Noninvasive assessment of systolic and diastolic left ventricular function in female runners

Nine female runners and 9 matched control subjects were investigatedwith echocardiography and Doppler velocimetry to assess cardiacstructure and systolic and diastolic left ventricular (LV) functionat rest. LV mass was considerably larger in the athletes (171vs 123 g; P <001). Minute distance, the Doppler index cardiacoutput, was similar in runners and controls; the lower heartrate (P<0.01) of the athletes was associated with a higherstroke distance (P<0.05). The latter could be attributedto a larger end-diastolic LV internal diameter (46 vs 43 mm;P<0.05); wall stress and the various indices of systolicLV function were not different between runners and controls.Early diastolic LV function, estimated from the velocity ofLV relaxation and the LV inflow pattern, and late diastolicfunction, assessed by Doppler velocimetry, were similar in runnersand controls. The unchanged ratio of the peak velocities ofLV filling during atrial contraction and early filling (0.49vs 0.44; NS) indicates that LV distensibility is unaltered inthe athletes.In conclusion, the higher left ventricular massof female runners is not associated with changes of systolicand diastolic LV function.     

Noninvasive assessment of systolic and diastolic left ventricular function in female runners

Nine female runners and 9 matched control subjects were investigatedwith echocardiography and Doppler velocimetry to assess cardiacstructure and systolic and diastolic left ventricular (LV) functionat rest. LV mass was considerably larger in the athletes (171vs 123 g; P <001). Minute distance, the Doppler index cardiacoutput, was similar in runners and controls; the lower heartrate (P<0.01) of the athletes was associated with a higherstroke distance (P<0.05). The latter could be attributedto a larger end-diastolic LV internal diameter (46 vs 43 mm;P<0.05); wall stress and the various indices of systolicLV function were not different between runners and controls.Early diastolic LV function, estimated from the velocity ofLV relaxation and the LV inflow pattern, and late diastolicfunction, assessed by Doppler velocimetry, were similar in runnersand controls. The unchanged ratio of the peak velocities ofLV filling during atrial contraction and early filling (0.49vs 0.44; NS) indicates that LV distensibility is unaltered inthe athletes.In conclusion, the higher left ventricular massof female runners is not associated with changes of systolicand diastolic LV function.     

Relationship of echocardiographic indices to pulmonary capillary wedge pressures in healthy volunteers

OBJECTIVES: We sought to determine the relationship between different echocardiographic indices and pulmonary capillary wedge pressures (PCWP) in normal volunteers. BACKGROUND: Indices based on tissue Doppler (TDE) and color M-mode (CMM) echocardiography have been proposed to reflect left (LV) ventricular filling pressures. These include the ratio of early diastolic transmitral velocity (E) to early myocardial velocity measured by TDE (E') and the ratio of E to the wave propagation velocity (Vp) measured from CMM images. These indices, however, have not been validated in normal individuals. METHODS: We studied seven volunteers during two phases of preload altering maneuvers, baseline, with two stages of lower body negative pressure, and repeat baseline with two stages of volume loading. The PCWP obtained from right heart catheterization was compared with diastolic indices using pulsed Doppler, TDE and CMM echocardiography. RESULTS: The PCWP ranged from 2.2 to 23.5 mm Hg. During preload alterations, significant changes in E and septal E' (both p < 0.05) but not lateral E' or Vp were observed. Furthermore, E, septal E' and E/Vp correlated with PCWP (all r > 0.80) but not combined E and TDE indices (both r < 0.15). Within individuals, a similar linear relationship was observed among E/Vp, E and septal E' (average r > 0.80). CONCLUSIONS: In subjects without heart disease, E, septal E' and E/Vp correlate with PCWP. Because the influence of ventricular relaxation is minimized, the ratio E/Vp may be the best overall index of LV filling pressures.     

