Novel approach to the quantitation of regional left ventricular systolic and diastolic function using tissue Doppler imaging to create a myocardial velocity profile and gradient

Assessment of strain and strain rate in embryonic chick heart in vivo using tissue Doppler optical coherence tomography

We present a method to assess the in vivo radial strain and strain rate of the myocardial wall, which is of great importance to understand the biomechanics of cardiac development, using tissue Doppler optical coherence tomography (tissue-DOCT). Combining the structure and velocity information acquired from tissue-DOCT, the velocity distribution in the myocardial wall is plotted, from which the radial strain and strain rate are evaluated. The results demonstrate that tissue-DOCT can be used as a useful tool to describe tissue deformation, especially, the biomechanical characteristics of the embryonic heart.

The origin and clinical significance of the signal opposite to the mitral E-wave: a simple and novel indicator of left ventricular filling pressure

OBJECTIVES

We noted a low-velocity signal opposite to the early diastolic transmitral flow (E) by pulsed Doppler echocardiography. The purpose of this study was to examine the origin and significance of this signal.

BACKGROUND

The background of the signal remains uncertain.

METHODS

We studied 59 adult patients (34 men and 25 women; mean age, 58.9 [20.2] years) without mitral valve heart disease. Mitral E-wave velocity and the signal (EW) opposite the E-wave were measured by pulsed Doppler echocardiography. Early diastolic mitral valve ring motion velocity (Ea) was measured by pulsed tissue Doppler echocardiography. Pulmonary capillary wedge pressure (PCWP) was measured by a Swan-Ganz catheter in 34 of the 59 patients.

RESULTS

A blue signal was observed during early diastole from the mitral valve ring to the mitral orifice areas by color tissue Doppler echocardiography. The velocity profile method revealed the same direction and time between peak Ea and EW. Peak EW positively correlated with Ea (r = 0.67, P < 0.01). There were significant positive correlations between mean PCWP and E/Ea (r = 0.61, P < 0.01) and E/EW (r = 0.59, P < 0.01). E/EW was significantly greater in patients with PCWP > 12 mmHg than in patients with PCWP ≤ 12 mmHg (5.6 [1.3] cm/s vs. 4.3 [0.9] cm/s, P < 0.01).

CONCLUSIONS

EW may be related to mitral valve ring motion, and the E/EW ratio may be a noninvasive simple parameter for assessing left ventricular filling pressure.

Left atrial distensibility and E/e' for estimating left ventricular filling pressure in patients with stable angina. -A comparative echocardiography and catheterization study-

BACKGROUND

Although E/e' (the ratio of early diastolic mitral inflow velocity to early diastolic mitral annular velocity) is widely used to measure left ventricular filling pressure (LVFP), its accuracy is questionable in coronary artery disease patients.

METHODS AND RESULTS

Echocardiograms and LVFP were obtained from 174 patients with stable angina (Canadian Cardiovascular Society angina grade I-II) who had received interventions for angiography-confirmed coronary stenosis. Compared with single-vessel groups, the multiple-vessel group exhibited lower mitral annular velocities, higher LVFP, and stronger correlations between E/regional e' and LVFP. Additionally, stronger correlations between E/regional e' and LVFP existed in patients with systolic dysfunction or lower variation of myocardial performance index (MPI) among anterior, inferior and lateral borders of mitral annulus. Average e' was not superior to any regional e' for assessing LVFP by the E/e' method. E/e' and left atrial (LA) ejection fraction (EF) correlated linearly with LVFP, but the correlation between LA distensibility and LVFP was logarithmical. Compared with E/e', LA distensibility and LAEF were superior for identifying high LVFP.

CONCLUSIONS

E/e' is not completely satisfactory for assessing LVFP in patients with stable angina, especially those with single-vessel disease, preserved systolic function or high MPI variation. For identifying high LVFP, LA distensibility and LAEF are better than E/e'.

Measurement of strain and strain rate in embryonic chick heart in vivo using spectral domain optical coherence tomography

The ability to measure in vivo strain and strain rate in embryonic chick heart is one of the key requirements for understanding the mechanisms of cardiac development. Due to its high temporal and spatial resolution as well as its fast imaging capability, optical coherence tomography (OCT) has the potential to reveal the complex myocardial activity in the living chick heart. We describe a method to evaluate the in vivo strain and strain rate of the myocardium through analyzing the periodic variation of the myocardial wall thickness calculated from real time serial OCT images. The results demonstrate that OCT can be a useful tool to describe the biomechanical characteristics of the embryonic heart.

