Sonia Chang

Echocardiographic Features of Atrial Septal Defect

Echocardiographic studies were performed on 39 adult patients with atrial septal defects. Findings were compared with those from normal subjects, patients with other congenital left-to-right shunts (ventricular septal defect and patent ductus arteriosus), patients with uncomplicated right ventricular pressure overload (pulmonic stenosis and pulmonary hypertension), and patients with pulmonary hypertension complicated by tricuspid regurgitation. Two echocardiographic features were assessed: 1) a right ventricular dimension, or RVD Index, representing the distance between the right ventricular epicardial echoes and echoes from the right side of the interventricular septum divided by the patients body surface area, and 2) motion of the interventricular septum.The increased RVD Index and abnormal septal motion observed in the patients with atrial septal defects provided an ultrasound complex that could clearly separate these patients from normal individuals, those with ventricular septal defect and patent ductus arteriosus, and those with uncomplicated right ventricular pressure overload. However, patients with tricuspid regurgitation could not be differentiated from the group with atrial septal defects, indicating that this echocardiographic complex reflected a volume overload of the right ventricle.

Identification of Ultrasound Echoes from the Left Ventricle by Use of Intracardiac Injections of Indocyanine Green

This study was designed to identify the ultrasound echoes originating from the left ventricle. Injections of indocyanine green and saline were made directly in the left ventricular cavity via a cardiac catheter in patients undergoing routine diagnostic cardiac catheterization. The injections produced a cloud of echoes that filled the left ventricular cavity and outlined the left side of the interventricular septum and the endocardial surface of the posterior left ventricular wall. The results of this study verified the origin of echoes that are vital to the ultrasound technics for the detection of pericardial effusion, left ventricular wall size, left ventricular cavity size, and left ventricular stroke volume. This study also provided ways of distinguishing between the true left ventricular wall echoes and intracavitary echoes that often cause confusion.

Analysis of left ventricular wall motion by reflected ultrasound. Application to assessment of myocardial function.

Ultrasound echocardiograms from the septal and posterior left ventricular walls were displayed with a simultaneously recorded electrocardiogram, phonocardiogram, and indirect carotid pulse. These echoes differed in both amplitude and waveform. The contour of the posterior wall echo resembled an inverted ventricular volume curve, while the septal echo was of smaller amplitude and had a characteristic notched appearance. Most of the movement of the left ventricular walls relative to the ultrasound transducer was attributable to systolic contraction and diastolic expansion of the cavity. However, superimposed on this motion due to change in cavity size was movement of the left ventricle as a whole, first anteriorly toward the ultrasound transducer during late systole then posteriorly away from it at the beginning of left ventricular relaxation. These movements added to the amplitude of posterior wall motion but subtracted from the motion of the septum and were responsible for the notch in the waveform of this echo. Attachment superiorly to the aortic root might also have limited septal motion which was less near the base than nearer the apex of the left ventricle.The internal left ventricular dimension measured by ultrasound was standardized by using the mitral valve as a landmark and by recording the motion of the left side of the interventricular septum and endocardial surface of the posterior left ventricular wall simultaneously. This measurement was reproducible. In normal subjects, the ultrasonic dimension measured 4.40 ± 0.28 cm at the beginning of systole and shortened by 35.5 ± 3.9% at a rate of 1.22 ± 0.31 lengths/sec. By contrast, the average figures for six patients with primary myocardial disease were 6.96 ± 0.43 cm, 14.9 ± 4.2%, and 0.64 ± 0.11 lengths/sec. Calculation of such indices of left ventricular size and of rate and extent of myocardial shortening should be useful in the detection of impaired myocardial function and in following its progress.

Use of Echocardiography in Patients with Prolapsed Mitral Valve

The echocardiographic findings are described for five patients who had the prolapsed mitral valve syndrome, proven by cardiac catheterization and angiocardiography. In all five patients, the echocardiograms demonstrated posterior displacement of the posterior mitral leaflet during systole. In four of the patients there was also posterior displacement of the anterior leaflet. Four of the five patients had mitral insufficiency, demonstrated by cineangiography. These four patients demonstrated echocardiographic separation of the anterior and posterior leaflets of the mitral valve in late systole. The fifth patient did not show this separation, and she had no mitral insufficiency by selective cineangiography. Two patients were given amyl nitrite during the echocardiographic examination, and the echogram showed earlier separation of the anterior and posterior leaflets as well as lengthening of the murmur. Echocardiography should be a very useful noninvasive, yet direct, method for diagnosing, studying, and following patients with prolapse of the mitral valve.

