Doppler Time Intervals Research Articles

Simple method to distinguish the type of fetal premature contraction using arterial Doppler time interval measurements.

AimThe purpose of this study was to establish a simple method to distinguish premature ventricular contractions (PVC) from premature atrial contractions (PAC) using a fetal Doppler ultrasound arterial pulse waveform to measure time intervals between sinus node restarting.MethodsWe retrospectively identified 14 fetuses with premature contraction (8 with PAC, 6 with PVC). We measured two distinct parts of time intervals using an arterial pulsed‐wave Doppler: the two consecutive waveforms just before the premature contraction (2‐V interval) and two consecutive waveforms including the premature contraction (XV interval) to measure time intervals between sinus node restarting. We then evaluated the time difference between the 2‐V and XV intervals in PVC compared to PAC.ResultsFor PVC, the difference between the 2‐V interval and the XV interval was significantly shorter than that for PAC. A cut‐off point of 33 ms, where a difference ≤33 ms was clearly shown to be associated with a PVC and a difference more than 33 ms signified a PAC was demonstrated.ConclusionThe 2‐V and XV interval measurements, used to measure time intervals between sinus node restarting, could easily distinguish PVC from PAC in utero. Therefore, this study could potentially be a feasible and effective method for obstetricians or sonographers to employ usefully.

A two year echocardiographic follow-up of patients with chronic total occlusion treated with percutaneous coronary intervention or receiving only medical therapy

Abstract Background Percutaneous coronary intervention of chronic total occlusion (PCI CTO) can reduce angina and the need for bypass surgery, however, it is still not clear how it effects the myocardial function. Conventional echocardiography is subjective and experience-dependent while tissue Doppler imaging together with strain imaging provides a more objective assessment of myocardial contractility. Purpose Our aim was to access the effectiveness of percutaneous coronary intervention (PCI) along with optimal medical therapy (OMT) on myocardial function. Methods We compared two groups of patients. The first group of patients underwent PCI CTO with OMT while the second group of patients only received OMT (control group). The echocardiographic exam was performed before randomization and after 24 months of follow-up. Doppler time intervals- isovolumetric relaxation time (IVRT), isovolumetric contraction time (IVCT) and ejection time (ET) were measured from mitral inflow and left ventricular outflow Doppler tracings. Myocardial performance index (MPI) is equal to the sum of the IVRT and IVCT divided by the ET. Velocity of early mitral filling wave (E) was measured and divided by average peak early diastolic annular velocity (e'). Peak longitudinal strain was assessed in 17 left ventricular segments. Time intervals from start Q/R on electrocardiogram to peak negative strain during the cardiac cycle were assessed. Mechanical dispersion was defined as the standard deviation of this time interval from 17 left ventricular segments, reflecting myocardial contraction heterogeneity Results Comparing the groups at follow up, there was no significant change in ejection fraction (EF), diastolic function, and mechanical dispersion, however, there was improvement in GLS and MPI (Table 1). Conclusion Global longitudinal strain as a parameter of systolic function and Myocardial performance index as a parametar of global systolic and diastolic function are sensitive markers that can detect subtle improvement in myocardial function after recanalisation of CTO. Funding Acknowledgement Type of funding source: None

P284 Patients with reduced systolic function benefit most from recanalisation of chronic total occlusion

