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Biomedical subjects

J C Dillon

Publications and source records attributed to J C Dillon.

At least 91 records · Page 5Linked to original sources

Pseudo-tricuspid stenosis: a rare entity.

A case is presented in which features of constrictive pericarditis and a pericardial pseudotumor coexisted. Preoperative cardiac catheterization revealed a gradient across the tricuspid valve. Exploratory surgery revealed a blood-filled cavity within the thickened pericardium overlying the right atrium and right ventricle and a normal tricuspid valve. After pericardiectomy, right cardiac catheterization revealed normal pressures and no gradients.

Fibroma↗

Echocardiography in bacterial endocarditis.

We examined 129 standard M-mode echocardiograms obtained in 65 patients (16 to 73 years old) with bacterial endocarditis. Twenty of the 22 patients with vegetations recognizable by echocargiography died, or underwent cardiac operation (mean interval from admission 22 days, and range two to 120 days). Vegetations were seen on the echocardiograms in 22 (aortic 10, mitral nine and tricuspid three, with anatomic confirmation in 19). Of patients without vegetations on echocardiography none underwent emergency operation or died as a result of cardiac disease (mean follow-up period of 14 months, range of two to 38 months). Other echocardiographic findings in those with vegetations included early mitral-valve closure (six), "flail" aortic leaflet (three), and "flail" mitral leaflet (three). Echocardiography can provide a rapid, reliable noninvasive diagnosis of bacterial vegetations in certain patients with bacterial endocarditis and may identify patients with more severe disease who may require operative intervention.

Adolescent↗

Cross-sectional echocardiography in evaluating patients with discrete subaortic stenosis.

Ten patients with discrete subvalvular aortic stenosis were examined using a real time, high resolution cross-sectional echocardiographic scanner. There were two patients (Group I) with a thin discrete subvalvular membrane, five (Group II) with a more extensive area of subvalvular narrowing and three with a residual area of outflow tract obstruction after surgical revision (Group III). In patients with a thin obstructing membrane (Group I), two distinct linear echoes were observed in the outflow tract. These echoes were not continuous with the walls of the outflow tract and showed some dynamic motion during the cardiac cycle. In four of the five patients with diffuse outflow tract narrowing (Group II), a relatively extensive area of inward bowing of both the anterior and posterior margins of the outflow tract was noted. In the fifth case, there was a prominent localized shelf-like increase in thickness of the basal portion of the muscular septum with a corresponding echo projecting anteriorly from the mid-portion of the anterior or mitral leaflet. The three cases examined after surgical revision of the outflow tract (Group III), had different patterns of outflow tract narrowing, but narrowing was clearly demonstrated. This study suggests that cross-sectional echocardiography offers an alternative and probably improved method for the noninvasive visualization of the left ventricular outflow tract.

Adolescent↗

Role of echocardiography in patients with coronary artery disease.

Impaired left ventricular performance, one of the hallmarks of coronary artery disease, can be detected by echocardiography in various ways. One of these approaches is the recording of abnormal wall motion. Because of the way in which the left ventricle can be examined echocardiographically, this technique has the capability of detecting regional wall abnormalities. In fact echocardiography is probably the most sensitive technique available, including even contrast ventriculography, for the detection of akinetic, hypokinetic or dyskinetic wall segments. With increasing experience it is apparent that more areas of the left ventricle can be examined echocardiographically than had previously been thought possible. Newer techniques include directing the ultrasonic beam not only through the body of the left ventricle but also toward the apical portion of the ventricle near the vicinity of the papillary muscles. In addition the true anterior left ventricular wall can be examined by moving the transducer laterally away from the left sternal border. Yet another approach utilizes a subxiphoid position for the transducer while the ultrasonic beam is directed through the medial portion of the septum and posterolateral wall of the left ventricle. M-mode scanning techniques together with recently developed cross-sectional echocardiographic instruments give great promise of improved detection of abnormalities of ventricular shape, especially the presence of aneurysms. The cross-sectional approach makes it possible to examine the left ventricular apex, an area virtually impossible to record with M-mode echocardiography. Recording of left ventricular dimensions and abnormal mitral valve motion may help in assessing overall left ventricular performance. A dilated left ventricular dimension in the vicinity of the mitral valve seems to be an ominous finding both in patients with acute myocardial infarction and in patients with chronic coronary disease being considered for possible surgery. Another echocardiographic sign of abnormal ventricular performance is altered closure of the mitral valve, which reflects a significantly elevated left ventricular diastolic pressure. These echocardiographic techniques are still in the investigational stages and are more technically difficult than the usual echocardiographic applications. However, the preliminary data are encouraging and make us hopeful that echocardiography will prove to be an important tool in the overall evaluation of the left ventricle in patients with coronary artery disease.

