Intraventricular early diastolic filling during acute myocardial ischemia, assessment by multigated color m-mode Doppler echocardiography

Echo Doppler Parameters of Diastolic Function

PURPOSE OF REVIEW

The purpose of this review is to highlight the echo Doppler parameters that form the cornerstone for the evaluation of diastolic function as per the guideline documents of the American Society of Echocardiography (ASE) and the European Association of Cardiovascular Imaging (EACVI). In addition, the individual Doppler-based parameters will be explored, with commentary on the rationale behind their use and the multi-parametric approach to the assessment of diastolic dysfunction (DD) using echocardiography.

RECENT FINDINGS

Previous guidelines for assessment of diastolic function are complex with modest diagnostic performance and significant inter-observer variability. The most recent guidelines have made the evaluation of DD more streamlined with excellent correlation with invasive measures of LV filling pressures. This is a review of the echo-derived Doppler parameters that are integral in the diagnosis and gradation of DD. A brief description of the physiological principles that govern changes in echocardiographic parameters during normal and abnormal diastolic function is also discussed for the appropriate diagnosis of DD using non-invasive Doppler echocardiography techniques.

Multimodality imaging in patients with heart failure and preserved ejection fraction: an expert consensus document of the European Association of Cardiovascular Imaging

Nearly half of all patients with heart failure (HF) have a normal left ventricular (LV) ejection fraction (EF) and the condition is termed heart failure with preserved ejection fraction (HFpEF). It is assumed that in these patients HF is due primarily to LV diastolic dysfunction. The prognosis in HFpEF is almost as severe as in HF with reduced EF (HFrEF). In contrast to HFrEF where drugs and devices are proven to reduce mortality, in HFpEF there has been limited therapy available with documented effects on prognosis. This may reflect that HFpEF encompasses a wide range of different pathological processes, which multimodality imaging is well placed to differentiate. Progress in developing therapies for HFpEF has been hampered by a lack of uniform diagnostic criteria. The present expert consensus document from the European Association of Cardiovascular Imaging (EACVI) provides recommendations regarding how to determine elevated LV filling pressure in the setting of suspected HFpEF and how to use multimodality imaging to determine specific aetiologies in patients with HFpEF.

The Relationship Between Heart Rate and Left Ventricular Isovolumic Relaxation During Normoxia and Hypoxia-Asphyxia in Newborn Piglets

Background: Many asphyxiated neonates have cardiac complications including arrhythmia and contractile dysfunction. Little is known about the relationship between heart rate (HR) and diastolic function in asphyxiated neonates. We aimed to study the relationship between HR and left ventricular (LV) isovolumic relaxation (IVR) in neonates with asphyxia using a swine model.

Methods: Term newborn piglets were anesthetized and acutely instrumented with the placement of Millar^® catheter in the left ventricle. Hemodynamic parameters including HR, cardiac output, stroke volume, dP/dt_max and dP/dt_min, and IVR time constant (Tau) were continuously measured and recorded. Sixteen piglets were exposed to 50-minute normocapnic hypoxia followed by asphyxia (mean of 3.2 min) by clamping of the endotracheal tube. Sham-operated piglets (n = 11) had no hypoxia nor asphyxia. The relationship between HR and other hemodynamic parameters were analyzed using Pearson Product Moment correlation test.

Results: Asphyxiated piglets had cardiogenic shock and metabolic acidosis (vs. sham-operated piglets). There were significant correlations between HR and diastolic function as shown by Tau at baseline (sham-operated: r = -0.68, p = 0.02; asphyxia: r = -0.55, p = 0.03) and during normoxia (53 min) of sham-operated piglets (r = -0.69, p = 0.02). HR and Tau was not correlated during hypoxia-asphyxia (HA) (r = -0.01, p = 0.97). Cardiac output was tightly correlated with stroke volume (p < 0.001) but not HR throughout the experimental period in both groups. There was no significant correlation between HR and other hemodynamic parameters during the experimental period in both groups.

