Doppler stress echocardiography of the left and right ventricle: a new echo device to quantify left ventricular backward failure

OBJECTIVES: A novel non-invasive procedure which evaluates left-right ventricular interaction is introduced. This procedure is suitable for the classification of congestive heart failure. METHODS: In 48 patients showing mild, moderate or advanced stage congestive heart failure (NYHA I-III) Doppler echocardiography was performed at rest, during and after submaximal bicycle exercise. Mitral (m) and tricuspid (t) filling parameters were determined: early diastolic (VEm, VEt) and atrial maximal velocities (VAm, VAt), the velocity integrals (Em, Et, Am, At) and the corresponding ratios (VE/VAm, VE/VAt, E/Am, E/At). Group 1 (n = 29) was composed of those patients presenting with a VE/VAm < 1 at rest. Four individuals (group 2) were found to have a VE/VAm ratio < 1 during exercise only. Six other patients showing a dilated left ventricle or an ejection fraction of less than 40% produced false negative results in left ventricular Doppler examination (VE/VAm > 1) at rest and during exercise (group 3). In 9 cases (group 4) systolic function, size and Doppler echocardiographic parameters of the left ventricle were proven to be normal. RESULTS: The VE/VAt-ratio decreased notably during exercise (p < 0.05) but increased again after exercise in group 3. In the groups 1 and 2 similar changes occurred as well, however not to a significant degree. In group 4, exercise VE/VAt ratio did not differ from values seen at rest or during recovery (variability 4%). CONCLUSION: The results of this study indicate, that high sensitivity towards left ventricular backward failure can be achieved for Doppler stress echocardiography by extending the examination to right-sided diastolic parameters.     

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.     

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.     

Diagnostic blood flow changes in the outflow tract of the left ventricle. A Doppler echocardiography study of arterial hypertension

In patients with arterial hypertension we analyzed left ventricular filling by pulsed wave (PW) Doppler in the left ventricular inflow and outflow tract (LVIT and LVOT resp.). Separately, we determined the optimal position of flow analysis within the LVOT. We investigated 20 normals (N) and 37 patients with hypertension present for more than 1 year and consistently above 160/95 mm Hg. There was no evidence of other diseases. Echocardiographic signs of left ventricular hypertrophy were present in 20 (H1) and absent in 17 patients (H2). The mean age was 50 years in all groups. We analyzed the velocities (V) and velocity time integrals (F) of the E- and A-waves, respectively, as well as their ratios [E-wave (Ve,Fe), A-wave (Va,Fa), Ve/Va, Fe/Fa]. In the LVOT, we determined the end-diastolic A*-wave (A-wave propagated from LVIT to LVOT) and the S-wave (systolic flow) [A*-wave (Va*,Fa*), S-wave (Vs,Fs), Va*/Vs, Fa*/Fs]. Altered flow patterns were detected more sensitively in the LVOT as compared to the LVIT, even without detectable hypertrophy: In the LVIT Va was significantly different in H1 as compared to N (0.62 +/- 0.15 m/s in H1 vs. 0.52 +/- 0.13 m/s in N; p < 0.05), while H2 and N were comparable. For Ve/Va the same results were obtained (0.97 +/- 0.33 in H1 vs. 1.29 +/- 0.40 in N; p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Massive air embolus to the left ventricle: diagnosis and monitoring by serial echocardiography

Air embolization is an unusual but potentially dangerous complication in left heart catheterization. Microbubbles can be detected with two-dimensional echocardiography, which is often used for this purpose during open heart and bypass surgeries. Permanent neurologic sequelae and hemodynamic collapse can result from embolization of air bubbles to the cerebral and coronary circulations, respectively. Hyperbaric oxygen is the treatment of choice for cerebral air embolization. We present a 39-year-old man who had air embolization during left ventriculography in the form of a large pocket of "pooled" air. The patient was treated with conservative therapy successfully. Two-dimensional transthoracic echocardiography was used to document the presence of the air and follow its dissolution.     

