, 10 July 1935. Historical review and analysis of 15 cases operated x ECG—absence of intraventricular upon at the Massachusetts General Hospital since 1929, conduction defect defining the disease and its treatment for the English speaking countries. Notable for the great chronicity of the cases and the predominant presentation with ascites. x Chest radiograph—pericardial calcification 2. Wood P. Chronic constrictive pericarditis. Am J Cardiol 1961;7:48–61. x CT/MRI—thickened pericardium • Analysis of 40 patients, mostly tuberculous, emphasising clinical differences between active and inactive cases. Long list of features differentiating constrictive pericarditis x Echocardiogram—septal notch from restrictive cardiomyopathy, before the introduction of echocardiography, Doppler or CT/MRI. x Doppler—ventricular interdependence 3. Ling LH, Oh JK, Schaff HV, et al. Constrictive pericarditis in the modern era: evolving clinical spectrum and x Cardiac catheterisation—close impact on outcome after pericardiectomy. Circulation 1999;100:1380–6. equilibration of diastolic pressures • In 135 patients with constrictive pericarditis seen during 1985 to 1995, the aetiology was previous cardiac surgery x Biopsy—absence of amyloid or other in 18%, and radiotherapy in 13%. There was only one proven tuberculous case. Emphasises the role of older age infiltrative disease and radiotherapy aetiology in increasing operative mortality and reducing the quality of long term results. 4. Hancock EW. On the elastic and rigid forms of patients with an intolerance of iodinated constrictive pericarditis. Am Heart J 1980;100:917–23. contrast agent. CT is analogous to a single 5. Hancock EW. Subacute effusive-constrictive pericarditis. Circulation 1971;43:183–92. “snapshot”, while MRI represents the average 6. Bush CA, Stang JM, Wooley CF, et al. Occult of many heart beats, gated to the cardiac cycle; constrictive pericardial disease. Diagnosis by rapid volume for this reason, neither method is well adapted expansion and correction by pericardiectomy. Circulation to assessing the variations in chamber volumes 1977;56:924–30. 7. Hasuda T, Satoh T, Yamada N, et al. Acaseof with respiration. constrictive pericarditis with local thickening of the pericardium without manifest ventricular interdependence. Endomyocardial biopsy Cardiology 1999;92:214–6. Endomyocardial biopsy is a nearly certain 8. Sagrista-Sauleda J G, Permanyer-Miralda G, Caudell-Riera J, et al. Transient cardiac constriction: an method of diagnosing cardiac amyloidosis. unrecognized pattern of evolution in effusive acute idiopathic Therefore, the form of restrictive cardiomyopa- pericarditis. Am J Cardiol 1987;59:961–6. • In 16 of 177 patients with acute pericarditis with effusion, thy that is the most frequent simulator of con- signs of constriction developed in the next 5–30 days, but http://heart.bmj.com/ strictive pericarditis should be diagnosable resolved within the next few months. The constriction was mostly mild and detected only on careful clinical and without exploratory thoracotomy, if the diag- haemodynamic evaluation. nosis is considered as a possibility preopera- 9. Goodwin JF, Gordon H, Hollman A, et al. Clinical tively. Some other entities such as haemochro- aspects of cardiomyopathy. BMJ 1961;i:69–79. matosis and eosinophilic cardiomyopathy can 10. Shabetai R. Controversial issues in restrictive cardiomyopathy. Postgrad Med J 1992;68:S47–51. also be diagnosed at biopsy. Cases of idiopathic • Takes the viewpoint that the term “restrictive restrictive cardiomyopathy, however, have only cardiomyopathy” should apply only to cases that are indistinguishable from constrictive pericarditis by physical non-specific abnormalities in the endomyocar- examination, chest x ray, and cardiac catheterisation, and on October 2, 2021 by guest. Protected copyright. dial biopsy, and such abnormalities may also be advocates a major role for endomyocardial biopsy. found in some cases of essentially uncompli- 11. Kabbani S, LeWinter MN. Diastolic heart failure. Constrictive, restrictive, and pericardial. Cardiol Clin cated constrictive pericarditis. The biopsy is 2000;18:501–9. therefore helpful chiefly if it shows a specific 20 12. Ammash NM, Seward JB, Bailey KR, et al. Clinical infiltrative disease. profile and outcome of idiopathic restrictive cardiomyopathy. Circulation 2000;101:2490–6. 