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Pulmonary valve echocardiography SG KarmarkarDepartment of Cardiology, Seth G. S. Medical College and K. E. M. Hospital, Parel, Bombay-400 012, India
Correspondence Address: Source of Support: None, Conflict of Interest: None PMID: 529181
Pulmonary valve echocardiography has been done in 11 cases of pulmonary hypertension, and 4 cases of right ventricular outflow tract obstruction, either at valvar, infundibular or combined level.
Methods of detection of pulmonary valve have already been described. [1] Normal pulmonary valve echogram is illustrated in [Figure 1] (see on page 218 B). The purpose of this study is to establish the usefulness of the echo pattern of pulmonary valve in the diagnosis of pulmonary hypertension and pulmonary stenosis.
Clinical material consisted of 15 patients in whom pulmonic valve was recorded by echocardiography prior to cardiac catheterization. There were 11 males and 4 females. Their ages ranged from 4 to 48 years, the average age being 19 years. There were 11 cases of pulmonary hypertension and 4 cases of pulmonary stenosis. The 11 cases of pulmonary hypertension were of diverse etiology [Table 1]. All patients in this group except one had mean pulmonary artery pressure above 40 mm Hg. Atrial fibrillation was present in one case. Out of four cases of pulmonary stenosis, one had infundibular-valvar stenosis, one case had isolated infundibular stenosis. The third patient was a case of infundibular stenosis and ventricular septal defect and the last patient was a case of valvar and infundibular pulmonary stenosis with ventricular septal defect. Two of these four cases had severe outflow obstruction (gradient > 100 mm Hg.) and the remaining two had moderate obstruction (gradient 50 to 100 mm Hg.). Echocardiographic examination was performed with a Unirad Sonograph with a Honeywell Fibreoptic model 1858, strip chart recorder. A 2.25 mHz transducer with 10 mm. outer diameter focussed at 7.5 cms. was used. The method already in use for recording pulmonary valve was followed.' All tracings were initially recorded at a paper speed of 25 mm/sec. followed by 100 mm/sec.
Pulmonary Hypertension: (1) `a' wave: Sinus rhythm was present in ten out of eleven cases. In these ten patients mean Amax was 1.2 mm. (0-5 mm); `a' wave was absent in six of these ten patients. In two cases it was 5 mm., in one 3 mm. and in the remaining patient it was 1 mm. It was observed that patients with diastolic gradient of more than 25 mm. across the pulmonary valve had `a' wave less than 1 mm (See [Figure 2] below). (2) be Slope (rate of systolic opening). This rate of systolic opening of pulmonary, valve ranged from 342-586 mm/sec. with .- a mean of 443 mm/sec. It was observed that all the eleven patients had increased `be' slope (See [Figure 3] on page 221). (1) be Amplitude (systolic opening amplitude). The mean amplitude of leaflet opening was 15.5mm . with a range of 12-17 mm. There was no correlation between the mean pulmonary artery pressure and the leaflet opening amplitude. (2) Midsystolic closure and fluttering: Midsystolic closure (See [Figure 4] on page 218 B) was present in 3 out of 11 cases of pulmonary hypertension. In all these 3 cases, mean pulmonary artery pressure was above 65 mm Hg. Two of these three patients also showed 'cd' segment fluttering. Three more patients showed 'cd' segment fluttering in whom the mean pulmonary artery pressure was > 50 mm Hg. (3) Right ventricular performance (RPEP : RVET) The ratio of RPEP and RVET which reflects the right ventricular performance was 0.21 (mean) with a range from 0.14 to 0.30. (4) of Slope: - There was no relationship between the 'ef' slope and the mean pulmonary artery `pressure. Pulmonary Stenosis: In the patient with both valvular and infudibular stenosis (B.D.) Amax was 7 mm with no systolic opening as the valve was wide open at the beginning of systole. Hence it has demonstrated premature diastolic opening (See [Figure 5] on page 218 B). It also showed coarse `cd' segment fluttering. Gradient across the pulmonary valve in this case was 200 mm Hg. The second patient (V.K.) with isolated infundibular pulmonary stenosis and a gradient across the outflow tract of 70 mm Hg. had Amax of 4 mm. and the `b' point returned to the base lane before inscribing the `be' slope. There was no 'cd' segment flutter. An eleven year old boy (R.N.) having infundibular stenosis and ventricular septal defect had gradient across the outflow tract of 75 mm Hg. Amax in this patient was 7 mm. and `b' point returned to semiclosed position. The `be' amplitude was 3 mm. and there was no 'cd' segment fluttering. The last patient (G.G.) with valvar and infundibular pulmonary stenosis and ventricular septal defect had gradient across the outflow tract of 190 mm Hg. Amax in this patient was 5 mm. The `b' point returned back to semiclosed position with 'be' amplitude of 3 mm. There was no `cd' segment fluttering.