Quantitative determination of left ventricular size using echocardiography

Recently, four genes encoding putative copper pumping ATPases have been cloned from widely different sources: two genes from Enterococcus hirae that are involved in copper metabolism and two human genes that are defective in the copper-related Wilson and Menkes disease. The predicted gene products are P-type ATPases. They exhibit extensive sequence similarity and appear to be members of a new class of ATP driven copper pumps involved in the regulation of cellular copper.     

Characterization of blood flow turbulence with pulsed-wave and power Doppler ultrasound imaging

Blood turbulence downstream of a concentric 86 percent area reduction stenosis was characterized using absolute and relative Doppler spectral broadening measurements, relative Doppler velocity fluctuation, and Doppler backscattered power. Bidimensional mappings of each Doppler index were obtained using a 10 MHz pulsed-wave Doppler system. Calf red cells suspended in a saline solution were used to scatter ultrasound and were circulated in an in vitro steady flow loop model. Results showed that the absolute spectral broadening was not a good index of turbulence because it was strongly affected by the deceleration of the jet and by the shear layer between the jet and the recirculation zones. Relative Doppler spectral broadening (absolute broadening divided by the frequency shift), velocity fluctuation, and Doppler power indices provided consistent mapping of the centerline axial variation of turbulence evaluated by hot-film anemometry. The best agreement between the hot-film and Doppler ultrasound methods was however obtained with the Doppler back-scattered power. The most consistent bidimensional mapping of the flow characteristics downstream of the stenosis was also observed with the Doppler power index. The relative broadening and the velocity fluctuation produced artifacts in the shear layer and in the recirculation zones. Power Doppler imaging is a new emerging technique that may provide reliable in vivo characterization of blood flow turbulence.     

Relationship between systolic and diastolic function of the left ventricle in patients with impaired relaxation of the left ventricle without symptoms of heart failure. Attempt at quantitative estimation of diastolic function in the impaired relaxation stage

Diastolic dysfunction of left ventricle appears very often in patients with coronary artery disease (CAD) and hypertension (HT) and is a main cause of heart failure in 30-40% of all cases. Relation between systolic and diastolic function of left ventricle (LV) is commonly known but not documented well enough. Moreover, no quantitative classification of diastolic dysfunction is still available. AIM OF THE STUDY: To find out the relations between the parameters of systolic and diastolic function of LV in patients with CAD or HT with impaired relaxation of LV without symptoms of heart failure and to make up the quantitative classification of diastolic dysfunction in the stage of impaired relaxation of LV. METHODS: Investigations were carried out in 57 patients (mean age 55.5 +/- 11.5) with angiographically proven CAD and in 91 patients (mean age 56.3 +/- 10.6) with HT and angiographically excluded CAD, all without regional myocardial contractility abnormalities and valvular heart diseases. Control group consisted of 54 healthy subjects (mean age 55.4 +/- 11.4). During 2D echocardiography examination left ventricular end-diastolic (LVEDD) and end-systolic diameters (LVESD) and left atrial dimension (LA) were obtained. Using Doppler method transmitral inflow indices: E velocity (E), A velocity (A), E velocity integral (E-VTI), A velocity integral (A-VTI), total velocity integral (T-VTI), E deceleration time (DT), isovolumic relaxation time (IVRT) and aortic flow velocity integral (Ao-VTI) were measured. Only patients with E/A < or = 1 and--to exclude pseudonormalization of mitral inflow--with DT > or = 140 ms were qualified to the study. We proposed diastolic dysfunction ratio (DDR) calculated from formula: DDR = E/A x E-VTI/T-VTI. Using AFVI, LV outflow diameter, heart rate (HR) and body surface area cardiac index (CI) was calculated. RESULTS: In studied group there were significantly higher values of LA, A, IVRT, DT and lower values of E, E/A, E-VTI and DDR compared to controls. There were no significant differences between these groups in HR, LVEDD, LVESD, T-VTI and CI. No significant differences in any of studied parameters were found between subgroups with CAD and HT. Among healthy subjects in subgroup with abnormal mitral inflow pattern (E/A < or = 1) there were significantly higher values of LA, IVRT, DT and lower values of DDR than in sugroup with normal one. Both subgroups did not differ in LVEDD, LVESD, CI. In the studied group there was positive correlation between DDR and CI (r = 0.69, p < 0.001), DDR and IVRT (r = 0.71, p < 0.001), DDR and DT (r = 0.61, p < 0.001), CI and E (r = 0.34, p < 0.01), CI and IVRT (r = 0.52, p < 0.001), CI and DT (r = 0.42, p < 0.001), CI and E/A (r = 0.54, p < 0.001), CI and E-VTI (r = 0.43, p < 0.001). In the control group significant correlation was found only between DDR and IVRT (r = 0.64, p < 0.02) and between DDR and DT (r = 0.52, p < 0.02) but not between DDR and CI. Using DDR DD was divided into 3 classes: class I with DDR > 0.47, class II with 0.47 > or = 0.30, and class III with DDR < 0.30. Applying of such intervals of values of DDR determined the groups which significantly differed between themselves in CI, IVRT and DT. CONCLUSIONS: (1) In patients with CAD or HT with impaired relaxation of LV without symptoms of heart failure there is relation between parameters of systolic and diastolic function of LV: the more advanced diastolic dysfunction, the more impaired systolic function. (2) In healthy subjects there is no relation between parameters of systolic and diastolic function of LV. (3) DDR is a good indicator of quantitative estimation of diastolic dysfunction in the stage of impaired relaxation of LV.     

