Echocardiographic features of the interventricular septal motion in constrictive pericarditisAV Katdare, AS Vengsarkar, KG Nair
Department of Cardiology, K.E.M Hospital, Parel, Bombay 400012, India
Echocardiographic features of interventricular septum were studied in four patients with constrictive pericarditis. The systolic motion was normal in one patient and paradoxic in the other three. All four patients had an abrupt anterior motion which was followed by a sudden brisk posterior motion immediately in early diastole, following the diastolic dip of the septum. This motion was coincident with the `y' trough of the jugular venous pulse. The septal thickening values were within normal range.
Though the usefulness of ultrasound in the diagnosis of pericardial effusion was mentioned by Edler in 1955, and has now become a routine non-invasive procedure for the same, its application in chronic constrictive pericarditis is attracting attention of the investigators only lately. There are many reports which state the importance of pericardial thickness, ,  premature opening of the pulmonary 'valve, , and left ventricular endocardial Motion , . In the diagnosis of chronic constrictive pericarditis. Recent reports of Gibson,  Pool  and Candell Riera  have emphasized constancy of the abnormal motion of interventricular septum in chronic constrictive pericarditis (C.P.).
The present study is being done to analyze the peculiarities of interventricular septal motion in C.P. and it is intended as a preliminary study.
Four patients of C.P. admitted to the department of Cardiology, K.E.M. Hospital form the basis of this report. All these cases were diagnosed as C.P. after fulfilling the clinical criteria  and confirmed by cardiac catheterization. Genesis of C.P. in all the patients was tubercular infection. Each patient was in sinus rhythm and one had paradoxical pulse. The jugular venous pulse demonstrated prominent x and y descent and right ventricular pressure showed an early diastolic dip.  Three patients had pericardia knock. None of them had any other cardiac lesion.
Echocardiographic examination was performed with a Unirad 100 echocardiograph and record was obtained on an ultraviolet ray sensitive paper by a Honey well 1858 strip chart recorder. A focussed Unirad transducer with a focal length of 4 to 7 cms and frequency of 2.25 mHz was placed in the third or fourth left intercostal space close to the sternal border and perpendicular to the chest. The interventricular septum was recorded at the chordal level. The jugular venous trace was obtained by a Hewlett-Pacard transducer No. 21051 D.
The echocardiograms were analyzed for the following things.
(1) Septal thickening (ST)
The interventricular septal thickness was measured at end-diastole (ED) (at the Q wave of the ECG) and at end-systole (ES) (at the maximum anterior motion of the left ventricular endocardium). The ST was calculated by the formula :
ES-ED/ED, The normal limit is >0.25. 
(2) Interventricular Septal Systolic Motion (IVSSM).
When septum moved normally the displacement of the left septum was measured. When motion was less than 3 mm. the septum was considered hypokinetic; anterior systolic motion was labelled as paradoxic.
(3) Interventricular Septal Diastolic Motion (IVSDM)
The details of the motion during diastole after ES were analyzed.
[Table 1] gives the hemodynamic data on all four cases. In all, the typical findings were, equally elevated right ventricular diastolic pressure, mean pulmonary artery wedge and mean right atrial pressure.
Echocardiographic features are given in [Table 2].
(A) Septal thickening: (ST)
The IVS thickness at ED varied from 8 to 12 mm. (mean 10.0 mm) and at ES from 10 to 15 mm (mean 12.75 _mm). The ST varied from 0.22 to 0.36 (mean 0.27).
This motion was paradoxic in three cases and normal in one.
(C) Interventricular septal diastolic motion (IVSDM)
This motion was abnormal in all the four patients. This motion consisted of brisk movement of the left septum anteriorly following diastolic dip. This movement was followed by an equally brisk posterior movement. Its peak coincided with `y' trough of the jugular venous pulse.
Abnormality of the valve structure or motion was not recorded in any patient.
Despite documentation of various signs, ,,, no consistently useful echocardiographic sign has been evolved so far in the diagnosis of constrictive pericarditis (See [Figure 1] on page 218 A).
However the most consistent sign in our study (See [Figure 1] on page ) was related to the anterior motion of the left side of the IVS which immediately followed the septal diastolic dip. This movement was immediately reversed and the left side of the IVS moved posteriorly and then remained flat. The apex of this movement coincided with the `y' trough of the jugular venous pulse. This finding has been recorded in all of their eight eases by Candeil-Riera et al  in a recent paper.
In the present study three cases had paradoxic motion in systole. This has been reported and stressed as a sign of C.P. by Pool et al  Gibson, et al  and Feigenbaum.  It is seen in many other conditions and thus lacks specificity.
The foremost effect of the constrictive pericarditis is reduction in the ventricular and pericardial compliance. Hence ventricular filling is impaired and stroke volume is reduced. Ventricular filling is rapid for a brief period in early diastole. As -the ventricular distensibility is limited right ventricular pressure tracing shows an early diastolic dip followed by a high diastolic plateau , This early diastolic dip is reflected in the rapid `y' trough of the jugular venous pulse. The abnormal diastolic movement of the IVS reported in this study occurs at the time of inscription of the `y' descent. Though the cause for this anterior motion is not clear it is possible that the compromised left ventricle accepts this sudden entry of blood at the expense of septum which moves anteriorly.
Another feature was seen in diastolic motion of the left side of the septum. It suddenly moved downwards producing a hump, at the time of the `a' wave of the anterior mitral leaflet. This coincided with the P wave of the electrocardiogram. Immediately after this the motion was anterior in systole in three cases. This feature has been demonstrated by Feigenbaum  According to him this abnormal anterior motion occurred well before the onset of ventricular depolarization. We found that this anterior movement clearly starts with the ventricular depolarization and actually ushers the systolic paradoxic motion (See [Figure 2] on page 218 A).
Septal thickening was found to be normal in three cases and slightly below normal in one case; similar findings have been reported by Popp.  On the contrary Gibson  and Candell-Riera  have decumented values below normal. Low va lues have been reported in cardiomyopathies and coronary artery disease. 
The peculiar IVSDM appears to be a fairly consistent findings in C.P. Though C.P. presents a characteristic hemodynamic data, many times it is difficuit to differentiate it from restrictive cardiomyopathy where IVSDM is reported to be absent. It is noteworthy that this IVSDM was absent in a case of endomyocardial fibrosis (See [Figure 3] on page 218 A), studied along with these cases.
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2]