Miguel Ares

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.

An integrated approach to the quantification of aortic regurgitation by Doppler echocardiography

BACKGROUND Although different Doppler methods have been proposed for the quantification of aortic regurgitation, no study has prospectively compared these methods with each other and their correlation with angiography. The aim of this study was to prospectively analyze the usefulness of different Doppler echocardiography parameters by testing all such parameters in each patient. METHODS Fifty-one patients with aortic regurgitation underwent 2-dimensional and Doppler echocardiographic studies and catheterization. The following Doppler indexes were analyzed and compared with aortography. Color Doppler: (1) jet color height/left ventricular outflow tract height in parasternal long-axis view, and (2) jet color area/left ventricular outflow tract area in short-axis view. Continuous Doppler: (3) regurgitant flow pressure half-time, (4) regurgitant flow time velocity integral (in centimeters), and (5) regurgitant flow time velocity integral (in centimeters)/diastolic period (in milliseconds). Pulsed Doppler in thoracic and abdominal aorta: (6) time velocity integral of diastolic reverse flow (in centimeters), (7) time velocity integral of systolic anterograde flow/integral of diastolic reverse flow, (8) (time velocity integral of diastolic reverse flow/diastolic period) x 100, and (9) diastolic reverse flow duration/diastolic period (as a percentage). We compared these parameters with severity of regurgitation measured by angiography and classified as mild, moderate, or severe. RESULTS The most useful parameters were (1) jet color height/left ventricular outflow tract height (correctly classified 42 of 49 patients), (2) (time velocity integral of diastolic reverse flow/diastolic period) x 100 in the thoracic aorta (correctly classified 41 of 46 patients), and (3) (time velocity integral of diastolic reverse flow/diastolic period) x 100 in the abdominal aorta (correctly classified 42 of 49 patients). Sequential integration of these 3 parameters correctly classified 96% of patients (44 of 46 patients) and was achieved in 90% of cases. CONCLUSION An integrated combination of several Doppler parameters can quickly and accurately classify the degree of aortic regurgitation as determined by angiography.

Comparison of persistent thallium perfusion defects by quantitative washout analysis with thallium reinjection in patients with coronary artery disease

Thallium reinjection can improve the detection of severely ischemic viable myocardium in patients with coronary artery disease. However, a disadvantage of this method is that it requires the acquisition of 3 separate sets of images and the administration of an additional dose of the radiotracer. Alternatively, quantitative analysis of the regional myocardial washout of thallium-201 can be easily obtained from the conventional postexercise and redistribution images without additional imaging time or radiation exposure to the patient. To determine whether this method can predict the results of thallium reinjection, this study analyzed thallium-201 images of 31 patients who had persistent perfusion defects in qualitative exercise/delayed redistribution single-photon emission computed tomographic thallium studies and who underwent thallium reinjection. The quantitative mean radioactive counts of each myocardial segment that had a persistent perfusion defect in the initial and delayed redistribution on 4-hour short-axis tomographic slices were measured to derive a delayed/initial ratio, and these values were compared with the results of thallium reinjection. The delayed/initial ratio was 1.06 +/- 0.22 in 39 segments that improved, versus 0.58 +/- 0.18 in 43 segments without improvement after reinjection (p < 0.001). Thirty-eight of the 39 segments that improved had a ratio of > or = 0.75, versus only 3 of the 43 segments that showed no improvement (sensitivity, 98%; specificity, 91%). The correlation between the delayed/initial ratio and reinjection results was equally high at any segment location or severity. It is concluded that quantitative regional thallium washout analysis predicts the results of thallium reinjection in segments with persistent thallium defects.(ABSTRACT TRUNCATED AT 250 WORDS)