Abstract Background Percutaneous coronary intervention of chronic total coronary occlusion (PCI of CTO) is proved to reduce symptoms of angina and long term survival. Purpose This study aimed to assess systolic and diastolic left ventricular function with standard echocardiographic indices. Methods We analyzed total of 46 CTO patients (age 58 ± 9, 73% male). Measures were obtained with the transducer in the apical four-chamber view. Doppler time intervals were measured from mitral inflow and left ventricular outflow Doppler tracings by pulsed wave Doppler. The isovolumetric relaxation time (IVRT) was measured from closure of the aortic valve to opening of the mitral valve. The isovolumetric contraction time (IVCT) was measured from closure of the mitral valve to opening of the aortic valve. Ejection time (ET) was measured from the opening to the closure of the aortic valve on the LV outflow velocity profile. Myocardial performance index (MPI) is simple method for evaluation of overall cardiac function and is independent of heart rate and blood pressure. MPI was equal to the sum of the IVRT and IVCT divided by the ET. Velocity of early mitral filling wave (E) was measured and divided by average peak early diastolic annular velocity (e") which was measured as average value between septal and lateral side of the mitral annulus using Doppler tissue imaging. The E/e’ ratio was calculated to estimate the LV filling pressures Results Six months after PCI of CTO patients showed no change in ejection fraction (EF) (55.69 ± 8.56% vs. 54.83 ± 8.44%, p = 0.10). MPI was significantly decreased (0.676 ± 0.99 vs. 0.632 ± 0.96 p < 0.01), E/e" was significantly reduced, (13,10 ± 6.90 vs. 12.05 ± 5.1 p < 0.05), and when we analyzed only patients with baseline EF < 50% (n = 9) improvement of diastolic function (reduction of E/e") was even greater (22.53 ± 5.52 vs. 15.65 ± 4.8 p < 0.01). Conclusion PCI of CTO improves overall cardiac function, particularly diastolic function in patients with reduced ejection fraction.

Validation of Noninvasive Measures of Left Ventricular Mechanics in Children: A Simultaneous Echocardiographic and Conductance Catheterization Study

The accuracy of echocardiography in evaluating left ventricular contractility has not been validated in children. The objective of this study was to compare echocardiographic measures of contractility with those derived from pressure-volume loop (PVL) analysis in children. Patients with relatively normal loading conditions undergoing routine left heart catheterization were prospectively enrolled. PVLs were obtained via conductance catheters. The gold-standard measure of contractility, end-systolic elastance (Ees), was obtained via balloon occlusion of one or both vena cavae. Echocardiograms were performed immediately after PVL analysis under the same anesthetic conditions. Single-beat estimations of echocardiographic Ees were calculated using four different methods. These estimates were calculated using a combination of noninvasive blood pressure readings, ventricular volumes derived from three-dimensional echocardiography, and Doppler time intervals. Of 24 patients, 18 patients were heart transplant recipients, and six patients had small patent ductus arteriosus or small coronary fistulae. The mean age was 9.1±5.6years. The average invasive Ees was3.04±1.65mmHg/mL. Invasive Ees correlated best with echocardiographic Ees by the method of Tanoue (r=0.85, P<.01), with a mean difference of -0.07mmHg/mL (95% limits of agreement, -2.0 to 1.4mmHg/mL). Echocardiographic estimates of Ees correlate well with gold-standard measures obtained via conductance catheters in children with relatively normal loading conditions. The use of these noninvasive measures in accurately assessing left ventricular contractility appears promising and merits further study in children.

Impact of Interatrial Communication on Left Ventricle Performance in Patients with Significant Post-tricuspid Shunt.

Infants with post-tricuspid valve shunts (PTS) may benefit from interatrial communication (IAC). The effect of IAC on left ventricular (LV) performance in these patients was studied. IAC was documented prospectively in 55 patients with PTS. Clinical status, echocardiographic dimensions of LV, mitral inflow Doppler, tissue Doppler velocities and time intervals were measured. Creatinine kinase (CK), CKMB, troponin-I and NT pro-brain natriuretic peptide (NT pro-BNP) were measured. Patients were divided into four groups: (A) PTS but no IAC (n = 32); (B) PTS and IAC (n = 23); (C) VSD but no IAC (n = 16); and (D) VSD and IAC (n = 19). Group A had more frequent mitral regurgitation (p = 0.041), larger mitral annulus (1.80 vs. 1.30 cm, p < 0.0001) and larger LV systolic and diastolic dimensions (2.01 vs. 1.40 and 3.28 vs. 2.35 cm, p < 0.001) than group B. The E-wave deceleration time tended to be longer in group A (121.0 vs. 106.8 ms, p = 0.06). By tissue Doppler, group A had E'- and S-waves significantly taller (15.51 vs. 13.14 and 7.69 vs. 6.72 cm, p = 0.04 and p = 0.005, respectively) than group B. Also, NT pro-BNP was significantly higher in group A (1116.15 vs. 458.73 pg/ml, p = 0.028). Group C had significant larger mitral z-score values (1.2 vs. 0.01, p < 0.001), larger LV diameter z-score (p = 0.001) and higher NT pro-BNP level (1477.37 vs. 451.66 pg/ml, p = 0.001) than group D. There was no significant difference in the clinical status between the groups. In children with PTS, the presence of IAC could be beneficial. Their echocardiographic parameters and biomarker show better systolic and diastolic LV performance.

