British Heart Journal, 1976, 38, 47-50.

Systolic time intervals in the differential diagnosis of constrictive pericarditis and cardiomyopathy J. C. Ghose, S. K. Mitra, and M. K. Chhetri From the Department of Cardiology, Institute of Postgraduate Medical Education and Research, Calcutta, India

Systolic time intervals (STI) were measured from simultaneously recorded phonocardiograms, carotid pulse tracings, and electrocardiograms in 11 patients with constnrctive pericarditis and in 10 patients with cardiomyopathy to assess the value of STI in the differential diagnosis of the two conditions. The predicted ejection fraction was calculated from the STI. The results were compared and found significantly different in the two groups of patients. The ratio PEP/L VET and the ejection fraction were found to have greater discriminatory values and separated the two groups clearly. Measurement of STI, a simple, noninvasive bedside technique, appears to be useful in distinguishing between constrictive pericarditis and cardiomyopathy. Clinical differentiation between constrictive peri- with cardiomyopathy with typical clinical and haemocarditis and cardiomyopathy, particularly the con- dynamic features. Fig. 1 shows the method of measuring the STI strictive or the restrictive variety, is often difficult Even sophisticated procedures like cardiac cathe- simultaneously from a phonocardiogram, carotid pulse and electrocardiogramrecorder recorded on a Gallileo terization and angiocardiography may not yield a tracing, at a paper speed of 100 mm/s. Adirect-writing crystal microphone for recording the definite diagnosis andexploration surgical exploration is some- three-channel, times necessary. Measurement of systolic time heart sounds was placed at a site over the praecordium intervals (STI) is a simple, noninvasive bedside which prior auscultation had shown to be the best for technique for assessing the left ventricular per- recording the aortic component of the second heart formance. In myocardial dysfunction such as in cardios 2 2 myopathy there is reduced myocardial contractile PHONO m.. performance leading to a decrease in the maximal rate of rise in isovolumetric pressure which reA2 sults in prolongation of the pre-ejection period ' (PEP) and a reduced rate of myocardial fibre shortening and thus a decrease in stroke volume and ejection fraction. In constrictive pericarditis, on CAROTID the other hand, the basic problem is one of impaired filling rather than of emptying, with normal C or near normal systolic contraction and ejection LVET fraction. This basic physiological difference prompted us to study the STI in these two disorders to assess their value in differential diagnosis.

definiter diagnosisiandzsurgical andsome-

Patients and methods Studies were made in 11 patients with chronic constrictive pericarditis, proved by cardiac catheterization and surgery in all but two patients, and in 10 patients Received 21 April 1975.

ECGc FIG. 1 Measurement of systolic time intervals from simultaneous phonocardiagram, carotid pulse tracing

and electrocardiogram.

48 Ghose, Mitra, and Chhetri regression equation of Garrard, Weissler, and Dodge

200

a O

o

180

(1970). Routine right and left heart catheterization

a CM ° CP

were

performed in all the patients.

0 0

E160 8 14 0

o

0

Results The haemodynamic findings in the 11 cases of constrictive pericarditis are shown in Table 1. The cardiac index was normal, with low stroke volume and stroke work, in most of the patients. The left

*

* .

140

120

.

.

*

ventricular and right ventricular end-diastolic

.

100

340 360 380 400 420 LVETc (ms)

440 460

FIG. 2 Relation between pre-ejection period (PEPc)

pressures were raised and nearly equal with a diastolic plateau. The haemodynamic findings in the 10 cases of cardiomyopathy (Table 2) show a low or low normal

cardiac index, low stroke volume and stroke work,

and left ventricular ejection time (LVETc) in constrictive pericarditis and cardiomyopathy. sound. The right carotid arterial pulse was recorded with a funnel-shaped pick-up attached by a polyethylene tubing to a piezo-electric crystal microphone. The electrocardiographic lead, usually lead II, that clearly showed the Q wave was selected. The time intervals were calculated as the mean value from at least 10 cardiac cycles. Left ventricular ejection time (LVET) was measured from the onset of the carotid upstroke to the incisura of the dicrotic notch. Pre-ejection period (PEP) was measured indirectly by subtracting left ventricular ejection time from the total electromechanical systole (Q-A2): thus PEP=QA2-LVET. The measurements of PEP and LVET were corrected for heart rate and sex by using the regression equation of Weissler, Harris, and Schoenfeld (1968). PEP/LVET ratio was calculated which was not significantly influenced by heart rate and sex. The predicted ejection fraction (EF) was calculated from the systolic time intervals by the

08 0-7

0>6 .

