Doppler echocardiography in the evaluation of valvular heart disease

Doppler echocardiography is a relatively new non-invasive technique which provides direct hemodynamic data that is complementary to M-Mode and 2-Dimensional echocardiography. This technique allows measurement of peak flow velocity through a stenotic valve and allows accurate prediction of the pressure gradient across the valve. It is a promising technique for screening patients with suspected pulmonic and aortic stenosis. It allows quantitation of gradient and valve area in patients with mitral stenosis. Doppler techniques are also valuable in detecting and semi-quantitating valvular regurgitation. Pulsed Doppler echocardiography is accurate in evaluating patients with multi-valvular disease. Finally, Doppler techniques are finding an important role in the evaluation of suspected prosthetic valve malfunction. In summary, Doppler echocardiography offers a complementary approach for direct evaluation of intracardiac hemodynamics in patients with valvular heart disease.     

Clinical evaluation versus Doppler echocardiography in the quantitative assessment of valvular heart disease

We tested the hypotheses that Doppler echocardiography has a higher accuracy than clinical evaluation in the detection of significant aortic and mitral valvular heart disease and that Doppler echocardiography is highly accurate as compared with cardiac catheterization for the assessment of valvular disease severity. Thus, cardiac catheterization for the assessment of valve lesion severity may be unnecessary in selected patients. We prospectively evaluated 75 consecutive patients, ages 20-74 years (mean, 52 years), with clinically suspected valvular heart disease. Specific clinical and Doppler echocardiographic criteria were used to categorize each valve lesion as absent, insignificant, or significant. Criteria for a significant lesion at cardiac catheterization was an aortic or mitral valve area less than 1.1 or 1.5 cm2, respectively, or equal to or greater than 3+ cm2 aortic or mitral regurgitation at angiography. In all valve lesions, Doppler echocardiography had a higher overall accuracy than clinical evaluation. Increases in accuracies of 28%, 19%, 15%, and 7% occurred for mitral stenosis, aortic stenosis, aortic regurgitation, and mitral regurgitation, respectively, resulting in overall accuracies of 97%, 100%, 95%, and 96%. Clinical evaluation alone made 28 errors (37% of patients and 19% of valve lesions assessed), and 17 of these errors (23% of patients and 12% of valve lesions) would have resulted in inappropriate management. In only four (24%) of these 17 patients, the attending cardiologist would not have proceeded to assess the valve at cardiac catheterization.(ABSTRACT TRUNCATED AT 250 WORDS)     

Shu 508 A (Levovist)-enhanced Doppler echocardiography improves the assessment of valvular heart disease

OBJECTIVE: To investigate whether intravenous injection of SHU 508 A improves the diagnostic accuracy of Doppler echocardiography in the assessment of valvular pathologies. METHODS AND RESULTS: One hundred and twenty-five consecutive patients with valvular pathology (aortic stenosis, n = 48; aortic regurgitation, n = 20; mitral stenosis, n = 21; and mitral regurgitation, n = 36) and diagnostically insufficient Doppler signal were enrolled in this multicenter study. The severity of valvular pathology was graded on a four-point scale using unenhanced and contrast-enhanced Doppler echocardiography as well as cardiac catheterization. Agreement with cardiac catheterization findings increased from 63% using the unenhanced examination to 73% using the contrast-enhanced Doppler examination. Grading was possible in all patients using SHU 508 A, whereas the unenhanced Doppler examination remained inconclusive in six patients. The weighted kappa coefficient between contrast-enhanced Doppler and cardiac catheterization for all diagnoses was 0.76 as compared to 0.68 between unenhanced Doppler and cardiac catheterization. Agreement was especially improved in aortic stenosis (kappa 0.69 unenhanced vs 0.81 contrast-enhanced) and in aortic regurgitation (kappa 0.45 unenhanced vs 0.75 contrast-enhanced). Patients with mitral stenosis and mitral regurgitation experienced less improvement. CONCLUSIONS: In case of an inconclusive unenhanced Doppler echo study, the administration of a left heart contrast agent should be considered. SHU 508 A is especially useful in improving the severity grading of aortic stenosis and aortic regurgitation, while grading of mitral stenosis and mitral regurgitation is less improved.     

