Table 3

Features useful in differentiating constrictive pericarditis from restrictive cardiomyopathy

Feature Constrictive pericarditis Restrictive cardiomyopathy
Past medical historyPrevious pericarditis, cardiac surgery, trauma, radiotherapy, connective tissue diseaseThese items rare
Jugular venous waveformX and Y dips brief and “flicking”, not conspicuous positive wavesX and Y dips less brief, may have conspicuous A wave or V wave
Extra sounds in diastoleEarly S3, high pitched “pericardial knock”. No S4Later S3, low pitched, “triple rhythm”. S4 in some cases
Mitral or tricuspid regurgitationUsually absentOften present
ECGP waves reflect intra-atrial conduction delay. Atrioventricular or intraventricular conduction defects rareP waves reflect right or left atrial hypertrophy or overload. Atrioventricular or intraventricular conduction defects not unusual
Plain chest radiographPericardial calcification in 20–30%Pericardial calcification rare
Ventricular septal movement in diastoleAbrupt septal movement (“notch”) in early diastole in most casesAbrupt septal movement in early diastole seen only occasionally
Ventricular septal movement with respirationNotable movement toward left ventricle in inspiration usually seenRelatively little movement toward left ventricle in most cases
Atrial enlargementSlight or moderate in most casesPronounced in most cases
Respiratory variation in mitral and tricuspid flow velocityGreater than 25% in most casesLess than 15% in most cases
Equilibration of diastolic pressures in all cardiac chambersWithin 5 mm Hg in nearly all cases, often essentially the sameWithin 5 mm Hg in a small proportion of cases
Dip–plateau waveform in the right ventricular pressure waveformEnd diastolic pressure more than one third of systolic pressure in many casesEnd diastolic pressure often less than one third of systolic pressure
Peak right ventricular systolic pressureNearly always less than 60 mm Hg, often less than 40 mm HgFrequently more than 40 and occasionally more than 60 mm Hg
Discordant respiratory variation of ventricular peak systolic pressuresRight and left ventricular peak systolic pressure variations are out-of-phaseRight and left ventricular peak systolic pressure variations are in-phase
Paradoxical pulseOften present to a moderate degreeRarely present
MR/CT imagingShows thick pericardium in most casesShows thick pericardium only rarely
Endomyocardial biopsyNormal, or non-specific abnormalitiesShows amyloid in some cases, rarely other specific infiltrative disease