Assessment of regional systolic and diastolic functions affected by atorvastatin in coronary artery disease using tissue Doppler imaging

BACKGROUND

Several studies have shown regional left ventricular (LV) systolic and diastolic changes associated with coronary artery disease (CAD). Statins may have beneficial pleiotropic effects in addition to their lipid-lowering properties.

HYPOTHESIS

We hypothesized that atorvastatin can improve regional LV systolic and diastolic functions in CAD patients using tissue Doppler imaging (TDI).

METHODS

A total of 63 patients with hyperlipemia and CAD were studied. Forty-three patients were given 10 mg daily of atorvastatin and 20 patients were assigned only a low-fat diet. Tissue Doppler imaging was applied to evaluate LV peak systolic velocity (VS), early diastolic velocity (VE), and late diastolic velocity (VA) in 18 segments. The mean value of LV peak systolic velocity (VS(')), the mean value of early diastolic velocity (VE(')), and the mean value of late diastolic velocity (VA(')), in 18 segments were calculated.

RESULTS

Compared with the baseline, VS('), and VE('), increased significantly after the therapy in the atorvastatin group (p < 0.05), while there was no change in the control group (p > 0.05). At 6 mo of therapy, a significant reduction in total cholesterol, triglyceride, and low-density lipoprotein (LDL) cholesterol was observed in the 2 groups (p < 0.05).

CONCLUSIONS

These findings demonstrate that atorvastatin can improve regional LV systolic and diastolic functions in CAD patients independent of its lipid-lowering properties.

Relationship between regional and global left ventricular systolic and diastolic function in patients with coronary artery disease assessed by strain rate imaging

BACKGROUND

The relationship between regional and global left ventricular function has not been evaluated. The present study aimed to assess whether regional myocardial contraction and relaxation reflect global left ventricular systolic and early diastolic function, respectively.

METHODS AND RESULTS

The study involved 45 patients with coronary artery disease (CAD). Conventional echocardiography was performed, and segmental peak strain rate (SR) in the systole (S(SR)) and early diastole (E(SR)) were obtained from tissue Doppler imaging in each of 18 segments of the left ventricular myocardium from the apical views. The E(SR) was significantly correlated with S(SR) in all studied segments (r=0.55, p<0.0001). The average values of SR indices in each patient were defined as S(SR) index and E(SR) index, which were derived by dividing the summed value of the S(SR) or E(SR) by the number of respective assessable segments. A significant positive relationship was observed between the S(SR) index and left ventricular ejection fraction (r=0.85, p<0.0001). Also, there was a positive correlation between the E(SR) index and mitral flow E (r=0.68, p<0.0001).

CONCLUSIONS

Regional myocardial contraction and relaxation, as assessed by SR imaging, were closely related in patients with CAD. Furthermore, regional myocardial contraction and relaxation are important factors affecting global left ventricular systolic and early diastolic function.

Left Ventricular Systolic Longitudinal Function: Comparison Among Simple M-Mode, Pulsed, and M-Mode Color Tissue Doppler of Mitral Annulus in Healthy Individuals

BACKGROUND

M-mode determination of left ventricular (LV) atrioventricular plane displacement (AVPD) allows a simple assessment of LV longitudinal systolic function. Color tissue Doppler (TD) M-mode-derived AVPD and pulsed TD-derived systolic annular velocity are more sophisticated tools.

OBJECTIVE

We sought to compare these 3 techniques for the analysis of LV longitudinal systolic function.

METHODS

Standard M-mode AVPD, color TD M-mode AVPD, and systolic annular velocity were measured at 4 annular levels in 56 healthy individuals. The time to onset and the electromechanical interval were also determined using each technique.

RESULTS

Standard M-mode AVPD (r = 0.56, P < .0001) and color TD M-mode AVPD (r = .65, P < .0001) showed good correlation with systolic annular velocity. All 3 techniques revealed an inhomogeneous systolic shifting among different annular portions. Systolic intervals showed small discrepancies but high concordance between M-mode techniques and pulsed TD.

CONCLUSIONS

Standard M-mode imaging of the mitral annulus may be considered a reliable method for the assessment of LV longitudinal function.

