Usefulness of early diastolic flow propagation velocity measured by color M-mode Doppler technique for the assessment of left ventricular diastolic function in patients with hypertrophic cardiomyopathy

Timolol 0.5% ophthalmic solution influences cardiac function in healthy cats

OBJECTIVES

The aim of this study was to ascertain the effect of a drop of timolol 0.5% ophthalmic solution on the systolic function of the left ventricle (LV) and left atrium (LA), and to confirm if timolol helped appraisal of diastolic function by reducing heart rate (HR) and separating the transmitral outflow waves from tissue Doppler imaging (TDI).

METHODS

A total of 41 client-owned healthy cats underwent two echocardiograms 20 mins apart. The timolol group (33 cats) received a drop of timolol solution after the first examination. Standard and speckle-tracking echocardiography evaluated the LV and LA function of both groups at the two time points evaluated.

RESULTS

Timolol reduced HR (19%), and fractional shortening from LV (20.3%) and LA (16.6%). Septal S' decreased by 51% (from 7.7 to 5.2 cm/s) and lateral S' dropped by 43.1% (7.3 to 5.1 cm/s). Most longitudinal techniques did not change after timolol, including the mitral annular plane systolic excursion from the interventricular annulus, tricuspid annular plane systolic excursion, LV longitudinal strain and LV tissue motion annular displacement. The isovolumic relaxation time increased by 15.2% (from 54 to 64.6 ms), with most cats presenting this variable above the reference (>60 ms). Timolol did not support diastolic assessment, enabling evaluation in only 2/11 cats when using lateral TDI and 1/9 cats using septal TDI. Regarding side effects, miosis occurred in 18 cats (54.5%).

CONCLUSIONS AND RELEVANCE

Timolol reduced systolic function, decreasing standard echocardiographic variables. Regarding diastolic evaluation, although timolol decreased HR, it did not separate the mitral diastolic waves, as expected.

Short- and long-term outcome after alcohol septal ablation in obstructive hypertrophic cardiomyopathy: Experience of a reference center

INTRODUCTION

In obstructive hypertrophic cardiomyopathy (HCM), alcohol septal ablation (ASA) can lead to gradient reduction and symptom improvement. We aimed to assess the efficacy and safety of ASA in a long-term outcome study.

METHODS

We analyzed patients who underwent ASA over a seven-year period in a tertiary center. The primary echocardiographic endpoint was >50% reduction in left ventricular outflow tract (LVOT) gradient within a year of the procedure. The primary clinical endpoints were improvement in functional capacity and a combined endpoint of cardiac death and rehospitalization for cardiac cause. The follow-up period was 4.17±2.13 years.

RESULTS

A total of 80 patients, mean age 63.9±12.3 years, 30.0% male, were analyzed. Baseline LVOT gradient was 96.3±34.6 mmHg and interventricular septal thickness was 21.6±3.1 mm. Minor complications were observed in 6.3% and major complications in 2.5%, and 8.8% received a permanent pacemaker. The primary echocardiographic endpoint was achieved by 85.7%. At three-month follow-up, LVOT gradient was 25.8±26.0 mmHg in the successful procedure group, compared to 69.2±35.6 mmHg in the other patients (p=0.001). At six months, LVOT gradient was 27.1±27.4 vs. 58.2±16.6 mmHg (p=0.024). Among 74 patients in NYHA class III/IV before the procedure, 57 (77%) improved to NHYA class I/II. The combined primary clinical endpoint (cardiac death and rehospitalization for cardiac cause) was observed in 27.5% (n=22). In the unsuccessful group, the combined endpoint was observed in 54.5%, compared to only 22.7% in the successful group. Only two patients died of cardiac causes.

CONCLUSION

ASA is a safe procedure with a high success rate. Patients who achieved significant reductions in LVOT gradient suffered less cardiac death and rehospitalization for cardiac cause.

