Tissue Doppler imaging in the evaluation of left ventricular diastolic function

Diastolic Dysfunction in Neonates With Hypoxic-Ischemic Encephalopathy During Therapeutic Hypothermia: A Tissue Doppler Study

Diastolic dysfunction often complicates myocardial ischemia with increased mortality rates. However, less is known about diastolic function after perinatal asphyxia in neonates with hypoxic-ischemic encephalopathy (HIE) during therapeutic hypothermia (TH) and rewarming.

AIM

The aim of this study was to assess diastolic function with tissue Doppler imaging (TDI) in neonates with moderate-severe HIE during TH and rewarming.

METHOD

Newborns at >36 weeks' gestation with moderate-severe HIE treated with TH were evaluated with targeted neonatal echocardiography (TNE), including TDI, within 24 h of TH initiation (T1), at 48-72 h of treatment (T2), and after rewarming (T3). These retrospective data were collected and compared with a control group of healthy babies at >36 weeks' gestation that was prospectively evaluated following the same protocol.

RESULTS

A total of 21 patients with HIE + TH and 15 controls were included in the study. Myocardial relaxation before the onset of biventricular filling was prolonged in the HIE + TH group during TH with significantly longer isovolumic relaxation time (IVRT') in the left ventricle (LV), the septum, and the right ventricle (RV). This was associated with slower RV early diastolic velocity (e') and prolonged filling on T1. Total isovolumic time (t-IVT; isovolumic contraction time [IVCT'] + IVRT') and myocardial performance index (MPI') were globally increased in asphyxiated neonates. All these differences persisted after correction for heart rate (HR) and normalized after rewarming. TDI parameters assessing late diastole (a' velocity or e'/a' and E/e' ratios) did not differ between groups.

CONCLUSION

TDI evaluation in our study demonstrated a pattern of early diastolic dysfunction during TH that normalized after rewarming, whereas late diastole seemed to be preserved. Our data also suggest a possible involvement of impaired twist/untwist motion and dyssynchrony. More studies are needed to investigate the impact and therapeutic implication of diastolic dysfunction in these babies, as well as to clarify the role of TH in these findings.

Echocardiographic Evaluation of Ventricular Function-For the Neonatologist and Pediatric Intensivist

In the neonatal and pediatric intensive care setting, bedside cardiac ultrasound is often used to assess ventricular dimensions and function. Depending upon the underlying disease process, it is necessary to be able to evaluate the systolic and diastolic function of left and or right ventricles. The systolic function of left ventricle is mostly assessed qualitatively on visual inspection "eye-balling" and quantitatively by measuring circumferential fraction shortening or calculating the ejection fraction by Simpson's planimetry. The assessment of left ventricular diastolic function relies essentially on the mitral valve and pulmonary venous Doppler tracings or tissue Doppler evaluation. The right ventricular particular shape and anatomical position does not permit to use the same parameters for measuring systolic function as is used for the LV. Tricuspid annular plane systolic excursion (TAPSE) and S' velocity on tissue Doppler imaging are more often used for quantitative assessment of right ventricle systolic function. Several parameters proposed to assess right ventricle systolic function such as fractional area change, 3D echocardiography, speckle tracking, and strain rate are being researched and normal values for children are being established. Diastolic function of right ventricle is evaluated by tricuspid valve and hepatic venous Doppler tracings or on tissue Doppler evaluation. The normal values for children are pretty similar to adults while normal values for the neonates, especially preterm infants, may differ significantly from adult population. The normal values for most of the parameters used to assess cardiac function in term neonates and children have now been established.

Evaluation of Myocardial Injury using Standard Diagnostic Tools and Tissue Doppler Imaging in Blunt Trauma Chest

INTRODUCTION

Myocardial contusion is an entity in chest trauma which is difficult to diagnose. Current practice relies more on cardiac-specific biochemical markers and standard echocardiography, but no gold standard test exists. The application of Tissue Doppler imaging is yet unexplored.

AIM

The present study was designed to evaluate cardiac injury in patients with blunt trauma chest using conventional trans-thoracic echocardiography parameters and Tissue Doppler imaging.

MATERIALS AND METHODS

After ethical approval was taken from the Hospital and University and a written informed consent from all patients/attendants, this prospective study was conducted on a total of 30 patients in range of 15-60 years of age with blunt trauma chest. Patients with positive Trop-T and raised CPK (> 308 IU/L), raised CK-MB (> 24 IU/L) levels were suspected to have myocardial injury and were enrolled in the study. All patients fulfilling the inclusion criteria then underwent 2D-Echo and Tissue Doppler Imaging. Results of the observations were analysed using chi-square test.

RESULTS

Out of the total of 30 patients, 63.3% showed ECG changes suggestive of cardiac injury. A 76.7% patients suffered systolic dysfunction and 36.6% patients suffered diastolic dysfunction irrespective of ECG changes. On comparison of early filling velocity wave i.e., E wave (measured by transthoracic echocardiography) and tricuspid annular velocity Em wave (measured by tissue Doppler echocardiography) at tricuspid valve, we found statistically significant difference among two techniques. (p = 0.04).

CONCLUSION

Echocardiography is very sensitive parameter for evaluation of myocardial contusion. Tissue Doppler imaging provides additional and reliable information.

Basics of Functional Echocardiography in Children and Neonates

Functional echocardiography has become an invaluable tool in the pediatric and neonatal intensive care unit. "Point-of-care," "target," or "focus" echocardiography allows bedside cardiac ultrasound evaluation of the hemodynamic status of the patient, helps in directing treatment, thus improves patients care. In order to be able to perform functional echocardiography, it is essential to understand the principles of ultrasound, to know the echocardiographic equipment and settings necessary to acquire the images. This article focuses therefore on the basics of cardiac ultrasound. It is meant to give an overview of two-dimensional echocardiographic views, M-mode imaging and Doppler echocardiography for neonatologists and pediatric intensivists. It is richly illustrated for better understanding with some examples of clinical applications of functional echocardiography in the intensive care setting.

