Use of pulsed Doppler tissue imaging to assess regional left ventricular diastolic dysfunction in hypertrophic cardiomyopathy

In this study, regional diastolic patterns and their relations with transmitral Doppler inflow were investigated in hypertrophic cardiomyopathy (HC) by pulsed Doppler tissue imaging (DTI). Doppler echocardiography and DTI of basal septum and lateral wall (apical 4-chamber view) were performed in 20 patients (15 men and 5 women) with HC and in 10 healthy subjects (7 men and 3 women). Diabetes, hypertension, coronary artery and valvular disease, mitral regurgitation, New York Heart Association functional classes III to IV, sinus tachycardia, atrial fibrillation, and inadequate echocardiograms were exclusion criteria. Peak velocity and time-velocity integral of early and late waves and their ratios, and deceleration and isovolumic relaxation times were determined by standard Doppler and by DTI at the septal and lateral wall levels. The 2 groups were comparable for age, heart rate, blood pressure, and ejection fraction. Transmitral peak velocity and time-velocity integral E/A ratios were reduced (both p <0.05) and deceleration and isovolumic relaxation times prolonged (both p <0.00001) in HC. Septal DTI showed lower peak velocity and time-velocity integral e/a ratios (p <0.00001 and p <0.001, respectively) and lengthened regional deceleration (p <0.01) and isovolumic (p <0.001) relaxation times. DTI of the lateral wall showed a prolongation of deceleration and isovolumic relaxation times (both p <0.01). By dividing HC according to transmitral E/A, 8 patients with E/A <1 had lower DTI septal e/a ratio (p <0.01) and prolonged septal deceleration and isovolumic relaxation times (both p <0.01) but no changes in DTI pattern of lateral wall than 12 patients with E/A > 1. In conclusion, DTI is useful and complementary to standard Doppler imaging to characterize diastolic properties in HC, reflecting a typical pattern of intramyocardial impaired relaxation at the level of hypertrophied septum and also providing information about the degree of this regional impairment. The lateral wall presents minor changes in diastolic times, which indicate how diastolic asynchrony is not confined to the hypertrophied segment in HC.     

Left ventricular diastolic properties of hypertensive patients measured by pulsed tissue Doppler imaging

Examination of left ventricular (LV) diastolic dysfunction in hypertensive patients has been based on parameters obtained from the transmitral flow velocity during pulsed Doppler echocardiography. However, these parameters are affected by loading conditions. We evaluated LV diastolic function along the longitudinal and transverse axes by pulsed tissue Doppler imaging (TDI) in 50 hypertensive (HT) patients and 36 age-matched healthy volunteers (N). Transmitral flow velocity was recorded by pulsed Doppler echocardiography. LV posterior wall motion velocity along the longitudinal and transverse axes also was recorded by pulsed TDI. In both groups, peak early diastolic velocity of the LV posterior wall (Ew) along the transverse axis (N: 15.8+/-5.2 cm/s, HT: 12.2+/-4.4 cm/s) was higher than that along the longitudinal axis (N: 12.7+/-3.1 cm/s, HT: 9.5+/-3.3 cm/s). Peak atrial systolic velocity of the LV posterior wall (Aw) along the longitudinal axis (N: 9.1+/-1.8 cm/s, HT: 9.7 +/-2.6 cm/s) significantly exceeded that along the transverse axis (N: 8.0+/-2.2 cm/s, HT: 8.4+/-2.4 cm/s) in both groups. The Ews were lower and the Aws were higher along both axes in the patient group than in the control group. The time intervals from the aortic component of the second heart sound to the peak of the early diastolic wave (IIA-Ews) along both the transverse (N: 142+/-18 ms, HT: 154+/-19 ms) and longitudinal (N: 151 16 ms, HT: 162+/-20 ms) axes were longer in the patient group. In 29 patients, Ews along both axes correlated negatively (transverse: r = -0.80, P < .0001; longitudinal: r = -0.71, P < .0001) and IIA-Ews correlated positively (transverse: r = 0.81, P < .0001; longitudinal: r = 0.74, P < .001) with the time constant of the LV pressure decay during isovolumic diastole. The Aws along both axes in the 24 patients without pseudonormalization in transmitral flow velocity correlated positively (transverse: r = 0.60, P < .001; longitudinal: r = 0.74, P < .0001) with the LV end-diastolic pressure. In conclusion, LV relaxation and filling along the longitudinal and transverse axes were impaired in many patients with hypertension. Pulsed TDI was useful for evaluating LV diastolic dynamics in this disease.     

