L. Leonardo Rodriguez

Recommendations for Evaluation of Prosthetic Valves With Echocardiography and Doppler Ultrasound. A Report From the American Society of Echocardiography's Guidelines and Standards Committee and the Task Force on Prosthetic Valves, Developed in Conjunction With the American College of Cardiology Cardiovascular Imaging Committee, Cardiac Imaging Committee of the American Heart Association

A Report From the American Society of Echocardiography’s Guidelines and Standards Committee and the Task Force on Prosthetic Valves, Developed in Conjunction With the American College of Cardiology Cardiovascular Imaging Committee, Cardiac Imaging Committee of the American Heart Association, the European Association of Echocardiography, a registered branch of the European Society of Cardiology, the Japanese Society of Echocardiography and the Canadian Society of Echocardiography, Endorsed by the American College of Cardiology Foundation, American Heart Association, European Association of Echocardiography, a registered branch of the European Society of Cardiology, the Japanese Society of Echocardiography, and Canadian Society of Echocardiography

Differentiation of Constrictive Pericarditis From Restrictive Cardiomyopathy: Assessment of Left Ventricular Diastolic Velocities in Longitudinal Axis by Doppler Tissue Imaging

OBJECTIVES We sought to determine the utility of left ventricular expansion velocities in differentiating constrictive pericarditis from restrictive cardiomyopathy. BACKGROUND Several studies have shown that left ventricular diastolic expansion is influenced by the elastic recoil forces of the myocardium. These forces are affected by intrinsic myocardial disease but should be preserved when diastole is impaired as a result of extrinsic causes. METHODS Using Doppler tissue imaging, we measured peak early velocity of longitudinal axis expansion (Ea) in 8 patients with constrictive pericarditis, 7 patients with restriction and 15 normal volunteers. Transmitral early (E) and late (A) Doppler flow velocities, left ventricular systolic and diastolic volumes, ejection fraction and mitral annular M-mode displacement were also compared between the groups. RESULTS The Ea value was significantly higher in normal subjects (14.5 +/- 4.7 cm/s [mean +/- SD]) and in patients with constriction (14.8 +/- 4.8 cm/s) than in those with restriction (5.1 +/- 1.4 cm/s, p < 0.001 constriction vs. restriction). There was weak correlation between Ea and the extent of annular displacement (r = 0.55, p = 0.004) and the E/A ratio (r = 0.44, p = 0.03). There was no correlation between Ea and E (r = 0.33, p = 0.07) or ejection fraction (r = 0.21, p = 0.26). By multivariate analysis, Ea was the best variable for differentiating constriction from restriction. CONCLUSIONS Our study indicates that longitudinal axis expansion velocities are markedly reduced in patients with restrictive cardiomyopathy. The poor correlation found with transvalvular flow velocities suggests that Ea may be relatively preload independent. The measurement of longitudinal axis expansion velocities provides a clinically useful distinction between constrictive pericarditis and restrictive cardiomyopathy and may prove to be valuable in the study of diastolic function.

AN INDEX OF EARLY LEFT VENTRICULAR FILLING THAT COMBINED WITH PULSED DOPPLER PEAK E VELOCITY MAY ESTIMATE CAPILLARY WEDGE PRESSURE

OBJECTIVES This study sought to determine the applicability of the combined information obtained from transmitral Doppler flow and color M-mode Doppler flow propagation velocities for estimating pulmonary capillary wedge pressure. BACKGROUND Although Doppler-derived measurements of left ventricular (LV) filling have been applied to determine left atrial pressure, their accuracy has been limited by the variable effect of ventricular relaxation in these indexes. Recently, flow propagation velocity measured by color M-mode Doppler echocardiography has been suggested as an index of ventricular relaxation. METHODS We studied 45 patients admitted to the intensive care unit who underwent invasive hemodynamic monitoring. We measured peak early (E) and late (A) transmitral Doppler velocities, E/A ratio and flow propagation velocity (vp) and compared them by linear regression with pulmonary capillary wedge pressure (pw). RESULTS We found a modest positive correlation between pw and E (r = 0.62, p < 0.001) and the E/A ratio (r = 0.52, p < 0.001) and a negative correlation between pw and vp (r = -0.34, p = 0.02). By stepwise linear regression, only E and vp were statistically significant predictors of pw. However, the E/vp ratio provided the best estimate of pw (r = 0.80, p < 0.001; pw = 5.27 x [E/vp] + 4.6, SEE 3.1 mm Hg). CONCLUSIONS The ratio of component velocity (E) over the color M-mode propagation velocity during early LV filling, by correcting for the effect of LV relaxation, provides a better estimate of pw than standard measurements of transmitral Doppler flow.