Impact of left ventricular function on the pulmonary vein Doppler spectrum: nonsimultaneous assessment with load-insensitive indices

Pulmonary vein Doppler spectrum is highly load-dependent and thus has been used to estimate left ventricular (LV) filling pressure. However, the impact of LV function on pulmonary vein Doppler spectrum remains obscure because only load-sensitive indices were studied previously. In the present study, measurements of the pulmonary vein Doppler spectrum were correlated with load-insensitive LV systolic (end-systolic elastance [Ees]) and diastolic (relaxation time constant [tau] and beta coefficient of the end-diastolic pressure volume relationship) function indices obtained from an invasive catheterization study nonsimultaneously. The peak velocity, velocity time integral, and duration of systolic forward spectrum were significantly correlated with Ees (r = 0.35, r = 0.36, and r = 0.41, respectively;P < 0.05). The pulmonary vein diastolic velocity time integral (PVDVTI) and duration of the diastolic forward spectrum were significantly correlated with Ees (r = 0.51 and r = 0.57, respectively;P < 0.01). PVDVTI was correlated with tau and the end-diastolic pressure-volume relationship (EDPVR) (r = 0.42 and r = 0.40 respectively,P < 0.05). On the other hand, the systolic fraction of the forward spectrum was significantly correlated with ejection fraction (for peak velocity,r = 0.63, P < 0.01; for velocity time integral,r = 0.37, P < 0.05) but not with Ees, and the diastolic fraction of the forward spectrum was significantly correlated with minimum pressure derivative over time (for peak velocity,r = 0.48, P < 0.05; for velocity time integral,r = 0.44, P < 0.05, respectively) but not with tau or EDPVR. In summary, the systolic and diastolic components of the pulmonary vein Doppler spectrum are affected variably by LV systolic and diastolic function, independent of the loading condition. The systolic and diastolic fraction of pulmonary vein Doppler spectrum appears to depend more on the loading condition than the LV systolic or diastolic function.     

The Natural History of Left Ventricular Filling Abnormalities: Assessment by Two-Dimensional and Doppler Echocardiography

Doppler and two-dimensional echocardiography are being increasingly used for the indirect assessment of left ventricular (LV) diastolic function. In this article the alterations in LV filling patterns that occur in patients with LV diastolic function are reviewed in the context of echocardiographic findings. A progression of LV filling abnormalities is presented in the sequential "stages" in which we believe they occur in most cardiac disease states. Patient symptoms, hemodynamics, pulmonary venous flow velocities, and left atrial function associated with the different LV filling patterns are also discussed.     

Usefulness of pulsed-wave tissue Doppler echocardiography for the assessment of the left and right ventricular function in patients with clinical hypothyroidism

Clinical hypothyroidism (HT) is often associated with cardiovascular disorders, such as endothelial and myocardial dysfunction. Previous studies have explored left ventricular (LV) function using pulsed-wave tissue Doppler echocardiography (TDE) in HT. However, no study has utilized this technique in the assessment of right ventricular (RV) function in HT. Accordingly, we investigated the effects of clinical HT on LV and RV function by TDE. The study subjects included 35 newly diagnosed HT patients and 32 healthy normal controls. For each subject, serum FT3, FT4, TT3, TT4, and thyroid stimulating hormone (TSH) levels were measured, and standard echocardiography and TDE were performed. No statistically significant difference was found between patients and controls with regard to age, gender, body mass index, heart rate, and blood pressure. Compared to controls, TSH levels were significantly higher, and TT4 and FT4 levels were significantly lower. TDE showed that patients had significantly lower early diastolic tricuspid annular velocity (Ea) and early/late (Ea/Aa) diastolic tricuspid annular velocity ratio (P < 0.001 and P < 0.001, respectively), and significantly longer isovolumetric relaxation time (P < 0.001) than those of the controls. Aa, Sa, isovolumetric contraction time, and ejection time did not significantly differ. In addition, a significant relationship between some TDE indexes, and thyroid hormones (TT4 and FT4) and TSH was observed. We showed that patients with clinical HT are associated with impaired RV diastolic function, in addition to impaired LV diastolic function using TDE.     