Echocardiographic Applications of M-Mode Ultrasonography in Anesthesiology and Critical Care

Proficiency in echocardiography and lung ultrasound has become essential for anesthesiologists and critical care physicians. Nonetheless, comprehensive echocardiography measurements often are time-consuming and technically challenging, and conventional 2-dimensional images do not permit evaluation of specific conditions (eg, systolic anterior motion of the mitral valve, pneumothorax), which have important clinical implications in the perioperative setting. M-mode (motion-based) ultrasonographic imaging, however, provides the most reliable temporal resolution in ultrasonography. Hence, M-mode can provide clinically relevant information in echocardiography and lung ultrasound-driven approaches for diagnosis, monitoring, and interventional procedures performed by anesthesiologists and intensivists. Although M-mode is feasible, this imaging modality progressively has been abandoned in echocardiography and is often underutilized in lung ultrasound. This article aims to comprehensively illustrate contemporary applications of M-mode ultrasonography in the anesthesia and critical care medicine practice. Information presented for each clinical application will include image acquisition and interpretation, evidence-based clinical implications in the critically ill and surgical patient, and limitations. The present article focuses on echocardiography and reviews left ventricular function (mitral annular plane systolic excursion, E-point septal separation, fractional shortening, and transmitral propagation velocity); right ventricular function (tricuspid annular plane systolic excursion, subcostal echocardiographic assessment of tricuspid annulus kick, outflow tract fractional shortening, ventricular septal motion, wall thickness, and outflow tract obstruction); volume status and responsiveness (inferior vena cava and superior vena cava diameter and respiratory variability [collapsibility and distensibility indexes]); cardiac tamponade; systolic anterior motion of the mitral valve; and aortic dissection.

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.

Applicability of published guidelines for assessment of left ventricular diastolic function in adults to children with restrictive cardiomyopathy: an observational study

Guidelines for diagnosis and grading of diastolic dysfunction (DD) in children have not been established. The applicability of adult parameters of DD to children has been questioned by recent studies. Although normal diastolic parameters in children have been published, the data to support application of these indices for the non-invasive diagnosis of DD and quantifying its degree are still being developed. Restrictive cardiomyopathy (RCM) is the only recognized disease entity in children that presents with isolated, irreversible DD as the predominant finding. The aim of this study was to investigate the applicability of current diastolic indices used for assessment of diastolic function in adults as reliable indicators of DD in children with established RCM. Retrospective review of institutional clinical database for the period of 2002-2010 was performed to identify patients with RCM who had had a comprehensive echocardiographic assessment of diastolic function. The following parameters were obtained from apical four chamber view: mitral valve (MV) inflow Doppler early filling velocity (E), late filling velocity (A), deceleration time (DT), color M-mode flow propagation from MV to apex (Vp), Doppler tissue imaging derived early diastolic velocity E' and late diastolic velocity A' at the LV lateral wall at MV annulus, RV at the tricuspid valve annulus, septum, and LA area. All parameters were compared to age and gender matched controls using student t test. : LA area/BSA was significantly larger in RCM group than the control group, median 22.8 cm(2)/m(2) (range 16.9-28.6) versus 10.3 cm(2)/m(2) (range 8.3-12.3), p value <0.001. MV inflow E and A were lower, and DT was shorter in the RCM group (p = 0.04, 0.02, and 0.005, respectively). A wave was absent in 3 of 9 patients in the RCM group. Ratio of E to A (E/A) was not different between the two groups. E' was significantly lower at all three sites in RCM group; however, there was some overlap between the two groups. E/septal E' ratio was statistically significantly higher in RCM group. A' was absent either at lateral wall or at septum in five patients. 7 of 9 patients in RCM group had L' wave (at lateral wall or septum) defined as negative deflection during diastasis. Vp was higher in RCM group than in the control group 81.4 ± 44.5 versus 52.9 ± 10.9, p value <0.01. Combination of increased left atrial size, septal E/E', and lack of A wave and presence of mid-diastolic L'-wave are the noted abnormalities in this group. Individual cut-offs for Doppler indices have very poor sensitivity in identifying restrictive physiology. These findings suggest that poor LV compliance is the hallmark of restrictive cardiomyopathy in children even in the presence of normal early relaxation and ventricular filling. These findings support the need for development of guidelines for diagnosis and physiologic grading of diastolic dysfunction in children.

Echocardiographic particle image velocimetry for the evaluation of diastolic function in hypertrophic nonobstructive cardiomyopathy

AIMS

To use particle image velocimetry (PIV) echocardiography for the evaluation of diastolic dysfunction (DD) in patients with hypertrophic nonobstructive cardiomyopathy (HNCM).

