Ventricular Inflow Obstruction Research Articles

Metastatic Malignant Melanoma Presenting Clinically as Obstruction of the Right Ventricular Inflow and Outflow Tracts: Characterization by Magnetic Resonance Imaging

Metastatic disease involving the heart may present in a variety of fashions. A patient with melanoma metastatic to the right ventricle which was diagnosed clinically by evidence of recent onset of right ventricular inflow and outflow tract obstruction is described. Important information regarding the extent of the metastatic process and potential resectability of the tumor was gained by magnetic resonance imaging.

EFFECTS OF INTRA-AORTIC BALLOON PUMPING DURING RIGHT VENTRICULAR INFLOW OBSTRUCTION IN THE NEWBORN LAMB

The intra-aortic balloon pump (IABP), while effective in adults, could be limited in effectiveness in infants because of differences in coronary dynamics, central vascular impedence, heart rate, and the hemodynamic indications for its use. One potential indication is the decreased cardiac output (CO) secondary to right ventricular inflow obstruction (RVIO). In 6 young lambs, catheters were placed in the vena cava, left atrium, coronary sinus, aorta, and pulmonary artery. An IABP was advanced via the femoral artery to the thoracic aorta. RVIO was produced by inflating a Foley catheter in the right atrium, reducing CO by 50%. Studies were performed at rest, rest + IABP, RVIO, and RVIO + IABP. Regional blood flows were measured by the microsphere method. During resting studies, the IABP did not alter CO, heart rate, aortic pressures, systemic or myocardial O2 consumption (VO2) or O2 transport, or regional blood flows. During RVIO, aortic and left atrial pressures decreased, vena caval pressure doubled, and systemic and myocardial VO2 and O2 delivery decreased. Blood flow and O2 delivery to all organs decreased. The IABP had no significant effect on any of these parameters. In conclusion, although the IABP does not interfere with resting hemodynamics or regional blood flows, there is no evidence for its effectiveness in clinical situations where CO is decreased because of RVIO. The utility of the IABP may be affected by the etiology of the reduction in CO, or by the presence of a normal coronary vascular bed.

Pulmonary venous and systemic ventricular inflow obstruction in patients with congenital heart disease: Detection by combined two-dimensional and Doppler echocardiography

Obstruction to pulmonary venous return may be associated with a number of congenital cardiovascular abnormalities occurring both before and after surgery. Hemodynamic assessment by cardiac catheterization is often difficult. A noninvasive method for detection and quantitation of obstruction to systemic ventricular inflow would be clinically useful. Two-dimensionally directed pulsed and continuous wave Doppler echocardiography was performed before cardiac catheterization in 31 patients thought clinically to have possible obstruction to left ventricular inflow or pulmonary venous return. Primary diagnoses included transposition of the great arteries after the Mustard or Senning procedure in nine patients, total anomalous pulmonary venous connection in nine (in two after surgical repair), cor triatriatum in eight (in four after surgical repair), congenital mitral stenosis in four (in one after surgical repair) and mitral atresia in one. Severe obstruction was defined as a mean pressure gradient at catheterization of greater than or equal to 16 mm Hg at any level of the pulmonary venous return or of the systemic ventricular inflow. Severe obstruction was predicted if Doppler examination measured a flow velocity of greater than or equal to 2 m/s across any area of inflow obstruction. At catheterization, 12 patients (39%) had severe obstruction to left ventricular inflow or pulmonary venous return and all obstructions were correctly detected by Doppler echocardiography. The site of pulmonary venous obstruction was localized by two-dimensionally directed pulsed Doppler study. Patients with a lesser degree of obstruction had a lower Doppler velocity, but none had a maximal Doppler velocity of greater than or equal to 2 ms/s.(ABSTRACT TRUNCATED AT 250 WORDS)

Doppler echocardiographic evaluation of ring mitral valvuloplasty for pure mitral regurgitation