"Pure" diastolic dysfunction is associated with long-axis systolic dysfunction. Implications for the diagnosis and classification of heart failure

AIMS: To investigate regional systolic function of the left ventricle, to test the hypothesis that "pure" diastolic dysfunction (impaired global diastolic filling, with a preserved ejection fraction > or = 50%) is associated with longitudinal systolic dysfunction. METHODS AND RESULTS: One hundred thirty subjects (31 patients with asymptomatic diastolic dysfunction, 30 with diastolic heart failure, 30 with systolic heart failure; and 39 age-matched normal volunteers) were studied by conventional and tissue Doppler echocardiography. Global diastolic function was assessed using the flow propagation velocity, and by estimating left ventricular filling pressure from the ratio of transmitral E and mitral annular E(TDE) velocities (E/E(TDE)); and global systolic function by measurement of ejection fraction. Radial and longitudinal functions were assessed separately from posterior wall and mitral annular velocities. Global and radial systolic function were similar in patients with "pure" diastolic dysfunction and normal subjects, but patients with either asymptomatic diastolic dysfunction or diastolic heart failure had impaired longitudinal systolic function (mean velocities: 8.0+/-1.2 and 7.7+/-1.5 cm/s, respectively, versus 10.1+/-1.5 cm/s in controls; p<0.001). In subjects with normal ejection fraction, global diastolic function correlated with longitudinal systolic function (r=0.56 for flow propagation velocity, and r=-0.53 for E/E(TDE) ratio, both p<0.001), but not with global systolic function. CONCLUSION: Worsening global diastolic dysfunction of the left ventricle is associated with a progressive decline in longitudinal systolic function. Diastolic heart failure as conventionally diagnosed is associated with regional, subendocardial systolic dysfunction that can be revealed by tissue Doppler of long-axis shortening. Diagnostic algorithms and definitions of heart failure need to be revised.     

Role of tissue Doppler and color M-mode imaging for evaluation of diastolic function in ambulatory patients with LV systolic dysfunction

INTRODUCTION: Tissue Doppler imaging (TDI) and color M-mode (CMM) indices provide assessment of left ventricular (LV) relaxation when combined with pulse-wave Doppler (PWD)-derived transmitral inflow, allows for estimation of LV filling pressures. However, use of these indices in patients with LV systolic dysfunction (LVSD) has not been well characterized. METHODS AND RESULTS: The study included 115 patients (age 58 +/- 11 years, 67% male) with LVSD (LV ejection fraction [LVEF] < 55%). Patients were grouped according to the diastolic LV filling pressure assessed by E/Em(septal) ratio as follows: 1) Normal (NFP), E/Em(septal) < 8; 2) Intermediate (IFP), E/Em(septal): 8-15; and 3) High (HFP), E/Em(septal) >15. Age-, gender-, and LVEF-adjusted analyses were performed. LV volumes and LVEF were significantly different between the groups (P < 0.01). PWD-derived E-wave velocity showed a significant stepwise increase across the three groups and the Em(septal) velocity demonstrated a stepwise decrease (P < 0.01 for both). CMM-derived diastolic intra-ventricular pressure gradient (IVPG) was significantly lower in the HFP compared to the other 2 groups (P < 0.01 for both); Vp was increased in the HFP compared to the other 2 groups (P < 0.01 for both), and Vp exhibited a U-shape relationship to LVEF. CONCLUSION: In patients with LVSD, abnormal LV relaxation is uniformly observed regardless of LV filling pressure. PWD-derived E-wave velocity and the TDI-derived Em velocity are important measurements to identify elevated LV filling pressures. CMM-derived Vp and IVPG were of limited incremental value for the evaluation of diastolic function in patients with LVSD.     

