Color Tissue Doppler Imaging M-mode Research Articles

Cardiac time intervals predict major adverse cardiovascular events in individuals with type 1 diabetes without known heart disease

Abstract Background Cardiac time intervals, and in particular the myocardial performance index (MPI) which combines systolic and diastolic function, are associated with cardiovascular prognosis in various populations. We aimed to investigate if cardiac time intervals offer prognostic information on cardiovascular risk in individuals with type 1 diabetes (T1DM). Methods We prospectively included 1,088 individuals with T1DM without known heart disease (mean age 50±15 years; 53% male; duration of diabetes 26±15 years; 30% had albuminuria). All enrolled individuals underwent an echocardiographic examination with assessment of cardiac time intervals by color Tissue Doppler imaging M-mode. We evaluated the isovolumetric relaxation and contraction time (IVRT; IVCT) and ejection time (ET). The MPI was calculated as [(IVRT+IVCT)/ET]. In Cox proportional hazards models, we assessed major adverse cardiovascular events (MACE), a composite of incident heart failure or hospitalization for acute coronary syndrome or PCI/CABG. Multivariable models were adjusted for clinical information, pharmacotherapy and echocardiographic parameters. Results During the median follow-up time of 6 years [IQR 6, 7 years], 106 (10%) experienced MACE. In adjusted survival analyses the IVRT (HR: 1.13 per 10ms increase [1.01 to 1.26], P=0.026) and MPI (HR: 1.03 per 1 unit increase [1.01 to 1.04], P=0.005) were associated with MACE. Overall, the association between IVCT and outcome was borderline significant (HR: 1.15 per 10ms increase [0.97 to 1.36], P=0.10) while there was no association for ET (HR: 0.97 per 10ms increase [0.89 to 1.05], P=0.43). Sex modified the association for IVCT (P interaction<0.05) such that IVCT (HR: 1.23 per 10ms increase [1.02 to 1.49], P=0.027) and MPI (HR 1.03 per 1 unit increase [1.01 to 1.05], P=0.005; Figure) were associated with MACE in women but not in men. Conclusion Cardiac time intervals are positively associated with MACE in T1D without known heart disease. Furthermore, the association is modified by sex in that the IVCT and MPI provide independent and prognostic information on the risk of future cardiovascular events particularly in female individuals while not significant in men. These findings suggest sex differences in myocardial impairment related to T1D. Association between MACE and MPI in DM1 Funding Acknowledgement Type of funding source: None

Abstract 16620: Left Ventricular Ejection Time is an Independent Predictor of Cardiovascular Morbidity and Mortality Following Acute Coronary Syndrome

Background: Color Tissue Doppler imaging M-mode through the mitral leaflet is an easy and precise method to obtain the cardiac time intervals including the left ventricular ejection time (LVET). The aim of this study was to investigate whether the LVET can be used to predict cardiovascular morbidity and mortality following acute coronary syndrome (ACS). Methods: We retrospectively studied 390 patients with ACS (mean age 64 ±12 years, men 74%, STEMI 81%, mean LVEF 41±11%, mean LVET 256±35ms) who underwent echocardiography, following percutaneous coronary intervention. The LVET was measured. The primary endpoint was major adverse cardiac events (MACE) and consisted of heart failure, myocardial infarction and cardiovascular death. The secondary endpoint was all-cause mortality. Patients with prevalent HF were excluded. Results: During a median follow-up of 3 years, 180 patients (46%) reached the composite endpoint MACE, and 77 (20%) suffered from all-cause mortality. LVET was significantly associated with risk of MACE (HR 1.13; 95% CI (1.08-1.18), p<0.001) with a 13% increase in risk per 10ms decrease in LVET (figure ). The association remained significant after adjusting for age, sex, hypertension, diabetes, body mass index, previous ischemic heart disease, STEMI, multivessel culprit lesions, left ventricular ejection fraction, left ventricular mass index, E/e’, E/A and deceleration time (HR 1.10; 95% CI (1.03-1.17), p=0.002 per 10ms decrease). Additionally, the LVET predicted all-cause mortality and the association remained significant even after multivariable adjustment (HR 1.11; 95% CI (1.01-1.21), p=0.032 per 10ms decrease). Conclusion: In patients with ACS the LVET provides novel and independent prognostic information on the risk of cardiovascular morbidity and mortality.

