Tissue Doppler imaging (TDI) for on-line detection of regional early diastolic ventricular asynchrony in patients with coronary artery disease

Continuous, Real-Time, Noninvasive Hemodynamic Cardiac Doppler Monitoring With a Novel Hands-Free Device: A Feasibility Study Compared to Standard Echo

This study sought to determine the feasibility of using noninvasive cardiac hemodynamics (NICHE), a new noninvasive Doppler-based device, to monitor real-time, simultaneous tissue and blood-flow Doppler measurements in a clinical setting, and to obtain preliminary performance data compared to a commercially available system. Doppler-based measurements have been shown to correlate well with invasive hemodynamic data and diastolic function, but their use in clinical applications has been limited by various technical issues. The NICHE device was developed to obtain simultaneous tissue and blood-flow Doppler measurements automatically, in real-time and in a hands-free manner. Thirty participants (ten normal volunteers and 20 patients in a cardiac rehab program) underwent standard echocardiographic/Doppler studies followed immediately by NICHE monitoring. Early diastolic transmitral blood-flow velocity (E) and tissue Doppler myocardial wall velocity during early relaxation (E′) were acquired using a standard echo device; and E/E′ was derived post hoc. NICHE measurements included E, E′, and directly measured instantaneous E/E′. NICHE was successfully used in 28 participants. Measurements of ENICHE ranged from 40 cm/s to over 120 cm/s and correlated well with Eecho (R = 0.93). ENICHE′ ranged from 2 to 23 cm/s and correlated well with the averaged Eecho′ (R = 0.91). Directly measured E/ENICHE′ ratios ranged from 3 to 23 and correlated well with derived E/Eecho′ (R = 0.91). The NICHE device can monitor patients in a hands-free manner and can supply real-time Doppler derived measurements of hemodynamic parameters and diastolic function that correlate well with measurements from standard echo devices.

The Utility of Systolic and Diastolic Echocardiographic Parameters for Predicting Coronary Artery Disease Burden as Defined by the SYNTAX Score

BACKGROUND

Early identification of high-grade ischemia based on echocardiographic diastolic abnormalities may be clinically useful in the acute coronary syndrome (ACS) setting. This could provide the clinician with an awareness of the burden of coronary artery disease (CAD) before angiography is performed to allow for early intervention of suspected ischemic lesions. The objective of the study was to assess whether 2D transthoracic echocardiography (TTE)-derived tissue Doppler imaging parameters can predict the severity of CAD in comparison with the cardiac catheterization-derived SYNTAX score.

METHODS

A retrospective study of 74 stable angina or patients with ACS was performed in 2012 at a single tertiary care center. In all study subjects, TTE and angiography were performed within 6 months of each other without revascularization in the interim.

RESULTS

The study population included a total of 74 patients (mean age 67 ± 12 years) with 77% presenting with an ACS. The median SYNTAX score was 24.0 (6.0-35.0). The E-wave velocity was higher, and deceleration time (DT) was lower in the high SYNTAX group in comparison with the low/intermediate SYNTAX group (P = 0.045 and P = 0.001, respectively). Septal mitral annular S' was lower in the high SYNTAX group (P = 0.02). After multivariate analysis, E/A ratio (OR 0.03, 95% 0.00-0.36, P = 0.0067), DT (OR 0.93, 95% CI 0.89-0.97, P = 0.0001) and septal annular S'-wave velocity (OR 0.34, 95% CI 0.16-0.71, P = 0.0038) remained strong predictors of a high SYNTAX score.

CONCLUSION

Early identification of systolic and diastolic dysfunction based on echocardiographic parameters may be of important clinical significance for predicting CAD burden prior to invasive angiography.