Beta-blocker infusion did not improve left ventricular diastolic function in myocardial infarction: A doppler echocardiography and cardiac catheterization study

Left ventricular (LV) diastolic function changes after myocardial infarction. It has been suggested that beta blockers may improve diastolic function in hypertensive and heart failure patients. Doppler echocardiographic filling patterns and invasive hemodynamic indices have been used to analyze LV diastolic function. To determine the effect of beta blockers on LV diastolic function, we studied 32 patients with anterior wall myocardial infarction with a mean age of 53 years. Peak early and late flow velocities, peak early-to-late flow velocities ratio, pressure half time, diastolic filling period, isovolumic relaxation time, cardiac index, mean arterial pressure, wedge pressure, and systemic and pulmonary vascular resistance indices were obtained simultaneously before and after an intravenous infusion of 10 mg of atenolol. Cardiac index decreased from 4.27 ± 0.97 to 3.19 ± 0.911/min/m² (p=0.0001); mean arterial pressure decreased from 85 ± 10 to 80 ± 11 mmHg (p=0.004); wedge pressure increased from 11 ± 5 to 13 ± 4 rnmHg (p = 0.002); systemic vascular resistance index increased from 1586 ± 409 to 1980 ± 634 dynm²s/cm⁵ (p = 0.0002); pulmonary vascular resistance index increased from 115 ± 58 to 163 ± 72 dynm²s/cm⁵ (p = 0.0004); peak late flow velocity decreased from 64 ± 15 to 49 ± 14 cm/s (p = 0.0001); early-to-late ratio increased from 0.95 ± 0.35 to 1.29 ± 0.36 (p = 0.0001); diastolic filling period increased from 300 ± 108 to 400 ± 110 ms (p=0.0001) and isovolumic relaxation time increased from 133 ± 29 to 143 ± 29 ms (p = 0.009). No significant changes were observed for peak early flow velocity and pressure half-time. Multivariate regression analysis suggests that significant changes observed on Doppler echocardiographic parameters can be attributed in part to beta-blocker effect on heart rate analyzed as diastolic filling period. We concluded that beta-blocker infusion changes LV diastolic function analyzed by Doppler echocardiography in patients with anterior wall myocardial infarction. Moreover, the increase observed on wedge pressure suggests deterioration in cardiac function.     

Differentiation of left ventricular diastolic dysfunction, identification of pseudonormal/restrictive mitral inflow pattern and determination of left ventricular filling pressure by Tei index obtained from tissue Doppler echocardiography

BACKGROUND: Tei index obtained from tissue Doppler echocardiography (TDE-Tei index) has an inherent advantage of recording its systolic and diastolic components simultaneously on the same cardiac cycle. The aims of this study are to evaluate whether TDE-Tei index also exerts a correlation with left ventricular (LV) systolic and diastolic function and filling pressure and to see whether it can effectively identify the pseudonormal/restrictive mitral filling pattern. METHODS: Echocardiographic examination was performed in 243 consecutive patients. These patients were classified into three groups as normal, abnormal relaxation, and pseudonormal/restrictive groups according to the transmitral E/A-wave velocity (E/A), early diastolic velocity of lateral mitral annulus (Ea) and E/Ea. RESULTS: Standard Doppler indices of LV filling such as E, A, E/A, and E-wave deceleration time had a bimodal distribution, but Ea decreased and E/Ea and TDE-Tei index increased progressively with worsening of LV diastolic function. The sensitivity and specificity of TDE-Tei index>0.51 in the discrimination of pseudonormal/restrictive filling pattern were 85% and 96%, respectively. After stepwise multiple linear regression analysis, TDE-Tei index had a significant negative correlation with Ea (beta=-0.296, P<0.001) and ejection fraction (beta=-0.293, P<0.001) and positive correlation with E/Ea (beta=0.235, P=0.001). CONCLUSIONS: TDE-Tei index increased with worsening of LV diastolic function and can effectively identify the pseudonormal/restrictive mitral inflow pattern. It also correlated with the echocardiographic parameters of LV systolic and diastolic function and filling pressure. It suggests that TDE-Tei index is a simple and feasible marker in assessing global LV function.     