Myocardial Performance Index in Neurocardiogenic Syncope Patients.

BackgroundMany syncopes resulting from neural reflexes in various conditions are called neurocardiogenic syncope (NCS). We aimed to investigate the presence of left ventricular (LV) myocardial performance index (MPI) in patients with NCS, which was diagnosed with head-up tilt table test (HUTT), and the accurateness of the test in order to use it as a method in patients with NCS. Assuming the MPI as a potential cause of syncope, we assessed the Tei index with non-invasive tissue Doppler echocardiography method.MethodsConsecutive outpatients with a history of recurrent unexplained syncope underwent HUTT. Twenty-nine HUTT (+) patients (24 female and five male, mean age: 30 ± 15 years) as the study group and HUTT (-) 23 healthy patients (six female and 17 male, mean age: 34 ± 16 years) as the control group were included into the study. Conventional and tissue Doppler echocardiography was performed to both groups. The MPI was determined by using PW Doppler. Measurements of Doppler time intervals, according to Tei index ((isovolumic contraction time + isovolumic relaxation time)/ejection time) is calculated as (a - b/b), where “a” is the interval between cessation and onset of the mitral inflow, and “b” is the ejection time (ET) at the LV outflow.ResultsWhen comparing the groups in terms of MPI and ET, there was significant difference between groups. Patients with NCS had significantly longer ET and lower MPI value than control group (284 ± 24 ms vs. 260 ± 24 ms, P < 0.001, respectively and 0.44 ± 0.7 vs. 0.52 ± 0.8, P < 0.001, respectively). There was no significant difference in ejection fraction between groups.ConclusionIn the present study, LV MPI value decreases in patients with NCS.

Right ventricular tissue doppler time intervals in congestive heart failure

Purpose: The purpose of our research was to study the changes in right ventricular (RV) TDI parameters in patients with Left Ventricular Heart Failure (HF).

Tissue Doppler Time Intervals Predict the Occurrence of Rehospitalization in Chronic Heart Failure: Data from the Daunia Heart Failure Registry

Patients with chronic heart failure (HF) are often rehospitalized; rehospitalization identifies subjects with a poorer quality of life and a worse prognosis. Estimates of the time intervals by tissue Doppler imaging (TDI) in patients with chronic HF has not been fully investigated, despite recent studies having explored the prognostic role of TDI-derived parameters in major cardiac diseases, such as HF. We, therefore, aimed to assess the prognostic value of time intervals evaluated by TDI in patients with chronic HF. A total of 249 patients with chronic HF enrolled in the Daunia Heart Failure Registry underwent echocardiography assessment and were followed prospectively for a mean 284 ± 210 days. Conventional echocardiography and TDI parameters were calculated; time intervals were calculated by TDI: ST (systolic time), ET (ejection time), FT (filling time), and ICT (isovolumic contraction time). We also have calculated ICT/ET and tissue myocardial performance index ([ICT+IRT]/ET). At univariate analysis, ET (RR: 0.80, 95% confidence interval [CI] 0.71-0.90, P < 0.001), ST (RR: 0.88, 95% CI 0.78-0.99, P < 0.05), FT (RR: 0.88, 95% CI 0.78-0.99, P < 0.05), ICT/ET (RR: 1.21, 95% CI 1.07-1.37, P < 0.01) were related to the occurrence of rehospitalization during follow-up. At multivariate Cox regression analysis, correlations remained significant for ET and ST (P < 0.05 and P < 0.01, respectively). Time intervals assessed by TDI may be helpful in predicting the risk of rehospitalization in subjects with chronic HF.