Predictors and Clinical Impacts of Aggravated Left Ventricular Diastolic Dysfunction After Off-Pump Coronary Artery Bypass Grafting

BACKGROUND

To determine the predictors of aggravated left ventricular diastolic dysfunction (LVDD) in patients undergoing off-pump coronary artery bypass grafting (OPCAB) and to compare late outcomes according to the aggravated LVDD.

METHODS AND RESULTS

OPCAB was performed in 1,101 patients (2001-2013). LVDD was classified as normal, mild, moderate or severe. Patients were divided into 2 groups: non-aggravated LVDD (group I) and aggravated LVDD (group II). The primary endpoint was aggravation of LVDD. The secondary endpoint was late mortality and morbidity such as major adverse cardiac and cerebrovascular events (MACCE) related to LVDD aggravation postoperatively. There were 894 patients in group I and 207 in group II. Multivariate analysis revealed that preoperative peripheral artery obstructive disease (PAOD) (P=0.04), renal failure (P<0.01), and A' velocity (P<0.01) anticipated aggravated LVDD. The Cox hazards model revealed that aggravated LVDD was a poor prognostic factor for MACCE (P<0.01) and overall survival (P<0.01). The Kaplan-Meier survival curve showed that aggravated LVDD was related to poor late outcomes (freedom from MACCE, P=0.01; overall survival, P<0.01).

CONCLUSIONS

Aggravated LVDD significantly affects late clinical outcomes after OPCAB and preoperative PAOD, renal failure, and A' velocity might be predictors. (Circ J 2016; 80: 1937-1945).

Echocardiography in the Assessment of Left Atrial Pressure After Pediatric Heart Surgery: A Comparison Study With Measurements Obtained From Left Atrial Catheter

BACKGROUND

Correlation between ventricular end-diastolic pressure and pulsed Doppler and tissue Doppler-derived E/e' ratio has been widely reported in adults but scarcely studied in children with congenital heart diseases. This ratio is defined as the relationship between diastolic transmitral flow velocity (cm/s; E) and myocardial diastolic relaxation velocity (cm/s; e') in the lateral aspect of the mitral annulus. Our main objective was to ascertain whether a correlation existed between direct measurement of left atrial pressure and echocardiographic E/e' ratio in children after heart surgery.

METHODS

Prospective study including 27 consecutive children after pediatric heart surgery. Data were analyzed according to whether they were obtained within the first 72 hours following surgery or later on. Sensitivity, specificity, positive and negative predictive values, and areas under the receiver-operating characteristics curve of E/e' ratio in detection of left atrial pressure values ≥13 mm Hg were evaluated.

RESULTS

Forty-eight studies were conducted in 27 patients. Thirty-two studies were performed during the first 72 hours after heart surgery and 16 beyond the third day. Median patient age was 0.82 years (5 days-16 years). Median left atrial pressure values and E/e' measurements of the whole cohort (N = 48) were 12.0 and 10.2, respectively. Intraclass correlation index between left atrial pressure values and echocardiographic E/e' ratio was 0.35, 0.25 for studies performed within 72 hours, but 0.78 (P < .01) for those performed later. There was also a high positive predictive value, since in 13 (87%) of 15 studies with an E/e' ratio ≥13, the left atrial pressure was ≥13 mm Hg.

CONCLUSION

While echocardiographic E/e' ratio did not show a good correlation with left atrial pressure in the immediate postoperative period, the positive predictive value may suffice to aid clinicians in predicting elevated pressures.

Serial assessment of right ventricular function using tissue Doppler imaging in preterm infants within 7 days of life

BACKGROUND

We aimed to evaluate right ventricular (RV) function longitudinally using tissue Doppler imaging (TDI) echocardiography in preterm infants.

METHODS

We selected 101 very-low-birth-weight (VLBW) infants for the study. Echocardiographic examinations including TDI were performed serially within 7days of life. Pulsed-Doppler TDI waveforms were recorded at the tricuspid valve annulus, and peak systolic velocities (Sa), early diastolic velocities (Ea), and late diastolic velocities (Aa) were measured.

RESULTS

Sa, Ea and Aa were all reduced significantly from 3h to 12h, and then increased gradually thereafter. These three velocities also increased with gestational age in the early neonatal period. The ratio of Ea to Aa (Ea/Aa) did not change significantly within the first week of life. The ratio of E to Ea (E/Ea) in VLBW infants also seemed to remain stable from birth to day 7. The values of Sa appeared to be associated with cardiac output in the early neonatal period. Both Sa and Aa in intubated infants were significantly higher than in non-intubated infants.

CONCLUSION

RV TDI velocities of preterm infants in the early neonatal period are influenced by gestational age, postnatal age, and respiratory status, although the RV E/Ea ratio appears to be almost stable throughout the neonatal period. Our findings may provide some basis for assessment of RV function in critically ill preterm infants.

Role of natriuretic peptide to predict cardiac abnormalities in patients with hereditary transthyretin amyloidosis

BACKGROUND

Familial amyloid polyneuropathy (FAP) mainly targets the peripheral nervous system and heart. Early noninvasive detection of cardiac impairment is critical for therapeutic management.

AIM

To assess if amino-terminal pro-brain natriuretic peptide (NT-proBNP) or troponin T (cTnT) can predict echocardiographic left-ventricle (LV) impairment in FAP.