Assessment of mitral annular dynamics during diastole by Doppler tissue imaging : Comparison with mitral Doppler inflow in subjects without heart disease and in patients with left ventricular hypertrophy

The purpose of this study was to determine the normal pattern and magnitude of mitral annular velocities in diastole by Doppler tissue imaging (DTI) and to assess whether this is altered in patients with left ventricular hypertrophy. Mitral annulus velocities were measured by DTI. Peak and time-velocity integral were measured from the DTI tracings and the timing of the velocities in relation to electrocardiogram. DTI was compared with M-mode echo of the annulus and mitral inflow Doppler velocities. Integrated annular velocities by DTI correlated with the annular displacement. Early diastolic velocities decreased with age and in patients with left ventricular hypertrophy. In the hypertrophy group, early diastolic velocities were significantly lower than normal even after correcting for age. Patients with left ventricular hypertrophy also showed a delay in peak early diastolic mitral annular velocity (5.5 +/- 21 msec after the E wave). In conclusion, mitral annular velocity in diastole is readily recorded by DTI. The magnitude and the pattern of these velocities are significantly altered by age and by left ventricular hypertrophy. This method provides a new insight into diastolic filling events and may prove useful in detecting abnormal diastolic function.

Myocardial wall velocity assessment by pulsed Doppler tissue imaging: Characteristic findings in normal subjects

To validate the use of pulsed Doppler tissue imaging that measures myocardial wall velocities and to define the characteristics of these velocities in normal subjects, we obtained and compared the anteroseptal and posterior wall velocities in 24 volunteers with pulsed Doppler tissue imaging and digitized M-mode echocardiography. We also studied the relation between velocity components and hemodynamic events timed by standard Doppler flows. There was an excellent correlation between Doppler and M-mode-derived velocities (r = 0.95, p < 0.001), with higher reproducibility for Doppler (r = 0.99) than for M-mode (r = 0.95, p < 0.001). Biphasic velocities that were uniformly present during isovolumic contraction and relaxation were attributed to geometric changes due to asynchronous contraction and ventricular interdependence. We conclude that wall velocities obtained by pulsed Doppler tissue imaging are accurate and reproducible. This method may prove useful for studying the contractile and elastic properties of the myocardium.

Comparison of New Doppler Echocardiographic Methods to Differentiate Constrictive Pericardial Heart Disease and Restrictive Cardiomyopathy

This study assesses how the newer modalities of tissue Doppler echocardiography and color M-mode flow propagation compare with respiratory variation of Doppler flow in distinguishing between constrictive pericarditis and restrictive cardiomyopathy. We studied 30 patients referred for further evaluation of diastolic function who had a diagnosis of constrictive pericarditis or restrictive cardiomyopathy established by diagnostic tests, including clinical assessment, magnetic resonance imaging, cardiac catheterization, endomyocardial biopsy, and surgical findings. Nineteen patients had constrictive pericarditis and 11 had restrictive cardiomyopathy. We performed 2-dimensional transesophageal echocardiography combined with pulsed-wave Doppler of the pulmonary veins and mitral inflow with respiratory monitoring, tissue Doppler echocardiography of the lateral mitral annulus, and color M-mode flow propagation of left ventricular filling. Respiratory variation of the mitral inflow peak early (peak E) velocity of > or =10% predicted constrictive pericarditis with 84% sensitivity and 91% specificity and variation in the pulmonary venous peak diastolic (peak D) flow velocity of > or =18% distinguished constriction with 79% sensitivity and 91% specificity. Using tissue Doppler echocardiography, a peak early velocity of longitudinal expansion (peak Ea) of > or =8.0 cm/s differentiated patients with constriction from restriction with 89% sensitivity and 100% specificity. A slope of > or =100 cm/s for the first aliasing contour in color M-mode flow propagation predicted patients with constriction with 74% sensitivity and 91% specificity. Thus, the newer methods of tissue Doppler echocardiography and color M-mode flow propagation are equivalent and complimentary with Doppler respiratory variation in distinguishing between constrictive pericarditis and restrictive cardiomyopathy. The additive role of the new methods needs to be established in difficult cases of constrictive pericarditis where respiratory variation may be absent or decreased.