Doppler echocardiography assessment of prosthetic heart valves

Transthoracic Doppler echocardiography is an accurate noninvasive method for the evaluation of prosthetic valve function. The flow characteristics and pressure gradients of normally functioning mechanical and bioprosthetic valves have been, in general established. Normal functioning mitral valve prostheses have a valve area > 1.8 cm² with the St. Jude valve having the largest effective valve area and normally functioning aortic prosthetic valves have a peak instantaneous gradient of < 45 mmHg, with the Starr-Edwards valves (Starr-Edwards, Irvine CA) showing the highest gradients. The incidence of minimal or mild regurgitation is approximately 15% to 30% in the mitral position and 25% to 50% in the aortic position, with the higher incidence of regurgitation seen with mechanical compared to bioprosthetic valves. Transthoracic Doppler echocardiography can accurately detect patients with prosthetic valvular stenosis. The presence of prosthetic aortic regurgitation can also generally be accurately assessed, except in the presence of both prosthetic aortic and mitral valves. Assessment of prosthetic mitral regurgitation remains limited due to significant attenuation of the ultrasound beam by the prosthesis and the frequent underestimation of severity of regurgitation. Other limitations of transthoracic studies include assessment of leaflet morphology, detection of vegetations and valve abscesses, and differentiation between valvular and paravalvular regurgitation.     

Quantification of valvular lesions in patients with left ventricular dysfunction

Echocardiography is the preferred method for assessment of aortic and mitral valvular lesions. The pressure gradient in aortic stenosis may be misleading in patients with poor left ventricular function. Aortic valve area planimetry by transesophageal echocardiography results in a flow independent anatomic measurement. Low-dose dobutamine stress echocardiography provides important prognostic information. Quantitative Doppler echocardiography allows accurate assessment of mitral regurgitation severity. However, the definition of what is severe mitral regurgitation is different in patients with left ventricular dysfunction.     

The clinical spectrum of tricuspid regurgitation detected by pulsed Doppler echocardiography

The clinical diagnosis of tricuspid regurgitation (TR) is often difficult. Two-dimensional pulsed Doppler echocardiography offers a sensitive and specific method for detecting and semi-quantitating tricuspid regurgitation. The clinical, radiographic, radionuclide, echocardiographic, and when available, the right cardiac catheterization findings were evaluated in 36 patients with a diagnosis of tricuspid regurgitation by pulsed Doppler. Ten healthy subjects served as controls. The underlying cardiac cause was rheumatic heart disease in 7 (20%), ischemic heart disease in 12 (33%), dilated cardiomyopathy in 5 (14%), hypertensive heart disease in 2 (5%), aortic valve stenosis and/or regurgitation in 3 (8%), mitral valve prolapse with mitral regurgitation in 1 (3%), and congenital heart disease in 6 (17%). Seven patients (19%) had a temporary or permanent transvenous right ventricular pacing wire. A systolic murmur was heard in 29 patients (81%) with 16 (46%) having an elevated jugular venous pressure. Tricuspid regurgitation was clinically suspected in only 2 patients (6%). Isolated tricuspid regurgitation was uncommon, seen in 6 patients (17%), and usually secondary to congenital heart disease, ischemic heart disease, with the use of a transvenous pacing wire and following mitral valve replacement. Right cardiac catheterization was performed in 10 patients, of which 7 demonstrated elevated right atrial and pulmonary artery pressure. Pulsed Doppler echocardiography offers a practical and accurate method of detecting and evaluating the severity of tricuspid regurgitation. Tricuspid regurgitation is generally a functional disorder, and frequently occurs in association with left sided valvular heart disease, cardiomyopathy or congenital heart disease.     