Conclusion: We observed an uncoupling between HR and IVR Tau of the neonatal heart during HA, which deserves further studies of the relationship between HR and LV diastolic function.

Evaluation of left ventricular diastolic function: state of the art after 35 years with Doppler assessment

Left ventricular (LV) diastolic function can be evaluated by echocardiographic indices of LV relaxation/restoring forces, diastolic compliance, and filling pressure. By using a combination of indices, diastolic function can be graded and LV filling pressure estimated with high feasibility and good accuracy. Evaluation of diastolic function is of particular importance in patients with unexplained exertional dyspnea or other symptoms or signs of heart failure which cannot be attributed to impaired LV systolic function and to assess filling pressure in patients with heart failure and reduced LV ejection fraction. Furthermore, grading of diastolic dysfunction can be used for risk assessment in asymptomatic subjects and in patients with heart disease.

Left Ventricular Velocity of Propagation: A Useful Non-Invasive Measurement When Assessing Hemodynamic Alterations in Pulmonary Arterial Hypertension

Background

Left ventricular (LV) velocity of propagation (Vp) has been shown to be inversely related to the LV relaxation time constant. We sought to examine Vp from a group of chronic pulmonary hypertension (cPH) patients and compare these values to Vp obtained in normal individuals and patients with known LV diastolic dysfunction (LVDD).

Methods

Echo-Doppler data and Vp measurements were retrospectively collected from all patients. The studied population was divided into four groups. Group I comprised of 15 patients with normal LV diastole, group II included 27 patients with stage 1 LVDD, group III was made up of 27 patients with stage 2 LVDD, and group IV included 66 patients with cPH.

Results

In the cPH population studied, patients had smaller end-diastolic LV cavities with the highest Vp values but their early mitral inflow to Vp ratios were not different from healthy controls. In addition, Vp values and pulmonary wedge capillary pressures were significantly associated in patients with LV dysfunction or pulmonary hypertension (P < 0.01).

Conclusions

LVVp might be a useful non-invasive measurement to be routinely obtained in cPH patients as it probably not only reflects the compressive forces being exerted on the LV, known to increase Vp, but also might be quite useful for the non-invasive assessment of pulmonary capillary wedge pressures in these patients.

Assessment of Diastolic Function in Congenital Heart Disease

Diastolic function is an important component of left ventricular (LV) function which is often overlooked. It can cause symptoms of heart failure in patients even in the presence of normal systolic function. The parameters used to assess diastolic function often measure flow and are affected by the loading conditions of the heart. The interpretation of diastolic function in the context of congenital heart disease requires some understanding of the effects of the lesions themselves on these parameters. Individual congenital lesions will be discussed in this paper. Recently, load-independent techniques have led to more accurate measurements of ventricular compliance and remodeling in heart disease. The combination of inflow velocities and tissue Doppler measurements can be used to estimate diastolic function and LV filling pressures. This review focuses on diastolic function and assessment in congenital heart disease.

Perioperative management of left ventricular diastolic dysfunction and heart failure: an anesthesiologist's perspective

Anesthesiologists frequently see asymptomatic patients with diastolic dysfunction or heart failure for various surgeries. These patients typically show normal systolic function but abnormal diastolic parameters in their preoperative echocardiographic evaluations. The symptoms that are sometimes seen are similar to those of chronic obstructive pulmonary disease. Patients with diastolic dysfunction, and even with diastolic heart failure, have the potential to develop a hypertensive crisis or pulmonary congestion. Thus, in addition to conventional perioperative risk quantification, it may be important to consider the results of diastolic assessment for predicting the postoperative outcome and making better decisions. If anesthesiologists see female patients older than 70 years of age who have hypertension, diabetes, chronic renal disease, recent weight gain, or exercise intolerance, they should focus on the patient's diastologic echocardiography indicators such as left atrial enlargement or left ventricular hypertrophy. In addition, there is a need for perioperative strategies to mitigate diastolic dysfunction-related morbidity. Specifically, hypertension should be controlled, keeping pulse pressure below diastolic blood pressure, maintaining a sinus rhythm and normovolemia, and avoiding tachycardia and myocardial ischemia. There is no need to classify these diastolic dysfunction, but it is important to manage this condition to avoid worsening outcomes.