13. Ling LH, Oh JK, Breen JF, et al. Calcific constrictive Conclusions pericarditis: is it still with us? Ann Intern Med 2000;132:444–50. • 135 cases of constrictive pericarditis seen during 1985 to 1995 had calcification in 27% of cases. Calcification was Many new diagnostic methods have been related to chronicity, atrial enlargement, atrial arrhythmia, and higher operative mortality. Ultrafast CT showed introduced since the earliest proposals that calcification in only one of six patients who had no only exploratory thoracotomy will diVerentiate calcification in the plain chest radiograph. constrictive pericarditis and restrictive cardio- 14. Hatle L, Appleton C, Popp R. Differentiation of constrictive pericarditis and restrictive cardiomyopathy by myopathy in all cases. It seems that exploratory Doppler echocardiography. Circulation 1989;79:357–70. thoracotomy should be needed very rarely if • Echo Doppler studies in seven patients with constrictive pericarditis, all successfully operated, and 12 with ever in the current era. However, a major pitfall restrictive cardiomyopathy, all with either infiltrative disease is to expect that only one or two diagnostic or extensive myocardial fibrosis in the biopsy. Exaggerated changes in mitral flow velocity with inspiration–expiration methods can be regularly decisive in making separated constrictive pericarditis from restrictive the diVerential diagnosis. The apparent urge to cardiomyopathy. Variation in tricuspid flow velocity with inspiration–expiration overlapped in the two conditions, but rely on one or two methods, to the relative averaged greater in constrictive pericarditis. They also neglect of other methods, may be a disadvan- noted that the rise and fall in right and left ventricular systolic peaks with inspiration–expiration was out-of-phase tage resulting from the current tendency to in constrictive pericarditis, while they were in-phase in divide cardiology into subspecialities based on restrictive cardiomyopathy.

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15. Oh JK, Hatle L, Seward JB, et al. Diagnostic role of 18. Hurrell DG, Nishimura RA, Higano T, et al. Value of Doppler echocardiography in constrictive pericarditis. JAm dynamic respiratory changes in left and right ventricular

Coll Cardiol 1994;23:154–62. pressures for the diagnosis of constrictive pericarditis. Heart: first published as 10.1136/heart.86.3.343 on 1 September 2001. Downloaded from 16. Rajagopaian N, Garcia MJ, Rodriguez L, et al. Circulation 1996;93:2007–13. Comparison of new Doppler echocardiographic methods to • Catheter tip manometer recordings in 15 patients with differentiate constrictive pericardial heart disease and constrictive pericarditis and 21 with congestive heart restrictive cardiomyopathy. Am J Cardiol 2001;87:86–94. failure of other types, including seven with restrictive • Studies in 19 patients with constrictive pericarditis (12 cardiomyopathy. Discordant changes in right and left operated) and 11 with restrictive cardiomyopathy (8 ventricular peak systolic pressure in inspiration amyloid). All had pulsed wave Doppler of pulmonary veins separated constrictive pericarditis from the other and mitral valve with respiration, tissue Doppler of lateral cases. 349 mitral annulus, and colour M mode Doppler flow propagation of left ventricular filling. The two new methods 19. Breen JF. Imaging of the pericardium. J Thorac Imaging were about equal to the Doppler respiratory methods in 2001;16:47–54. differentiating the two conditions. They suggest that the new methods might be useful in cases where exaggerated 20. Schoenfeld M, Supple E, Dec W, et al. Restrictive respiratory variation may be absent in constrictive cardiomyopathy versus constrictive pericarditis: role of pericarditis (5/19 in this series). endomyocardial biopsy in avoiding unnecessary thoracotomy. Circulation 1987;75:1012–7. 17. Vaitkus PT, Kussmaul WG. Constrictive pericarditis • Analysis of 54 biopsies during 1975-85 in patients versus restrictive cardiomyopathy: a reappraisal and update of diagnostic criteria. Am Heart J 1991;122:1431–41. with congestive heart failure and constrictive/restrictive • Analysis of haemodynamic criteria in 82 cases of physiology, showing amyloid in 11. Fourteen cases constriction and 37 cases of restrictive cardiomyopathy in with constrictive pericarditis showed normal biopsy the literature, concluding that a quarter of cases would be in three patients, non-specific abnormality in nine, not be correctly classified by haemodynamic criteria. and myocarditis in two. They consider that biopsy is Suggests an algorithm including CT/MR imaging of the essential if thoracotomy for constriction is pericardium and endomyocardial biopsy. contemplated. http://heart.bmj.com/ on October 2, 2021 by guest. Protected copyright.