Tissue Doppler time intervals and derived indices in hypoplastic left heart syndrome

To describe tissue Doppler time intervals and derived indices in hypoplastic left heart syndrome (HLHS) across surgical stages, taking account of age-related changes in the heart rate. Correlation of the myocardial performance index (MPI) and the systolic to diastolic (S:D) time ratio with other echocardiographic and magnetic resonance imaging (MRI) measures of cardiac performance. Fifty-seven patients at different stages of HLHS palliation were studied prospectively using tissue Doppler imaging of the right ventricular free wall, with simultaneous cardiac MRI in the majority. Both isovolumic contraction time and isovolumic relaxation time were prolonged compared with the normal left and right ventricle: median (range) z-scores for the tricuspid annulus 1.9 (-1.2 to 9.3) and 1.3 (-2.0 to 5.5), respectively. When adjusted for heart rate, the ejection, systolic, and diastolic times in HLHS were not significantly different from published normal data. The MPI was increased at all surgical stages in HLHS. Neither MPI nor heart rate-specific S:D time ratio z-score correlated with MRI ejection fraction or indexed cardiac output when the confounding effect of significant tricuspid regurgitation was taken into consideration. The prolongation in isovolumic relaxation and contraction times may be due to adaptation or reduced myocardial performance. Differences in the S:D time ratio between surgical stages can be accounted for by the heart rate alone. Neither MPI z-score nor S:D z-score correlated with MRI or other echocardiographic indices of systolic or diastolic function with the exception of a negative correlation between central venous pressure and S:D ratio z-score.

An Echocardiographic Study of the Limitations of the Tei Index in Aortic Stenosis

The omnibus Tei index, the sum of isovolumic contraction and relaxation times divided by the ejection time, is a good indicator of global cardiac function. However, these time intervals can be influenced by valvular heart disease and the role of the Tei index among patients with aortic stenosis (AS) and left ventricular systolic dysfunction remains incompletely defined. Doppler time intervals were measured retrospectively by two observers, and the Tei index were calculated on 80 patients with various degrees of left ventricular systolic dysfunction and severity of AS. Differences between observers were resolved by consensus. Ejection fraction (EF) was visually estimated, and the aortic valve area (AVA) was calculated using the continuity equation. The mean AVA was 1.1+/-0.5 cm(2) and the mean EF was 0.39+/-0.15. Although correlation (r = 0.61, P < 0.001) and agreement (intraclass correlation coefficient=0.55) for the Tei index were satisfactory, there were significant differences between observers (P < 0.001). Using consensus data, the mean Tei index was 0.32+/-0.20 and significantly lower among patients with severe compared with less severe AS (P=0.01). The index varied inversely with left ventricular function (P=0.003). However, receiver operating characteristic analysis shows that the Tei index lacks discrimination in accurately identifying poor left ventricular function or severe AS or both. The Tei index varies inversely with systolic ventricular function (low index with good EF) and positively with severity of AS (low index with smaller valve area). As such, it may have limited utility among individual patients with AS.