METHODS

This study included 50 individuals, thereof 30 patients with DD due to HNCM and 20 healthy individuals who served as controls. HNCM patients were divided into 3 groups according to DD severity. All subjects underwent clinical assessment, exercise testing, and standard as well as PIV echocardiography.

RESULTS

Energy dissipation was higher in DD patients than in the control group. The severity of flow pattern disturbance corresponded to the degree of DD. In a subgroup of 20 HNCM patients we found significant correlations between invasive measured left ventricular end-diastolic pressure and noninvasive PIV parameters for intraventricular pressure differences and filling. Inter-observer variability (mean difference ± 1.96 SD) for all tested PIV measurements was good.

CONCLUSION

According to DD severity, patients with HNCM have disturbed intraventricular flow and reduced intraventricular pressure differences, consistent with a reduced intraventricular suction. PIV echocardiography appears to be feasible for detailed analysis of ventricular vortex flow in DD conditions. Further research using PIV echocardiography in different cardiac pathologies seems warranted.

Color M-mode sonography for evaluation of fetal arrhythmias

Fetal arrhythmias can be challenging to diagnose, even with the use of 2-dimensional, M-mode, and spectral Doppler sonography of myocardial or blood flow signals to determine the rate, synchrony, and timing. Color Doppler sonography combined with M-mode echocardiography uses the myocardium and blood flow to provide a robust evaluation of cardiac rhythm. Limited descriptions of color M-mode sonography have been published. This article describes the systematic application of the color M-mode technique using 4 specific clinical case examples and contrasts this technique with more conventional approaches to fetal arrhythmia diagnosis.

NONINVASIVE ASSESSMENT OF LEFT VENTRICULAR DIASTOLIC FUNCTION BY COLOR M-MODE DOPPLER ECHOCARDIOGRAPHY

Transmitral flow velocity pattern obtained by pulsed Doppler technique reflects left ventricular (LV)diastolic function, but an increase in left atrial pressure pseudo-normalizes the flow pattern and masks diastolic dysfunction. Flow propagation velocity (FPV) measured, using color M-mode Doppler and baseline-shift technique, represents an average velocity of early diastolic LV filling flow from mitral orifice to mid-ventricle. In patients with ischemic heart disease and dilated cardiomyopathy, including those with pseudonormalized transmitral flow pattern, FPV had good correlation with the time constant of early diastolic LV pressure decay (Tau), indicating that FPV is a useful noninvasive diastolic-function parameter which does not pseudo-normalize. Unlike the conventional Doppler parameters, FPV was well correlated with Tau in patients with hypertrophic cardiomyopathy, and was distinctly decreased even in hypertensive patents without LV hypertrophy. Thus, FPV is a unique noninvasive diastolic parameter, which can sensitively and accurately detect LV diastolic impairment.

The detection of left ventricular diastolic dysfunction in hypertensive patients: Performance of N-terminal probrain natriuretic peptide

AIM

Diastolic dysfunction (DD) results in increased cardiovascular risk in hypertensives. We studied the performance of N-terminal probrain natriuretic peptide (NT-proBNP) in detecting DD.

MATERIALS AND METHODS

241 hypertensive patients admitted to cardiology polyclinics were included in this study. They were grouped according to the presence of DD. Group 1: Essential hypertensive patients without DD (n= 119); group 2: essential hypertensive patients with DD (n= 122). All underwent trans-thoracic echocardiography for the evaluation of transvalvular flow, morphology, left ventricular wall motion abnormalities and ejection fraction. NT-proBNP levels were measured by an electrochemiluminescence immunoassay.

RESULTS

The systolic blood pressure (BP) (mean+/-SD) was 140+/-12 mmHg in group 1 and 144+/-16 mmHg in group 2 (p=0.049), the diastolic BP (mean+/-SD) was 88+/-10 mmHg in group 1 and 90+/-14 mmHg in group 2 (p=0.043). The median (1st-3rd quartile) NT-proBNP level in group 2 was significantly higher than group 1 [121.05 (61.03-207.66) and 31.17 (17.07-54.09) pg/ml, respectively (p<0.001)]. In the receiver operating characteristics analysis, the area under the curve was 0.862 (95% CI 0.816-0.908). At the cut-off of 45 pg/ml, sensitivity was 86.9%, specificity was 62.4%, and at the cut-off 65 pg/ml, sensitivity was 74.6%, specificity was 83.8%.