Usefulness of the Myocardial Performance Index Determined by Tissue Doppler Imaging M-Mode for Predicting Mortality in the General Population

The objective of this study was to evaluate the prognostic value of the myocardial performance index (MPI), assessed by color-coded tissue Doppler imaging (TDI) M-mode through the anterior mitral leaflet. Color TDI M-mode through the mitral leaflet is an easy, very fast, and precise method to estimate cardiac intervals and thus obtain the MPI, but the diagnostic and prognostic values of this parameter are unknown. In a large population study, cardiac function was evaluated in 1,100 participants by conventional echocardiography and TDI. MPI was calculated from pulse-wave Doppler analyses of left ventricular in- and outflow using standard procedures (MPI(conv)) and by color-coded TDI M-mode through the mitral leaflet in the apical 4-chamber view (MPI(TDI)). MPI(TDI) was increased in subjects with coronary heart disease (CHD) compared to controls, even after multivariable adjustment (p <0.002). During follow-up (median 5.3 years), 90 participants died. MPI(TDI) was significantly associated with overall mortality, and risk of dying increased by 31% per 0.1 increase in MPI(TDI). In contrast to MPI(conv), MPI(TDI) provided independent prognostic information in a multivariable Cox proportional hazard model (adjusting for age, gender, body mass index, heart rate, mean arterial blood pressure, and CHD), with a hazard ratio of 1.18 (p = 0.01) per 0.1 increase in MPI(TDI). In conclusion, MPI(TDI) is a quick, simple, and reproducible measurement, which is increased in subjects with CHD and provides independent prognostic information in a low-risk population.

In vivo measurement of proximal pulmonary artery elastic modulus in the neonatal calf model of pulmonary hypertension: development and ex vivo validation

Developing clinical work suggests that vascular stiffening plays a role in the progression of pulmonary hypertension (PH), while recent studies in animal models of hypoxic PH have found significant proximal vascular stiffening in the diseased population. Here, we develop and validate a minimally invasive, clinically realizable method to estimate the local elastic modulus of the proximal pulmonary arteries from pressure-diameter (PD) data. PD measurements were made in the main pulmonary arteries of 16 calves; lumen diameter was assessed using color M-mode tissue Doppler imaging ultrasound, while pressure was measured via catheter. Two methods corresponding to thin-walled pressure vessel theory ("thin") and Lame's equation for a thick-walled cylinder ("thick") were used to approximate the artery elastic modulus from PD measurements. The harvested arteries were tested independently to determine their "true" ex vivo elastic modulus and stiffness. Both approximations displayed excellent correlation with ex vivo elastic modulus of the calf main pulmonary artery (thin r(2) = 0.811; thick r(2) = 0.844; both P < 0.01). Bland-Altman analysis indicated that the thick-walled approximation has better overall agreement with ex vivo modulus. The approximations displayed quantitatively distinct regression slopes that were statistically different (P = 0.02). The elastic modulus of the main pulmonary artery can be reasonably estimated from combined color M-mode tissue Doppler imaging ultrasound and catheter pressure measurements in calves. Such measurements may be a valuable tool in the diagnosis and treatment of human PH.

Abstract 4388: In-Vivo Pulmonary Vascular Stiffness Obtained from Color M-Mode Tissue Doppler Imaging and Pressure Measurements Predicts Clinical Outcomes Better than Indexed Pulmonary Vascular Resistance in Pediatric Patients with Pulmonary Arterial Hypertension

Introduction: Pulmonary vascular stiffness (PVS) is increasingly recognized as an important component of right ventricular afterload in patients with pulmonary arterial hypertension (PAH). In adult and pediatric PAH populations, stiffness has also been shown to improve prediction of mortality and outcomes, respectively. Despite these promising findings, methods to determine PVS clinically remain limited. Here we examine the ability of a minimally-invasive method to quantify proximal PVS in a pediatric PAH population, and hypothesize this measurement will offer better disease outcomes prediction over indexed pulmonary vascular resistance (PVRI), the current gold standard. Methods: Color M-mode Tissue Doppler Images of the right pulmonary artery (RPA) were obtained using ultrasound during right-heart catheterization of 36 individuals undergoing reactivity testing (n=86) who ranged in age from 1 month to 19 yrs (mean = 6.5±5.2 yrs, 19 males). These measurements yielded RPA diameter and intravascular pressure, from which an estimate of the circumferential elastic (Young’s) modulus (E), the continuum component of stiffness, was derived. Echo imaging added only 5 minutes to the procedure. Follow up was obtained in 19 patients (mean = 4.9±4.7 yrs, range 1 month to 16 yrs, 9 males) at a median time of 15 months (range 1–26 months). Cumulative logistic regression was used to relate continuous values of E and PVRI to three outcomes categories: improvement; stable (no change); or worsening. These were determined from change in WHO score from initial assessment to follow up. Results: E had better correlation to pulse pressure (PP) (R2=0.61) compared to mean pressure (R2=0.43); this agrees with other findings of PP as a good proxy of stiffness. E displayed substantially better correlation (R2L=0.49) to outcomes compared to PVRI (R2L=0.33). In more practical terms, E wrongly predicted outcome only once (5%), compared to four errors by PVRI (21%), and offered clearer prognosis in an additional 3 individuals; thus 37% of the group would benefit from such improved prediction. Conclusion: We conclude that elastic modulus is a measure of proximal vascular stiffening and most importantly offers superior outcomes prediction compared to pulmonary vascular resistance.