Simultaneous measurement of pulmonary venous flow by intravascular catheter Doppler velocimetry and transesophageal Doppler echocardiography: relation to left atrial pressure and left atrial and left ventricular function

OBJECTIVES: The aim of our study was to compare measurements of pulmonary venous flow velocity obtained either by transesophageal Doppler echocardiography or by intravascular catheter Doppler velocimetry. Furthermore, the relation among pulmonary venous flow velocity, left atrial compliance and left atrial pressure was evaluated. BACKGROUND: Data about the relation between left atrial pressure and pulmonary venous flow velocity are controversial. METHODS: A total of 32 patients undergoing elective open heart surgery for coronary artery bypass grafting were included prospectively in the study. Pulmonary venous flow velocity (Doppler catheter) and left atrial pressure (microtip pressure transducer) were recorded simultaneously with recordings of pulmonary venous flow velocity obtained by transesophageal Doppler echocardiography. RESULTS: Agreement between Doppler catheter and Doppler echocardiographic measurements of pulmonary venous flow velocity (n = 18 patients) was analyzed using the Bland-Altmann technique. The 95% limits of agreement were -0.16 to +0.11 m/s for systolic peak velocity, -0.14 to +0.09 m/s for diastolic peak velocity and -0.12 to +0.10 m/s for atrial peak velocity. The closest agreement between both methods was found for the ratio of systolic to diastolic peak velocity, the ratio of systolic to diastolic flow duration and the time from Q deflection on the electrocardiogram to maximal flow velocity. Mean left atrial pressure was strongly correlated with the ratio of systolic to diastolic peak velocity (r = -0.829), systolic velocity-time integral (r = -0.653), time to maximal flow velocity (r = 0.844) and the ratio of systolic to diastolic flow duration (r = -0.556). The ratio of systolic to diastolic peak velocity and the time to maximal flow velocity were identified as strong independent predictors of mean left atrial pressure. Left atrial compliance was not found to be an independent predictor of mean left atrial pressure. CONCLUSIONS: Flow velocity in the left upper pulmonary vein can be reliably recorded by transesophageal pulsed wave Doppler echocardiography. Our data reveal further evidence that mean left atrial pressure can be estimated by the pattern of pulmonary venous flow velocity.     