CONCLUSION

Plasma NT-proBNP levels may be useful for identifying patients with DD and it is conceivable to use a cut-off level 65 pg/ml as a "rule in" test.

Effects of percutaneous transluminal septal myocardial ablation for obstructive hypertrophic cardiomyopathy on systolic and diastolic left ventricular function assessed by pressure-volume loops

The aim of the present study was to determine the long-term effects of percutaneous transluminal septal myocardial ablation (PTSMA) on systolic and diastolic left ventricular (LV) functions in patients with obstructive hypertrophic cardiomyopathy (HC). Ten consecutive patients with symptomatic HC despite optimal medical treatment were referred for PTSMA at our center. LV systolic and diastolic functions were assessed by online LV pressure-volume loops obtained by conductance catheter at baseline and at 6 months after the procedure. At follow-up, the mean gradients at rest and after extrasystole were significantly decreased compared with baseline (88 +/- 29 to 21 +/- 11 mm Hg and 130 +/- 50 to 35 +/- 22 mm Hg, respectively, p <0.01 for the 2 comparisons). End-systolic and end-diastolic pressures significantly decreased (p <0.01), whereas end-systolic and end-diastolic LV volumes significantly increased (p <0.01 for the 2 comparisons). Cardiac output and stroke volume were unchanged, as were ejection fraction (p = 0.25) and maximum dP/dt (p = 0.13). The slope of the end-systolic pressure-volume relation was not decreased, indicating a preserved contractility. The relaxation constant time, end-diastolic stiffness, projected volume of the end-diastolic pressure-volume relation at 30 mm Hg, and diastolic stiffness constant showed a significant improvement of active and passive myocardial diastolic properties. In conclusion, PTSMA is an effective method in the treatment of symptomatic patients with HC. At 6-month follow-up, the LV-aortic gradient was decreased and active and passive LV diastolic properties were increased. Myocardial contractility was not decreased and general hemodynamics was maintained.

Assessment of variables affecting flow propagation velocity of the left ventricle in healthy children

BACKGROUND

The purpose of the present study was to establish the normal values of flow propagation velocity (FPV) in healthy children and examine the variables that affect FPV in clinical situations.

METHODS

Two hundred and thirty- five healthy children and adolescents were assessed (aged 0-22.6 years, mean age 7.4 +/- 5.4 years; male, n = 142; female, n = 93). FPV was obtained from an apical four-chamber view and determined as the slope of aliasing velocity of early diastolic transmitral flow on the color M-mode using Aloka SSD-5500 with 5.0 MHz transducer. Aliasing velocity was set at 50-70% of the peak transmitral flow velocity. Peak transmitral flow velocities in early diastole (E) and during atrial contraction (A), and the ratio of early to late peak velocity (E/A) were obtained. Tei index was also measured for analysis of general left ventricular performance. Left ventricular mass index (LVMI) was obtained from conventional echo measurement. E, E/A, Tei index and LVMI were compared with FPV in healthy subjects.

RESULTS

FPV obtained from all subjects ranged from 23.7 to 96.0 cm/s (61.3 +/- 13.6 cm/s). Normal value of FPV was less dependent on age, body size, heart rate and left ventricular dimension. In contrast, although there was no significant correlation between FPV and ejection fraction, statistically significant correlation was found between FPV, LVMI (P = 0.0008) and Tei index (P = 0.025).

CONCLUSIONS

FPV is independent of age, body size and heart rate and is useful to assess left ventricular relaxation in children.

Left Ventricular Diastolic Dysfunction in Chronic Aortic Dissection

BACKGROUND

In chronic aortic dissection, compression of the true lumen by the expanded false lumen may be a cause of left ventricular afterload elevation, which may result in diastolic dysfunction. We compared the left ventricular diastolic function by echocardiography between those patients who had double-barrel descending aortic dissection and those who did not.

METHODS

Twelve patients (mean age, 61 +/- 12 years) with chronic type B aortic dissection were enrolled in this study. Patients in group I had double-barrel aortic dissection that had expanded the patent false lumen and narrowed the true lumen (n = 7, 58.3%), and patients in group II had a wider-caliber true lumen with a thrombosed false lumen (n = 5, 41.7%). We evaluated the left ventricular diastolic function with the transmitral flow pattern (E and A waves) with the pulsed Doppler method and flow propagation velocity (FPV) with color M-mode Doppler images, and classified its severity into grade I (abnormal relaxation), grade II (pseudonormalization) and grade III (restriction).