Doppler echocardiographic studies were performed in 21 consecutive patients (mean age 56 ± 11 years) to evaluate postoperative results of mitral ring anuloplasty. All patients were symptomatic and all had clinically severe isolated mitral regurgitation (MR). The origin of MR was myxomatous degeneration, coronary artery disease, rheumatic heart disease or congestive cardiomyopathy. In 20 patients ring anuloplasty was performed using the Carpentier ring and 1 patient using the Duran ring. Postoperative Doppler echocardiographic studies were performed to detect and semiquantitate residual MR by flow mapping and to identify left ventricular inflow or outflow obstruction. The severity of MR was assessed by flow mapping in the left atrium and graded from I to IV in increasing severity. Blood flow velocity spectra were recorded from the left ventricular outflow tract during systole and from the left ventricle subjacent to the mitral valve during diastole. Pressure half-time, mitral valve area and mitral valve gradient were derived from digitized mitral diastolic flow velocity spectra. After ring valvuloplasty, 9 patients had no MR and 6 had grade I, 3 grade II, 2 grade III and 1 patient grade IV MR. Peak diastolic mitral valve gradient was 8 ± 4 mm Hg, mean diastolic gradient was 3 ± 2 mm Hg and pressure half-time was 83 ± 17 ms, representing a calculated mean mitral valve area of 2.9 ± 0.8 cm. Peak velocity in the left ventricular outflow tract was 0.9 ± 0.2 m/s, indicating no obstruction to outflow. Our study confirms that mitral ring valvuloplasty produces a significant reduction in severity of MR, and this is achieved without obstructing left ventricular inflow or outflow.

Obstruction of right ventricular inflow and outflow in corrected transposition of the great arteries {S,L,L}: Two-dimensional echocardiographic diagnosis

Obstruction of systemic ventricular inflow and outflow is considered uncommon in corrected transposition of the great arteries (S,L,L). Between 1979 and 1985, 42 patients with corrected transposition and two ventricles and atrioventricular valves underwent two-dimensional echocardiography. Obstruction of right ventricular inflow and outflow was present and diagnosed by two-dimensional echocardiography in 5 of the 42 patients. A supratricuspid stenosing ring, recognized in the apical or subxiphoid four chamber view as a bright, linear structure on the left atrial side of the tricuspid valve, occurred in two patients. Subaortic obstruction due to infundibular hypertrophy with or without displaced muscle bundles was seen in three patients. Subxiphoid long- and short-axis views and parasternal long-axis views best displayed these features. Aortic coarctation was present in four cases and could be diagnosed using modified suprasternal notch views. Thus, systemic ventricular inflow and outflow obstruction may be more common in corrected transposition than previously believed (occurring in up to 10 to 15% of patients). The mechanisms producing the obstruction appear to be characteristic of the left atrium and right ventricle irrespective of location or connections. Echocardiography appears to be an excellent technique for diagnosing these associated lesions in corrected transposition.

Membranous supravalvular mitral stenosis: A treatable form of congenital heart disease

The clinical data, echocardiographic findings, operative anatomy and postoperative follow-up were assessed in 14 patients who had surgery for membranous supravalvular mitral stenosis between 1978 and 1985. The patients ranged in age from 6 weeks to 13 years at the time of operation, and 8 of the 14 had associated mitral valve abnormalities. Other associated lesions included ventricular septal defect (n = 7), coarctation of the aorta (n = 5), left superior vena cava (n = 6), subaortic stenosis (n = 3) and atrial septal defect (n = 1). Twelve of the 14 patients had successful removal of the supravalvular membrane, which was usually adherent to the valve, and 2 patients with associated mitral valve abnormalities underwent mitral valve replacement. There were no operative deaths. Review of preoperative two-dimensional echocardiograms, which were available in 11 patients, revealed two types of membranous supravalvular mitral stenosis in 10 patients. In four of these patients, the membrane was only evident after repeated stop action viewing from a single subcostal or parasternal location. The membrane was never seen in one patient. Eleven patients had follow-up in excess of 1 year, and there was one late death. Eight of the remaining 10 patients are asymptomatic, and 7 have no clinical evidence of residual mitral obstruction. Failure to recognize membranous supravalvular mitral stenosis can result in undue delay of cardiac surgery with resultant cardiopulmonary deterioration. Patients with evidence of left ventricular inflow obstruction should have extensive echocardiographic evaluation in an effort to detect membranous supravalvular mitral stenosis, which may be amenable to surgical repair.