METHODS

Thirty-six asymptomatic carriers and patients with FAP had echocardiographic measurement of left-ventricular (LV) systolic function, hypertrophy (LVH) and estimation of filling pressure (FP).

RESULTS

Overall, median age, NT-proBNP, and LV ejection fraction were, respectively, 59 years (41-74), 323 pg/ml (58-1960), and 60% (51-66). Twelve patients had increased cTnT. Prevalence of ATTR gene mutations was 53% for Val30Met. Four individuals were asymptomatic, 6 patients had isolated neurological clinical signs, and 26 had echo-LV abnormalities. The ROC curve identified NT-proBNP patients with echo-LV abnormalities (area: 0.92; (0.83-0.99), p = 0.001) at a threshold >82 pg/ml with a sensitivity of 92%, and a specificity of 90%. Increased in NT-proBNP occurred in patients with SD and/or LVH with or without increase in FP. Elevated cTnT (>0.01 ng/ml) was only observed in patients with LVH and systolic dysfunction, with or without FP.

CONCLUSION

In FAP, NT-proBNP was associated with cardiac impairment suggesting that NT-proBNP could be used in carriers or in FAP patients with only neurologic symptoms for identifying the appropriate time to start cardiac echocardiographic assessment and follow-up. cTnT identified patients with severe cardiac disease.

Epidemiology of heart failure

Heart failure (HF) has been singled out as an epidemic and is a staggering clinical and public health problem, associated with significant mortality, morbidity, and healthcare expenditures, particularly among those aged ≥ 65 years. The case mix of HF is changing over time with a growing proportion of cases presenting with preserved ejection fraction for which there is no specific treatment. Despite progress in reducing HF-related mortality, hospitalizations for HF remain frequent and rates of readmissions continue to rise. To prevent hospitalizations, a comprehensive characterization of predictors of readmission in patients with HF is imperative and must integrate the impact of multimorbidity related to coexisting conditions. New models of patient-centered care that draw on community-based resources to support HF patients with complex coexisting conditions are needed to decrease hospitalizations.

Left ventricular diastolic dysfunction in asymptomatic type 2 diabetic patients: detection and evaluation by tissue Doppler imaging

CONFLICT OF INTEREST: NONE DECLARED

The aim of the study was detection of diastolic dysfunction of myocardium with Tissue Doppler Imaging (TDI) in asymptomatic type 2 diabetic patients, in five years duration of disease, and normal cardiac function on conventional echocardiography (CE), according to the performance showed on exercise stress test.

Serial assessment of left-ventricular function using tissue Doppler imaging in premature infants within 7 days of life

Although many echocardiographic parameters can assess cardiac function noninvasively in preterm infants, it has not been determined what indices are the best. We assessed left-ventricular performance in 101 very low-birth weight (VLBW) infants using tissue Doppler imaging (TDI) echocardiography. Echocardiographic examinations, including TDI, were performed serially within 7 days of life. Pulsed-Doppler TDI waveforms were recorded at the mitral valve annulus, and peak systolic velocities (Sa), early diastolic velocities (Ea), and late diastolic velocities (Aa) were measured. Sa and Aa velocities were both decreased significantly from 3 to 12 h and then gradually increased. Ea velocities showed no significant, longitudinal changes, but Ea values in premature groups appeared to be significantly lower than those in mature groups. The ratio of E to Ea (E/Ea) of VLBW infants seemed to be almost stable from birth to day 7, and this also showed no significant differences between different gestational age groups. E/Ea values in infants with patent ductus arteriosus (PDA) appeared to be greater than those in non-PDA infants. Our present findings suggest that TDI assessment in the early neonatal period might be useful in detecting latent systolic/diastolic failure of critically ill preterm infants.

Evaluation of cardiac functions with tissue Doppler imaging in prediabetic subjects

Background and Objectives

The aim of the present study was to evaluate left ventricle systolic and diastolic function, using tissue Doppler echocardiography (TDE), in relation to blood glucose status in prediabetic patients who had no evidence of heart disease by conventional echocardiography (CE).

Subjects and Methods

We included 60 patients (30 female, 30 male) and 20 healthy controls (10 male, 10 female). All participants were randomised into four groups according to their oral glucose tolerance test. Group-I consisted of those patients who had only impaired fasting glucose (IFG). group-II consisted of patients who had only impaired glucose tolerance (IGT) and group-III consisted of patients who had both IFG and IGT, that is so-called combined glucose intolerance. Group-IV included the healthy controls. All subjects underwent both CE and TDE.

Results

No significant differences were found among the four groups in terms of CE. There was no significant difference between group-IV and group-I with respect to the early peak diastolic velocity (Ea) of medial mitral annulus (11.65±0.66 vs. 9.72±1.58, p>0.05), whereas a statistically significant difference was found between group-IV and group-II (11.65±0.66 vs. 9.06±1.07, p<0.001) and between group-IV and group-III (11.65±0.66 vs. 9.74±1.09, p<0.05).

Conclusion

Diastolic myocardial dysfunction in prediabetic patients may be identified by quantitative TDE before the appearance of CE indices of myocardial dysfunction.

Prevalence of echocardiographic criteria for the diagnosis of pulmonary hypertension in patients with Graves' disease: before and after antithyroid treatment

BACKGROUND

Right-sided heart failure with clinical manifestation is only occasionally seen in patients with Graves' disease (GD). Recent studies revealed that pulmonary hypertension (PHT) detected by echocardiography was not rare in patients with GD. We performed this study to investigate the prevalence of PHT in patients with GD before and after antithyroid treatment, and to assess potential mechanisms from the relationship with clinical and echocardiographic features.