Coronary Disease↗

Localization of left ventricular outflow obstruction by cross-sectional echocardiography.

Cross-sectional echocardiographic studies were performed using a high resolution real time mechanical sector scanner in 70 patients with left ventricular outflow obstruction. Seven separate obstructive patterns were recorded in these patients. An area of aortic narrowing just distal to the aortic valve at the superior border of the left atrium was noted with supravalvular aortic stenosis. With congenital valvular aortic stenosis there was an increase in echo production by the thickened aortic leaflets. During systole these prominent leaflet echoes curved inward toward the center of the aortic root reflecting the systolic doming of the valve. With calcific aortic stenosis, the calcification produced an area of dense linear echoes attached in varying degrees to either the anterior or posterior border of the aortic root. At the subvalvular level three obstructive patterns were recorded; with a discrete subvalvular obstructive membrane two linear echoes apparently produced by the inner margins of the obstructing membrane were recorded in the outflow tract. With more extensive fibromuscular narrowing of the subvalvular area, there was inward bowing of the echoes from both the anterior and posterior walls of the outflow tract. In one case this was a dense shelf-like mass of echoes extending downward from the basal portion of the interventricular septum toward the mid-portion of the anterior mitral leaflet with corresponding systolic anterior motion of the mitral leaflet. In patients with idiopathic hypertrophic subaortic stenosis there was systolic anterior motion of the anterior mitral leaflet beginning just distal to the point of coaptation of the mitral leaflets and extending distally toward the papillary muscles. This report suggests that the enlarged field of vision and spatial orientation provided by the cross-sectional echocardiographic technic should improve our ability to record and characterize areas of obstruction to left ventricular outflow.

Aortic Stenosis, Subvalvular↗

The effect of nitroglycerin upon pulmonary and left atrial pressures in patients with mitral stenosis.

In all nine patients studied with mitral stenosis and no evidence of left ventricular failure, nitroglycerin caused a decrease in pulmonary arterial, left atrial, and left ventricular pressures and pulmonary vascular resistance. The decrease in left atrial pressure was attributable to the combination of a reduction in left ventricular filling pressure and a reduction in mitral valve gradient. While there was no significant mean change in heart rate, cardiac index, or mitral valve flow, there was a significant correlation between a decrease in each of these determinants of mitral valve gradient and the observed decline in left atrial pressure in individual patients. However, even those patients who had an increase in heart rate or cardiac output, either of which normally aggravates pulmonary congestion in mitral stenosis, had a decrease in their pulmonary and left atrial pressures in response to TNG. It is likely that nitroglycerin reduced pulmonary and left atrial pressures by either (1) systemic venous dilatation, causing a reduction in right heart filling and pulmonary blood volume, or (2) pulmonary arteriolar and venous dilatation, causing a decrease in pulmonary vascular resistance and an increase in pulmonary vascular compliance. Because of the efficacy of TNG in lowering pulmonary and left atrial pressures in this study, TNG may prove useful in the clinical management of symptomatic pulmonary congestion in mitral stenosis.

Blood Pressure↗

M-mode echocardiography in the evaluation of patients for aneurysmectomy.

In order to determine whether echocardiography could be useful in predicting surgical mortality of aneurysmectomy, preoperative condensed M-mode echocardiographic scans were taken from both mid (standard position) and low (nearer apex) intercostal spaces and/or from the subxiphoid area in eighteen patients who were sent to surgery for aneurysmectomy. Eleven of the eighteen patients survived aneurysmectomy. All eleven had mid left ventricular dimensions less than 3.3 cm/m2 and low dimensions of 3.8 cm/m2 or less. Of the seven patients who died, the mid and low left ventricular dimensions exceeded 3.3 cm/m2 and 3.8 cm/m2, respectively, with one exception. The combination of abnormal mitral valve closure, a dilated mid dimension and lack of normal motion in opposing wall segments was only seen in six nonsurvivors. Echocardiography can provide information concerning the state of the left ventricle in patients with ventricular aneurysms and these findings may be helpful in predicting surgical mortality for aneurysmectomy.

Adult↗

Noninvasive visualization of the left main coronary artery by cross-sectional echocardiography.