Left Ventricular Outflow Tract Obstruction Related to a Valve Prosthesis: Case Caused by a Low-Profile Mitral Prosthesis

Mechanical and bioprosthetic mitral prostheses may have many potential complications. In patients with isolated mitral stenosis and a small left ventricular cavity, low-profile prostheses are recommended to avoid myocardial impingement that can result from a high-profile valve and lead to possible left ventricular inflow or outflow obstruction or ventricular arrhythmias. This case report illustrates that left ventricular outflow obstruction may also result from a low-profile mitral valve prosthesis. This obstruction was not diagnosed before cardiac catheterization. Assessment of patients with suspected prosthetic valve dysfunction is difficult and may necessitate cardiac catheterization or even direct surgical inspection for conclusive information.

Frequency of mitral valve dysfunction from mitral anular calcium as detected by Doppler echocardiography

Doppler echocardiography is useful for detecting and quantifying mitral regurgitation (MR) and mitral stenosis (MS). To determine the prevalence of these abnormalities in patients with mitral anular calcium (MAC), 51 consecutive patients who had an echocardiographic diagnosis of MAC were examined by Doppler ultrasound. Transmitral flow was evaluated to determine the presence of MR or left ventricular inflow obstruction (MS) by continuous and pulsed-wave Doppler echocardiography. The severity of these hemodynamic abnormalities was quantitated by previously described techniques. Eleven patients (22%) had mild MR, 17 (33%) had moderate to severe MR and 4(8%) had significant MS. Clinical findings such as a systolic murmur, evidence of congestive heart failure, and dyspnea on exertion were not helpful in distinguishing patients with no or mild MR from those who had moderate to severe MR. M-mode measured left atrial size was significantly larger (p < 0.05) in patients with moderate to severe MR. This study suggests that MR is often associated with MAC, that MS is not a rare finding with MAC, and that Doppler echocardiography can quantitate these lesions in the elderly when symptoms are not specific and physical findings are inconclusive or absent.

Echocardiographic assessment of congenital mitral stenosis

To assess the severity and precise anatomy of congenital mitral stenosis (MS), 17 patients with congenital left ventricular inflow obstruction were studied by M-mode and two-dimensional echocardiography (2DE) and by cardiac catheterization. In six patients MS was an isolated lesion and in 11 it was combined with other cardiovascular malformations. The diagnosis was confirmed at operation or autopsy in 15 patients. Twenty normal subjects of the same age and sex were selected as controls. M-mode amplitude and speed of diastolic closure (E-F slope) of the anterior mitral valve leaflet were determined in all patients. Mitral valve areas were traced after careful short-axis 2DE scans in 15 patients. Supravalvar, valvar, or subvalvar obstruction was evaluated in patients with surgical or autopsy documentation. Analysis of M-mode echocardiograms showed a reduction of E-F slope in all patients compared to normal control subjects but a poor correlation between E-F slope and hemodynamic data (mitral valve areas or pressure gradients). Diastolic fluttering of either or both mitral valve leaflets was found in 12 patients. It is concluded tha M-mode echocardiography may be useful for qualitative assessment of congenital MS, even in the presence of associated heart defects, but less useful in evaluating its severity. Analysis of 2DE revealed good correlation between mitral valve areas as calculated with 2DE and with the Gorlin formula at cardiac catheterization, despite the complexity of the congenital mitral lesion. Anatomic varieties of congenital left ventricular inflow obstruction, such as stenosing supravalvar mitral ring or parachute deformity of the mitral valve, were recognized at 2DE. It is concluded that 2DE may be useful in estimating the severity of congenital MS and determining the site of the inflow obstruction.

Echocardiographic diagnosis and postoperative estimation for congenital left ventricular inflow obstruction

Echocardiographic diagnosis and postoperative estimation for congenital left ventricular inflow obstruction

Prospective study comparing different echocardiographic measurements of pulmonary capillary wedge pressure in patients with organic heart disease other than mitral stenosis