SUBJECTS AND METHODS

Serial echocardiographic examinations were performed in 64 patients with newly diagnosed GD before and after antithyroid treatment to measure cardiac factors, such as pulmonary artery systolic pressure (PAPs), cardiac output, total vascular resistance, left ventricular filling pressure and right ventricular (RV) function. PHT was defined as PAPs of at least 35 mmHg.

RESULTS

The prevalence of PHT in untreated GD patients was 44% (28 out of 64 patients). The presence of systemic hypertension was associated with PHT, especially with pulmonary venous hypertension. GD patients with PHT showed reduced RV function represented by higher RV myocardial performance index without difference of pulmonary vascular resistance, RV wall thickness and peak systolic velocity of free wall side of tricuspid annulus. Follow-up echocardiography was performed in 20 out of 28 GD patients with PHT, and PHT disappeared in all except one patient.

CONCLUSION

PHT is a frequent and reversible complication in patients with GD. Our study suggests that PHT in GD may not be related to underlying autoimmune process and increased pulmonary blood flow from thyrotoxicosis might contributes to the pathogenesis of PHT related to GD.

Early cardiac abnormalities and increased C-reactive protein levels in a cohort of children with sleep disordered breathing

BACKGROUND

This study aims to evaluate left ventricular (LV) structure and function and inflammation in a paediatric population with sleep disordered breathing (SDB) and in control subjects.

METHODS

Forty-nine children with SDB and 21 healthy, age-matched subjects were enrolled. The diagnosis of obstructive sleep apnoea syndrome (OSAS) was confirmed by the laboratory polysomnography, showing an obstructive apnoea/hypopnoea index of more than one per hour, according to the criteria of the American Academy of Sleep Medicine and modified for paediatric population. Fasting blood samples for the biochemical evaluation (including high-sensitivity C-reactive protein (hsCRP) were drawn in the morning, after the polysomnographic examination in all patients with SDB and in the control group. All children underwent a two-dimensional colour Doppler cardiac examination with LV mass assessment and systolic and diastolic function evaluation.

RESULTS

Higher hsCRP levels were observed in subjects with OSAS than in children with primary snoring and in controls (0.8 ± 0.7 vs 0.3 ± 0.1 ng/dl, p = 0.001, and 0.4 ± 0.2 ng/dl, p = 0.01, respectively). The LV diastolic dysfunction was significantly more frequent in patients with severe OSAS and higher hsCRP levels than in control group.

CONCLUSIONS

This study shows that OSAS in children is associated with higher LV mass, early LV diastolic dysfunction and a pro-inflammatory state (high CRP levels). These findings might help to explain the higher incidence of cardiovascular morbidity in patients with OSAS.

Reproducibility of Doppler measures of ventricular function during maximal upright cycling

Echocardiographic measures of ventricular function during exercise may prove useful in assessing myocardial health. This study examined test-retest reproducibility of measurements of Doppler mitral flow velocity (E-wave) and myocardial tissue Doppler imaging (E'-, S-waves) during a progressive maximal upright cycle test in 12 healthy lean adolescent males. Measurements were taken as subjects pedalled to exhaustion with 35 watt work increments in two separate trials. We observed no significant differences in mean values at rest, submaximal (70 watts) exercise, or maximal exercise for all three variables. Coefficients of variation at maximal exercise were 5.3%, 7.4%, and 8.1% for mitral E, tissue Doppler-S, and tissue Doppler-E', respectively. These findings indicated acceptable levels of reproducibility of Doppler ultrasound techniques for assessing ventricular systolic and diastolic functional response to maximal exercise in young lean male subjects.

Usefulness of a Z-score of E' versus raw E' velocities to detect left ventricular dysfunction in patients with mitral or aortic regurgitation or dilated cardiomyopathy

Despite their potential as a sensitive measure of ventricular performance, tissue Doppler velocities vary with normal aging. This is inconvenient for nonspecialists to interpret and makes it difficult to use as an entry criterion for clinical studies. The age-adjusted tissue Doppler Z-scores might avoid these disadvantages and be more discriminant for myocardial impairment than the raw velocities. We conducted a meta-regression of studies reporting age-specific normal tissue Doppler velocities to determine a consensus formula for Z-scores (8 studies, 1,867 patients) that we then tested in an independent study at our institution. We next compared the Z-scores head-to-head with the raw velocities for their ability to distinguish a fresh set of 81 healthy subjects from groups in whom subtle ventricular dysfunction might be expected, including 50 patients with dilated cardiomyopathy, 50 with aortic regurgitation, and 50 with mitral regurgitation. The discriminant capacity, assessed by the area under the receiver operating characteristic curves, was higher for the Z-scores than for the raw velocities in each patient group. At the septal angle of the mitral annulus: dilated cardiomyopathy 0.95 versus 0.92 (p = 0.03), aortic regurgitation 0.83 versus 0.78 (p = 0.02), mitral regurgitation 0.85 versus 0.81 (p = 0.04). At the lateral angle: dilated cardiomyopathy 0.94 versus 0.88 (p = 0.005), aortic regurgitation 0.92 versus 0.83 (p = 0.001), mitral regurgitation 0.87 versus 0.85 (p = 0.31). In conclusion, the Z-scores of the tissue Doppler velocities were better than the raw velocities at detecting myocardial impairment in valvular or heart muscle disease. The calculation needs only the raw velocity and patient age. Tissue Doppler Z-scores could be used to create a novel, more sensitive, definition of ventricular dysfunction and might make it easier for nonspecialists to interpret the reports.

Intra-arrest rapid head cooling improves postresuscitation myocardial function in comparison with delayed postresuscitation surface cooling

OBJECTIVE

To compare resuscitation outcomes and myocardial function among intra-arrest head cooling, delayed surface cooling, and uncooled controls.