A way to improve the reproducibility of measurements of myocardial velocity gradients.

A peak negative myocardial velocity gradient (MVG) across the left ventricular wall is an important indicator of diastolic performance. The reproducibility of MVG measurements by color M-Mode tissue Doppler imaging (TDI) is still unsatisfactory, restraining its use in clinical practice. Aim of the study was to improve the reproducibility of measurements of MVG. The peak diastolic MVG of left ventricular posterior wall was determined in 50 consecutive patients by two investigators in two ways: (1) using directly standard anatomic color M-Mode TDI and (2) by the same technique, but guided by a preliminary MVG estimation with pulsed TDI using four measurement sets within the ventricular wall. The interobserver agreement limits of the combined method [-0.78 s(-1) (95% CI: -0.95 to -0.6 s(-1)) to 0.57 s(-1) (95% CI: 0.4-0.75 s(-1))] were clearly superior to those shown by color M-Mode TDI without B-Mode pre-assessment [-1.35 s(-1) (95% CI: -1.72 to -0.98 s(-1)) to 1.5 s(-1) (95% CI: 1.13-1.87 s(-1))]. An initial estimation by pulsed TDI is useful to achieve a clinically acceptable reproducibility of MVG measurements.

1054-147 Use of color M-mode tissue Doppler imaging to calculate dynamic compliance of the pulmonary arteries in pulmonary hypertension: Validation in an animal model

1054-147 Use of color M-mode tissue Doppler imaging to calculate dynamic compliance of the pulmonary arteries in pulmonary hypertension: Validation in an animal model

Peak Mean Myocardial Velocities and Velocity Gradients Measured by Color M-Mode Tissue Doppler Imaging in Healthy Cats

Peak Mean Myocardial Velocities and Velocity Gradients Measured by Color M-Mode Tissue Doppler Imaging in Healthy Cats

Tissue Doppler imaging: A useful echocardiographic method for the cardiac sonographer to assess systolic and diastolic ventricular function

Tissue Doppler imaging (TDI) has evolved to become a useful noninvasive method that can complement other echocardiographic techniques in the assessment of left ventricular myocardial velocities in a variety of clinical conditions. Color 2-dimensional and color M-mode TDI are used for quantification of systolic myocardial velocities during myocardial ischemia at rest and with pharmacologic stress testing. Spectral pulsed TDI can provide measurements of regional systolic and diastolic myocardial velocities, and it is particularly useful in the identification of abnormalities of left ventricular diastolic relaxation. This review summarizes the clinical applications of TDI to promote understanding of its utility in the evaluation of left ventricular myocardial function. (J Am Soc Echocardiogr 2001;14:1143-52.)

Tissue Doppler imaging differentiates transmural from nontransmural acute myocardial infarction after reperfusion therapy.

The evaluation of transmural extent of necrosis after acute myocardial infarction remains a major problem in clinical practice. We sought to determine whether color M-mode tissue Doppler imaging (TDI) could differentiate transmural from nontransmural myocardial infarction. Twenty-one anesthetized open-chest dogs underwent 90 or 120 minutes of left anterior descending coronary artery occlusion followed by 180 minutes of reperfusion. The transmural extension of infarct was measured by triphenyltetrazolium chloride (TTC) staining. Segment shortening in the endocardium and epicardium of the anterior and posterior walls was assessed by sonomicrometry. Regional myocardial blood flow was measured by radioactive microspheres. TDI was obtained from an epicardial short-axis view. We calculated systolic and diastolic velocities within the endocardium and epicardium of myocardial walls and the subsequent myocardial velocity gradient (MVG). TTC staining could identify 2 groups according to the transmural extent of necrosis: 15 dogs had a nontransmural (NT) necrosis (42+/-3% of wall thickness), and 6 dogs developed a transmural (T) infarct (81+/-4% of wall thickness). In both groups, ischemia resulted in a significant and similar reduction in endocardial and epicardial velocities, with a resulting low systolic MVG in the anterior wall (0.10+/-0.07 in NT and 0.10+/-0.08 s(-1) in T). At 60 minutes of reperfusion, systolic MVG failed to change significantly in the transmural group (-0.20+/-0.09 s(-1)). In contrast, it increased significantly after reflow in the NT group compared with ischemic values (-0.99+/-0.20 versus 0.10+/-0.07 s(-1), P:<0.05). TDI can differentiate transmural from nontransmural myocardial infarction early after reperfusion.