Increased LV apical untwist during preload reduction in healthy humans: an echocardiographic speckle tracking study during lower body negative pressure

We sought to investigate the effect of reduced preload on left ventricle (LV) untwist and early diastolic filling in healthy individuals. Twelve healthy men, 22 (22, 23) years of age, were examined at rest and during applied lower body negative pressure (LBNP) of −20 mmHg and −40 mmHg, respectively. Regional untwist and untwist rate during IVRT were calculated at LV basal, papillary, subpapillary, and apical short axis levels by two dimensional speckle tracking echocardiography. Left ventricle early diastolic filling was assessed by transmitral E-wave (E) peak velocity by pulsed Doppler and flow propagation velocity (Vp) by color M-mode Doppler and early diastolic pulsed Doppler tissue velocities (E') from septal and lateral mitral annulus. From rest to LBNP −40 mmHg, the LV untwist and untwist rate at subpapillary level increased from 2.3 (1.4, 3.5) to 4.5 (3.1, 7.6) degrees and from −36 (−51, −25) to −69 (−127, −42) °/s (P < 0.001, P = 0.003), respectively, while apical untwist and untwist rate increased from 3.9 (2.3, 4.3) to 7.6 (6.4, 10.5) degrees and from −51 (−69, −40) to −118 (−170, −84) °/s (P < 0.001, P < 0.001), respectively. Since untwist and untwist rate at the basal level were unchanged, this created markedly larger base to apical untwist and untwist rate gradients from rest to LBNP −40 mmHg. E, Vp, and E' were reduced by 34, 32, and 39%, respectively. LV untwist and untwist rate during IVRT were increased at apical levels, which might be a physiological mechanism to minimize the impairment in LV early diastolic filling during preload reduction.

Practical diastology

Left ventricular (LV) diastolic dysfunction is being recognized as an important part in the pre-operative evaluation. Pre-operative LV diastolic dysfunction has been associated with increased risk of post-operative complications. Furthermore guidelines have been published on the assessment of LV diastolic function. However LV diastolic function is significantly influenced by loading conditions which are typically altered during cardiac and non-cardiac surgery. In addition, waveform analysis from the pulmonary artery catheter tend to correlate with diastolic function and loading conditions. The advantage of hemodynamic monitoring being that they are continuously displayed as opposed to intermittent diastolic parameters. Finally if the importance of diastolic function assessment is to estimate filling pressure, the presence of B lines with the use of lung ultrasound is a simpler method in detecting pulmonary edema. Another indirect evidence of either LV systolic or diastolic dysfunction is an abnormal near-infrared spectroscopy value. Finally it might be more important to evaluate right ventricular (RV) diastolic dysfunction as RV dysfunction is significantly associated with pulmonary hypertension and consequently mortality. Such assessment of RV diastolic dysfunction can be obtained continuously with the use of RV pressure waveform monitoring.