Myocardial involvement during the early course of type 2 diabetes mellitus: usefulness of Myocardial Performance Index

To evaluate whether myocardial performance index detects a subclinical impairment of left ventricular systolic and diastolic function in patients with early stage of type 2 diabetes, without coronary artery disease, with or without hypertension. Furthermore, to evaluate whether some echocardiographic parameters relate to the metabolic control. Fourty-five consecutive male patients (mean age 52.5 years) with type 2 diabetes mellitus of recent onset (23 hypertensives and 22 normotensives) and 22 age matched healthy controls males were analysed. All participants had normal exercise ECG. All subjects underwent standard and Doppler echocardiography for the assessment of the isovolumic Doppler time interval and Doppler-derived myocardial performance index. In all diabetic patients a glycated haemoglobin test was also performed.No differences were observed in blood pressure, heart rate, and conventional echocardiographic parameters comparing the 2 subgroups of diabetic patients and the controls. Myocardial performance index was significantly higher in diabetic patients independently of the hypertension occurrence, compared to the controls (0.49 and 0.49 diabetic normotensives and hypertensives respectively vs. 0.39, p < 0.01). Myocardial performance index correlated to glycated haemoglobin significantly (r = 0.37, p < 0.01) in both diabetic subgroups. Thus, an early involvement of left ventricular performance was shown by myocardial performance index in patients with type 2 diabetes of recent onset without coronary artery disease, independently of the hypertension presence. These abnormalities can provide a feasible approach to detect a pre-clinical diabetic cardiomyopathy and could be useful for an indirect assessment of the metabolic control.

Right Ventricular Tissue Doppler and Strain Imaging: Ready for Clinical Use?

Although tissue Doppler (TD) imaging of the left ventricle is now commonly used in clinical settings, TD imaging of the right ventricle (RV) is not routinely practiced. Yet, there are significant data on clinical uses of RV TD imaging, including established normal values using both color and spectral TD. In acute left ventricular (LV) inferior wall myocardial infarction, depressed RV TD velocities have been shown to correlate with the presence of RV impairment, and with patient outcome. In patients with LV heart failure, TD imaging has been correlated to RV ejection fraction by radionuclide angiography, and is an independent predictor of outcome. In patients with congenital heart disease, RV TD has been especially valuable for assessing RV function, and has been correlated to invasive hemodynamic indices, and RV ejection fraction by magnetic resonance imaging. The RV performance (Tei) index has been calculated and validated using TD-derived, rather than conventional pulsed Doppler time intervals. RV TD indices have been shown to be useful in the detection of subclinical and clinical disease in morbid obesity, chronic pulmonary, and systemic disease. TD-derived RV strain imaging can detect segmental myocardial dysfunction, overcoming limitations to conventional TD imaging resulting from tethering. For both TD velocity and strain imaging, however, appreciation of the limitations of these techniques is necessary for their appropriate use. Given its rapid acquisition times, reproducibility, and ease of addition to standard transthoracic echocardiographic protocols, RV TD and strain imaging are important additional modalities in the comprehensive echo-Doppler assessment of RV function.

Tissue Doppler Image-Derived Myocardial Performance(Tei Index) as a Simple Assessment of Global Cardiac Function in Adults

Background and Objectives：A new Doppler time index of myocardial performance (the Tei index) has been studied as a useful predictor of global cardiac function. It is defined as (a-b)/b, where a is the interval between the end and onset of the mitral inflow, and b is the ejection time of the left ventricular outflow. However, the Doppler time intervals are not measured on the same cardiac cycle. Subjects and Methods：We compared the tissue Doppler imaging (TDI)-derived Tei index, which can be measured on the same cardiac cycle, with the conventional Tei index as measured by pulsed wave Doppler method, in healthy persons (n=44), in patients having diastolic dysfunction with an E/E’ ratio >10 (DD, n=56), and in patients having systolic dysfunction with an ejection fraction <50% (SD, n=10). At the septal and lateral mitral annulus from the apical 4-chamber view, the time interval between the end and onset of the mitral annular velocities during diastole (a’) minus the duration of the systolic wave (b’) divided by b’, which is (a’-b’)/b’, is defined as the TDI-tei index. Results： The TDI-Tei index and the conventional Tei index were significantly higher in the SD group than in the DD group, and they were also higher in the DD group than in the healthy controls. The TDI-Tei index at the septal and lateral annulus correlated well with the Tei index (r=0.71, r=0.65, respectively, p<0.001) and this showed a good correlation with other echocardiographic parameters of diastolic function. Conclusion：We demonstrated that the TDI-Tei index correlates well with the conventional Tei index along with having the advantage of simultaneous recording of the systolic and diastolic velocities in adults. (Korean Circulation J 2005;35:315-321)