DESIGN

Prospective animal study.

SETTING

University-affiliated animal research laboratory.

SUBJECTS

Twenty-four male domestic pigs.

INTERVENTIONS

Ventricular fibrillation remained untreated for 10 mins after which animals were assigned into three groups: 1) intra-arrest head cooling, 2) postresuscitation surface cooling, and 3) uncooled controls. Head cooling by evaporative perfluorochemical began coincident with the start of cardiopulmonary resuscitation and continued for a total of 4 hrs. Surface cooling using a cooling blanket began at 2 hrs after return of spontaneous circulation and continued for 8 hrs. Control animals were treated identically with the exception for cooling.

MEASUREMENTS AND MAIN RESULTS

Return of spontaneous circulation was achieved in eight of eight head-cooled animals, in seven of eight surface-cooled animals, and in seven of eight of controls. Myocardial functions measured by transthoracic echocardiography were significantly better in the head-cooled animals than in surface-cooled and controls. All head-cooled animals survived for more than 96 hrs. This contrasted with six of eight survivors after surface cooling, and only two of eight among controls.

CONCLUSIONS

Both intra-arrest head cooling and delayed surface cooling improved postresuscitation myocardial dysfunction. The beneficial effects were greatest with head cooling initiated with cardiopulmonary resuscitation.

The heart failure epidemic

Heart failure has been singled out as an emerging epidemic, which could be the result of increased incidence and/or increased survival leading to increased prevalence. Knowledge of the responsibility of each factor in the genesis of the epidemic is crucial for prevention. Population-based studies have shown that, over time, the incidence of heart failure remained overall stable, while survival improved. Therefore, the heart failure epidemic is chiefly one of hospitalizations. Data on temporal trends in the incidence and prevalence of heart failure according to ejection fraction and how it may have changed over time are needed while interventions should focus on reducing the burden of hospitalizations in hear failure.

Prediction of hospital outcome in septic shock: a prospective comparison of tissue Doppler and cardiac biomarkers

Introduction

Diastolic dysfunction as demonstrated by tissue Doppler imaging (TDI), particularly E/e' (peak early diastolic transmitral/peak early diastolic mitral annular velocity) is common in critical illness. In septic shock, the prognostic value of TDI is undefined. This study sought to evaluate and compare the prognostic significance of TDI and cardiac biomarkers (B-type natriuretic peptide (BNP); N-terminal proBNP (NTproBNP); troponin T (TnT)) in septic shock. The contribution of fluid management and diastolic dysfunction to elevation of BNP was also evaluated.

Methods

Twenty-one consecutive adult patients from a multidisciplinary intensive care unit underwent transthoracic echocardiography and blood collection within 72 hours of developing septic shock.

Results

Mean ± SD APACHE III score was 80.1 ± 23.8. Hospital mortality was 29%. E/e' was significantly higher in hospital non-survivors (15.32 ± 2.74, survivors 9.05 ± 2.75; P = 0.0002). Area under ROC curves were E/e' 0.94, TnT 0.86, BNP 0.78 and NTproBNP 0.67. An E/e' threshold of 14.5 offered 100% sensitivity and 83% specificity. Adjustment for APACHE III, cardiac disease, fluid balance and grade of diastolic function, demonstrated E/e' as an independent predictor of hospital mortality (P = 0.019). Multiple linear regression incorporating APACHE III, gender, cardiac disease, fluid balance, noradrenaline dose, C reactive protein, ejection fraction and diastolic dysfunction yielded APACHE III (P = 0.033), fluid balance (P = 0.001) and diastolic dysfunction (P = 0.009) as independent predictors of BNP concentration.

Conclusions

E/e' is an independent predictor of hospital survival in septic shock. It offers better discrimination between survivors and non-survivors than cardiac biomarkers. Fluid balance and diastolic dysfunction were independent predictors of BNP concentration in septic shock.

Recent advances in the application of computational mechanics to the diagnosis and treatment of cardiovascular disease

During the last 30 years, research into the pathogenesis and progression of cardiovascular disease has had to employ a multidisciplinary approach involving a wide range of subject areas, from molecular and cell biology to computational mechanics and experimental solid and fluid mechanics. In general, research was driven by the need to provide answers to questions of critical importance for disease management. Ongoing improvements in the spatial resolution of medical imaging equipment coupled to an exponential growth in the capacity, flexibility and speed of computational techniques have provided a valuable opportunity for numerical simulations and complex experimental techniques to make a contribution to improving the diagnosis and clinical management of many forms of cardiovascular disease. This paper contains a review of recent progress in the numerical simulation of cardiovascular mechanics, focusing on three particular areas: patient-specific modeling and the optimization of surgery in pediatric cardiology, evaluating the risk of rupture in aortic aneurysms, and noninvasive characterization of intraventricular flow in the management of heart failure.

Hemodynamic correlates of the third heart sound and systolic time intervals

Bedside diagnostic tools remain important in the care of patients with heart failure. Over the past two centuries, cardiac auscultation and phonocardiography have been essential in understanding cardiac pathophysiology and caring for patients with heart disease. Diastolic heart sounds (S3 and S4) and systolic time intervals have been particularly useful in this regard. Unfortunately, auscultation skills have declined considerably, and systolic time intervals have traditionally required carotid pulse tracings. Newer technology allows the automated detection of heart sounds and measurement of systolic time intervals in a simple, inexpensive, noninvasive system. Using the newer system, the authors present data on the hemodynamic correlates of the S3 and abnormal systolic time intervals. These data serve as the foundation for using the system to better understand the test characteristics and pathophysiology of the S3 and systolic time intervals, and help to define their use in improving the bedside diagnosis and management of patients with heart failure.