Initial experience with the Cosgrove-Edwards annuloplasty system

BACKGROUND The mitral valve has a nonplanar shape and a sphincter action. Pathologic dilatation occurs along the posterior annulus. To preserve the physiologic function and correct annular dilatation, we developed an annuloplasty system that is universally flexible and produces a measured plication of the posterior annulus (Cosgrove-Edwards Annuloplasty System). METHODS The results of 150 consecutive mitral valve repairs using this system were analyzed. Mean age was 58 +/- 13 years; 59% were men. The cause of the valve disease was degenerative in 75% of the patients, rheumatic in 13%, ischemic in 8%, and infectious in 4%. Associated procedures were performed in 61 patients (41%). RESULTS Echocardiographic mitral regurgitation decreased from 3.7 +/- 0.6 before repair to 0.2 +/- 0.4 after repair (p < 0.0001). There were no hospital deaths and no cases of hemodynamically significant systolic anterior motion or other annuloplasty-related complications. Follow-up was 100% complete at a mean of 3.1 +/- 3.6 months. There were three late deaths, three transient ischemic attacks, and one episode of endocarditis. Five patients (3.3%) have undergone reoperation for recurrent mitral insufficiency; no reoperations were related to the annuloplasty system. At a mean of 9 months, three-dimensional reconstruction of the mitral annulus from multiple echocardiographic images confirmed the nonplanar shape and sphincter mechanism of the annulus. Annular orifice area decreased 19% during the cardiac cycle from a mean of 10.3 cm2 in diastole to 8.6 cm2 in systole. CONCLUSIONS This annuloplasty system is effective for repair of insufficiency secondary to all causes, preserves physiologic annulus function, and is associated with a low incidence of valve-related complication.

Impact of finite orifice size on proximal flow convergence. Implications for Doppler quantification of valvular regurgitation.

Analysis of velocity acceleration proximal to a regurgitant valve has been proposed as a method to quantify the regurgitant flow rate (Qo). Previous work has assumed inviscid flow through an infinitesimal orifice, predicting hemispheric isovelocity shells, with calculated flow rate given by Qc = 2 pi rN2vN, where vN is user-selected velocity of interest and rN is the distance from that velocity to the orifice. To validate this approach more rigorously and investigate the impact of finite orifice size on the assumption of hemispheric symmetry, numerical and in vitro modeling was used. Finite-difference modeling demonstrated hemispheric shape for contours more than two orifice diameters from the orifice. More proximal than this (where the measured velocity vN exceeded 3% of the orifice velocity vo), flow was progressively underestimated, with a proportional error delta Q/Qo nearly identical to the ratio of contour velocity to orifice velocity, vN/vo. For the in vitro investigations, flow rates from 4.3 to 150 cm3/sec through 0.3 and 1.0 cm2 circular orifices were imaged with color Doppler with aliasing velocities from 19 to 36 cm/sec. Overall, the calculated flow (assuming hemispheric symmetry) correlated well with the true flow, Qc = 0.88Qo-7.82 (r = 0.945, SD = 12.2 cm3/sec, p less than 0.0001, n = 48), but progressively underestimated flow when the vN approached the orifice velocity vo. Applying a correction factor predicted by the numerical modeling, delta Q was improved from -13.81 +/- 13.01 cm3/sec (mean +/- SD) to +1.54 +/- 5.67 cm3/sec.(ABSTRACT TRUNCATED AT 250 WORDS)

Validation of the proximal flow convergence method. Calculation of orifice area in patients with mitral stenosis.