老年人退行性心脏瓣膜病166例超声心动图分析

目的探讨老年人退行性心脏瓣膜病的超声心动图特点。方法采用美国HP5500及飞凡彩色多普勒超声诊断仪，观察166例老年退行性心脏瓣膜病患者的心脏结构及心功能变化。结果单纯主动脉瓣膜钙化者93例（56．0％），单纯二尖瓣钙化18例（10．8％），主动脉瓣和二尖瓣联合钙化为55例（33．1％）；左房扩大116例（69．9％），左心室舒张功能减退142例（85．5％）；136例导致心脏瓣膜功能障碍，其中主动脉瓣返流70例，占42．2％，主动脉瓣狭窄23例，占13．9％，二尖瓣返流20例，占12．0％，二尖瓣狭窄8例，占4．8％，主动脉瓣返流＋主动脉瓣狭窄10例，占6．0％，二尖瓣返流＋二尖瓣狭窄5例，占3．0％。瓣膜功能障碍检出率最高为主动脉关闭不全（42．2％），其次为主动脉瓣狭窄（13．9％），发病率最低为二尖瓣狭窄伴关闭不全（3．0％）。结论老年人退行性心脏瓣膜病缺乏特异的临床表现，随着年龄的增加，联合瓣膜钙化比例增加，瓣膜功能障碍中主动脉瓣关闭不全比例最高，左房扩大的比例也增加。     

Radionuclide ventriculography in aortic and mitral valve insufficiency. Pre- and post-operative studies of valve replacement surgery

Radionuclide ventriculography (RNV) is now a well-established procedure for the noninvasive evaluation of cardiac hemodynamics, including the detection and quantification of valvular regurgitation. 46 patients undergoing aortic or mitral valve replacement were examined by RNV pre- and postoperatively. The specificity of RNV in the diagnosis of aortic or mitral incompetence was high. All cases of moderate to severe aortic regurgitation were identified. This, however, was not true for mitral incompetence. A significant overlap between the left atrium and the left ventricle in the LAO view is held responsible for this decrease in sensitivity. The quantification of aortic regurgitation and the assessment of left ventricular function by RNV appears to hold promise in the preoperative workup. This diagnostic approach yields important additional information, which may be essential in the appropriate timing of surgical intervention. Aortic valve replacement for incompetence as well as for stenosis was accompanied by a significant improvement in global left ventricular ejection fraction. No postoperative change in ejection fraction was found in cases of mitral incompetence, while a slight increase was observed following operative therapy for mitral stenosis. The radioisotope findings were correlated to the results obtained by cardiac catheterization and noninvasive techniques such as echocardiography. The place of RNV in the pre- and postoperative management of valvular heart disease is delineated in this paper. It is of special value in the evaluation of aortic incompetence and may be an important diagnostic adjunct in the approach to the patient with mitral valve disease or aortic stenosis.     

Comparison of Doppler echocardiography and cardiac catheterization in patients requiring valve surgery: search for a 'gold standard'.