Real time cross-sectional echocardiographic studies of the left main coronary artery (LMCA) were performed in 15 normal patients, 15 patients with angiographically proven coronary artery disease but normal left main coronary segments, three patients with greater than 75% obstruction of the left main coronary artery, and one patient with a larger aneurysm of the left main coronary artery. In normal subjects the LMCA evaginates from in inferolateral wall of the aorta. The artery appears as two dominant parallel linear echoes separated by a clear space representing the lumen of the vessel. The LMCA courses beneath the right ventricular outflow tract and can generally be followed to its expected point of bifurcation. Confirmation that this structure was in fact the LMCA was obtained by injection of cardiogreen dye directly into the LMCA in two cases and by visualization of dye in this structure following aortic flush in one case. In the three cases with obstructive lesions of the LMCA, there was an area of inward bending of the parallel vessel wall echoes resulting in varying degrees of narrowing of the arterial lumen. In the case with the aneurysmal dilatation of the LMCA, an echo-free circular bulge in the distal portion of the LMCA was recorded. This study demonstrates the fesibility of recording the left main coronary artery using the cross-sectional echocardiographic technique.

Adolescent↗

Mechanism of abnormal septal motion in patients with right ventricular volume overload: a cross-sectional echocardiographic study.

To evaluate the mechanism of paradoxical septal motion in patients with right ventricular volume overload (RVVO), short axis cross-sectional, echocardiographic studies of the left ventricle (LV) and interventricular septum (IVS) were performed in 19 patients with paradoxical septal motion due to RVVO and in 20 normal subjects. Short axis study in normal subjects revealed the left ventricle to be a relatively circular structure during both diastole and systole. In patients with RVVO a change in LC diastolic shape was observed. This change in shape varied from a slight flattening of the LV and IVS during diastole to total reversal of the normal direction of septal curvature such that the IVS became concave toward the RV and convex toward the LV. During systole the LV and IVS returned to their normal relatively circular configuration. This change in LV shape from diastole to systole resulted in net motion of the IVS toward the right ventricle (paradoxically). This study therefore suggests that paradoxical septal motion in patients with right ventricular volume overload is a result of a change in the diastolic shape of the left ventricle.

Adolescent↗

Detection of left ventricular aneurysms by cross-sectional echocardiography.

Real-time cross-sectional echocardiographic studies of the left ventricle were performed in 31 consecutive patients with angiographically proven left ventricular aneurysms (group I). In each of these patients the presence and location of the aneurysm was visualized by the cross-sectional echocardiography. In four patients discrepancy in the extent of the aneurysm was noted due either to failure of the cross-sectional technique to visualize the entire anterior wall of the ventricle (3) or failure of the single plane angiogram to adequately define the lateral extent of the aneurysm (1). Ventricular shape and contraction sequence in patients with aneurysms were compared with similar patterns in 20 patients with normal left ventricles (group II), and 20 patients with ischemic heart disease and localized ventricular dysfunction without aneurysm formation (group III). Other noninvasive methods for detecting aneurysms (including physical examination, chest roentgenography, electrocardiography, and M-mode echocardiography) were also evaluated in the aneurysm group. This report suggests that cross-sectional echocardiography is a useful method for detecting ventricular aneurysms noninvasively.

Adult↗

Echocardiographic manifestations of aortic cusp rupture in a myxomatous aortic valve.

A 16-year-old pregnant black girl who had spontaneous perforation of the aortic valve associated with myxomatous aortic valvular degeneration is presented. The echocardiogram revealed chaotic systolic motion of one of the aortic cusps, diastolic aortic valvular fluttering, and abnormal diastolic echoes in the left ventricular outflow tract. The report illustrates that the echocardiographic features associated with valvular vegetations are not specific for infectious endocarditis.

Adolescent↗

Intracavitary echoes in patients with mitral prosthetic valves.

In the course of doing routine echocardiograms on patients with mitral prosthetic valves, we observed peculiar intracavitary echoes within the left ventricle. Of the 36 valves studied in 31 different patients, 14 echocardiograms demonstrated the abnormal intracavitary echoes and 22 did not. The presence of mitral insufficiency, atrial fibrillation, systemic emboli and warfarin sodium (Coumadin) therapy were roughly equal in the two groups. A higher percentage of abnormal intracavitary echoes occurred in patients with a hemoglobin less than 11 gm/100 ml, other prosthetic valves, cloth covered valves, low platelets, and functional class III-IV. Although this study does not clarify the origin of these abnormal echoes, it is possible that they originate from particulate matter such as tiny fibrin clots or fibers from the cloth covering of the valve.