Effect of Programmed Atrioventricular Delay on the Patterns of Mitral and Pulmonary Vein Flow Profiles and Their Durations in Patients with Dual-Chamber Pacemakers

Cardiac pacemakers are increasingly used in patients with dilated and hypertrophic cardiomyopathy. In these patients, unusually short atrioventricular (AV) delays are used. Changing the AV delay has been shown to affect the mitral E/A velocity ratio, but its effect on the duration of left ventricular (LV) isovolumic relaxation time, LV filling time, or pulmonary vein flow pattern has not been investigated. Twelve patients with dual-chamber pacemakers were studied. The pacemaker was set at a rate of 70 beats/min, and the AV delay was programmed from 25 to 250 msec in 25-msec increments. At each stage, mitral and pulmonary vein flow velocities were recorded using pulsed-wave Doppler technique. Increasing AV delay resulted in a shortened LV diastolic filling period, a change in LV isovolumic relaxation time, a reduction in the E/A velocity ratio, and an increase in A – AR wave duration. These findings have implications not only in the optimization of LV filling but also in the interpretation of mitral and pulmonary vein flow profiles in the evaluation of LV diastolic function and filling pressures.     

Echocardiographic estimation of left ventricular filling pressures in patients with mitral valve stenosis

Mitral stenosis (MS) is prevalent in developing countries. By improving healthcare systems, it could be expected that the incidence of new cases would decrease and therefore the mean age of mitral stenosis patients would increase. This increase in age of MS patients is accompanied by the occurrence of other diseases, such as coronary artery disease, hypertension, diabetes mellitus and chronic obstructive pulmonary disease.In a number of patients with MS, the question arises of the impact of mitral valve disease (MVD) on the presenting symptom. For example, in patients presenting with dyspnea, with both significant MS and hypertension, increased left ventricular (LV) filling pressure due to hypertension could influence assessment of the severity of MS. In these patients, severity of MS could be underestimated because the increased diastolic pressure reduces the mitral valve gradient, and the increased LV stiffness shortens pressure half-time (PHT).Similarly, patients with both pulmonary disease and MS may have dyspnoea because of pulmonary rather than cardiac cause. It is therefore advantageous to assess LV filling pressure in these cases in an attempt to prove or refute a cardiac cause for dyspnoea.Using Doppler measurements to estimate LV filling pressures is desirable. However, conventional Doppler measurements have limitations in the prediction of left ventricular end-diastolic pressure (LVEDP) in this group of patients. For example, in patients with MS, the left atrium (LA) is enlarged to compensate for the increase in LA pressure. Similarly, mitral inflow peak early diastolic velocity (E) is highly dependent on LA pressure1 and also preload.2 Pulmonary venous (PV) flow also has a blunted pattern in most patients with MS.3 Therefore, in MS patients, LA size, mitral inflow pattern and pulmonary venous pattern are all altered, making these measurements unreliable for the estimation of LVEDPHowever, other Doppler and tissue Doppler echocardiographic indices and time intervals, such as peak early diastolic velocity of mitral annulus (Ea), E/Ea ratio, mitral inflow propagation velocity (VP), E/VP, pulmonary vein velocities, Tei index and the ratio of isovolumic relaxation time (IVRT) to interval between the onset of mitral E and annular Ea (TE–Ea), which have shown promising values in the prediction of LV filling pressure in a variety of diseases,4-11 have not been assessed in the setting of mitral stenosis.The aim of this study was to analyse the components of mitral and pulmonary waves in patients with mitral stenosis and to construct a Doppler-derived LVEDP prediction model based on the combined analysis of transmitral and pulmonary venous flow velocity curves.     

Can Transesophageal Pulse‐Wave Tissue Doppler Imaging Be Used to Evaluate Left Ventricular Function?