In 25 patients with cardiac disease, but free of left ventricular inflow obstruction, the electrocardiogram and M-mode echocardiogram of the aortic root, left atrium and both the mitral and the aortic valves were obtained simultaneously with the pulmonary artery wedge pressure (PAWP) during right heart catheterization. The echocardiographic measurements of the left atrial size, PR-AC interval, left atrial emptying index and the ratio between the electrocardiographic Q wave to mitral valve closure (Q-MVC) and between aortic valve closure to the mitral E point (AVC-E) were correlated to the pulmonary artery wedge pressure by means of linear regression analysis. A formula in which PAWP = 36.6 (Q-MVC/AVC-E)-- 2 was prospectively used to study the measured pressure in the current group of patients. The pulmonary artery wedge pressure derived from these latter measurements correlated well with the invasive measurement of this pressure (r = 0.91). The pulmonary artery wedge pressure calculated by echocardiography differed from the pulmonary artery wedge pressure measured by catheterization by 3 mm Hg or less in 19 of the 25 patients, by 4 mm Hg or less in 22 patients and by 6 mm Hg or less in 24 patients. Although the correlation between the (Q-MVC/AVC-E) ratio and measured pulmonary artery wedge pressure was highly significant (r = 0.91, probability [p] less than 0.001, n = 25), the left atrial emptying index, PR-AC and left atrial size revealed poor correlation coefficients (r = 0.45, r = 0.45 and r = 0.56 [p less than 0.05]), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Transesophageal two-dimensional echocardiography in the diagnosis of cor triatriatum in the adult

Two adult patients with left ventricular inflow obstruction are presented. Conventional two-dimensional echocardiography had failed to yield a definite diagnosis, whereas transesophageal two-dimensional echocardiography clearly documented a membraneous echo structure within the left atrium, diagnostic of cor triatriatum. On the basis of the transesophageal echocardiographic findings, left heart catheterization and angiocardiography were not performed and both patients successfully underwent cardiac surgery.

Sterile, caseous mitral anular abscess

Echocardiography identified three patients with a mitral anular mass. Fluoroscopy demonstrated a faint, homogeneous intracardiac calcific density in each patient. Cardiac catheterization and angiography were performed and showed no left ventricular inflow or outflow obstruction. One patient died suddenly and two patients had cardiac surgery (one for mitral regurgitation and another for constrictive pericarditis). Examination demonstrated that each mass was nonencapsulated, sterile and acellular and contained cholesterol, calcium and fatty acids. The clinical significance and cause of these masses are unclear at present.

Concealed left atrial membrane: Pitfalls in the diagnosis of cor triatriatum and supravalve mitral ring

Cor triatriatum and supravalve mitral ring are forms of congenital left ventricular inflow obstruction produced by membranes within the left atrium. Typically, these defects occur as isolated anomalies with manifestations of pulmonary venous obstruction. Four children are presented whose left atrial membrane was associated with other significant cardiac defects, including, in one patient each, simple coarctation of the aorta, sinus venosus atrial septal defect, tricuspid atresia and complex coarctation of the aorta syndrome. The patient with the latter defect had undergone previous pulmonary arterial banding. None of these patients demonstrated significant pulmonary venous obstruction at cardiac catheterization. All patients had a normal value for either pulmonary arterial diastolic or pulmonary arterial wedge pressure. Three mechanisms explained the lack of pulmonary venous obstruction: (1) a large cross-sectional area of membrane openings, (2) an atrial septal defect that was confined to the pulmonary venous chamber and decompressed it by allowing blood to escape into the right atrium, and (3) decreased pulmonary blood flow. The diagnosis was facilitated by two dimensional echocardiography. Accurate diagnosis of left atrial membrane in the setting of other cardiac defects is of practical significance because pulmonary venous obstruction may occur after surgery for the associated defects.

Left ventricular inflow obstruction and atrial septal deffect: Diagnosis by real time two-dimensional echocardiography

This report describes the usefulness of real time two-dimensional echocardiography in the diagnosis of left ventricular inflow obstruction associated with atrial septal defect. Echocardiographically, left ventricular inflow obstruction was at the level of the mitral valve in case one, mitral and subvalvular in cases 2 and 3 and supravalvular in case 4 (left atrial membrane). In all patients the defect was of the secundum variety and was seen as a constant discontinuity in the atrial septal image. The diagnosis was confirmed in all patients by cardiac catheterization, surgery or autopsy.

Congenital mitral stenosis. Anatomical and functional assessment by echocardiography.

Digitised left ventricular echocardiograms were studied in nine children with congenital mitral stenosis to assess the severity of inflow obstruction. In six children the two prime indices of mitral stenosis were abnormal, with a prolonged time from minimum dimension to 20 per cent dimension change and a reduced peak dimension change during diastole. In three, however, these values did not suggest inflow obstruction, depsite significant gradients at cardiac catheterisation. Two-dimensional echocardiography was performed in 10 children with congenital mitral stenosis to determine the mitral annular size and the morphology of the valve and subvalvular apparatus. The annular size and number of papillary muscles could be assessed along with the detection of combined mitral abnormalities. Two-dimensional studies can reliably delineate the type of mitral abnormality, and should be performed in all cases with congenital heart disease having a high incidence of associated left ventricular inflow obstruction. Digitised M-mode left ventricular echocardiography is in general unreliable in assessing congenital obstruction, though it may be of some value in individual cases.