Intraventricular Pressure Gradients in Heart Failure

The aim of the present study was to characterize intraventricular pressure gradients (IVPGs) in an animal model of chronic heart failure. New Zealand rabbits were treated with doxorubicin (heart failure group, n=5) or saline (control group, n=5) and instrumented with pressure catheters placed in the apex and outflow-tract of left ventricle (LV) and with sonomicrometer crystals placed in the apex and base of the LV free wall. In heart failure animals, ventricular filling was delayed and slower when compared with control animals. Moreover, the physiological nonuniformity observed between apical and basal segments in normal hearts was abolished in failing hearts. Simultaneously, physiological IVPGs observed during normal ventricular filling were entirely lost in heart failure animals. During ventricular emptying physiological nonuniformity between apical and basal segments observed in control animals was also abolished in heart failure animals. In failing hearts minimal length occurred later and almost at same time both in apical and in basal myocardial segments. Simultaneously, the characteristic IVPG pattern observed in healthy hearts during systole, which promotes ventricular emptying, was not observed in failing hearts. The present study showed that diastolic IVPGs, a marker of normal ventricular filling, and systolic IVPGs, a marker of normal ventricular emptying, are abolished in heart failure.

Left intraventricular diastolic and systolic pressure gradients

To describe left ventricular (LV) function comprehensively, it is crucial to characterize precisely transmitral, intraventricular and transaortic pressure–flow relations. The site of measurement is important; as the measurement location is moved from the mitral valve toward the apex and the outflow tract, important regional pressure differences are recorded inside the LV. These intraventricular pressure gradients (IVPGs) play an important role in ventricular filling in the normal heart and may be abolished by systolic or diastolic dysfunction. Despite their apparent importance in ventricular filling and diastolic function, IVPGs have never been utilized in clinical cardiology, due to the complexity of their acquisition. The application of Doppler echocardiography allows the reconstruction of diastolic IVPGs completely non-invasively, thus avoiding the risk and expense of a cardiac catheterization. Regional pressure gradients are also present during ventricular emptying but their correlation with systolic function is not so clear. The current minireview highlights theories and experimental data on invasive and non-invasive assessment of diastolic and systolic IVPGs and their role in LV filling and emptying. We also review the pathophysiological modulation of regional gradients, their importance in understanding and evaluating the complex phenomena underlying ventricular filling, as well as their potential clinical application.

Perioperative assessment of diastolic dysfunction

Assessment of diastolic function should be a component of a comprehensive perioperative transesophageal echocardiographic examination. Abnormal diastolic function exists in >50% of patients presenting for cardiac and high-risk noncardiac surgery, and has been shown to be an independent predictor of adverse postoperative outcome. Normalcy of systolic function in 50% of patients with congestive heart failure implicates diastolic dysfunction as the probable etiology. Comprehensive evaluation of diastolic function requires the use of various, load-dependent Doppler techniques This is further complicated by the additional effects of dehydration and anesthetic drugs on myocardial relaxation and compliance as assessed by these Doppler measures. The availability of more sophisticated Doppler techniques, e.g., Doppler tissue imaging and flow propagation velocity, makes it possible to interrogate left ventricular diastolic function with greater precision, analyze specific stages of diastole, and to differentiate abnormalities of relaxation from compliance. Additionally, various Doppler-derived ratios can be used to estimate left ventricular filling pressures. The varying hemodynamic environment of the operating room mandates modification of the diagnostic algorithms used for ambulatory cardiac patients when left ventricular diastolic function is evaluated with transesophageal echocardiography in anesthetized surgical patients.

A comparison of echocardiographic measures of diastolic function for predicting all-cause mortality in a predominantly male population

BACKGROUND

Prior studies demonstrating the prognostic value of echocardiographic measures of diastolic function have been limited by sample size, have included only select clinical populations, and have not incorporated newer measures of diastolic function nor determined their independent prognostic value. The objective of this study is to determine the independent prognostic value of established and new echocardiographic parameters of diastolic function.

METHODS

We included 3,604 consecutive patients referred to 1 of 3 echocardiography laboratories over a 2-year period. We obtained measurements of mitral inflow velocities, pulmonary vein filling pattern, mitral annulus motion (e'), and propagation velocity (V(p)). The primary end point was 1-year all-cause mortality.