161 Evaluation of preload dependency of mitral inflow, tissue Doppler and color M-mode velocities and time intervals

161 Evaluation of preload dependency of mitral inflow, tissue Doppler and color M-mode velocities and time intervals

Impact of essential hypertension and diabetes mellitus on left ventricular systolic and diastolic performance.

To investigate left ventricular systolic and diastolic function in patients with essential hypertension and diabetes mellitus associated with hypertension by the myocardial performance index (MPI). The study included 45 patients with essential hypertension, 45 patients with diabetes mellitus and hypertension and 45 normal subjects, who underwent a complete two-dimensional and Doppler echocardiography including assessment of the isovolumetric Doppler time intervals for the estimation of the Doppler-derived MPI. The MPI was significantly higher in patients with essential hypertension and diabetes with hypertension, compared to controls (Essential hypertension=0.51+/-0.12; Diabetes=0.51+/-0.12 vs. controls 0.40+/-0.05, P=0.001). The isovolumetric contraction time was significantly prolonged in essential hypertension (56+/-26 msec vs. 40+/-17 msec, P<0.01 respectively) and among diabetes patients isovolumetric relaxation time was prolonged compared to normal subjects (100+/-20 ms vs. 87+/-16 ms, P<0.01, respectively). The index was not related to left ventricular mass, age or ejection fraction, but significantly correlated to E-wave deceleration time (rho=0.48, P<0.001). The MPI is increased, in both essential hypertensive patients and diabetes patients with associated hypertension, despite normal ejection fraction.

Doppler flow velocity measurement to assess changes in inotropy and afterload: a study in healthy dogs.

Myocardial contractility and afterload are important factors for adequate circulation. To noninvasively assess changes in inotropy and afterload, ascending aortic blood flow was measured by continuous-wave Doppler echocardiography before and after the administration of an inotrope and a vasodilator in eight open chest dogs. Data were collected in the baseline, at three different doses of epinephrine (0.1, 0.5, and 1 microg/kg/min) and nitroprusside (1, 4, and 8 microg/kg/min) administration, and after a simultaneous infusion of both drugs in various combinations. Epinephrine infusion caused increases in peak velocity (PV), mean acceleration (MA), velocity time integral (VTI), and minute distance without a significant change in afterload. Acceleration time (AT) and ejection time (ET) showed a slight tendency to decrease with an increase in inotropy, but with no significance. Nitroprusside infusion produced dose-dependent decreases in blood pressure and index of systemic vascular resistance (ISVR), which was associated with increases in PV, MA, and minute distance, and with a decrease in AT. The combined infusion of nitroprusside and epinephrine, unless ISVR was elevated, produced synergistic effects on PV, MA, VTI, and minute distance. However, these Doppler parameters tended to diminish with an elevation in afterload. ISVR obtained during nitroprusside infusion had a better correlation with both PV and MA than with VTI or the Doppler time intervals. Our study suggests that Doppler measurement of aortic blood flow velocity and acceleration can be used for the noninvasive assessment of changes in inotropy and afterload.

Analysis of systolic and diastolic time intervals during dobutamine-atropine stress echocardiography: Diagnostic potential of the doppler myocardial performance index

Systolic and especially diastolic Doppler time intervals may be early markers of myocardial ischemia inducible by dobutamine-atropine stress echocardiography (DASE). We postulated that the Doppler myocardial performance index (MPI) may help differentiate ischemic from nonischemic responses. Hemodynamic and Doppler echocardiography variables were measured prospectively at every stress level of DASE in 32 patients (mean age 67 +/- 13 years). Adequate recordings were obtained in 27 patients; 13 had an ischemic response (group I) and 14 a nonischemic response (group II). Heart rate differed between groups at baseline. At equivalent peak stress, left ventricular wall motion score index was significantly greater and ejection fraction lower in group I patients. Of the Doppler variables, only the MPI consistently differed between groups, irrespective of the number of stress levels compared. The Doppler MPI may be a useful adjunct to wall motion analysis in the detection of myocardial ischemia during DASE.