OBJECTIVE: To compare the sensitivities of Doppler echocardiography and cardiac catheterization in the diagnosis of severe valvular heart disease in patients requiring valve surgery. DESIGN: Retrospective analysis of Doppler echocardiograms and cardiac catheterizations. SETTING: Tertiary referral cardiovascular centre in a university setting. PATIENTS: Sixty-nine patients undergoing valve surgery between July 1988 and July 1990. RESULTS: The sensitivities of echocardiography and cardiac catheterization were 84 and 87%, respectively (P = 1.0) in 32 patients who underwent aortic valve surgery primarily for severe aortic stenosis; 83 and 67%, respectively (P = 1.0) in six patients with severe aortic regurgitation, and 100 and 85%, respectively (P = 1.0) in seven patients with combined severe aortic stenosis and regurgitation. The sensitivities of echocardiography and cardiac catheterization in 11 patients who underwent mitral valve surgery for severe mitral stenosis were 73 and 91%, respectively (P = 0.6) and 69 and 92%, respectively (P = 0.3) in 13 patients with severe mitral regurgitation. Sensitivities of echocardiography and cardiac catheterization in the diagnosis of severe tricuspid regurgitation in five patients who had tricuspid valve repair were 100 and 80%, respectively (P = 1.0). Two patients with severe aortic stenosis by echocardiography, but not by catheterization, did not undergo aortic valve replacement during valvular surgery; both required aortic valve replacement within two years of initial surgery because of heart failure. Four patients with severe tricuspid regurgitation identified by echocardiography did not have tricuspid repair; three had pulmonary hypertension and these patients had resolution of tricuspid regurgitation on follow-up. One patient with severe tricuspid regurgitation and absence of pulmonary hypertension required reoperation for tricuspid valve repair 10 months after initial operation. CONCLUSIONS: The sensitivity of echocardiography and cardiac catheterization in the detection of severe valvular lesions requiring surgery is similar. Discordant results should be reviewed carefully with knowledge of the inherent pitfalls of both techniques in order to ensure optimal patient outcome.     

Noninvasive assessment of an aortic bioprosthesis malfunction with Doppler echocardiography

A 27-year-old patient with aortic stenosis received a Carpentier Edwards bioprosthesis and a reconstruction of the mitral valve, in 1978. With auscultation, M-mode and two-dimensional echocardiography, we diagnosed in 1985 a malfunction of the aortic prosthesis with restenosis, insufficiency and mitral insufficiency. A reliable qualitative and quantitative non-invasive assessment, however, was only possible with Doppler echocardiography. The velocity of blood flow over the aortic valve was measured with the continuous-wave Doppler technique; the aortic valve pressure gradient and the valve area were determined. The pulsed Doppler allowed a semi-quantitative evaluation of the severity of the aortic and mitral insufficiency. The intraoperative and pathological anatomical results confirmed the results from Doppler echocardiography: aortic valve prosthesis malfunction with restenosis and insufficiency and mild haemodynamically insignificant mitral valve insufficiency. The need for cardiac catheterization in patients with valvular heart disease and prosthesis is discussed.     

Valvular heart disease: clinical approach to acute decompensation of left-sided lesions

Acute valvular heart disease is often life-threatening. The diagnosis of acute valvular decompensation is made by attention to the physical assessment and appropriate use of diagnostic techniques. Recent advances in valvular heart disease have centered around noninvasive diagnostics. Doppler echocardiography can accurately diagnose and quantify stenotic and regurgitant lesions; its use with M-mode and two-dimensional echocardiography makes these the noninvasive diagnostic procedures of choice. Acute decompensation is often related to preexisting critical aortic or mitral stenosis, or more commonly, acute severe regurgitation. Although of different etiologies, acute mitral and aortic regurgitation are associated with similar diagnostic and therapeutic modalities. Emergency treatment consists of vasodilator and, possibly, inotropic therapy. However, definitive therapy generally requires surgical intervention.     

Valvular regurgitation in patients with complete heart block by color Doppler echocardiography

We studied valvular regurgitation (pulmonary, aortic, tricuspid and mitral regurgitation) in 30 patients with complete heart block by color Doppler echocardiography, pulse Doppler and continuous wave Doppler echocardiography. The prevalence rate of multivalvular regurgitation of these subjects was 83.3%. Regurgitation involving all four valves appeared in 30.0% of these patients. The prevalence rate of pulmonary, aortic, tricuspid and mitral regurgitation was 56.7%, 33.3%, 100%, and 76.7% respectively. Pulmonary regurgitation (PR) was observed in patients with complete heart block without pulmonary hypertension. PR velocity was slow and interrupted by atrial contraction. It might be possible to evaluate atrial pressure from the interruption of PR. Tricuspid regurgitation (TR) during systole was often present in patients with right ventricular endocardial pacing. Systolic TR was influenced by atrial contraction. When atrial contraction occurred during systole, TR was interrupted, or shortened. Diastolic TR and MR were easily detected by M mode color Doppler echocardiography. The diastolic TR and MR were of slow velocity and appeared 240-290 msec after P wave. These atypical valvular regurgitation in patients with complete heart block reflect of the inverse atrial-ventricular pressure gradient across the atrio-ventricular valve.     