Impact of obstructive sleep apnea on the atrial electromechanical activation time

BACKGROUND

Obstructive sleep apnea (OSA) is closely associated with atrial fibrillation, which is provoked by electrical and structural remodeling. However, the association between OSA and atrial remodeling has not been fully elucidated.

METHODS AND RESULTS

Atrial electromechanical activation time (EMAT) was investigated using tissue Doppler imaging (TDI) in men with severe OSA (n=24) and control subjects (n=24). The EMAT was determined as the time interval from the initiation of P-wave deflection until the peak of local lateral left atrial (LA) TDI signal. The early diastolic velocity of the mitral annulus (E(a)) and the EMAT were significantly lower and longer in OSA cases than in controls (E(a): 6.1+/-0.9 cm/s vs 7.3+/-1.5 cm/s, P=0.001; EMAT: 129.7+/-11.5 ms vs 118.5+/-12.3 ms, P=0.002). Among OSA cases, the apnea - hypopnea index (AHI) was significantly correlated with EMAT (r=0.660, P<0.001), E(a) (r=-0.609, P=0.002), LA dimension (r=0.486, P=0.016), and early diastolic velocity of mitral flow (E)/E(a) ratio (r=0.418, P=0.042). In multivariate stepwise linear regression analysis, EMAT was independently associated with AHI (P=0.025) and E(a) (P=0.028) in OSA cases.

CONCLUSION

EMAT measured by TDI could be a useful parameter for identifying atrial remodeling in patients with severe OSA.

The effect of nondipping blood pressure patterns on cardiac structural changes and left ventricular diastolic functions in normotensives

BACKGROUND

Cardiac structural changes have been reported to be more prominent in nondipper normotensives than the dipper ones. But the influence of nondipping status on cardiac diastolic functions of normotensives has not been studied yet. In this study, we investigated the effect of nondipping status on both cardiac structural changes and left ventricular (LV) diastolic functions in normotensives.

METHODS

We performed ambulatory blood pressure (BP) monitoring (ABPM) and echocardiography in 62 normotensive subjects with the following criteria: (1) office BP < 140/90 mmHg; (2) average 24-hour ambulatory BP < 130/80 mmHg.

RESULTS

In the evaluation by tissue Doppler imaging (TDI), the early diastolic myocardial peak velocity (Em) and Em/late diastolic myocardial peak velocity (Am) ratio (Em/Am ratio) were lower in nondippers than those in dippers (P = 0.009 and P < 0.001, respectively). Isovolumic relaxation time (IRT) and myocardial performance index (MPI) were higher in nondippers than those in dippers (P = 0.036 and P = 0.026, respectively). Nondipping status, independent of other factors, was observed to cause both a decrease in the Em and Em/Am ratio and an increase in IRT. However, its effect on IRT was not statistically significant (coefficient =-0.27, P = 0.027; coefficient =-0.37, P = 0.002; coefficient = 0.20, P = 0.082, respectively).

CONCLUSIONS

Nondipping of nocturnal BP seems to be a determinant of cardiac remodeling and LV diastolic dysfunction (LVDD) and may result in a cardiovascular (CV) risk independent of the increase in LV mass (LVM) in normotensives.

Impact of obstructive sleep apnea on left ventricular diastolic function

The aim of this study was to investigate the impact of obstructive sleep apnea (OSA) on left ventricular (LV) functional changes by using tissue Doppler imaging-derived indexes in patients with OSA. We studied 62 patients classified into 3 groups, namely 18 with mild to moderate OSA, 24 with severe OSA, and 20 control subjects without OSA according to the apnea-hypopnea index (AHI) on complete overnight polysomnogram. All underwent conventional and tissue Doppler echocardiographies. Only early diastolic velocity (Ea; -6.2 +/- 0.3 vs -7.1 +/- 0.3 vs -7.3 +/- 0.3 cm/s, respectively, for the 3 groups, p = 0.023) was significantly decreased in the severe OSA group. Other echocardiographic parameters of diastolic function such as isovolumic relaxation time, deceleration time, mitral inflow early/late wave velocity ratio, and pulmonary vein systolic/diastolic pulmonary vein velocity ratio were comparable among the 3 groups. AHI was correlated only with tissue Doppler imaging-derived indexes of LV diastolic function (Ea r = -0.382, p = 0.002; Ea/late diastolic velocity r = -0.329, p = 0.009), but not with conventional Doppler indexes. AHI remained a significant predictor of Ea after adjusting for age, heart rate, fasting glucose level, blood pressure, body mass index, and LV mass index in a multiple stepwise linear regression model (p = 0.007). In conclusion, only patients with severe OSA showed a greater impairment of LV diastolic function. Of all echocardiographic parameters of diastolic dysfunction investigated, only Ea was identified as the best index to demonstrate an association between LV diastolic dysfunction and severity of OSA independently of body mass index, diabetes mellitus, and hypertension.

Tissue Doppler in critical illness: a retrospective cohort study

BACKGROUND

There is a paucity of published data on tissue Doppler imaging (TDI) in the critically ill. In a critically ill cohort, we studied the distribution of TDI and its correlation with other echocardiographic indices of preload. To aid hypothesis generation and sample size calculation, associations between echocardiographic variables, including the ratio of peak early diastolic transmitral velocity (E) to peak early diastolic mitral annular velocity (E'), and mortality were also explored.

METHODS

This retrospective study was performed in a combined medical/surgical, tertiary referral intensive care unit. Over a 2-year period, 94 consecutive patients who underwent transthoracic echocardiography with E/E' measurement were studied.