Inversion algorithm to measure velocity profiles by laser Doppler velocimetry with a small signal

In this paper we obtain a simple algorithm, based on laser Doppler velocimetry and time interval measurement, to determine the velocity distribution of a fluid when the scattered intensity is small. Knowledge of the intensity distribution of the interference fringes is not necessary. The behaviour of the algorithm is verified by computer simulation. The results are good even in the case of a rectangular velocity profile, where the sharp edges could have been a source of problems.

Doppler evaluation of left ventricular diastolic filling in children with systemic hypertension

To assess left ventricular (LV) diastolic function in children with systemic hypertension, 11 patients with hypertension (mean blood pressure 99 mm Hg) and 7 normal patients (mean blood pressure 78 mm Hg) underwent M-mode echocardiography and pulsed Doppler examination of the LV inflow. From a digitized trace of the LV endocardium and a simultaneous phonocardiogram, echocardiographic diastolic time intervals, peak rate of increase in LV dimension ( dD dt ), and dD dt normalized for LV end-diastolic dimension ( dD dt ) were measured. Doppler diastolic time intervals, peak velocities at rapid filling (E velocity) and atrial contraction (A velocity), and the ratio of E and A velocities were measured. The following areas under the Doppler curve and their percent of the total area were determined: first 33% of diastole (0.33 area), first 50% of diastole, triangle under the A velocity (A area), and the triangle under the E velocity (E area). The A velocity (patients with hypertension = 0.68 ± 0.11 m/s, normal subjects = 0.49 ± 0.08 m/s), the 0.33 area/total area (patients with hypertension = 0.49 ± 0.09, normal subjects = 0.58 ± 0.08), the A area (patients with hypertension = 0.17 ± 0.05, normal subjects = 0.12 ± 0.03), and the A area/total area (patients with hypertension = 0.30 ± 0.11, normal subjects = 0.20 ± 0.07) were significantly different between groups (p < 0.05). M-mode and Doppler time intervals, dt D , E velocity, and the remaining Doppler areas were not significantly different between groups. The normal subjects and patients with hypertension did not differ significantly in echocardiographic LV size and thickness or in percent shortening fraction. This study shows that abnormal patterns of LV diastolic filling occur in children with mild systemic hypertension. These diastolic abnormalities are detectable by mitral valve Doppler ultrasound examination when standard M-mode echocardiographic indexes of diastolic function are still normal and before the development of systolic function abnormalities or LV hypertrophy on the M-mode echocardiogram.

Noninvasive assessment of surgical systemic to pulmonary artery shunts by range-gated pulsed Doppler echocardiography

Suprasternal range-gated pulsed Doppler echocardiography was used to evaluate surgical shunt patency in children with cyanotic congenital heart disease and right ventricular outflow obstruction following systemic artery to pulmonary artery anastomoses. Normal patients had laminar Doppler auditory signals and time interval histogram flow patterns because right pulmonary artery turbulence was not present during systole or diastole. Patients with pulmonary valvar stenosis had turbulence during systole only. In all nine postoperative patients with surgical shunts, turbulent systolic and diastolic time interval histograms and abnormal auditory signals were present. A typical shunt murmur was not audible to auscultation in six of the postsurgical patients at the time of the study. Suprasternal range-gated pulsed Doppler echocardiography affords an accurate, safe and simple noninvasive bedside means for confirming shunt patency in patients who have undergone surgical systemic artery to pulmonary artery anastomoses.