Assessment of nonuniformity of transmural myocardial velocities by color-coded tissue Doppler imaging: characterization of normal, ischemic, and stunned myocardium.

Transmural myocardial contractile performance is nonuniform across the different layers of the left ventricular wall. We evaluated the accuracy of color M-mode tissue Doppler imaging (TDI) to assess the transmural distribution of myocardial velocities and to quantify the severity of dysfunction induced by acute ischemia and reperfusion in the inner and outer myocardial layers. Thirteen open-chest dogs underwent 15 minutes of left anterior descending coronary artery occlusion followed by 120 minutes of reperfusion. M-mode TDI was obtained from an epicardial short-axis view. Systolic velocities were calculated within endocardium and epicardium of the anterior and posterior walls. Regional myocardial blood flow was assessed by radioactive microspheres. Segment shortening was measured by sonomicrometry in endocardium and epicardium of both the anterior and posterior walls. At baseline, endocardial velocities were higher than epicardial velocities, resulting in an inner/outer myocardial velocity gradient. Ischemia caused a significant and comparable reduction in endocardial and epicardial systolic velocities in the anterior wall with the disappearance of the velocity gradient. Systolic velocities significantly correlated with segment shortening in both endocardium and epicardium during ischemia and reperfusion. In the first minutes after reflow, endocardial velocities showed a greater improvement than epicardial velocities, and the velocity gradient resumed although to a limited extent, indicative of stunning. TDI is an accurate method to assess the nonuniformity of transmural velocities and may be a promising new tool for quantifying ischemia-induced regional myocardial dysfunction.

Dobutamine stress echocardiography at 7.5 μg/kg/min using color tissue Doppler imaging M-mode safely predicts reversible dysfunction early after reperfusion in patients with acute myocardial infarction

Dobutamine stress echocardiography (DSE) is widely used to predict reversible left ventricular dysfunction, but evaluation by this method is subjective. The recently developed color tissue Doppler imaging (TDI) M-mode may permit objective and quantitative assessment of changes in wall motion induced by DSE. We tested the hypothesis that this new method can detect sensitively reversible dysfunction in the post–myocardial infarction setting. DSE with color TDI M-mode and conventional DSE were performed to predict reversible dysfunction in 53 patients at a mean of 3 days after infarction using 7.5 and 10 μg/kg/min of dobutamine. Follow-up regular echocardiography (4 weeks later) was used as the reference technique to define reversible dysfunction segments. To predict reversible dysfunction segments, the standard segmental wall motion score change on conventional DSE and the ratio of the segmental wall velocity difference at rest versus stress (7.5 and 10 μg/kg/min) on DSE with color TDI M-mode (7.5-TDI-M and 10-TDI-M, respectively) were used. With 7.5 μg/kg/min of dobutamine, the sensitivity for predicting reversible dysfunction using color TDI M-mode (7.5-TDI-M) was significantly higher than that of conventional DSE (89% vs 73%, p <0.05) whereas specificities and predictive values were almost identical. With a 10-μg/kg/min dose, color TDI-M mode (10-TDI-M) and conventional DSE were not significantly different in predicting reversible dysfunction. With use of color TDI-M mode, regional wall motion during DSE was analyzed objectively and quantitatively. Moreover, combined TDI-M and conventional data were slightly superior to either mode alone. There were no arrhythmias during 7.5 μg/kg/min of dobutamine, but 9 arrhythmias occurred during the 10-μg/kg/min dose in patients with acute myocardial infarction. In conclusion, color TDI M-mode permits objective and quantitative assessment of regional ventricular wall motion and gives additional information for detecting reversible dysfunction in DSE. Improvement of sensitivity at a lower dose of dobutamine with color TDI-M mode may increase the safety of DSE in the post–myocardial infarction setting.

Resting and active mechanical properties of trabeculae carneae from aged male rats.

Resting and active mechanical properties of trabeculae carneae from aged male rats.