RESULTS

Mean Acute Physiology and Chronic Health Evaluation III score was 72 +/- 25. Echocardiography was performed 5 +/- 6 days after intensive care unit admission. TDI variables exhibited a wide range (E' 4.7-18.2 cm/s and E/E' 3.3 to 27.2). E' below 9.6 cm/s was observed in 63 patients (rate of myocardial relaxation below lower 95% confidence limit of normal individuals). Fourteen patients had E/E' above 15 (evidence of raised left ventricular filling pressure). E/E' correlated with left atrial area (r = 0.27, P = 0.01) but not inferior vena cava diameter (r = 0.16, P = 0.21) or left ventricular end-diastolic volume (r = 0.16, P = 0.14). In this cohort, increased left ventricular end-systolic volume, but not E/E', appeared to be an independent predictor (odds ratio 2.1, P = 0.007) of 28-day mortality (31%; n = 29).

CONCLUSION

There was a wide range of TDI values. TDI evidence of diastolic dysfunction was common. E/E' did not correlate strongly with other echocardiographic indices of preload. Further evaluation of echocardiographic variables, particularly left ventricular end-systolic volume, for risk stratification in the critically ill appears warranted.

Physiology of the Third Heart Sound: Novel Insights from Tissue Doppler Imaging

BACKGROUND

The third heart sound (S(3)) is thought to be caused by the abrupt deceleration of left ventricular (LV) inflow during early diastole, increased LV filling pressures, and decreased LV compliance. We sought to determine whether the ratio of early mitral inflow velocity to diastolic velocity of the mitral annulus (E/E') could confirm the proposed mechanism of the S(3).

METHODS

A total of 90 subjects underwent phonocardiography, echocardiography, tissue Doppler imaging, and left-sided heart catheterization.

RESULTS

Phonocardiography detected an S(3) in 21 patients (23%). Subjects with an S(3) had lower ejection fraction (P = .0006) and increased E deceleration rate (P < .0001), E/E' (P < .0001) and filling pressures (P < .0001). The phonocardiographic S(3) confidence score correlated with E/E' (r = 0.46; P < .0001) and E deceleration rate (r = 0.43, P = .0001). Of the echocardiographic variables, only E/E' was independently associated with the S(3) confidence score (P = .009), independently of invasively determined LV filling pressures (P = .001).

CONCLUSIONS

The most important determinants of the pathologic S(3) are an increased deceleration rate of early mitral inflow, elevated LV filling pressures, and abnormal compliance of the myocardium as measured by tissue Doppler imaging.

Preliminary clinical study of real-time three-dimensional echocardiographic volume-time curve in evaluating left ventricular diastolic function

The volume-time curve change in patients with normal left ventricular (LV) diastolic function and diastolic dysfunction was evaluated by real-time three-dimensional echocardiography (RT3DE). LV diastolic dysfunction was defined by E'<A' in pulse-wave tissue Doppler for inter-ventricular septal (IVS) of mitral annulus. In 24 patients with LV diastolic dysfunction, including 12 patients with delayed relaxation (delayed relaxation group) and 12 patients with pseudo-normal function (pseudo-normal group) and 24 normal volunteers (control group), data of full-volume image were acquired by real-time three-dimensional echocardiography and subjected to volume-time curve analysis. EDV (end-diastolic volume), ESV (end-systolic volume), LVEF (left ventricular ejection fraction), PER (peak ejection rate), PFR (peak filling rate) from RT3DE were examined in the three groups. Compared to the control group, PFR (diastolic filling index of RT3DE) was significantly reduced in the delayed relaxation group and pseudo-normal group (P<0.05). There were no significant differences in EDV, ESV, LVEF, PER (P>0.05). It is concluded that PFR, as a diastolic filling index of RT3DE, can reflect the early diastolic function and serve as a new non-invasive, quick and accurate tool for clinical assessment of LV diastolic function.

Aortic elastic properties are related to left ventricular diastolic function in patients with type 1 diabetes mellitus

OBJECTIVE

The aim of the study was to evaluate left ventricular diastolic function and its relation to aortic wall stiffness in patients with type 1 diabetes mellitus without coronary artery disease or hypertension.

PATIENTS

Sixty-six patients with type 1 diabetes mellitus were examined by echocardiography and divided into two groups according to the diastolic filling pattern determined by mitral annulus tissue Doppler velocities. Group A patients (n = 21) presented diastolic dysfunction with a peak early diastolic mitral annular velocity (Em)/peak late diastolic mitral annular velocity (Am) ratio <1 whereas in group B patients (n = 45) the Em/Am ratio was >1. Coronary artery disease was excluded based on normal thallium scintigraphy. Aortic stiffness index was calculated from aortic diameters measured by echocardiography, using accepted criteria.

RESULTS

Aortic stiffness index differed significantly among the two groups. Significant correlations were found between parameters of left ventricular diastolic function (Em/Am, isovolumic relaxation time, deceleration time) and aortic stiffness index. Multiple stepwise linear regression analysis revealed aortic stiffness index (beta = -0.39, p = 0.001) and isovolumic relaxation time (beta = -0.46, p < 0.001) as the main predictors of Em/Am ratio.

CONCLUSIONS

Aortic stiffness is increased in type 1 diabetic patients with left ventricular diastolic dysfunction. This impairment in aortic elastic properties seems to be related to parameters of diastolic function.

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.

Tissue Doppler Assessment of Ventricular Function during Cycling in 7- to 12-yr-old Boys

PURPOSE

Studies utilizing submaximal supine exercise have indicated that tissue Doppler imaging (TDI) may be useful for assessing ventricular systolic and diastolic function during exercise and might offer a means of detecting patients with early myocardial dysfunction. This investigation of 14 healthy boys ages 7-12 yr was designed to assess measures of inotropic and lusitropic function during maximal upright cycle exercise.