RESULTS

The mean age of the patients was 68 years, and 95% were male. There were 277 deaths during a mean follow-up of 248 ± 221 days. For patients with reduced left ventricular ejection fraction (LVEF), all measured parameters except for e' were associated with mortality (P < .05) on univariate analysis. For patients with preserved LVEF, the E-wave velocity was significantly associated with mortality (P < .05) on univariate analysis. The deceleration time/E-wave velocity ratio, V(p), and pulmonary vein filling pattern were borderline significant (P < .10). With multivariate analysis, only V(p) was associated with survival for both reduced (P = .02) and preserved LVEF groups (P = .01).

CONCLUSION

In a large, clinically diverse population, most measures of diastolic function were predictive of all-cause mortality without adjustment for patient characteristics. On multivariate analysis, only V(p) was independently associated with total mortality. This association with mortality may be related to factors other than diastolic function and warrants further investigation.

Is the E/V p index useful for evaluating prognosis in chronic heart failure with atrial fibrillation? A pilot study

BACKGROUND

The ratio of transmitral peak E wave velocity to color flow propagation velocity (E/V p index) has proved to be a significant predictor of prognosis in cardiac diseases with sinus rhythm. However, its usefulness in patients with atrial fibrillation (AF) and heart failure has not yet been established. The aim of this study was to determine the feasibility of using the E/V p index for the prediction of mortality and heart failure hospitalization in this group.

METHODS

We studied 66 ambulatory patients with stable congestive heart failure (CHF) functional class I-III and AF. Patients were divided into group A and B according to an E/V p index <1.5 and ≥1.5, respectively.

RESULTS

During follow-up (average 430 days) events were more common in group B (75 vs. 17%, log rank test; hazard ratio (HR)  = 6.8). By means of multivariate logistic regression analysis, E/V p proved to be an independent predictor of events (p = 0.0012).

CONCLUSIONS

In our patients with stable CHF and AF the E/V p index is a significant predictor of clinical outcome.

Effects of on-pump and off-pump coronary artery bypass grafting on left ventricular relaxation and compliance: a comprehensive perioperative echocardiography study

AIMS

The short-term effect of coronary artery bypass grafting (CABG) on diastolic function is only moderately investigated. Furthermore, it remains unknown whether avoidance of cardioplegic arrest by an off-pump CABG procedure has advantages over on-pump procedure regarding diastolic relaxation and compliance. We investigated whether components of diastolic function would be improved the day after CABG depending on the type of the surgical procedure.

METHODS AND RESULTS

Spontaneously breathing on-pump (n = 20) and off-pump CABG (n = 12) patients underwent a comprehensive transthoracic echocardiography examination the day before and the day after elective CABG, including transmitral and pulmonary vein flow parameters, colour M-mode flow propagation velocity (Vp) and tissue Doppler assessment of the average mitral annulus diastolic velocity (Em). Isovolumic relaxation and E-wave deceleration time were corrected for heart rate (IVRTcHR and DTcHR). Left ventricular (LV) relaxation time (τ) and LV operating stiffness (LVOS) were calculated. Overall and independent from operation type and preload, CABG decreased IVRTcHR (107 ± 20 vs. 93 ± 15 ms) (P < 0.01) and τ (54 ± 10 vs. 45 ± 10 ms) (P < 0.01), increased Vp (49 ± 22 vs. 75 ± 37 cm/s) (P < 0.01), and increased Em (6.6 ± 2.0 vs. 7.3 ± 1.3 cm/s, P = 0.06), indicating improved relaxation. LVOS increased (0.13 ± 0.06 vs. 0.22 ± 0.05 mmHg/mL) (P < 0.01), compatible with an impaired compliance. A similar improvement in relaxation and impairment in compliance were observed in both groups.

CONCLUSION

Myocardial relaxation improved the day after CABG irrespective of the use of cardiopulmonary bypass with cardioplegic arrest. Impairment in compliance could not be prevented by the avoidance of cardioplegia.