0

\

5

04. 03 o CM

*u

CYCP

0-2 01 c

\

0:1 0-2 0*3 PEP/LVET

0'4 0.5

0-6 0.7 0-8 0(9

FIG. 3 Relation between PEP/LVET ratio and

ejection fraction (EF) in constrictive pericarditis and

cardiomyopathy. TABLE 1 Haemodynamic findings in 11 patients with constrictive pericarditis Case No. 1 2 3 4 5 6 7 8 9 10 11

Age (years) 18 17 12 12 26 59 25 17 30 15 35

CI

SV

(llminperm2) (ml/beat) 2-6 3-0

3-2 3-8 2-0

3-0 4.5

3-0 4-6 3.7

2-1

27 34 21 30 23 68 59 53 60 35 28

MPAP RVEDP MRAP LVSW LVEDP PCWP (mm Hg) (mm Hg) (mm Hg) (mm Hg) (mm Hg) (g-m) 33 25 25 25 35 20 22 27 28 25

30 24 22 19 22 18 25 21 28 24 25

35 27 28 19 31 33 22 30 36 31 30

CI=cardiac index; SV=stroke volume; LVEDP=left ventricular end-diastolic pressure; PCWP=pulmonary capillary wedge pressure; MPAP=mean pulmonary artery pressure;

RVEDP=right ventricular end-diastolic pressure; MRAP=mean right atrial pressure; LVSW=left ventricular stroke work. Conversion from Traditional Units to SI Units: Imm Hg s 0.133 kPa.

33 25 22 19 20 20 20 27 28 25 30

28 17 20 15 22 14 19 16 21 21 25

18-3 24-0 27-1 21.2 14-0 61.9 53-7

46-8 46*5 29-9 -

Constrictive pericarditis and cardiomyopathy 49 TABLE 2 Haemodynamic findings in 10 patients with cardiomyopathy Case No. 1 2 3 4 5 6 7 8 9 10

Age (years)

(I/minperM2) (mllbeat)

LVEDP PCWP MPAP (mm Hg) (mm Hg) (mm Hg)

35 32 16 11 30 15 30 23 30 30

2-4 1-5 2-3 30 1-5 1-7 2-2 1-8 3-3 3-4

5 15 10 15 35 25 28 30 12 15

CI

SV 42 30 45 30 20 24 40 24 50 64

7 15 10 12 25 25 30 18 10 16

16 29 14 30 34 24 34 36 19 30

RVEDP (mm Hg)

MRAP (mm Hg)

LVSW (g-m)

2 12 8 17 20 23 25 18 2 5

7 7 6 8 12 18 27 13 2 3

42-2 29-0 42-3 29-3 13-6 21*2 46-7 17-6 51-0 47-8

Conversion from Traditional Units to SI Units: 1mm Hg P 0.133 kPa.

400 and a raised or normal left ventricular end-diastolic ± 17 365 pressure. 400 ±14 The relation between the corrected PEP (PEPc) and corrected LVET (LVETc) in the two groups 350 of patients is shown in Fig. 2. The PEPc in 300 X patients with cardiomyopathy was greater than 160 m/s and the LVETc less than 380 m/s, while the PEPc in patients with constrictive pericarditis E250 was less than 160 m/s and the LVETc greater than -E 200 380 m/s. There was only a slight overlap between Lu the two groups. The relation between the PEP/ > 150, LVET ratio and the predicted EF is shown in 100 Fig. 3. Again there is a clear discrimination between the two groups of patients. The PEP/LVET X 50 ratio of 0-5 and the EF of 0-5 are the dividing lines.0 CP CM Statistical analysis of the haemodynamic findings P'0.001 (Figs. 4, 5, 6, and 7) shows highly significant differences between the two groups of patients. FIG. 5 Statistical analysis of the results of LVETc in constrictive pericarditis and cardiomyopathy. 200 180 160

168 ±13 -

136 ±16 p

140

1I20-

062 ±0-08

08 07

0-6

0O41 ~.0 5 ±0.07

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