A new diagnostic procedure for assessing intracardiac flow disturbances in patients with heart valve disease

BACKGROUND: Until now no diagnostic technique was available for the three-dimensional (3D) study of intracardiac blood flow abnormalities in patients with heart valve disease. 3D color Doppler is a new diagnostic technique first developed at our institution. METHODS: The 3D reconstructions of the blood flow velocity data have been obtained from conventional multiplanar transesophageal or transthoracic Doppler echocardiographic examinations. We analyzed 111 reconstructions of color Doppler data obtained from 85 patients with different heart valve diseases who underwent intraoperative transesophageal echocardiography. Sixty-nine patients had a significant mitral regurgitation, 7 mitral stenosis, 9 aortic regurgitation, 12 aortic stenosis, 14 tricuspid regurgitation. Three patients had pulmonary regurgitation associated with mitral valve disease. RESULTS: 3D color Doppler disclosed the complex spatial spreading of the blood flow abnormalities caused by heart valve disease. New patterns of intracardiac blood flow disturbances could be observed and classified. CONCLUSIONS: This paper shows the first clinical applications of 3D color Doppler in patients with heart valve disease. The new insights derived from the 3D study of intracardiac blood flow dynamics revealed a great impact of this technique on the clinical management of patients with heart valve disease.     

The effect of cardiac catheterization upon management of advanced aortic and mitral valve disease

We assessed the incremental effect of cardiac catheterization upon the management of 93 adult patients with aortic and/or mitral valve disease, referred for surgical consideration. There were 52 patients with aortic valve disease, 29 with mitral valve disease and 12 with aortic and mitral valve disease. Prior to cardiac catheterization, a detailed unblinded ultrasound assessment of each valve was made utilizing 2D and Doppler ultrasound. Based upon the ultrasound result and the clinical assessment, the patient's cardiologist recorded a grading of valve severity and a management decision for each valve. Following catheterization and coronary angiography, the cardiologist repeated the gradings of valve severity and recorded a final management decision. After catheterization, management changed in nine patients and was unchanged in 84. Reasons for management change included differences between echocardiographic and catheterization assessment of valvular regurgitation (three patients), information on coronary anatomy (two patients), minor differences in assessed aortic valve area (one patient) and left ventricular function (one patient), and confirmation of ultrasound findings where clinical and ultrasound findings had been conflicting before catheterization (two patients). Both mitral and aortic valve disease were present in the three patients in whom management changed as a result of significant differences between echocardiography and catheterization assessment of valvular regurgitation. Management was unchanged in the 16 patients with isolated mitral stenosis. In this study, a combination of clinical and noninvasive assessment including Doppler echocardiography, resulted in a reliable evaluation of valvular disease in a large majority of patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of cardiac catheterization and Doppler echocardiography in the decision to operate in aortic and mitral valve disease