BACKGROUND It has been proposed recently that measuring the flow convergence region proximal to an orifice by Doppler flow mapping can provide a means of calculating regurgitant flow rate. Although verified in experimental models, this approach is difficult to validate clinically because there is no ideal gold standard for regurgitant flows in patients. However, this method also can be used to derive cardiac output or flow rate proximal to stenotic orifices and therefore to calculate their areas by the continuity equation (area = flow rate/velocity). Applying this method in mitral stenosis would provide a unique way of validating the underlying concept because the predicted areas could be compared with those measured directly by planimetry. METHODS AND RESULTS We studied 40 patients with mitral stenosis using imaging and Doppler echocardiography. Doppler color flow recordings of mitral inflow were obtained from the apex, and the radius of the proximal flow convergence region was measured at its peak diastolic value from the orifice to the first color alias along the axis of flow. Flow rate was calculated assuming uniform radial flow convergence toward the orifice, modified by a factor that accounted for the inflow funnel angle formed by the mitral leaflets. Mitral valve area was then calculated as peak flow rate divided by peak velocity by continuous-wave Doppler. The calculated areas agreed well with those from three comparative techniques over a range of 0.5 to 2.2 cm2: 1) cross-sectional area by planimetry (y = 1.08x-0.13, r = .91, SEE = 0.21 cm2); 2) area derived from the Doppler pressure half-time (y = 1.02x-0.14, r = .89, SEE = 0.24 cm2); and 3) area calculated by the Gorlin equation in the 26 patients who underwent catheterization (y = 0.89x + 0.08, r = .86, SEE = 0.24 cm2). Agreement with planimetry was similar for 22 patients with mitral regurgitation and 18 without it (P > .6), as well as for 6 in atrial fibrillation (P > .2). CONCLUSIONS These results validate the proximal flow convergence concept in the clinical setting and also demonstrate that it can be extended to orifice area calculation using the continuity equation.

Noninvasive estimation of the instantaneous first derivative of left ventricular pressure using continuous-wave Doppler echocardiography.

BackgroundThe complete continuous-wave Doppler mitral regurgitant velocity curve should allow reconstruction of the ventriculoatrial (VA) pressure gradient from mitral valve closure to opening, including left ventricular (LV) isovolumic contraction, ejection, and isovolumic relaxation. Assuming that the left atrial pressure fluctuation is relatively minor in comparison with the corresponding LV pressure changes during systole, the first derivative of the Doppler-derived VA pressure gradient curve (Doppler dP/dt) might be used to estimate the LV dP/dt curve, previously measurable only at catheterization (catheter dP/dt). Methods and ResultsThis hypothesis was examined in an in vivo mitral regurgitant model during 30 hemodynamic stages in eight dogs. Contractility and relaxation were altered by inotropic stimulation and hypothermia. The Doppler mitral regurgitant velocity spectrum was recorded along with simultaneously acquired micromanometer LV and left atrial pressures. The regurgitant velocity profiles were digitized and converted to VA pressure gradient curves using the simplified Bernoulli equation. The instantaneous dP/dt of the VA pressure gradient curve was then derived. The instantaneous Doppler-derived VA pressure gradients, instantaneous Doppler dP/dt, dP/dtmax, and −dP/dtmax were compared with corresponding catheter measurements. This method of estimating dP/dtmax, from the instantaneous dP/dt curve was also compared with a previously proposed Doppler method of estimating dP/dtmax using the Doppler-derived mean rate of LV pressure rise over the time period between velocities of 1 and 3 m/sec on the ascending slope of the Doppler velocity spectrum. Both instantaneous Doppler-derived VA pressure gradients (r = 0.95, p < O.OOOl) and Doppler dP/dt (r = 0.92, p < 0.0001) correlated well with corresponding measurements by catheter during systolic contraction and isovolumic relaxation (pooled data). The Doppler dP/dtmax (1,266 ± 701 mm Hg/sec) also correlated well (r = 0.94) with the catheter dP/dtmax (1,200 ± 573 mm Hg/sec). There was no difference between the two methods for measurement of dP/dtmax (p=NS). Although Doppler −dP/dt. was slightly lower than the catheter measurement (961 ± 511 versus 1,057540 mm Hg/sec, p < 0.01), the correlation between measurements by Doppler and catheter was excellent (r = 0.93, p < 0.0001). The alternative method ofmean isovolumic pressure rise (896 ± 465 mm Hg/sec) underestimated the catheter dP/dtmax, (1,200 ± 573 mm Hg/sec) significantly (on average, 25%; p < O.001). ConclusionsThe present study demonstrated an accurate and reliable noninvasive Doppler method for estimating instantaneous LV dP/dt, dP/dtma, and −dP/dtmax. (Circulation 1991; 83:2101—2110)