Tissue Doppler imaging for diagnosis of coronary artery disease: a systematic review and meta-analysis

Global and regional left ventricular (LV) systolic dysfunction is a marker of coronary artery disease (CAD), which is conventionally assessed using two-dimensional echocardiography. Tissue Doppler imaging (TDI) has emerged as an adjunct tool in the diagnosis of regional wall motion abnormalities from CAD. We performed a systematic review and meta-analysis to assess the efficacy of TDI indices in the diagnosis of CAD. We searched MEDLINE and the Cochrane Library for controlled studies comparing TDI measurements in those with and without CAD as confirmed by coronary angiography. Meta-analyses of mean differences in TDI velocities between these populations were performed. Screening of titles and abstracts followed by full-text screening identified 8 studies. At rest, TDI was associated with a significant decrease in the pooled maximum systolic velocity among CAD patients compared to those without CAD [mean difference (MD): -0.66; 95% confidence interval (CI): -0.98 to −0.34]. There were no significant differences in maximum early and late diastolic velocities. Post-stress, TDI was associated with a significant decrease in maximum early diastolic velocity (MD: -1.91; 95% CI: -2.74 to −1.09) and maximum late diastolic velocity (MD: -1.57; 95% CI: -2.95 to −0.18) among CAD patients compared to those without CAD. There was no significant difference in maximum systolic velocity post-stress. Our results suggest that TDI may have a role in the evaluation of CAD. Future studies should evaluate the incremental value of TDI velocities over LV ejection fraction and two dimensional wall motion analysis in the detection of CAD and assessment of its severity. (Word Count: 249)

The right ventricular annular velocity reduction caused by coronary artery bypass graft surgery occurs at the moment of pericardial incision

Background

Right ventricular (RV) long-axis function is known to be depressed after cardiac surgery, but the mechanism is not known. We hypothesized that intraoperative transesophageal echocardiography could pinpoint the time at which this happens to help narrow the range of plausible mechanisms.

Method

Transthoracic echocardiography was conducted in 33 patients before and after elective coronary artery bypass graft. In an intensively monitored cohort of 9 patients, we also monitored RV function intraoperatively using serial pulsed wave tissue Doppler (PW TD) transesophageal echocardiography.

Results

There was no significant difference in myocardial velocities from the onset of the operation up to the beginning of pericardial incision, change in RV PW TD S′ velocities 3% ± 2% (P = not significant).

Within the first 3 minutes of opening the pericardium, RV PW TD S′ velocities had reduced by 43% ± 17% (P < .001). At 5 minutes postpericardial incision, 2 minutes later, the velocities had more than halved, by 54% ± 11% (P < .0001). Velocities thereafter remained depressed throughout the operation, with final intraoperative S′ reduction being 61% ± 11% (P < .0001).

One month after surgery, in the full 33-patient cohort, transthoracic echocardiogram data showed a 55% ± 12% (P < .0001) reduction in RV S′ velocities compared with preoperative values.

Conclusions

Minute-by-minute monitoring during cardiac surgery reveals that, virtually, all the losses in RV systolic velocity occurs within the first 3 minutes after pericardial incision. Right ventricular long-axis reduction during coronary bypass surgery results not from cardiopulmonary bypass but rather from pericardial incision.

Age and gender related reference values for transthoracic Doppler-echocardiography in the anesthetized CD1 mouse

OBJECTIVE

Doppler-echocardiography of the mouse has evolved to a commonly used technique in the past years as recent advances in imaging quality have substantially improved spatial and temporal resolution allowing the adaptation of this technique to murine models. Although mouse echocardiography is widely used, there is only little information on reference data for wild-type animals available, particularly in older mice.

METHODS

We therefore established a database with echocardiographic reference-values in a large set of young (8 weeks) and older adult (52 weeks) Swiss type CD1-mice of either sex. We performed a complete Doppler-echocardiographic examination under light Ketamine-Xylazine-anesthesia. LV-mass was calculated and compared with necropsy heart weights to validate the LV-mass calculation.

RESULTS

Doppler-echocardiographic measurements in mice were feasible to assess cardiac morphology and function. Sonomorphological and functional parameters hardly changed between the age of 12 and 52 weeks. Wall thickness, LV-mass and cardiac output were stable with aging. There was a good relative correlation between echocardiographically estimated LV-mass and necropsy heart weight although absolute values differed. There were no significant echocardiographic differences between male and female mice.

CONCLUSIONS

The reference values established in this study can be useful in recording and quantifying pathological changes in murine models of cardiovascular diseases. There is hardly any change of cardiac function between the age of 12 and 52 weeks.

Detection of a pseudonormal mitral inflow pattern: an echocardiographic and tissue Doppler study

OBJECTIVE

The aim of this study was to assess the ability of several echocardiographic and tissue Doppler imaging (TDI) derived parameters to improve the noninvasive diagnosis of a pseudonormal mitral inflow pattern.