BACKGROUND: This study aimed to evaluate the efficiency of transesophageal tissue Doppler echocardiography (TDE) in evaluation of the left ventricular functions. To this end, the data obtained by transoesophageal tissue Doppler echocardiography and by transthoracic tissue Doppler echocardiography were compared simultaneously. METHODS: Nineteen consecutive patients (7 female and 12 male) underwent a clinically indicated study. In transthoracic (TTE) and transoesophageal (TEE) echocardiographic study, a Vingmed System Five Doppler echocardiographic unit (GE Vingmed) was used. For the assessment of the left ventricular function using transthoracic and transoesophageal TDE, the mitral annular peak systolic (S), early diastolic (E), late diastolic velocities (A), late to early velocity ratio (E/A), deceleration times (DT), left ventricular isovolumetric relaxation times (IVRT) were measured at the lateral, medial, anterior, and posterior corners at the mitral annulus by activating TDE mode in the transthoracic and transoesophageal apical four- and two-chamber view. Bland-Altman plots were used to compare the two measurement techniques. The differences between the groups were assessed by Mann-Whitney U test. All the data were expressed as mean +/- SD. A P-value of <0.05 was considered significant. RESULTS: There were no significant differences between two techniques in terms of blood pressure and heart rate. Two techniques were compared for the transthoracic and transoesophageal TDE parameters. Bland-Altman analysis showed comparable values for E, A, E/A, S, and mE/E, although the measurements of DT and IVRT were different. CONCLUSION: PW tissue Doppler echocardiographic approach during TEE may be suitable for assessment of the left ventricular function.     

Effect of preload reduction by hemodialysis on conventional and novel echocardiographic parameters of left ventricular structure and function

BACKGROUND: Available studies of the effect of hemodialysis (HD) on left ventricular (LV) performance brought ambiguous results. Therefore we aimed to investigate the effect of acute preload reduction induced by HD on conventional and novel parameters of LV structure and function. METHODS: Thirty-six patients underwent echocardiography 1 hour prior to and 1 hour following regular HD. M-mode, two-dimensional, and Doppler echocardiography were used to analyze conventional LV structural and functional parameters. Systolic and diastolic mitral annular velocities assessed by pulsed-wave tissue Doppler echocardiography (PW-TDE) and flow propagation velocity (Vp) of early LV inflow were measured as novel indices of LV systolic and diastolic function. RESULTS: After HD, all heart chambers including LV significantly reduced in their size. The reduction in LV mass was also observed. Parameters of LV systolic function-ejection fraction and systolic mitral annular velocity, significantly improved, whereas fractional shortening did not. As for LV diastolic function, conventional Doppler parameters and Vp were substantially changed after HD. Conversely, PW-TDE diastolic velocities were not significantly affected. CONCLUSIONS: The fluid removal induced by HD leads to a substantial decrease in LV size and mass. The improvement of LV longitudinal contraction documented by PW-TDE seems to be responsible for the increase in global LV systolic function after HD. While standard Doppler parameters of LV diastolic function and Vp are significantly affected by preload reduction, PW-TDE diastolic indices appears to be less load dependent. Therefore, PW-TDE represents a promising method for the LV diastolic function assessment in patients on HD.     

Spectral pulsed tissue Doppler imaging in diastole: a tool to increase our insight in and assessment of diastolic relaxation of the left ventricle

Background

Conventional Doppler echocardiography offers an indirect assessment of left ventricular (LV) diastolic function, hampered by preload dependency. Tissue Doppler imaging (TDI) is a tool to study diastolic function in a more direct and less preload-dependent manner.

Methods

The Medline database has been searched for literature on TDI for the analysis of diastolic function. A secondary search reviewed the relevant references related to TDI or diastolic function in general.

Results

TDI measures myocardial velocities with a high temporal and velocity resolution but lacks spatial information. In particular, the velocity of early diastolic wall motion (E_m) and its timing are promising indices of local myocardial relaxation. E_m at the mitral annulus offers fair estimates of ventricular relaxation, relatively independent of preload and systolic function. Combined with early transmitral flow velocity (E), detection of pseudo-normalized filling patterns and estimation of filling pressures are enhanced by E/E_m.