Losartan improves regional left ventricular systolic and diastolic function in patients with hypertension: accurate evaluation using a newly developed color-coded tissue doppler imaging technique

BACKGROUND

Angiotensin II receptor antagonists have recently been accepted as antihypertensive therapy. Tissue Doppler imaging (TDI) has been developed as a noninvasive tool to assess quantitatively regional myocardial motion abnormalities. This study was designed to determine whether our newly developed technique of color-coded TDI may be a useful means of quantifying the improvement in regional left ventricular (LV) myocardial contractility and relaxation after treatment with losartan in patients with hypertension.

METHODS AND RESULTS

Losartan (50 to 100 mg) was administered for 6 months to 37 previously untreated patients with essential hypertension. Averaged myocardial velocity profiles (MVPs) for color-coded TDI were recorded in the ventricular septum and LV posterior wall before and after treatment. Peak myocardial velocities and peak myocardial velocity gradients (MVGs) in the LV walls were determined during systole and early diastole. The plasma concentration of transforming growth factor (TGF)-beta1 also was measured in all patients. Blood pressure and plasma TGF-beta1 level decreased after initiation of losartan therapy. The LV mass index and LV meridional end-systolic wall stress also decreased after treatment with losartan. LV geometry changed from a pattern consistent with concentric hypertrophy to normal geometry in 10 patients and to a pattern consistent with concentric remodeling in 5 patients, and from concentric remodeling to normal geometry in 5 patients after treatment with losartan. The ratio of early to late diastolic filling for the transmitral flow velocity increased after losartan treatment. The peak systolic and early diastolic myocardial velocities and MVGs in the ventricular septum and LV posterior wall increased after treatment with losartan, although the values 6 months after treatment with losartan were still lower than those in normal individuals. There were good correlations between changes in plasma TGF-beta1 level and changes in systolic and early diastolic MVGs 6 months after losartan. However, there were no significant correlations between changes in the systolic blood pressure and LV end-systolic wall stress and changes in the TDI parameters.

CONCLUSION

Losartan improves regional LV function in patients with hypertension. Our newly developed averaged MVP and MVG measurements may be useful for accurately evaluating regional LV myocardial contractility and relaxation in these patients.

Relationship Between Asynchronous Myocardial Contraction and Left Ventricular Systolic and Diastolic Function-Assessment Using the ECG-Gated Polar Map With 99mTc-Methoxy-Isobutyl Isonitrile-

BACKGROUND

To quantitate the degree of 3-dimensional asynchronous myocardial contraction, an ECG-gated polar map method was developed with (99m)Tc-methoxy-isobutyl isonitrile, and used to investigate the relationship between asynchrony and left ventricular (LV) function.

METHODS AND RESULTS

Twelve normal subjects and 38 patients with an old myocardial infarction were studied with ECG-gated single-photon emission computed tomography (SPECT). In each frame, a myocardial perfusion polar map was reconstructed and the peak contraction phase in each pixel was displayed (phase map). The degree of asynchronous contraction was assessed from the standard deviations of the peak contraction phase (SDP) on the phase map. Ejection fraction (EF), peak ejection rate (PER), 1/3EF, peak filling rate (PFR) and 1/3 filling fraction (1/3FF) were calculated by the quantitative gated SPECT software, and E/A from Doppler echocardiography. The SDP was compared with these parameters. Correlation coefficients and p values between the SDP and parameters of cardiac function were as follows: EF, r=-0.69 (p<0.001); PER, r=-0.54 (p<0.001); 1/3EF, r=-0.57 (p<0.001); PFR, r=-0.29 (p<0.05); 1/3FF, r=-0.63 (p<0.001); E/A, r=-0.11 (p=0.51).

CONCLUSIONS

There was a negative correlation between the SDP and LV systolic and diastolic function, which confirmed the functional significance of asynchrony on cardiac function.

Preload-Adjusted 2 Wave-Intensity Peaks Reflect Simultaneous Assessment of Left Ventricular Contractility and Relaxation

BACKGROUND

The magnitudes of the first (WI1) and the second wave-intensity peak (WI2) during the ejection period can be used as indices of left ventricular (LV) contractility and relaxation, respectively. However, use of WI to characterize LV dp/dt and the end-diastolic volume (V ed) relationship may be more problematic, as WI may be affected by changes in preload.