Echocardiographic patterns of pulmonic valve motion with pulmonary hypertension.

Echocardiographic tracings of the pulmonic valve were examined in two groups of patients. The first group contained 24 normal patients. The second group consisted of 32 patients with pulmonary hypertension (mean pulmonary artery pressure ≥20 mm Hg). Parameters considered included presence or absence and depth of the “a’ wave, amplitude of valve opening (b-c separation), diastolic (e-f) slope, and presence or absence of mid-systolic closure or fluttering of the pulmonic leaflet. An “a’ wave was present in all 24 normal subjects. The “a’ wave varied with respiration and the maximum “a’ wave depth (A Max) averaged 3.7 ± 1.2 mm (mean ± SD, range 2-7 mm). A Max was ≥2 mm in all 24 normal patients. In 19 of 24 patients with pulmonary hypertension and sinus rhythm no “a’ wave was present. In the other five patients small “a’ waves (≤2 mm) occurred. In four of these five patients, right heart failure was present. The diastolic (e-f) slope averaged 36.9 ± 25.4 mm/sec (range 6-115 mm/sec) in normals. With pulmonary hypertension, this slope was significantly less than normal (average 5.2 ± 8.9 mm/sec, range −9 to +30 mm/sec, P < .001). In six patients with pulmonary hypertension a negative e-f slope was seen; this never occurred in normals. Mid-systolic closure or notching of the systolic (c-d) segment occurred in 18 of 20 subjects with pulmonary hypertension in whom the leaflet was clearly recorded in mid-systole. This finding was not observed in normals. Likewise, mid-systolic fluttering was present in 22 of 24 patients with pulmonary hypertension. There was no difference in amplitude of leaflet opening between the two groups.

Echocardiographic Manifestations of Left Bundle Branch Block

Seventeen patients with left bundle branch block were studied using standard echocardiographic techniques employing a strip chart recorder. All 17 patients were found to have specific echocardiographic findings of abnormal septal motion uniquely different from previously described forms found in volume overload states of the right ventricle as well as coronary artery disease. The specific echocardiographic abnormality demonstrated in left bundle branch block is a very dynamic posterior motion of the interventricular septum occurring within 0.04 seconds of the onset of the QRS and preceding the anterior motion of the posterior left ventricular wall during ventricular ejection. This type of septal motion is not seen in the other forms of abnormal septal motion and appears to be specific for left bundle branch block.

Detection of Left Ventricular Asynergy by Echocardiography

The purpose of this study was to determnie if echocardiography could detect left ventricular asynergy. Forty-eight patients underwent selective coronary arteriography and cineventriculography for the evaluation of chest pain. Four patients were studied twice: three before and after myocardial revascularization and one before and after an intervening myocardial infarction. Echocardiographic M-mode scans were registered on a strip chart as the left ventricle was scanned with an ultrasonic beam from the aortic root to the region of the posterior papillary muscle approximately 18 hrs prior to the catheterization studies.Ten of the forty-eight patients had no evidence of coronary artery disease. All ten patients had normal ventriculograms in right anterior oblique projection and their echocardiographic scans showed all areas of the left ventricular posterior wall endocardium to move anteriorly 0.9-1.4 cm (mean 1.2 cm) and all parts of the left side of the interventricular septum to move posteriorly 0.3-0.8 cm (mean 0.5 cm) during systole. The 38 patients with significant obstructive coronary artery disease had a total of 42 studies; 25 of these studies showed left ventricular asynergy on the ventriculogram taken in right anterior oblique. The echocardiograms associated with all but one of these studies demonstrating left ventricular asynergy had abnormal motion of some part of the interventricular septum and/or left ventricular posterior wall. Seventeen studies in patients with significant coronary artery disease did not exhibit left ventricular asynergy on the ventriculogram but eight of these studies were associated with distinctly abnormal echocardiograms.None of the ten patients with significant coronary artery disease and normal echocardiograms had evidence of transmural infarction on their electrocardiograms. Echocardiographic abnormalities correlated with the anatomic area predicted by the myocardial infarction pattern on the electrocardiogram in 18 of 20 patients.All patients demonstrating abnormal echographic interventricular septal motion had a significant obstructive lesion in the left anterior descending coronary artery. In the absence of significant involvement of the left anterior descending coronary artery, echographically recorded interventricular septal motion was invariably normal. On the other hand, eight patients had significant obstruction in their left anterior descending coronary artery and their echographic interventricular septal motion was normal.The results of this correlative study indicate that M-mode echocardiographic scans can detect left ventricular asynergy and may possibly predict regional myocardial involvement in coronary artery disease.