Conclusion

TDI has an emerging role in the study and assessment of diastolic function. However, TDI-derived information needs to be integrated with other echocardiographic data because single diagnostic accuracy remains unsatisfactory.     

Cardiac Manifestations of Exhaustive Exercise in Nonathletic Adults: Does Cardiac Fatigue Occur?

The aim of the study was to examine the impact of prolonged exercise leading to physical exhaustion on left ventricular (LV) systolic and diastolic function in untrained healthy subjects, and to examine cardiovascular determinants of exercise performance. Twenty-four nonathletic healthy adults (14 males, 10 females; mean age 42 +/- 11 years) were exercised on a treadmill at 70% of maximal oxygen consumption until physical exhaustion occurred after an average of 84 +/- 39 minutes. Two-dimensional and Doppler echocardiography was performed before and 15 minutes after exercise to assess LV function and geometry, and right ventricular (RV) systolic function. After prolonged exercise, LV ejection fraction and geometry were unchanged, but LV end-diastolic volume, end-systolic volume, and stroke volume decreased. However, due to a higher heart rate (HR), cardiac output increased at 15 minutes post exercise. RV fractional shortening was unchanged. LV peak early to atrial filling velocity ratio decreased post exercise, with an increase in percent atrial contribution. However, less preload-dependent variables of LV diastolic function such as deceleration time, LV inflow propagation rate, mitral annular tissue Doppler and myocardial performance index were unchanged. Preexercise stroke volume and HR were the only predictors (r = 0.86, P < 0.01) of exercise duration. However, age, resting blood pressure, indices of systolic and diastolic function, and LV geometry were not predictors. Prolonged exercise leading to physical exhaustion is not associated with systolic or diastolic dysfunction. Reduced early LV diastolic filling and the relative increase in left atrial contribution seen with prolonged exercise are likely due to preload reduction rather than true diastolic dysfunction.     

Spectral and color M-mode Doppler in genetically altered mice. Assessment of diastolic function

Doppler indices of transmitral flow are used commonly to assess noninvasively LV diastolic function in man and in large animals. This review examines echocardiographic indices of LV diastole (focusing on color M-mode) in mice with abnormal LV relaxation and hypertrophic cardiomyopathy based on genetic alterations of phospholamban and alpha-tropomyosin, respectively. Phospholamban (PLB) reversibly inhibits the sarcoplasmic reticulum Ca(2+) ATPase and is a crucial regulator of myocardial relaxation; tropomyosin is a contractile protein that plays a critical role in regulating contractile activity vis-à-vis interactions with the actin and troponin complex. Accordingly, diastolic function was assessed in PLB knockout mice (PLB/KO) and age-matched transgenic mice expressing a mutant, superinhibiting form of PLB (PLB/N27A), and in mice with cardiac-specific expression a mutant a-tropomyosin (TM-180). Transmitral Doppler flow indexes suggested impaired diastolic filling in the PLB/N27A mice, but improved LV diastolic function in the PLB/KO mice and TM-180 mutants. However, the propagation velocity of early flow into the LV cavity, measured by color M-mode Doppler, confirmed the expected direction of altered LV relaxation in each mouse model. We conclude that transmitral filling patterns and color M-mode flow propagation velocity reflect changes in myocardial relaxation in genetically engineered mice, and may be useful tools to characterize LV diastolic function in other mouse models of disease.     