Clinical decisions utilizing either Doppler echocardiographic or cardiac catheterization data were compared in adult patients with isolated or combined aortic and mitral valve disease. A clinical decision to operate, not operate or remain uncertain was made by experienced cardiologists given either Doppler echocardiographic or cardiac catheterization data. A prospective evaluation was performed on 189 consecutive patients (mean age 67 years) with valvular heart disease who were being considered for surgical treatment on the basis of clinical information. All patients underwent cardiac catheterization and detailed Doppler echocardiographic examination. Three sets of two cardiologist decision makers who did not know patient identity were given clinical information in combination with either Doppler echocardiographic or cardiac catheterization data. The combination of Doppler echocardiographic and clinical data was considered inadequate for clinical decision making in 21% of patients with aortic and 5% of patients with mitral valve disease. The combination of cardiac catheterization and clinical data was considered inadequate in 2% of patients with aortic and 2% of patients with mitral valve disease. Among the remaining patients, the cardiologists using echocardiographic or angiographic data were in agreement on the decision to operate or not operate in 113 (76% overall). When the data were analyzed by specific valve lesion, decisions based on Doppler echocardiography or catheterization were in agreement in 92%, 90%, 83% and 69%, respectively, of patients with aortic regurgitation, mitral stenosis, aortic stenosis and mitral regurgitation. Differences in cardiac output determination, estimation of valvular regurgitation and information concerning coronary anatomy were the main reasons for different clinical management decisions. These results suggest that for most adult patients with aortic or mitral valve disease, alone or in combination, Doppler echocardiographic data enable the clinician to make the same decision reached with catheterization data.     

Assessment of rheumatic mitral valve disease. Value of echocardiography in patients clinically suspected of predominant stenosis.

The value of echocardiography as compared with cardiac catheterisation was evaluated prospectively in 33 consecutive patients clinically suspected of predominant mitral stenosis. Patients with clinical signs of accompanying mitral regurgitation, no matter how severe, and patients with clinical findings indicating insignificant aortic valve disease were included. Critical mitral stenosis was defined by a valve area of less than or equal to 1 cm2. Severe mitral regurgitation was diagnosed by echocardiography on the basis of left ventricular dilatation (more than 3.2 cm/m2 at end-diastole) if not explained otherwise. Significant aortic valve disease was suspected in cases with aortic valve deformity and left ventricular dilatation or hypertrophy as defined by echocardiography. Mitral valve area by echocardiography correlated well with mitral valve area calculated from catheterisation data and a good interobserver correlation was found for echocardiographic measurement. Mitral stenosis, critical or non-critical, may mask significant coexistent valve lesions; echocardiography failed to discover severe mitral regurgitation requiring valve replacement in two patients with non-critical stenosis, and significant aortic regurgitation needing valve replacement was underestimated in one patient with critical mitral stenosis. A correct echocardiographic classification with respect to surgery, however, was obtained in: (1) all patients with clinically pure mitral stenosis (nine patients), and (2) all patients with combined mitral stenosis and regurgitation when either critical stenosis or severe regurgitation was found at echocardiography (12 patients). It thus appears that two out of three patients with mitral valve disease in whom the clinical findings indicate predominant stenosis can be correctly evaluated with the echocardiogram.     

Heart valve involvement in systemic lupus erythematosus: an echocardiographic study]

The purpose of this study was to evaluate the spectrum of morphologic and functional cardiac involvement in a selected population of patients with systemic lupus erythematosus (SLE) by means of echocardiography. Thirteen patients (2 male and 11 female) affected by SLE, mean age 41.9 years (range, 21-64), underwent M-Mode, two-dimensional and Doppler echocardiography. Eleven patients had renal disease and 3 of them were undergoing dialysis. One patient had findings of active disease. Six patients had systemic hypertension. None had a history suggestive of rheumatic fever or infective endocarditis. At echocardiographic study nine patients demonstrated findings of valvular involvement. These alterations were defined, according to the echocardiographic features, in two types: vegetation (verrucous Libman-Sacks endocarditis) and thickening. Vegetations were present in 6 patients, involving the mitral valve in all six and the aortic valve in three. The mitral valve vegetations were more frequent on the subannular portion of the posterior leaflet. Seven patients had valvular thickening: involvement of both mitral and aortic valve was present in five, and isolated mitral or aortic valve lesions in the remaining two patients. Combined valvular vegetation and thickening were observed in 4 patients. Eight patients had mild valvular dysfunction on Doppler examination: five isolated mitral regurgitation, two combined mitral and aortic regurgitation and one combined mitral stenosis and regurgitation. In agreement with previous reports, our study shows that valvular involvement in SLE is relatively frequent. Echocardiography can identify additional patterns of valvular lesions different from the known "verrucous Libman-Sacks endocarditis". The degree of valvular dysfunction is not important.     