Evaluation of the severity of aortic stenosis using 2-dimensional Doppler echocardiography

Hemodynamic evaluation of aortic ostial stenosis (AOS) was made in 89 patients at Doppler echocardiography. Maximal circulation rate (MCR) through the aortic valve averaged 3.47 +/- 0.073 m/s, maximal transaortic pressure gradient (TPG) made up 49.97 +/- 2.11 mm Hg, the aortic ostium area (AOA) amounted to 0.85 +/- 0.031 sm2. It was established that AOA evaluation is most reasonable, as MCR and TPG vary with cardiac output. Especially desirable this measurement is believed in patients with TPG under 64 mm Hg and small left ventricular ejection. Mitral regurgitation is a frequent finding in AOS patients. Unless calcinosis of the mitral ring, mitral valve affection would be absent. In mitral regurgitation the disease took a more severe course, the patients having reduced AOA and left ventricular ejection, though larger end-diastolic diameter and end-diastolic volume. The emergence of mitral regurgitation in AOS is a result of left ventricular hypertrophy and dilatation suggesting a low compensatory reserve of the myocardium.     

A comparison of left ventricular volumes and regurgitant fraction by Doppler echocardiography and angiography in children

In the period 1985-1991, 21,675 infants were born at the University Hospital of Copenhagen, Hvidovre Hospital, Denmark. Two hundred and twenty-four infants (10.3%) with birth weights < or = 1500 g and gestational ages < or = 32 completed weeks were transferred to the neonatal intensive care unit of the hospital. One hundred and eighty survived to at least 8 weeks of age and 170 had eye examinations. Forty-five of the 170 infants examined (26.5%) had retinopathy of prematurity (ROP) and 18 (40%) of these developed blindness or severely impaired vision, a higher incidence than reported in other studies. Significant differences were found between infants with and without ROP for: birth weight, gestational age, Apgar score at 1 min, resuscitation, ventilator treatment, duration of supplementary oxygen, severe complications in the neonatal period and sequels from the central nervous system. Statistical analysis, corrected for correlations, showed that the occurrence of ROP was related significantly to early intubation, hypotension, persistent ductus arteriosus and necrotizing enterocolitis.     

Approximation of the left ventricle by a cone of revolution using biplane measurements

A new method based only on area measurements was developed for calculating left ventricular volume from biplane (RAO and LAO) left ventriculograms; the ventricle was approximated by a cone of revolution. Twenty-three patients with normal and 23 patients with abnormal left ventricles were studied. The Dodge method provided reference values. There was no significant difference between values for EDV calculated by either method; values for ESV calculated by the cone method were consistently higher, but the error is acceptable. The cone method provides results similar to those obtained by the corrected Dodge method, eliminating the problem of choosing and measuring the long axis.     

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.     

Preload and incident angle independent index of left ventricular contractility determined by continuous wave Doppler echocardiography

BACKGROUND: Incubating blood with phosphoenolpyruvate decreases hemoglobin oxygen affinity (HOA). This study compared transfusion with phosphoenolpyruvate-treated blood and conventionally stored blood on oxygen consumption in acutely anemic dogs. METHODS: Dogs underwent isovolemic hemodilution (hematocrit = 10%). After 1 hour they were transfused to a hematocrit of 18% with control or phosphoenolpyruvate treated blood. Cardiac output, co-oxymetry, and hemoglobin P50 measurements allowed calculation of oxygen consumption during anemia, and posttransfusion. RESULTS: Hemodilution doubled cardiac output. Transfusion with phosphoenolpyruvate-treated blood allowed greater O2 consumption than control (8.31+/-2.1 and 3.73+/-0.11 cc/kg/mm). There were no differences in arterial or venous PO2 or pH; there were marked differences in HOA, measured by posttransfusion P50 (21+/-3 versus 47+/-4), and mixed venous O2 saturation. CONCLUSIONS: Decreased HOA results in increased O2 consumption in dogs subjected to anemic hypoxia. Phosphoenolpyruvate-treated blood provides increased oxygen consumption at a similar hematocrit when compared with untreated banked blood.     