Non-invasive assessment of left ventricular relaxation during atrial fibrillation using mitral flow propagation velocity

AIMS

To elucidate the usefulness of the early diastolic mitral flow propagation velocity (V(p)) obtained from colour M-mode Doppler for non-invasively assessing left-ventricular (LV) relaxation during atrial fibrillation (AF).

METHODS AND RESULTS

Ten healthy adult dogs were studied to correlate V(p) with the invasive minimum value of the first derivative of LV pressure decay (dP/dt(min)) and the time constant of isovolumic LV pressure decay (tau) at baseline, during rapid and slow AF, and during AF after inducing myocardial infarction. There were significant positive and negative curvilinear relationships between V(p) and dP/dt(min) and tau, respectively, during rapid AF. After slowing the ventricular rate, the average value of V(p) increased, while dP/dt(min) increased and tau decreased. After inducing myocardial infarction, the average value of V(p) decreased, while dP/dt(min) decreased and tau increased.

CONCLUSION

The non-invasively obtained V(p) evaluates LV relaxation even during AF regardless of ventricular rhythm or the presence of pathological changes.

Echocardiographic assessment of left ventricular diastolic function and filling pressure in atrial fibrillation

Diastolic dysfunction has been linked to 2 epidemics: atrial fibrillation (AF) and heart failure. The presence and severity of diastolic dysfunction are associated with an increased risk for first AF and first heart failure in patients with sinus rhythm. Furthermore, the risk for heart failure is markedly increased once AF develops. The evaluation of diastolic function once AF has developed remains a clinical challenge. The conventional use of Doppler echocardiography for the assessment and grading of diastolic dysfunction relies heavily on evaluating the relation of ventricular and atrial flow characteristics. The mechanical impairment of the left atrium and the variable cycle lengths in AF render the evaluation of diastolic function difficult. A few Doppler echocardiographic methods have been proved clinically useful for the estimation of diastolic left ventricular filling pressures in AF, but these appear to be underutilized. Several innovative methods are emerging that promise to provide greater precision in diastolic function assessment, but their clinical utility in AF remains to be established. In conclusion, this review provides an up-to-date discussion of the evaluation of diastolic function assessment in AF and how it may be important in the clinical management of patients with AF.

Peak mitral annular velocity during early diastole and propagation velocity of early diastolic filling flow are not interchangeable as the parameters of left ventricular early diastolic function

The difference between peak mitral annular velocity during early diastole (Ea) and the propagation velocity of left ventricular (LV) early diastolic filling flow (Vp) obtained using Doppler imaging as LV relaxation parameters was not fully elucidated. Thus, this issue was investigated in 117 patients with suspected coronary artery disease. During cardiac catheterization, LV volumes, the LV relaxation time constant Tp, and inertia force of late systolic aortic flow were obtained. Ea significantly and closely correlated with Tp (r = -0.70, p <0.0001) and significantly but weakly correlated with LV ejection fraction (r = 0.37, p <0.0001) and inertia force (r = 0.34, p = 0.0002). Conversely, Vp significantly and closely correlated with both LV ejection fraction (r = 0.66, p <0.0001) and inertia force (r = 0.72, p <0.0001) and significantly but weakly correlated with Tp (r = - 0.35, p = 0.0001). In conclusion, Ea and Vp reflect different aspects of LV behavior from end-systole to early diastole. Ea can be used to index LV relaxation, whereas Vp might not be a proper parameter of LV intrinsic relaxation because it is significantly dependent on LV systolic function and LV chamber size at end-systole. Both parameters are not interchangeable as those of LV early diastolic function. Vp may be a noninvasive parameter of LV elastic recoil.