Quantification of left-side intracardiac pressures and gradients using mitral and aortic regurgitant velocities by simultaneous left and right catheterization and continuous-wave doppler echocardiography

Noninvasive determination of left-side intracardiac pressures is of clinical importance in many cardiac diseases. To test the reliability and accuracy of left-side intracardiac pressure measurements by continuous-wave Doppler echocardiography, using left-side valvular regurgitations, 47 patients with mitral regurgitation, with or without associated aortic regurgitation, underwent simultaneous Doppler and left and right catheterization. Doppler-derived left atrial and ventricular end-diastolic pressures were respectively estimated by subtracting mitral regurgitant gradient from systolic blood pressure and by diastolic blood pressure minus aortic regurgitant gradient. There were high correlations of mitral (r = 0.961) and aortic regurgitant gradients (r = 0.896) and of left atrial (r = 0.945) and ventricular end-diastolic pressures (r=0.854) between noninvasive and invasive measurements. Also, agreement analyses showed that there was close agreement between the two technical measurements for each parameter. The present study concluded that continuous-wave Doppler echocardiography provides a reliable and accurate method for the noninvasive evaluation of left-side intracardiac pressures and gradients in patients with mitral and aortic regurgitations.     

Doppler echocardiographic evaluation of aortic stenosis

Doppler echocardiography allows accurate noninvasive measurement of transaortic velocity and pressure gradient in patients with valvular aortic stenosis. Because pressure gradients vary with transaortic volume flow, calculation of aortic valve area with the continuity equation is essential for complete echocardiographic evaluation of adult patients. The physician and sonographer should be aware of potential technical and physiologic pitfalls in applying Doppler echocardiographic techniques to the evaluation of the adult with aortic stenosis. With proper training and experience, however, the needed data can be obtained reliably and reproducibly. Doppler evaluation of patients with aortic stenosis has improved our understanding of the prevalence and natural history of this disease. In addition, Doppler measures of stenosis severity can be used in a cost-effective manner for clinical decision making regarding the need for valve replacement in symptomatic adults. It now has supplanted the need for invasive measures of stenosis severity in many of these patients.     

Assessment of valvular lesions with M-mode, two-dimensional and Doppler echocardiography

M-mode, two-dimensional and Doppler echocardiography enable evaluation of morphologic changes in valvular structures, detection of secondary changes in cardiac chambers and left ventricular function and quantification of blood flow patterns. In mitral stenosis, with M-mode echocardiography the diagnosis can be established on the basis of defined criteria, two-dimensional echocardiography enables planimetric calculation of the orifice area and Doppler echocardiography allows determination of the transvalvular pressure gradient and estimation of orifice area as well as detection of concomitant lesions. In mitral regurgitation, M-mode and two-dimensional echocardiography are less sensitive in its detection but they may be useful in delineating the etiology and whether the disease is of acute onset or chronic; the severity can only be judged indirectly on the basis of chamber dimensions. Doppler techniques render extremely sensitive and specific detection of mitral regurgitation as well as a means of quantifying severity. In this lesion, echocardiographic parameters have proven useful in the timing of valve replacement through early detection of myocardial dysfunction. In aortic regurgitation, M-mode and two-dimensional echocardiography may be useful in establishing the diagnosis, etiology, duration and, through assessment of dimensions and motion, estimating the severity as well. Doppler echocardiography is extremely sensitive and specific in the detection of aortic regurgitation and, additionally, provides a quantitative means for evaluation of severity. In aortic stenosis, both M-mode and two-dimensional echocardiography are sensitive in detection of changes in valve structure and motion but these methods are not capable of rendering reliable quantification of severity. Doppler techniques readily identify aortic stenosis and render, in addition, a close estimation of the transvalvular pressure gradient.