Assessment of skeletal muscle ventricle function using tissue velocity imaging

Because the visibility of homeless persons congregating in urban areas has increased since the 1980's, the relationship between homelessness and mental illness has caused more and more concern. A multitude of epidemiological surveys have been organized in Great Britain, Australia, Canada, and mainly in United States, and have attempted to evaluate scientifically the psychiatric morbidity of this population. This literature review reveals disparity of epidemiological methods in assessing the type and extent of mental illness among homeless adults. The lack of consensual definition of homelessness, the choice of different settings in which the research is organized (street, health centres, shelters), and the use of diverse instruments of psychiatric evaluation (diagnosis by clinician, by scale or by structured diagnostic interview) lead to a great disparity of the results. Thus, 1/3 of the homeless adults had prior history of psychiatric hospitalisation. Rates of psychosis range to 70% and it is estimated that 4% to 74% of the homeless persons suffer from affective disorders. Substance abuse disorder remains a problem for a significant number of these individuals, with a high frequency of dual diagnosis. Such divergent data highlight the anglo-saxon debate between those who accuse desinstitutionnalisation as a reason of homelessness, and those who blame the socioeconomic background.     

Assessment of colour Doppler tissue imaging using test-phantoms

An investigation has been carried out on the velocity resolution, spatial resolution and accuracy of Doppler images as part of a study into the Doppler display of cardiac tissue motion. Test-phantoms were designed to perform this work and images were captured on a computer. The characteristics of the phantom images and of the image capture process were studied. The smallest spatial detail that was observed in the Doppler image was 3 mm by 3 mm. Doppler receive gain and Doppler ensemble size both affected velocity resolution. Different target materials gave different measures for velocity resolution. This could be related to the different back-scatter intensities of the materials.     

Transgastric Doppler echocardiographic assessment of the severity of aortic stenosis using multiplane transesophageal echocardiography

We investigated whether multiplane transesophageal Doppler echocardiography using transgastral views allows determination of pressure gadients and valve areas in patients with aortic stenosis. This technique was feasible in 35 of 39 patients (90%), with highly significant correlations with results obtained from transthoracic Doppler echocardiography and cardiac catheterization, thus offering an alternative approach for quantification of aortic stenosis.     

Communication between the left ventricle and the right atrium in infectious endocarditis. Diagnosis using Doppler-echocardiography

OBJECTIVE: To examine regional distribution of blood flow in the brain of horses at rest and during exercise. ANIMALS: 9 clinically normal horses. PROCEDURE: Regional brain blood flow was measured using radionuclide-labeled 15-microns-diameter microspheres injected into the left ventricle, while reference blood samples were obtained from the aorta. RESULTS: At rest, cerebral cortex and caudate nuclei received significantly higher blood flow, compared with cerebral white matter. A similar perfusion heterogeneity existed in the cerebellum. In the brain stem, a gradual tapering of blood flow from thalamus-hypothalamus towards medulla was observed in standing horses. Progressive significant increases in heart rate and in aortic and right atrial pressures occurred during exercise at 8 and 13 m/s, and horses developed significant arterial hypoxemia and hypercapnia. Cerebral and cerebellar gray- to white-matter perfusion heterogeneity was maintained during exercise, indicating differential metabolic O2 needs. Despite arterial hypoxemia, hypercapnia, and hypertension, exercise did not result in significant changes in blood flow to the cerebral cortex and caudate nuclei whereas, in cerebral white matter, a significant decrease in blood flow was observed. In all cerebral tissues, vascular resistance increased during exercise, indicating autoregulation of cerebral blood flow. In the cerebellar cortex, blood flow increased significantly with strenuous exercise as vasodilation occurred. Vascular resistance in cerebellar white matter increased during exercise at 13 m/s. Blood flow in the medulla, pons, midbrain, and thalamus-hypothalamus was not significantly altered during exercise from that at rest. CONCLUSION: Despite arterial hypoxemia, hypercapnia, and hypertension, autoregulation of cerebral and cerebellar blood flow is maintained in horses during exercise.