Congenital left ventricular inflow obstruction evaluated by two-dimensional echocardiography.

Several forms of congenital heart disease that cause left ventricular inflow obstruction have similar M-mode findings, and frequently the exact anatomic diagnosis cannot be made by M-mode echocardiography alone. We examined five children with various forms of left ventricular inflow obstruction using two-dimensional echocardiography. The diagnosis was confirmed by cardiac catheterization and surgery in all five patients. In one patient with congenital mitral valve stenosis, a thick mitral valve with two papillary muscles was imaged. This patient was easily distinguished from a second child with parachute deformity of the mitral valve in whom a single papillary muscle arising from the left ventricular apex was seen. These two patients with mitral valve stenosis were easily differentiated from the three patients in whom the left ventricular inflow obstruction was caused by a membrane within the left atrium. The membrane could be seen in several spatial planes; however, we could not distinguish by two-dimensional echocardiography one child who had cor triatriatum from the other two patients who had a supravalvar mitral ring. Because of its spatial anatomic display, the two-dimensional echocardiogram provides information for a more detailed anatomic diagnosis in children with congenital left ventricular inflow obstruction.

Frequency and direction of interatrial shunting in valvular pulmonic stenosis with intact ventricular septum and without left ventricular inflow or outflow obstruction: An analysis of 127 patients treated by valvulotomy

This report summarizes observations in 127 patients who underwent pulmonic valvulotomy for valvular pulmonic stenosis with intact ventricular septum and without obstruction to left ventricular inflow or outflow. Of the 127 patients, 30 (24%) preoperatively by dye dilution curves had shunting at the atrial level: in 19 (63%), the shunt was right-to-left, and in the other 11 (27%), entirely left-to-right. The patients with right-to-left interatrial shunts had severe pulmonic valve stenosis (average peak systolic pressure gradient = 120 ± 11 mm. Hg) and small (average diameter 1.1 ± 0.1 cm.) sized defects in the atrial septum (patent foramen ovale). In contrast, the patients with left-to-right shunts had mild to moderate pulmonic valve stenosis (average peak systolic pressure gradient = 60 ± 5 mm. Hg) and relatively large (average diameter = 2.8 ± 0.1 cm.) defects in the atrial septum (true atrial septal defect). The patients with right-to-left interatrial shunts had no significant differences in right versus left atrial pressures. The patients with left-to-right interatrial shunts, however, had left atrial pressures significantly greater than right atrial pressures (7 ± 0.5 vs 5 ± 0.5, p < 0.05). No significant differences were found in ventricular end-diastolic pressures.

Cardiomyopathies characterized by evidence of resistance to left ventricular inflow.

Restrictive cardiomyopathy characterized by evidence of left ventricular inflow obstruction was studied in four cases--one child and three adults. In three of the cases, including the child, there was pathologic evidence of hypertrophic cardiomyopathy with asymmetric septal hypertrophy. In the fourth case, no cardiac disease was identified as the anatomic basis for the inflow restriction. This latter case broadens the concept of restrictive cardiomyopathies.

Echocardiographic features of congenital left ventricular inflow obstruction.

The echocardiographic features of congenital left ventricular inflow obstruction are described in six patients. The echocardiograms in two patients with cor triatriatum were distinguished by normal mitral valve motion and an abnormal echo within the left atrium. In two patients with supravalvar mitral ring, in addition to abnormal mitral valve motion, an abnormal echo, presumably originating from the obstructive membrane, was located between the anterior and posterior mitral leaflets. In two cases of parachute mitral valve, mitral valve motion was abnormal. In one of these cases there were multiple mitral valve echoes similar to those found in supravalvar mitral ring. The echocardiographic identification of an obstructive membrane within the left atrium is difficult because of the occurrence of artifacts. However, membranes may be identified if careful scanning techniques are employed in patients in whom left ventricular inflow obstruction is suspected. The echocardiogram is useful in detecting mitral valve abnormalities in these patients and is valuable in cases where mitral valve replacement is contemplated.