Evaluation of left ventricular diastolic function from the pattern of left ventricular filling

The pattern of left ventricular (LV) filling can be determined by Doppler echocardiography. Normally most LV filling occurs early in diastole, with some additional filling occurring during atrial systole, late in diastole. In the absence of mitral stenosis, three patterns of LV filling indicate progressively greater diastolic dysfunction: (1) Reduced early diastolic filling with a compensatory increase in importance of atrial filling, termed a pattern of “impaired relaxation;” (2) “pseudo-normalization” with most filling early in diastole but with rapid deceleration of mitral flow; and (3) “restricted filling” with almost all filling of the LV occurring very early in diastole in association with very rapid deceleration of mitral flow. A large, prolonged atrial regurgitant flow in the pulmonary veins also indicates impaired diastolic performance. The time for early filling deceleration is predominantly determined by LV stiffness: the shorter the deceleration time, the stiffer the LV. Patients with short deceleration time have a poor prognosis.     

Physiologic Determinants of Mitral Inflow Pattern Using a Computer Simulation: Insights into Doppler Echocardiography in Diverse Phenotypes

Background: Although echo Doppler recordings of mitral inflow patterns are often employed clinically to identify "diastolic dysfunction," abnormal flow profiles may be seen in a diverse set of disorders in which the specific physiologic determinants are not well defined. Methods: We used a validated cardiovascular simulation model to assess the effects of four hemodynamic parameters on Doppler measures of LV filling: (1) total blood volume, (2) diastolic stiffness (LV Beta), (3) systemic vascular resistance (SVR), and (4) pulmonary vascular resistance (PVR). In each simulation, we calculated instantaneous flow through the mitral valve as a function of time. Results: Increases in blood volume led to an increase in the E:A ratio and a decrease in deceleration time ( DT), such that for every 100 mL of volume, DT decreased by ∼3 ms. Increases in LV Beta increased the E:A ratio and decreased DT such that for every 0.005 mmHg/mL increase in LV Beta, DT decreased by ∼8 ms. While changes in SVR did not significantly alter the Doppler pattern, increases in PVR effected a prolongation of DT and an impaired relaxation E:A pattern. Increasing blood volume and LV Beta simultaneously was additive, while increasing PVR attenuated the effect of increasing volume on the E:A ratio. Conclusions: Computer simulations demonstrate that both blood volume and LV stiffness significantly impact the mitral inflow profile indicating that both filling pressure and intrinsic properties of the ventricle are contributors. These data confirm that there are multiple determinants of the Doppler mitral inflow pattern and suggest a new approach toward understanding complex physiologic interactions.     

Automatic Border Detection for Assessment of Left Ventricular Diastolic Function Among Normal Neonates: Comparison with Doppler Echocardiography

Doppler echocardiography is the standard noninvasive method to assess left ventricular (LV) diastolic function. Recently, automatic border detection (ABD), a method based on analysis of integrated ultrasonic backscatter, has been introduced permitting real-time, on-line assessment of LV diastolic function. A comparison of these methods in normal, full-term neonates has not been performed. Therefore, the objectives of this study were to evaluate the usefulness of ABD in the assessment of LV diastolic function among normal neonates, to compare parameters obtained with the ABD method with standard Doppler-derived indexes of diastolic function, and to assess the reproducibility of ABD measurements. We studied 17 consecutive normal neonates during natural sleep with both methods shortly after birth (mean 17.4 ± 3.9 h) and approximately 2 weeks later (mean 14.8 ± 2.2 days). An average of five consecutive cardiac cycles were performed. Similar to Doppler indexes, no significant change in any ABD parameter of diastolic function occurred between the early and later studies. A complete ABD study could be performed within 5 minutes. Mean interobserver variation for individual ABD measurements ranged from 0% to 11%. Compared with Doppler, rapid filling fraction was greater and atrial filling fraction was less with ABD. Regression analysis showed poor correlation of these parameters between methods, but their ratio by each method remained constant between studies. A similar poor correlation existed between peak E wave velocity by Doppler and peak rapid filling rate by ABD and between peak A wave velocity by Doppler and peak atrial filling rate by ABD. These differences may be explained by technical factors and different aspects of diastolic filling assessed by each method. This study indicated that ABD was a feasible and reproducible method compared with Doppler echocardiography for serial evaluation of LV diastolic function among neonates.