A new approach for evaluation of left ventricular diastolic function: spatial and temporal analysis of left ventricular filling flow propagation by color M-mode Doppler echocardiography

OBJECTIVES: To evaluate left ventricular diastolic function and differentiate the pseudonormalized transmitral flow pattern from the normal pattern, the propagation of left ventricular early filling flow was assessed quantitatively using color M-mode Doppler echocardiography. BACKGROUND: Because the propagation of left ventricular early filling flow is disturbed in the left ventricle with impaired relaxation, quantification of such alterations should provide useful indexes for the evaluation of left ventricular diastolic function. METHODS: Study subjects were classified into three groups according to the ratio of early to late transmitral flow velocity (E/A ratio) and left ventricular ejection fraction: 29 subjects with an ejection fraction > or = 60% (control group); 34 with an ejection fraction < 60% and E/A ratio < 1 (group I); and 25 with ejection fraction < 60% and E/A ratio > or = 1 (group II). The propagation of peak early filling flow was visualized by changing the first aliasing limit of the color Doppler signals. The rate of propagation of peak early filling flow velocity was defined as the distance/time ratio between two sampling points: the point of the maximal velocity around the mitral orifice and the point in the mid-left ventricle at which the velocity decreased to 70% of its initial value. High fidelity manometer-tipped measurement was performed in 40 randomly selected subjects. RESULTS: The rate of propagation decreased in groups I and II compared with that in the control group (33.8 +/- 13.8 [mean +/- SD] and 30.0 +/- 8.6 vs. 74.3 +/- 17.4 cm/s, p < 0.001, respectively) and correlated inversely with the time constant of left ventricular isovolumetric relaxation and the minimal first derivative of left ventricular pressure (peak negative dP/dt) (r = 0.82 and r = 0.72, respectively). CONCLUSIONS: Spatial and temporal analysis of filling flow propagation by color M-mode Doppler echocardiography was free of pseudonormalization and correlated well with the invasive variables of left ventricular relaxation.     

Clinical application of pulsed Doppler tissue imaging for assessing abnormal left ventricular relaxation

Conventional assessment of left ventricular (LV) relaxation by calculating the time constant of LV pressure decay during the isovolumic diastole requires an invasive approach. Conversely, noninvasive parameters obtained by measuring isovolumic relaxation time and transmitral flow velocity often give inaccurate information. Using LV pressure curve, pulsed Doppler echocardiography, and pulsed Doppler tissue imaging in 38 patients with heart disease and 12 control subjects, we calculated the time constant and recorded transmitral flow velocity and motion velocities at the endocardial portions of the ventricular septum and LV posterior wall. Compared with the controls, patients exhibited a prolonged time constant, a decreased peak early diastolic velocity of the LV posterior wall, and a prolonged time interval from the second heart sound to the peak of the early diastolic wave. The time constant correlated well with the isovolumic relaxation time and various parameters calculated from the transmitral flow velocity, except in patients with elevated LV end-diastolic pressure. In all subjects, the time constant correlated negatively with the peak early diastolic velocity of the posterior wall and positively with the time from the second heart sound to the peak of the early diastolic wave. Thus, early diastolic parameters derived from the motion velocity of the LV posterior wall by pulsed Doppler tissue imaging were closely related to the time constant. This technique may allow noninvasive evaluation of abnormal LV relaxation in patients with various heart diseases.     