METHODS

Ninety-eight consecutive patients with age-related normal transmitral Doppler profile underwent echocardiography including TDI and measurement of left ventricular end-diastolic pressure (LVEDP) using fluid-filled catheters. Peak transmitral velocities were determined at rest (E, A) and during the strain phase of a Valsalva maneuver. The difference in duration between the pulmonary venous retrograde velocity and the transmitral A-velocity (PVR-A) was calculated from pulsed Doppler recordings. Propagation velocity of the early mitral inflow (VP) was determined by color M-mode. Early diastolic peak mitral annulus velocities (E') and the early diastolic transmyocardial velocity gradient of the posterior basal wall (MVG) were obtained by TDI.

RESULTS

Fifty-two patients presented with normal diastolic function (group I: LVEDP9.5 +/- 3 mm Hg, E/A1.1 +/- 0.19), while pseudonormalization, defined as LVEDP 15 mm Hg and E/A > 0.9, was found in 46 patients (group II: LVEDP23 +/- 7 mm Hg, E/A1.43 +/- 0.83). The coefficient of linear correlation (r) and the area under ROC - curve (AUC) to predict LVEDP values 15 mm Hg were maximal for the index PVR-A (AUC = 0.92, r = 0.77), followed byE/E' (AUC = 0.80, r = 0.46), MVG (AUC = 0.65, r = 0.33) and E/VP (AUC = 0.69, r = 0.30), P < 0.01, whereas the decrease in E/A ratio during Valsalva maneuver failed to reach significance. Similar results were observed when echocardiographic parameters were used to estimate the left ventricular diastolic pressure before atrial contraction.

CONCLUSIONS

PVR-A enabled the most accurate estimation of LVEDP. TDI-derived indices E/E' and MVG are also reliable alternatives superior to the classical Valsalva maneuver to detect a pseudonormal transmitral Doppler profile.

Fetal tissue Doppler echocardiography: detection rates of cardiac structures and quantitative assessment of the fetal heart

OBJECTIVES

Tissue Doppler echocardiography (TDE) has been developed in adult cardiology, but only recently has it been applied to fetal heart studies. We implemented TDE on a high-resolution ultrasound system used for prenatal scanning by changing the Doppler settings, but without specific TDE equipment, to study cardiac tissue motion of normal fetuses in the second and third trimesters.

METHODS

Using color Doppler settings optimized for low velocity motion assessment, detection rates of cardiac structures were measured in 47 fetuses. With pulsed Doppler, axial diastolic and systolic cardiac wall velocities were recorded in another 30 fetuses.

RESULTS

In all fetuses TDE could detect cardiac wall motion. The right ventricular wall and the level of the atrioventricular valves were most easily seen. Axial contraction velocities of the fetal heart increased with gestational age.

CONCLUSIONS

TDE can be used to study normal fetal cardiac function throughout gestation. A regular ultrasound system without additional hardware or software is suitable for screening studies using TDE.

Post-endsystolic active shortening in the non-ischemic region impairs left ventricular pressure fall in acute ischemic heart

To investigate the relation between the impairment of isovolumic relaxation and the regional wall motion in acute ischemia, the left ventricular pressure fall and regional myocardial motion were examined in the relaxation phase in dogs during both acute coronary artery occlusion (n = 12) and a regional coronary flow reduction (n = 6). Fifteen to 40 seconds after complete coronary artery occlusion or in the stable state after a regional coronary flow reduction by 70 to 90% of the control state, a shortening of the non-ischemic region at the early isovolumic relaxation phase (the post-endsystolic shortening) appeared, combined with lengthening of the ischemic region. In these situations, the logarithmic plots of the left ventricular pressure fall was composed of two components (time constant of early part [Ta] and at latter part [Tb]). Ta was greater than Tb (64.3 +/- 13.8 milliseconds vs. 36.6 +/- 10.4 milliseconds at 15 seconds after coronary occlusion, p < 0.01; 67.6 +/- 22.9 milliseconds vs. 45.1 +/- 17.5 milliseconds at flow reduction, p < 0.01) and the time constant at control (p < 0.01). These findings suggested that post-endsystolic shortening in the non-ischemic region played a role in a the non-uniformity of the left ventricular contraction and contributed to the impairment of the left ventricular pressure fall in acute regional ischemia, especially in early isovolumic relaxation.