RESULTS

All patients in group II had grade I diastolic dysfunction, with an E/A of less than 1.0. By contrast, 4 of the 7 patients in group I had grade II diastolic dysfunction, with an FPV/E of less than 0.6 and a pseudonormalized (> 1.0) E/A ratio (p = 0.081). Consequently, the E/A ratio was higher in group I than in group II (1.16 +/- 0.39 versus 0.68 +/- 0.18; p < 0.05).

CONCLUSIONS

It is suggested that left ventricular diastolic function is severely reduced in the patients having aortic dissection with a double-barrel and narrowed true lumen.

Role of Left Ventricular Regional Diastolic Abnormalities for Global Diastolic Dysfunction in Patients with Hypertrophic Cardiomyopathy

BACKGROUND

The usefulness of Doppler strain rate imaging for assessment of left ventricular regional diastolic function has not been fully determined.

OBJECTIVE

We aimed to clarify the relationships between diastolic strain rates and global diastolic function and find a useful index for regional diastolic function in patients with hypertrophic cardiomyopathy (HCM).

METHODS

Strain rate curves were obtained using an apical approach at 12 different sites of the left ventricular myocardium in 25 patients with HCM and 20 control subjects, and peak early diastolic strain rate (ESR), peak late diastolic strain rate, and the time from QRS to ESR were measured. The flow propagation velocity was measured using color M-mode Doppler echocardiography as a global diastolic index.

RESULTS

Each of the spatially averaged values of ESR and ESR/peak late diastolic strain rate and the coefficients of variation of time from QRS to ESR was significantly correlated with flow propagation velocity, but the best correlation was observed in ESR. Although both ESR and peak late diastolic strain rate of each myocardial segment of patients with HCM tended to decrease as the wall thickness increased, only ESR significantly decreased even in the segments without apparent hypertrophy.

CONCLUSIONS

In patients with HCM, the reduction of ESR was more closely associated with global diastolic dysfunction than asynchrony, and ESR may be a useful and sensitive index for regional diastolic function.

Increased plasma concentrations of N-terminal pro-brain natriuretic peptide reflect the presence of mildly reduced left ventricular diastolic function in hypertension

BACKGROUND

The potential use of assays of N-terminal pro-brain natriuretic peptide for detection of diastolic abnormalities associated with alterations in blood pressure has not been elucidated. This study was designed to determine whether increased plasma concentrations of N-terminal pro-brain natriuretic peptide sensitively reflect abnormal diastolic function associated with hypertension.

METHODS

Concentrations of N-terminal pro-brain natriuretic peptide in plasma were assayed in 40 previously untreated hypertensive patients without overt congestive heart failure and in 20 age and sex-matched controls. Hypertensive patients were studied with the use of pulsed Doppler and color M-mode Doppler echocardiography for the evaluation of left ventricular diastolic function.

RESULTS

Concentrations of N-terminal pro-brain natriuretic peptide were elevated in hypertensive patients [75.1+/-75.2 (SD) pg/ml compared with 37.9+/-38.5 in controls, P<0.05]. In hypertensive patients, concentrations of N-terminal pro-brain natriuretic peptide were negatively correlated with the ratio of color M-mode flow propagation velocity to transmitral E velocity consistent with the view that increased concentrations of N-terminal pro-brain natriuretic peptide are indicative of alterations in diastolic function. Hypertensive patients with N-terminal pro-brain natriuretic peptide values above the mean value in the control group exhibited significantly increased brachial intimal-medial thickness and reduced wall stress, consistent with the view that increased N-terminal pro-brain natriuretic peptide was associated with favorable peripheral arterial remodeling.

CONCLUSIONS

Elevated concentrations of N-terminal pro-brain natriuretic peptide in plasma reflect the presence of left ventricular diastolic abnormalities and peripheral arterial remodeling in asymptomatic patients with hypertension.