Doppler echocardiographic assessment of left ventricular diastolic function in myotonic dystrophy

To determine the increased production and release of vascular endothelial growth factor (VEGF) from the retina in the eye with non-angiogenic retinal detachment in which relative blood supply disturbance may be present, the concentration of VEGF in subretinal fluid and vitreous fluid collected from the eyes was investigated by enzyme linked immunospecific assay. The average concentration of VEGF was 0.5 +/- 1.1 ng/ml (mean +/- standard deviation) in nine samples of vitreous fluid collected from proliferative retinal detachment, and was 1.2 +/- 1.2 ng/ml in eleven samples of subretinal fluid from rhegmatogenous retinal detachment. The concentration of VEGF in six samples of vitreous fluid from angiogenic diabetic eyes (5.0 +/- 2.8 ng/ml) was significantly higher than in the samples from eyes with retinal detachment. The results suggest that the relative ischemic insult to the detached retina increases the release of VEGF into the vitreous cavity and subretinal space. The increased concentration of VEGF does not induce remarkable angiogenesis since the concentration is lower than the biological threshold, or the effect is modulated by inhibitors.     

Negative intraventricular diastolic pressure in patients with mitral stenosis: evidence of left ventricular diastolic suction

Left ventricular diastolic pressure was evaluated in 15 patients with mitral stenosis and 16 patients with no significant heart disease to determine if a stenotic mitral valve can cause the left ventricle to produce a negative diastolic pressure, indicative of ventricular diastolic suction. The minimal level of diastolic pressure in patients with mitral stenosis ranged between 6 and -7 mm Hg; in normal subjects it did not fall below 0. The average value of minimal diastolic pressure in patients with mitral stenosis (-2 +/- 1 mm Hg [mean +/- standard error of the mean]) was significantly lower than in patients without significant heart disease (5 +/- 1 mm Hg) (p less than 0.001). These observations indicate that the human left ventricle, in the presence of mitral stenosis, can generate a negative diastolic pressure. The presence of a negative diastolic pressure in patients with mitral stenosis suggests that the dynamics of the ventricle during diastole may contribute to the filling process.     

Color-coded measures of myocardial velocity throughout the cardiac cycle by tissue Doppler imaging to quantify regional left ventricular function

TDI is a new echocardiographic technique that calculates and displays color-coded myocardial velocity on-line. To determine the feasibility of endocardial velocity throughout the cardiac cycle as a means to quantify regional function, 20 normal subjects aged 30 +/- 5 years and 12 patients with heart disease aged 62 +/- 17 years were studied with a prototype TDI system. TDI M-mode images were acquired by using a multicolored velocity map (display range, -30 to 30 mm/sec; temporal resolution, 90 Hz). Color-coded velocity data were then converted to numeric values off-line at 50 msec intervals. Posterior wall velocities throughout the cardiac cycle by TDI were closely correlated with velocity calculations from the first derivative of routine digitized M-mode tracings (group mean r = 0.88 +/- 0.03, SEE = 7.0 +/- 1.1 mm/sec). Anteroseptal TDI color-coded systolic velocity occurred 164 +/- 84 msec from the onset of the electrocardiographic QRS compared with 203 +/- 33 msec in the posterior wall (P < 0.05) in normal subjects, consistent with normal electrical activation. Significant differences in systolic and diastolic posterior wall TDI velocity data were observed in patients with hypokinetic or akinetic segments assessed by independent routine study when compared with normal controls. Calculated systolic and early diastolic posterior wall TDI indexes correlated significantly with percentage of wall thickening. Of abnormal anteroseptal segments, TDI systolic time velocity integrals were significantly different than normal and correlated with percentage of wall thickening. TDI has potential to quantitatively assess regional left ventricular function.     

Beta-adrenergic stimulation enhances left ventricular diastolic performance in normal subjects