Echocardiography↗

Echocardiographic differentiation of infundibular from valvular pulmonary stenosis.

Echocardiographic tracings of the pulmonary valve were examined in 24 normal subjects, 16 patients with valvular pulmonary stenosis and 3 patients with infundibular pulmonary stenosis. In normal subjects, atrial contraction produced a slight posterior opening motion of the pulmonary valve leaflet (a wave). This presystolic opening motion (a wave) varied with respiration, and maximal a wave depth recorded during quiet inspiration (Amax) averaged 3.7 plus or minus 1.2 (standard error of the mean) mm (range 2 to 7 mm). In the 10 cases with moderate or severe valvular pulmonary stenosis, increased force of right atrial contraction and elevated right ventricular end-diastolic pressure resulted in an increased posterior or opening motion of the pulmonary valve leaflet, and Amax averaged 9.6 plus or minus 2.0 mm (range 8 to 13 mm, P less than 0.001 versus normal). When both anterior and posterior leaflets were recorded, presystolic opening or doming of the valve was observed. In six cases of mild valvular pulmonary stenosis, Amax averaged 4 plus or minus 2.5 mm (not significant). In patients with infundibular pulmonary stenosis, marked chaotic systolic fluttering of the valve leaflet, which lies in the turbulent stream of blood distal to the obstruction, was recorded. This finding was never seen with valvular pulmonary stenosis. In two cases of mild infundibular pulmonary stenosis, the amplitude of presystolic opening motion was within the normal range of 3 and 7 mm. In one case of severe infundibular pulmonary stenosis, no presystolic opening motion was recorded, thus suggesting that the small pressure changes produced by atrial systole failed to reach the valve leaflets. Echocardiography, therefore, should be of use in differentiating valvular from infundibular pulmonary stenosis.

Adolescent↗

Pulmonary valve echo motion in pulmonary regurgitation.

Four cases are presented to illustrate the echo patterns of pulmonary valve motion in patients with pulmonary regurgitation caused by pulmonary hypertension, idiopathic dilatation of the pulmonary artery, or congenital absence of the pulmonary valve or in association with pulmonary stenosis. Absence of the pulmonary 'a' wave, fluttering of the e-f slope, and midsystolic closure or 'notching' of the valve were noted with pulmonary hypertension. In the case with idiopathic dilatation of the pulmonary artery a normal echo pattern of pulmonary valve motion along with distinct dilatation of the pulmonary artery at the valvular level were present. Pronounced dilatation and systolic expansion of the pulmonary artery along with dilatation of the right ventricle were seen with congenital absence of the pulmonary valve. No pulmonary valve could be demonstrated on multiple scans from the right ventricle to pulmonary artery. In Case 4 large 'a' waves (14 mm) were noted, indicating a reversal of the normal end-diastolic gradient across the valve and suggesting that pulmonary regurgitation in this case was associated with right ventricular outflow obstruction. Study of the echo pattern of pulmonary valve motion may therefore provide useful information in establishing the cause of pulmonary regurgitation.

Adolescent↗

Premature pulmonic valve opening following sinus of Valsalva aneurysm rupture into the right atrium.

Echocardiographic features of a patient with sinus of Valsalva aneurysm rupture into the right atrium are described. The aneurysm presented as a dense echo-producing mass in the right atrium which descended into the tricuspid orifice during diastole and withdrew back into the atrium during ventricular systole. Pulmonic valve exho motion demonstrated early diastolic pulmonic valve opening indicating an early right ventricular diastolic pressure rise exceeding simultaneous pulmonary artery pressure. Since the aorta is the only source of early diastolic pressure in excess of pulmonary artery pressure available to the right heart, this finding of early diastolic pulmonic valve opening indicated the presence of a fistula between the aorta and right heart. Other interesting echocardiographic features of this case are also presented.

Adult↗

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 less than 0.005; moderate vs mild P less than 0.001; and mild vs normal P less than 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.

Aortic Valve Stenosis↗

An unusual precordial pulse and sound assoicated with large pericardial effusion.

An unusual, high-pitched, early diastolic sound coinciding with a prominent, sharp precordial pulse was observed in a patient with a large chronic pericardial effusion. The pulse and sound coincided exactly with the anterior excursion of the heart within the fluid-filled pericardial sac, suggesting that the sound and pulse result from the ballistic effect of the heart striking the anterior pericardium and chest wall. This finding may be specific for large pericardial effusion with a "swinging heart."

Aged↗