Colour M-mode velocity propagation: a glance at intra-ventricular pressure gradients and early diastolic ventricular performance

The physiology of early-diastolic filling comprises ventricular performance and fluid dynamical principles. Elastic recoil and myocardial relaxation rate determine left ventricular early diastolic performance. The integrity of left ventricular synchrony and geometry is essential to maintain the effect of their timely action on early diastolic left ventricular filling. These factors not only are prime determinants of left ventricular pressure decay during isovolumic relaxation and immediately after mitral valve opening; they also instigate the generation of a sufficient intra-ventricular pressure gradient, which enhances efficient early diastolic left ventricular filling. Accurate assessment of diastolic (dys)function by non-invasive techniques has important therapeutic and prognostic implications but remains a challenge to the cardiologist. The evaluation of left ventricular relaxation by the standard Doppler echocardiographic parameters is hindered by their preload dependency. The colour M-mode velocity propagation of early diastolic inflow (Vp) correlates with intra-ventricular pressure gradients and is a largely preload independent index of ventricular diastolic performance. In this article, the physiologic background, utility and limitations of this promising new tool for the study of early diastolic filling are reviewed.

[Functional assessment of patients with hypertrophic cardiomyopathy by maximal oxygen consumption]

INTRODUCTION AND OBJECTIVES

Differences between anatomical severity and clinical manifestations are frequent in patients with hypertrophic cardiomyopathy. Our objective was to assess functional capacity in a consecutive group of patients with hypertrophic cardiomyopathy measuring exercise aerobic parameters, as well as clinical and echocardiographic variables.

PATIENTS AND METHOD

We studied 98 consecutive patients with hypertrophic cardiomyopathy. All patients underwent both echocardiographic and cardiopulmonary exercise testing. The control group consisted of 22 untrained persons. We studied exercise capacity by analyzing maximal oxygen consumption and aerobic functional capacity, among other variables.

RESULTS

Patients with hypertrophic cardiomyopathy attained significantly lower maximal oxygen consumption values than controls (24.1 5.9 vs 36.4 5.9 ml/kg/min; p = 0.0001). Maximal aerobic capacity was significantly different among patients with NYHA functional capacity class I, II or III (78.9 13.5%; 71.9 14.7%; 63.9 15.7%; p = 0.009). However, considerable overlap was found between groups in maximal aerobic capacity. Functional impairment was greater in patients with left ventricular thickness > 20 mm, ejection fraction < 50%, left atrial dimension > 45 mm and pseudonormal or restrictive transmitral flow pattern.

CONCLUSIONS

Patients with hypertrophic cardiomyopathy show significant functional impairment, which is difficult to detect from their clinical manifestations. Optimal assessment requires cardiopulmonary exercise testing.

Improvement in diastolic intraventricular pressure gradients in patients with HOCM after ethanol septal reduction

We sought to validate measurement of intraventricular pressure gradients (IVPG) and analyze their change in patients with hypertrophic obstructive cardiomyopathy (HOCM) after ethanol septal reduction (ESR). Quantitative analysis of color M-mode Doppler (CMM) images may be used to estimate diastolic IVPG noninvasively. Noninvasive IVPG measurement was validated in 10 patients undergoing surgical myectomy. Echocardiograms were then analyzed in 19 patients at baseline and after ESR. Pulsed Doppler data through the mitral valve and pulmonary venous flow were obtained. CMM was used to obtain the flow propagation velocity (Vp) and to calculate IVPG off-line. Left atrial pressure was estimated with the use of previously validated Doppler equations. Data were compared before and after ESR. CMM-derived IVPG correlated well with invasive measurements obtained before and after surgical myectomy [r = 0.8, P < 0.01, Delta(CMM - invasive IVPG) = 0.09 +/- 0.45 mmHg]. ESR resulted in a decrease of resting LVOT systolic gradient from 62 +/- 10 to 29 +/- 5 mmHg (P < 0.001). There was a significant increase in the Vp and IVPG (from 48 +/- 5to 74 +/- 7 cm/s and from 1.5 +/- 0.2 to 2.6 +/- 0.3 mmHg, respectively, P < 0.001 for both). Estimated left atrial pressure decreased from 16.2 +/- 1.1 to 11.5 +/- 0.9 mmHg (P < 0.001). The increase in IVPG correlated with the reduction in the LVOT gradient (r = 0.6, P < 0.01). Reduction of LVOT obstruction after ESR is associated with an improvement in diastolic suction force. Noninvasive measurements of IVPG may be used as an indicator of diastolic function improvement in HOCM.