To determine the effects of beta-adrenergic stimulation on transmitral Doppler echocardiography flow characteristics of left ventricular diastolic filling, we studied 10 healthy volunteers aged 23-31 years (mean age, 26.6 years) during intravenous infusion of isoprenaline in consecutive steps of 0.1, 0.2, 0.4, 0.75, and 1.5 micrograms/min (each for 15 min). Saline control infusion was given in the same manner in a crossover and blinded protocol. Compared with the infusion of placebo, stepwise increasing doses of isoprenaline caused a dose-related increase in early and late diastolic filling velocities and velocity-time integrals, a lengthening of the acceleration time, and a shortening of the deceleration and filling time. The chosen method proved highly sensitive, as statistically significant changes were detectable at the lowest dose of 0.1 microgram/min for all variables except velocity-time integral of late filling and deceleration time (> or = 0.2 microgram/min). The effects related to dose in a log-linear fashion except for the lengthening of the acceleration time (early ceiling), the increase of peak early filling velocity (increased steepness at higher doses), and the shortening of the filling time. Inclusion of the associated increases in heart rate and systolic blood pressure and the decrease in diastolic blood pressure blunted all treatment contrasts except for the increase of peak early filling velocity. In addition, the hemodynamics with respect to heart rate and loading conditions were not altered at low dosages of drug (< 0.4 microgram/min). Effects of at least the peak early filling velocity must be interpreted as an active adrenergically mediated myocardial relaxation process. These findings have potentially important clinical implications for this noninvasive, readily available, and convenient technique in clinical pharmacology, stress testing, and possibly therapeutic interventions in diastolic dysfunction in humans.     

Comparison of regional myocardial velocities assessed by quantitative 2-dimensional and M-mode color Doppler tissue imaging: influence of the signal-to-noise ratio of color Doppler myocardial images on velocity estimators of the Doppler tissue imaging system

M-mode color Doppler imaging of the myocardium affords a greater sampling rate and signal-to-noise (S/N) ratio than 2-dimensional (2D) imaging. In this study, we compared myocardial velocities assessed by 2D and M-mode Doppler tissue imaging (DTI) at the same site and evaluated the influence of the S/N ratio on velocity estimates of the currently used DTI systems. In patients with and without impaired regional left ventricular function, myocardial velocities assessed by 2D DTI were lower than those obtained with M-mode DTI. The difference between regional velocities derived from both imaging techniques was positively correlated with the extent of the "black zone," which could be considered as indirectly reflecting the S/N ratio for each frame. Thus in the clinical setting and on currently used echocardiographs, 2D DTI may provide underestimated regional myocardial velocities when compared with M-mode, mainly because of the influence of the lower sampling rate and S/N ratio on velocity estimators of the imaging system.     

Right ventricular diastolic disfunction and its relation to left ventricular performance in patients with hypertension

The potential effects of propofol emulsion (Diprivan) on the neuromuscular transmission and muscular contraction were studied using in vitro and in vivo nerve-muscle preparations of rats. The contractions of the isolated rat diaphragm elicited by either indirect or direct electrical stimulation were inhibited by propofol emulsion at threshold concentrations of 42 and 112 mumol l-1, respectively. Similarly, the gastrocnemius muscle contractions induced by either indirect or direct electrical stimulation in vivo were inhibited by propofol emulsion administration as a bolus injection of 2.5 mg kg-1 intravenously, followed by intravenous infusion of 150 micrograms kg-1 min-1 for 1 h into rats. The inhibitory effects of propofol in both preparations were greater with indirect rather than direct stimulation. Propofol emulsion was found to be capable of enhancing the paralysis of the indirectly stimulated rat diaphragm in vitro and gastrocnemius muscle in vivo induced by either pipecuronium or succinylcholine. The combination of propofol and pipecuronium led to a synergistic inhibition of the neuromuscular transmission, while the combination of propofol and succinylcholine led to additive inhibition. Pretreatment with propofol emulsion at these threshold concentrations markedly inhibited the stimulant effects of aminophylline and digoxin on the indirectly and directly induced diaphragmatic contractions. Also, the enhancement effects of aminophylline on the indirectly and directly and of digoxin on indirectly induced rat gastrocnemius muscle contractions were markedly inhibited by propofol emulsion administration to rats. Pretreatment with propofol emulsion at the threshold concentrations enhanced the inhibitory effects of verapamil on diaphragmatic contractions elicited either indirectly or directly and enhanced the inhibitory effect of adenosine on the contractions elicited indirectly. Similarly, the inhibitory effects of verapamil on the indirectly and directly and of adenosine on indirectly induced rat gastrocnemius muscle contractions were markedly potentiated by propofol emulsion administration to rats. In addition, doubling the concentration of calcium in the bathing fluid produced no change in the inhibitory effects of propofol emulsion on either indirectly or directly elicited diaphragmatic contractions, while doubling the concentration of external magnesium potentiated the propofol effects. Pretreatment with 4-aminopyridine suppressed the inhibitory effects of propofol emulsion on diaphragmatic contractions elicited either indirectly or directly. These results suggest that propofol acts presynaptically to inhibit the neuromuscular transmission and acts at the muscle membrane to inhibit the muscular contraction.     