METHODS AND RESULTS

The LV pressure-volume data sets, consisting of 23 recordings obtained by the conductance method from 12 heart disease patients, were studied. End-systolic elastance (E es) and volume-axis-intercept (V0) were calculated with varying preload. Time constant of LV relaxation (tau), V ed, and WI were calculated from steady-state averaged data. The E es showed a weak correlation with WI1 (r = 0.46, p < 0.05) but a better correlation with preload-adjusted WI1 [WI1/V ed; r=0.86, WI1/V(ed)2; r = 0.92, WI1/(V ed - V0)2; r = 0.89, all p < 0.01]. Similarly, tau did not correlate with WI2 but did correlate with preload-adjusted WI2 [WI2/V ed; r = -0.73, WI2/V(ed) 2; r = -0.63, WI2/(V ed - V0)2; r = -0.78, all p < 0.01].

CONCLUSIONS

These data demonstrate the importance of preload-adjustment when using the WI index for simultaneous assessment of LV contractility and relaxation.

Can Transthoracic Doppler Echocardiography Predict the Discrepancy Between Left Ventricular End-Diastolic Pressure and Mean Pulmonary Capillary Wedge Pressure in Patients With Heart Failure?

BACKGROUND

Left ventricular end-diastolic pressure (LVEDP) is difficult to measure continuously; therefore, pulmonary capillary wedge pressure (PCWP) is frequently used instead for hemodynamic monitoring in patients with heart failure. However, a discrepancy between LVEDP and mean PCWP is sometimes observed.

METHODS AND RESULTS

To assess the feasibility of evaluating this discrepancy using echo-Doppler indexes, 140 consecutive patients with heart disease were studied. Transthoracic Doppler echocardiography (TTDE) was performed immediately before bilateral-sided cardiac catheterization. We measured peak velocities of early (E: cm/s) and late (A: cm/s) diastolic transmitral flow, and duration of A wave (MAd: ms). We also measured the duration of atrial reversal of pulmonary venous flow (PAd: ms). The difference between PAd and MAd (Deltad = PAd-MAd: ms) was calculated. The ratio of E to tissue Doppler-derived peak early diastolic velocity of mitral annulus (Ea: cm/s) was also calculated (E/Ea). There was a good positive correlation between LVEDP and Deltad (r = 0.77, p < 0.001). There was a modest correlation between mean PCWP and E/Ea (r = 0.56, p < 0.001). When patients were classified by Deltad > or = 10 ms and E/Ea < or = 14, elevated LVEDP (> or = 17 mmHg) and normal mean PCWP (< or = 12 mmHg) were predicted with 100% sensitivity and 85% specificity.

CONCLUSIONS

Evaluation of the discrepancy between LVEDP and mean PCWP in patients with heart failure was feasible by separately estimating LVEDP by Deltad and mean PCWP by E/Ea using noninvasive TTDE. Early detection of patients with elevated LVEDP and normal mean PCWP may be useful for preventing acute exacerbation of chronic heart failure.

Tissue Doppler Imaging and Strain Doppler Imaging as Modalities for Predicting Clinical Improvement in Patients Receiving Biventricular Pacing

BACKGROUND

The purpose of this study was to determine the utility and efficacy of tissue Doppler imaging (TDI) and strain Doppler imaging (SDI) for evaluating ventricular synchrony and function, and for predicting the long-term clinical improvement in patients undergoing biventricular pacing (BVP).

METHODS AND RESULTS

TDI and SDI were performed before and <1 month after initiating BVP in 17 patients with advanced heart failure. An intraventricular conduction delay between the left ventricular (LV) septal and lateral walls was measured by TDI. The average LV strain (LV-strain) was calculated from data obtained at the center of 6 regions of the LV (base and mid-point between the basal and apical portions, and the mid-point between these 2 points on the septal and lateral walls). During a 23+/-7 month follow-up period, 12 patients improved clinically and did not require re-hospitalization for heart failure (responder group), but the remaining 5 did not improve (nonresponder group). Before BVP, the intraventricular conduction delay was greater in the responder group than in the nonresponder group (p<0.01), but after BVP, it did not differ between the 2 groups. LV-strain improved after BVP in the responder group but not in the nonresponder group (p<0.05).

CONCLUSION

A high intraventricular conduction delay before BVP and decreased strain shortly after BVP may predict long-term clinical improvement in patients undergoing this treatment.