Color M-mode and Doppler tissue evaluation of diastolic function in children: simultaneous correlation with invasive indices

OBJECTIVE

The purpose of this study was to explore the validity of diastolic indices derived from color M-mode Doppler and Doppler tissue imaging in a heterogeneous group of pediatric patients by comparing them with simultaneously obtained invasive indices of diastolic function.

METHODS

A total of 20 children undergoing left heart catheterization had echocardiographic images recorded simultaneously with high-fidelity left ventricular (LV) pressure tracings. Transmitral Doppler, pulmonary vein Doppler, Doppler tissue imaging, and color M-mode Doppler flow propagation velocity were recorded. LV peak negative dP/dt, the time constant of isovolumic relaxation, and LV end-diastolic pressure were compared with the echocardiographic indices.

RESULTS

The ratio of peak E-wave mitral velocity/propagation velocity correlated significantly with LV end-diastolic pressure (r = 0.71; P <.001). Propagation velocity correlated with the time constant of isovolumic relaxation (r = -0.56; P =.01) and peak negative dP/dt (r = 0.50; P <.03). Septal mitral annular myocardial velocity correlated significantly with the time constant of isovolumic relaxation (r = -0.58, P =.01).

CONCLUSION

The newer diastolic indices derived from color M-mode Doppler and Doppler tissue imaging appear to be a helpful adjunct in the noninvasive assessment of diastolic function in children.

Comparison of left ventricular diastolic function in obstructive hypertrophic cardiomyopathy in patients undergoing percutaneous septal alcohol ablation versus surgical myotomy/myectomy

Both percutaneous transcoronary alcohol septal reduction (ASR) and surgical myectomy are effective treatments to relieve left ventricular (LV) outflow tract obstruction in obstructive hypertrophic cardiomyopathy (HC). LV diastolic function was assessed by echocardiography in 57 patients with obstructive HC at baseline and 5 +/- 4 months after ASR (n = 37) or surgical myectomy (n = 20). LV outflow tract pressure gradient decreased from 65 +/- 40 to 23 +/- 21 mm Hg (p <0.01) after treatment. The ratio of the early-to-late peak diastolic LV inflow velocities, and the ratio of the early peak diastolic LV inflow velocity to the lateral mitral annulus early diastolic velocity determined by tissue Doppler imaging significantly decreased after the procedures (1.6 +/- 1.7 vs 1.0 +/- 0.7 and 15 +/- 8 vs 11 +/- 5, respectively), whereas LV inflow propagation velocity significantly increased (60 +/- 24 vs 71 +/- 36 cm/s). Left atrial size decreased from 29 +/- 7 to 25 +/- 6 cm(2) (p <0.05). Patients had a significant improvement in New York Heart Association functional class and in exercise performance. When comparing ASR with myectomy, no difference was found in the degree of change in any parameter of diastolic function. Thus, diastolic function indexes obtained by echocardiography changed after septal reduction interventions in patients with obstructive HC; this change was similar to that after surgical myectomy and ASR.

Intraoperative assessment of diastolic function: utility of echocardiography

PURPOSE OF REVIEW

This review discusses the current and future applications of different echocardiographic modalities in evaluating diastolic function intraoperatively.

RECENT FINDINGS

Normal diastolic function is required for optimal cardiac performance. There is sufficient evidence to support the significant prevalence of preoperative diastolic dysfunction and its incidence following cardiac surgery, however controversy still exists regarding the impact of diastolic dysfunction on adverse outcomes. Echocardiography provides a relatively safe, practical and noninvasive means to evaluate perioperative diastolic function, however conventional measures may be limited by the impact of changes in heart rate, rhythm and loading conditions. Newer echocardiographic modalities are reportedly less sensitive to acute changes in loading conditions, and may therefore complement the use of conventional echocardiographic techniques in the perioperative period.

SUMMARY

The availability of effective technology for diagnosing the presence and progression of perioperative diastolic function should assist in the identification of high-risk cardiac surgical patients who may benefit from appropriate triaging and therapeutic intervention.

Comparison between invasive hemodynamic measurements and noninvasive assessment of left ventricular diastolic function by use of Doppler echocardiography in healthy anesthetized cats

OBJECTIVE

To compare Doppler echocardiographic variables of left ventricular (LV) function with those obtained invasively via cardiac catheterization under a range of hemodynamic conditions.