Pulmonary Hypertension: `a' wave of the pulmonary valve echogram represents a movement of the valve cusps towards open position and it is as a response to the low pressure events in the right ventricle associated with atrial systole. in In pulmonary hypertension the inc - .eased pulmonary artery pressure results in pulmonary valve opening in a relatively high portion of the right ventricular pressure curve where the pressure is rising rapidly. This probably explains the accelerated opening rate of the pulmonary valve observed in all our patients. Similar finding have already been reported . [3] It has been observed in this series that the diastolic position of the pulmonary valve i.e. 'ef' slope although useful in identifying pulmonary hypertension, does not help in evaluating its severity. Two of our patents showed a negative [5] 'ef' slope, six patients had flat [5] `ef' slope and the remaining three had normal [5] 'ef' slope though they had moderately severe pulmonary hyprtension. It is therefore observed that flat or negative 'ef' slope could be a good predictor of pulmonary hypertension. The same view has been shared by other investigators. [3],[5] Mid-systolic closure and fluttering was observed by Weyman et al [5] in 22 out of 24 patients with pulmonary hypertension. We have observed this finding in only 3 out of 11 patients. The reason for this midsystolic phenomenon might be a decrease of pulmonary blood flow in pulmonary hypertension which allows early closure of the leaflets. [5] Pulmonary artery dilatation which occurs in pulmonary hypertension permits the fully open leaflets to remain in the turbulant stream of blood and this may be the explanation for midsystolic fluttering observed in cases of pulmonary hypertension. [5] The amplitude of valve opening movement (bc slope) was found to be least useful criterion in separating pulmonary hypertensive from a normotensive patient. This view has also been shared by previous authors. [3] The ratio of RPFP and RVET which reflects the right ventricular performance was not found to be increased by us, as reported previously. [2] Pulmonary Stenonsis This group with right ventricular outflow obstruction is indeed limited, but all the echographs were studied in retrospect after the correlates in surgery and angiography were obtained. First patient with valvar and infundibular stenosis with right ventricular pressure of 250/0 mm Hg. and main pulmonary artery pressure of 50/10 mm Hg. had Amax of 7 mm. with no change in 'a' wave depth with respiration. Right atrial `a' wave was 9 mm Hg. Interestingly the valve had been wide open before the onset of, ventricular systole. This phenomenon of presystolic opening of the pulmonary valve though commonly found in severe pulmonary stenosis is not specific for the same. Its presence depend upon the relative pressures existing across the pulmonary valve after atria contraction, and upon an increase in the right ventricular end-diastolic pressure in the presence of normal or low pulmonary artery pressure. Similar findings have been reported in rupture of the sinus of valsalva aneurysm into right atrium [6] and Loeffler's endocarditis with tricuspid in sufficiency. [4] Systolic fluttering of the pulmonary valve was observed in the same patient. This finding has been known to be associated with pure infundibular stenosis and said to differentiate it from isolated valvar stenosis; [7] it was absent in the patient with isolated infundibular stenosis in this series. The sign is less useful in combined valvar and infundibular stenosis when its occurrence is variable. Systolic fluttering of the pulmonary valve was also observed in this series (See [Figure 6] on page 218'B) in a case of large isolated subaortic membranous ventricular septal defect with left to right shunt and no gradient across the pulmonary valve. Two patients with ventricular septal defect, associated with infundibular stenosis and combined valvar infundibular stenosis had no echographic features suggestive of either valvar or infundibular pulmonary stenosis
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]
[Table 1]
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