New echocardiographic applications for assessing global left ventricular diastolic function

A number of promising and highly technological echocardiographic imaging tools have recently been introduced to assess left ventricular diastolic function (i.e., the capacity of the ventricle to relax and fill). They permit quantification of distinct features of intraventricular blood flow velocity and pressure fields and myocardial tissue velocities. However, accurate interpretation of the new images and clinical indices is still cumbersome, as basic knowledge about intraventricular hemodynamics and ventricular wall mechanics is often insufficient. This review article provides a comprehensive and original overview of the hemodynamical and mechanical events that occur during diastole and discusses how this new information can be used in the clinical and research setting to evaluate diastolic function in the healthy and the diseased heart. It furthermore aims to explain the underpinnings of the techniques in such a way that the underlying biomechanical concepts (fluid dynamics and wall mechanics) become less obscure to cardiologists and echocardiographers and such that the biomedical engineers are given some insights into the avalanche of diastolic performance indices that currently exist.

Diastolic heart failure in anaesthesia and critical care

Diastolic heart failure is an underestimated pathology with a high risk of acute decompensation during the perioperative period. This article reviews the epidemiology, risk factors, pathophysiology, and treatment of diastolic heart failure. Although frequently underestimated, diastolic heart failure is a common pathology. Diastolic heart failure involves heart failure with preserved left ventricular (LV) function, and LV diastolic dysfunction may account for acute heart failure occurring in critical care situations. Hypertensive crisis, sepsis, and myocardial ischaemia are frequently associated with acute diastolic heart failure. Symptomatic treatment focuses on the reduction in pulmonary congestion and the improvement in LV filling. Specific treatment is actually lacking, but encouraging data are emerging concerning the use of renin-angiotensin-aldosterone axis blockers, nitric oxide donors, or, very recently, new agents specifically targeting actin-myosin cross-bridges.

Assessment of left ventricular function by cardiac ultrasound

Our understanding of the physical underpinnings of the assessment of cardiac function is becoming increasingly sophisticated. Recent developments in cardiac ultrasound permit exploitation of many of these newer physical concepts with current echocardiographic machines. This review will first focus on the current approach to the assessment of cardiovascular hemodynamics by cardiac ultrasound. The next focus will be the assessment of global cardiac mechanics in systole and diastole. Finally, relationships between the cardiac structure and regional myocardial function, and the way regional function can be quantified by ultrasound, will be presented. This review also discusses the clinical impact of echocardiography and its future directions and developments.

Intraventricular Pressure Gradients in Left Ventricular Aneurysms Determined by Color M-Mode Doppler Method: An Animal Study

BACKGROUND

Left ventricular aneurysm (LVA) may affect diastolic intraventricular blood flow. Color M-mode (CMM) Doppler flow propagation patterns are abnormal in the presence of apical aneurysms. The aim of this study was to validate the accuracy of CMM echocardiography for assessing the existence and size of LVA and to determine the intraventricular pressure gradient in LVA.

METHODS

CMM of the transmitral inflow in early diastole was obtained from the apical 4-chamber view in 19 sheep. The presence of the break point where the velocity decreased abruptly in the mitral inflow (point D) was determined and the distance between the apex and point D was measured. The intraventricular pressure difference between the base and the apex was measured by a catheter while it was calculated using CMM with the Euler equation.

RESULTS

The presence of the break point D showed 84% sensitivity and 100% specificity for determining the existence of an LVA. Distance between the apex and point D correlated well with scar size. Catheter- and CMM-derived intraventricular pressure difference correlated and agreed well (y = 1.0 x -0.2, r = 0.94).

CONCLUSIONS

The point of abrupt decrease in propagation velocity of the CMM recording indicated the presence and size of LVA. Intraventricular pressure gradients were determined noninvasively by CMM echocardiography with reasonable accuracy.

Technical Aspects of Diastology: Why Mitral Inflow and Tissue Doppler Imaging Are the Preferred Parameters?