ANIMALS

7 healthy anesthetized cats (1 to 3 years of age).

PROCEDURE

Cats were anesthetized and instrumented to measure the time constant of isovolumic relaxation (tau [tau]), LV end-diastolic pressure (LVEDP), peak negative and positive rate of change of LV pressure, arterial blood pressure, and cardiac output. Echocardiographic variables of diastolic function (isovolumic relaxation time [IVRT], early LV flow propagation velocity [Vp], transmitral and pulmonary venous flow velocity indices, and LV tissue Doppler imaging indices) were measured simultaneously over a range of hemodynamic states induced by treatments with esmolol, dobutamine, cilobradine, and volume loading. Correlation between invasive and noninvasive measures of LV filling was determined by univariate and multivariate regression analyses.

RESULTS

Significant correlations were found between tau and IVRT, peak Vp, peak late transmitral flow velocity, and peak systolic pulmonary venous flow velocity. A significant correlation was found between LVEDP and early diastolic transmitral flow velocity (peak E) and the ratio of peak E to peak Vp, but not between LVEDP and peak Vp.

CONCLUSIONS AND CLINICAL RELEVANCE

IVRT and Vp can be used as noninvasive indices of LV relaxation; Vp was independent of preload and heart rate in this study. The E:Vp ratio may be useful as an indicator of LV filling pressure.

Left ventricular inflow propagation velocity: comparisons between pulsed wave and color M-mode Doppler echocardiography

Sixty-six participants (age 58 +/- 16 years) were included for evaluation of the relationship between color M-mode and pulsed wave Doppler left ventricular inflow propagation velocity (LVIPVcmm and LVIPVpw, respectively). LVIPVpw was measured through the application of the range ambiguity phenomenon, and LVIPVcmm was obtained by manually tracing the first aliasing velocity during the early filling. The variability for LVIPVpw measurements was significantly less than that for LVIPVcmm measurements. There was a significant correlation (r = 0.678, P <.001) between LVIPVcmm and LVIPVpw for all study participants. However, LVIPVpw was greater than LVIPVcmm, especially when the inflow propagation time was relatively short. Age was the only determinant of both LVIPVcmm and LVIPVpw in the control group. As for the patients with diseases retarding inflow propagation, age remained its determinant. However, its impact decreased and the end-systolic dimension and fractional shortening of the left ventricle, instead, turned out to be its major determinant. In conclusion, LVIPVpw measurements are more reproducible than LVIPVcmm measurements. LVIPVpw correlates with LVIPVcmm and their difference significantly correlates with left ventricular inflow propagation time.

Mitral flow propagation velocity identifies patients with abnormal diastolic function during coronary artery bypass graft surgery

Flow propagation velocity (Vp) is a new method of assessing left ventricular (LV) diastolic (D) function that seems to be insensitive to heart rate and preload changes. We hypothesized that Vp <50 cm/s identifies patients with D dysfunction and that Vp provides an assessment of D function when standard Doppler techniques are uninterpretable. We conducted a prospective Doppler echocardiographic assessment of D function in 63 patients undergoing coronary artery bypass graft surgery. Doppler derivatives of mitral inflow and pulmonary vein flow profiles as well as isovolumic relaxation time were compared with Vp before and after cardiopulmonary bypass. A Valsalva maneuver was used to decrease preload. All patients with D dysfunction had Vp <50 cm/s. A Valsalva maneuver did not affect Vp. Vp remained a reliable measure of LV D function when mitral flow profiles could not be determined because of changes in heart rate and rhythm. LV filling patterns did not change significantly after cardiopulmonary bypass. We conclude that Vp is a simple measure of D function during coronary artery bypass graft surgery that correlates with standard, load-dependent Doppler echocardiographic techniques to identify D dysfunction. Vp <50 cm/s identifies abnormal D function in this patient population.

IMPLICATIONS

Mitral propagation velocity (Vp) is a simple, reproducible measure of diastolic function during coronary artery bypass graft surgery that correlates with standard Doppler echocardiographic techniques to identify dysfunction in the setting of a rapid heart rate or variable preload. Vp <50 cm/s identifies abnormal diastolic function in this patient population.