Abnormal Mitral Valve Motion in Patients with Elevated Left Ventricular Diastolic Pressures

In order to see whether or not the echocardiographically recorded mitral valve could reflect alterations in left ventricular pressure, simultaneous mitral valve echograms and left ventricular pressures were obtained on patients undergoing diagnostic cardiac catheterization. Attention was given to the left ventricular initial diastolic pressure (LVIDP), left ventricular end-diastolic pressure (LVEDP), and the atrial component of the left ventricular pressure (LVa). The echocardiographic measurements included the opening velocity of the mitral valve in early diastole (D-E slope) and the interval between the A point, which is the onset of closure of the mitral valve following atrial systole, and the C point, which represents closure of the mitral valve as indicated by the meeting of the anterior and posterior mitral leaflets. In order to compensate for variations in atrioventricular conduction, the A-C interval was subtracted from the electrocardiographic P-R interval. In 19 patients, the LVIDP was less than 14 mm Hg, the LVEDP was less than 20 mm Hg, and the LVa was less than 8 mm Hg. In these patients, the D-E slope was greater than 25 cm/sec and the PR-AC interval was greater than 0.06 sec. Six patients who had an LVIDP of 14 mm Hg or greater had a D-E slope of less than 25 cm/sec. There were 14 patients with an LVEDP greater than 20 mm Hg and an LVa of 8 mm Hg or greater. All of these patients had a PR-AC interval of less than 0.06 sec. There were an additional three patients who had an LVEDP above 20 mm Hg, but whose LVa was less than 8 mm Hg. In these three patients, the PR-AC interval was greater than 0.06 sec. Thus, the shortened PR-AC interval correlated primarily with an elevated LVa. This study indicates that the echocardiographic pattern of mitral valve motion is altered in patients who have markedly elevated left ventricular diastolic pressures.

Cross-sectional echocardiography in assessing the severity of valvular aortic stenosis.

Real-time, cross-sectional echocardiograms were recorded in 28 consecutive adult patients with valvular aortic stenosis using a high resolution, mechanical sector scanner. Using the cross-sectional technique, the aortic valve orifice diameter was recorded in each of the 28 patients. With M-mode echocardiographic examination of these same patients, this value could be estimated in only 21 of these 28 patients (75%). The maximum aortic valve diameter recorded during the cross-sectional study averaged 7.9 ± 1.8 mm (range 4-11 mm) in 15 patients with severe aortic stenosis; 11.6 ± 2.3 mm (range 9-15 mm) in five patients with moderate aortic stenosis; 16.9 ± 2.0 mm (range 14-20 mm) in eight patients with mild aortic stenosis; and 20.5 ± 2.8 mm (range 15-26 mm) in 25 patients with no evidence of aortic valve disease. Comparing the means of these groups yielded the following: severe vs moderate P < 0.005; moderate vs mild P < 0.001; and mild vs normal P < 0.001. Although there was some overlap between the individual groups, a clear separation existed between patients with severe and mild aortic stenosis. In addition, the group of patients in whom surgical intervention was recommended was also separated from the other subjects. When the aortic valve orifice was recorded using the M-mode technique, there was also a good correlation with the severity of the stenosis; however, the tendency of the M-mode study to overestimate severity in individual patients with calcific aortic stenosis and to underestimate severity in congenital aortic stenosis was again demonstrated. This study suggests that real-time, high resolution, cross-sectional echocardiography should be valuable in the noninvasive assessment of patients with aortic stenosis.

The posterior mitral valve echo and the echocardiographic diagnosis of mitral stenosis

Abstract The detection of mitral stenosis has been a classic application of echocardiography. The technique utilizes the recording of an echo from the anterior leaflet of the mitral valve. A reduced diastolic slope is the principal criterion for the diagnosis of mitral stenosis. Several investigators have noted that a similar pattern of mitral valve motion can occur in patients without mitral stenosis. This study shows how the recording of the posterior leaflet of the mitral valve can help alleviate this confusion. Anterior and posterior mitral valve echograms were obtained in normal subjects, patients with mitral stenosis proved at cardiac catheterization, and patients with abnormal anterior mitral valve motion but no evidence of mitral stenosis at catheterization. The results demonstrate that in normal persons the posterior and anterior leaflets move in virtually opposite directions. In patients with true mitral stenosis the leaflets move in essentially the same direction but to a different degree. In patients with an abnormal diastolic mitral valve motion, possibly due to reduced rates of left ventricular filling, the posterior leaflet moves in a direction opposite to that of the anterior leaflet. Thus, this study can clearly distinguish these patients from those with true mitral stenosis.