Grading of mitral regurgitation by quantitative Doppler echocardiography: calibration by left ventricular angiography in routine clinical practice

BACKGROUND: Quantitative Doppler echocardiography and proximal flow convergence methods are validated techniques for quantifying mitral regurgitation. However, the clinical interpretation of the values calculated is hindered by the absence of calibration of ranges of severity in large numbers of patients. METHODS AND RESULTS: In 180 consecutive patients (men, 62%; mean age+/-SD, 66+/-11 years), the results of Doppler quantification of isolated mitral regurgitation were calibrated by use of left ventricular angiographic grading performed within 3 months in routine practice and without intervening events. The thresholds of the quantitative variables corresponding to the angiographic grades were identified by maximizing the sum of sensitivity and specificity and minimizing their difference. The mitral regurgitation grade by angiography was 2.7+/-1.3. The mean value and correlation with angiographic grades for effective regurgitant orifice were 43+/-37 mm and r=.79 (P<.0001); for regurgitant volume, 62+/-45 mL and r=.80 (P<.0001); and for regurgitant fraction, 45+/-17% and r=.78 (P<.0001). Despite some overlap, differences between mitral regurgitation grades were all significant (all P<.05). The thresholds for severe mitral regurgitation (grade 4) were 60 mL, 50%, and 40 mm2 for regurgitant volume, regurgitant fraction, and orifice, respectively. CONCLUSIONS: In routine practice in large numbers of patients in a clinical laboratory, Doppler echocardiographic quantification of mitral regurgitation shows highly significant correlation with qualitative angiographic grades. Despite an expected overlap between classes, the calibration by angiography of grading ranges for the quantitative variables provides a framework for their interpretation and allows the definition in clinical practice of thresholds for severe mitral regurgitation.     

Doppler estimation of left ventricular filling pressure in sinus tachycardia. A new application of tissue doppler imaging

BACKGROUND: Doppler echocardiography is frequently used to predict filling pressures in normal sinus rhythm, but it is unknown whether it can be applied in sinus tachycardia, with merging of E and A velocities. Tissue Doppler imaging (TDI) can record the mitral annular velocity. The early diastolic velocity (Ea) behaves as a relative load-independent index of left ventricular relaxation, which corrects the influence of relaxation on the transmitral E velocity. METHODS AND RESULTS: We evaluated 100 patients 64+/-12 years old with simultaneous Doppler and invasive hemodynamics. Mitral inflow was classified into 3 patterns: complete merging of E and A velocities (pattern A), discernible velocities with A dominance (B), or E dominance (C). The Doppler data were analyzed at the mitral valve tips for E, acceleration and deceleration times of E, and isovolumic relaxation time. In patterns B and C, the A velocity, E/A ratio, and atrial filling fraction were derived. Pulmonary venous flow velocities were also measured, and TDI was used to acquire Ea and Aa. Weak significant relations were observed between pulmonary capillary wedge pressure (PCWP) and sole parameters of mitral flow, pulmonary venous flow, and annular measurements. These were better for patterns A and C. E/Ea ratio had the strongest relation to PCWP [r=0.86, PCWP=1.55+1.47(E/Ea)], irrespective of the pattern and ejection fraction. This equation was tested prospectively in 20 patients with sinus tachycardia. A strong relation was observed between catheter and Doppler PCWP (r=0.91), with a mean difference of 0.4+/-2.8 mm Hg. CONCLUSIONS: The ratio of transmitral E velocity to Ea can be used to estimate PCWP with reasonable accuracy in sinus tachycardia, even with complete merging of E and A velocities.     