Doppler methods for assessing left ventricular (LV) diastolic function have increased in number and complexity. However, time constraints may prevent measurement of all parameters during routine transthoracic echocardiography. Therefore, we designed a study to determine which Doppler parameters could be most successfully and quickly obtained. The recording success rate and time required to record different LV diastolic function parameters were evaluated in 80 patients. A specific recording protocol was followed by an experienced, credentialed sonographer and time intervals to record each parameter were measured. In comparison with color Doppler M-mode of LV inflow propagation velocities (Vp) and pulmonary venous (PV) flow measurements, transmitral valve (MV) flow and tissue Doppler imaging (TDI) of the mitral annulus had the highest recording success rate and required the shortest time to record. PV flow and Vp took longer to obtain (80.1+/-34.3 sec and 57.1+/-29.1 sec, respectively) than did mitral valve inflow (36.3+/-20.7 sec) and mitral valve annular TDI (29.3+/-18.4 sec for septal and 33.3+/-14.5 sec for lateral). MV flow velocities, Vp, and TDI were successfully recorded in virtually all patients (99-100%). In comparison, the PV flow velocities and durations were successfully recorded less often. The range of success rates for the six PV flow parameters was 49-84%. Since MV flow and TDI also have been shown by us to have the lowest interreader variability, measurement of these two parameters may be preferred for routine clinical evaluation of LV diastolic function in a busy echocardiography laboratory.

Combined use of propagation velocity and intraventricular dispersion of E wave velocity for the evaluation of diastolic functions in patients with rheumatoid arthritis

PURPOSE

The aim of this study was to evaluate diastolic functions in patients with rheumatoid arthritis (RA) by propagation velocity and intraventricular dispersion of E wave velocity.

METHODS

Thirty-four patients fulfilling American Rheumatism Association (ARA) criteria for the diagnosis of RA without evidence of cardiac disease and left ventricular systolic dysfunction were enrolled in this study. Echocardiographic examinations were performed for the evaluation of diastolic dysfunction in all patients.

RESULTS

Propagation velocity in RA patients was significantly lower than the control group (42+/-16 cm/s, 54+/-15 cm/s, p=0.002). There was significant intraventricular dispersion of E wave velocity towards the cardiac apex in RA patients (p<0.001) when compared with the controls (p=0.79). There was a significant correlation between intraventricular dispersion of E wave velocity and diastolic dysfunction in the patients in which the duration of illness was longer than 10 years (p<0.001).

CONCLUSION

Structural myocardial abnormalities may cause impaired left ventricular relaxation in RA patients and these changes are correlated with the duration of the disease. Our findings demonstrate that combined use of propagation velocity and intraventricular dispersion of E wave velocity can help the early determination of diastolic functions in the patients with RA.

Color M-mode flow propagation velocity: is it really preload independent?

OBJECTIVE

This study investigates the change in flow propagation velocity (FPV) in uremic patients who undergo regular hemodialysis (H/D).

MATERIALS AND METHODS

We studied 93 uremic patients (44 men and 49 women; 59 +/- 14-years-old) receiving regular hemodialysis. Patients were separated by baseline left ventricular ejection fraction (LVEF): 71 patients with LVEF > 50% (group 1), 13 patients with LVEF 35-50% (group 2), 7 patients with LVEF < 35% (group 3). All patients were in sinus rhythm before H/D. They received complete transthoracic echocardiographic examinations. Flow propagation velocity was measured by color M-mode echocardiography in apical four chambers view. All these parameters were obtained before and after H/D. Paired data were compared. According to different H/D amounts, we viewed the FPV response after H/D in variant baseline LVEF groups.

RESULT

The baseline FPV became lower in patients with low LVEF. After H/D, obvious decrement of FPV occurred in group 1, but there were no obvious changes in groups 2 and 3. In fact, a slight increment of FPV was found in group 3. In patients with baseline LVEF > 50%, FPV after H/D was almost always lower, regardless of H/D amount. But there was different response in patients with baseline LVEF < 50%.

CONCLUSION

Flow propagation velocity is preload independent in patients with LVEF < 50%, but it is preload-dependent in patients with LVEF > 50%.