Left ventricular diastolic filling alterations in subjects with mitral valve prolapse: a Doppler echocardiographic study

To assess left ventricular diastolic filling in mitral valve prolapse (MVP), we studied 22 patients with idiopathic MVP and 22 healthy controls matched for sex, age, body surface area and heart rate. A two-dimensional, M-mode and Doppler echocardiographic examination was performed to exclude any cardiac abnormalities. The two groups had similar diastolic and systolic left ventricular volumes, left ventricle mass and ejection fraction. Doppler measurements of mitral inflow were: E and A areas (the components of the total flow velocity-time integral in the early passive period of ventricular filling, E; and the late active period of atrial emptying, A), the peak E and A velocities (cm.s-1), acceleration and deceleration half-times (ms) of early diastolic rapid inflow, acceleration time of early diastolic flow (AT), total diastolic filling time (DFT) (ms), and the deceleration of early diastolic flow (cm.s-2). From these measurements were calculate: peak A/E ratio (A/E), E area/A area, the early filling fraction, the atrial filling fraction, AT/DFT ratio. All the Doppler measurements reported are the average of three cardiac cycles selected at end expiration. The mean peak A velocity, A/E velocity ratio, deceleration half time and atrial filling fraction were each significantly higher for subjects presenting a MVP (60 +/- 12 cm.s-1 vs 49 +/- 14, P < 0.008; 98 +/- 13% vs 64 +/- 12%, P < 0.0001; 120 +/- 36 ms vs 92 +/- 11, P < 0.002; 0.45 +/- 0.14 vs 0.36 +/- 0.08, P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of felodipine on left ventricular systolic and diastolic performance in congestive heart failure

We studied the effects of a dihydropyridine calcium blocker, felodipine, on left ventricular (LV) contractile performance and diastolic filling dynamics in conscious dogs with pacing-induced congestive heart failure (CHF) before and after autonomic blockade. Eleven conscious dogs were instrumented to measure micromanometer LV and left atrial (LA) pressure (P) and to determine LV volume (V) from three dimensions. CHF was induced by 4 to 5 weeks of right ventricular pacing. After CHF, the mean LV end-diastolic (ED) P increased (9.7 +/- 2.9 vs. 27.9 +/- 6.8 mm Hg, P < .05), LVEDV and end-systolic (ES) V increased and stroke volume (SV) decreased (15.3 +/- 2.4 vs. 9.6 +/- 3.0 ml, P < .05). The time constant of LV relaxation (T) (25.9 +/- 2.9 vs. 37.9 +/- 5.1 msec, P < .05) and LVES wall stress (WS) (63.4 +/- 21.0 vs. 74.6 +/- 23.7 g/cm2, P < .05) also increased. After CHF, felodipine (25 nmol/kg i.v., plasma concentrations 17.4 +/- 3.2 nmol/L) produced significant decreases in LVESP (119 +/- 12 vs. 96 +/- 11 mm Hg, P < .05), arterial elastance, total systolic resistance (TSR) (0.11 +/- 0.04 vs. 0.07 +/- 0.03 mm Hg/ml/min, P < .05) and LVESWS (74.6 +/- 23.7 vs. 60.2 +/- 17.3 g/cm2, P < .05). Felodipine increased the slopes of the ESP-V relation (5.6 +/- 1.5 vs. 7.8 +/- 0.7 mm Hg/ml, P < .05), the dP/dtmax-EDV relation (51.4 +/- 6.1 vs. 85.3 +/- 10.1 mm Hg/ml sec, P < .05) and the stroke work-EDV relation (69.8 +/- 7.1 vs. 78.9 +/- 7.1 mm Hg, P < .05) and shifted all three relations to the left, indicating enhanced contractile performance.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of myocardial velocities by tissue color Doppler imaging in normal subjects and in dilated cardiomyopathy

The authors studied 35 normal subjects (41 +/- 6 years) and 22 patients with idiopathic dilated cardiomyopathy 48 +/- 7 years; ejection fraction: 31 +/- 12%) in order to determine normal values of myocardial velocities and to demonstrate the sensitivity of Doppler tissue imaging in detecting a significant decrease in myocardial velocities in patients with abnormal left ventricular contractility. Interventricular septal and left ventricular posterior wall velocities were recorded by M mode long axis parasternal views. In normal subjects, a velocity gradient in the posterior wall was observed, higher in the endocardium than in epicardium, in systole (5.1 +/- 1.5 versus 2.8 +/- 1 cm/s, p < 0.01), and early diastole (13.7 +/- 3.5 versus 5.7 +/- 2 cm/s, p < 0.001) and late diastole at the time of atrial contraction (2.7 +/- 2.1 versus 1.8 +/- 1.7 cm/s, p < 0.01). Moreover, the velocities are higher in the posterior wall than in the interventricular septum throughout the cardiac cycle. Finally, the velocities are higher in early diastole than in systole, both in the interventricular septum and posterior wall. In the group of patients with idiopathic dilated cardiomyopathy, the intramyocardial velocities were lower than in normal subjects. In addition, the velocity gradient in the posterior wall was absent in 15 of the 22 patients. The authors conclude that Doppler tissue imaging provides new information in the analysis of myocardial function both in systole and diastole.     

Evaluation of breast tumors with color Doppler imaging: a comparison with image-directed Doppler ultrasound

Preclinical experience has shown that it is possible to maintain and expand hematopoietic cells in liquid culture systems by provision of optimal combinations of colony-stimulating factors (CSF). Ex vivo hematopoietic cell expansion (HCE) would be expected to reduce harvesting time and effort and could also decrease the infusion dose necessary for hematopoietic reconstitution after bone marrow transplantation. In addition, ex vivo expanded cells might be of value for therapeutic gene transfer. The central question in ex vivo HCE is whether the CSF combinations employed provide not only amplification of the late progenitor pools, but also maintenance or expansion of the stem cell compartment to ensure long term engraftment. Choice of CSF and experimental parameters in the culture system appear to be the most critical factors influencing the outcome of strategies for ex vivo HCE. Moreover, it is essential to define the goal of HCE and to adapt the experimental conditions to obtain the required cell populations. In future work, it remains to test the potential applicability of ex vivo expanded cells and to carefully monitor the possibility of the expansion of tumoral cells in ex vivo proliferation systems.     

Usefulness of combined color Doppler/contrast in providing complete delineation of left ventricular cavity

Although detection of disease-induced hepatitis A virus (HAV)-specific antibodies in saliva has been successfully utilized in a few epidemiological studies, available assays fail to detect lower salivary anti-HAV levels associated with vaccine-induced immunity. We present a new capture enzyme immunoassay which employs a three-layer antibody recognition system. Evaluation of paired saliva-serum specimens from 1,025 international travellers, 134 other volunteers, and 91 hepatitis A vaccine recipients demonstrated 99.6% (95% confidence interval, 98.4 to 99.9) specificity and 98.7% (95% confidence interval, 97.7 to 99.4) sensitivity of this salivary assay in differentiating between immune and susceptible individuals, compared with serum-based methods. We conclude that this assay is sufficiently sensitive for reliable detection of both vaccine- and infection-induced HAV-specific immunoglobulin G in saliva, even when corresponding anti-HAV levels in serum are very low (< 1 IU/ml).     

Effects of verapamil on left ventricular diastolic dysfunction

To assess the effects of verapamil on left ventricular relaxation and filling dynamics in patients with left ventricular diastolic dysfunction (LVDD), Doppler echocardiography (DE) and cardiac catheterization (Cath) were simultaneously performed in 30 cases with LVDD. The left ventricular filling and relaxation indices were measured with DE and Cath respectively, before and after intravenous injection of verapamil. The result showed that after verapamil injection all left ventricular filling measured with DE were significantly improved in all cases, while left ventricular relaxation indices showed significant improvement only in patients with hypertrophic cardiomyopathy and hypertensive heart disease but no changes in patients with old myocardial infarction. There were no significant correlations between left ventricular filling and relaxation indices. It is concluded that the major mechanism of left ventricular filling improvement induced by verapamil is the reduction of left ventricular afterload and verapamil has different therapeutic effects on LVDD with different etiology.