METHODS

Color tissue Doppler imaging (S and E' waves, indicative of systolic and diastolic function, respectively), stroke volume, and mitral peak inflow velocity (E wave) were recorded at rest and during a progressive upright cycle test to exhaustion.

RESULTS

Values of TDI-S and TDI-E' were obtained at exhaustive exercise in all but one subject. Mean value of S rose 163% (3.8+/-1.2 to 10.0+/-2.5 cm.s), and average E' increased by 92% (-6.3+/-2.2 to -12.1+/-3.2 cm.s). No significant changes were observed in the ratio of E' to mitral peak flow velocity (E), suggesting that left ventricular end-diastolic pressure remained stable.

CONCLUSIONS

These data indicate that measurement of TDI is feasible during maximal upright exercise, and velocities obtained may provide insights into ventricular systolic and diastolic functional capacity.

Diagnostic accuracy of tissue Doppler echocardiography for patients with acute heart failure

BACKGROUND

Acute heart failure leads to high mortality and morbidity rates. The symptom of acute dyspnoea is non-specific and the diagnostic tools of acute heart failure are still not satisfactory. Tissue Doppler echocardiography is accurate in evaluating cardiac function; however, its efficacy in diagnosing patients with acute dyspnoea in emergency departments remains unclear.

METHODS

Patients with acute dyspnoea were included prospectively while visiting the emergency department. Tissue Doppler echocardiography was carried out and the ratios of peak early diastolic transmitral blood flow velocity (E) to the peak early diastolic tissue velocity over mitral annulus (Ea) were recorded. The sensitivity, specificity and accuracy of tissue Doppler parameters and the receiver-operating characteristic curves for diagnosing acute heart failure were also evaluated.

RESULTS

A total of 92 patients were enrolled. The ratio E:Ea was found to be a good diagnostic test to estimate the diagnostic performances of tissue Doppler echocardiography using receiver-operating characteristic curves in cases of acute heart failure in patients with preserved left ventricular systolic function (mean (SD) area under the curve = 0.875 (0.049); p<0.001; cut-off value = 11) and with left ventricular systolic dysfunction (mean (SD) area under the curve = 0.903 (0.061); p = 0.003; cut-off value = 16). E:Ea was an independent predictor of acute heart failure in multiple logistic regressions. For patients with a B-type natriuretic peptide level between 100 and 500 pg/ml, E:Ea provided an accuracy of 90.9% (p = 0.015) for diagnosing acute heart failure.

CONCLUSIONS

Tissue Doppler echocardiography is accurate in diagnosing patients with acute heart failure in emergency departments. It can be a useful supplementary diagnostic tool for patients with inconclusive blood B-type natriuretic peptide level.

Cardiovascular responses to static exercise in boys: insights from tissue Doppler imaging

Ventricular functional changes and mechanisms of the cardiovascular responses during static exercise have not been well delineated in children. In this study, Doppler echocardiographic techniques were utilized to assess cardiovascular adaptations to bilateral isometric leg extension at 30% maximal voluntary contraction for three minutes in a group of 14 healthy boys (mean age 10.2 +/- 1.5 years). Mean heart rate rose from 77 +/- 9 to 106 +/- 11 bpm, stroke volume fell from 59 +/- 9 to 52 +/- 7 ml, and cardiac output increased from 4.58 +/- 0.58 to 5.62 +/- 0.81 l min(-1) (P < 0.05). Mean arterial pressure rose from 86 +/- 7 to 109 +/- 9 mm Hg, with no significant change in peripheral vascular resistance. By tissue Doppler imaging markers, inotropic function improved by 59%, while lusitropic function increased 38%. These findings suggest that (1) cardiovascular responses to static leg extension in boys are similar to those in adult men, and (2) isometric leg extension triggers modest increases in both systolic and diastolic function.

Which Doppler Parameters Are Load Independent? A Study in Normal Volunteers After Blood Donation

OBJECTIVES

We sought to assess the effects of blood donation on different echocardiographic parameters in healthy volunteers.

METHODS

A total of 101 healthy male volunteers were evaluated by echocardiography before and immediately after a 500-mL blood donation. In addition to traditional Doppler indices of left ventricular filling, Doppler tissue, color flow propagation, strain (epsilon), and epsilon rate were measured.

RESULTS

There was a statistically significant decrease in mitral peak E and A values after blood donation (E wave 0.85 +/- 0.12 vs 0.79 +/- 0.14 cm/s, P = .01; A wave 0.65 +/- 0.10 vs 0.60 +/- 0.12 cm/s, P = .05). Mitral color flow propagation velocity was not affected (560 +/- 123 vs 571 +/- 132 mm/s, P = not significant). There were no significant differences in the Doppler tissue parameters of peak systolic, and early and late diastolic velocities after blood donation (Sm 13.5 +/- 4.6 vs 13.3 +/- 4.9 cm/s, P = not significant; Em 15.5 +/- 4.9 vs 15.9 +/- 5.1 cm/s, P = not significant; and Am 14.1 +/- 3.9 vs 14.1 +/- 3.5 cm/s, P = not significant, respectively). The peak systolic decreased significantly (-28 +/- 8% vs -21 +/- 4%, P = .03) whereas the peak systolic rate was not affected (1.5 +/- 0.35 vs 1.4 +/- 0.40 s(-1), P = not significant).

CONCLUSION

In healthy male volunteers, preload reduction induced by a 500-mL blood donation does not affect the color propagation velocity, rate, and Doppler tissue velocities.

Early detection of diabetic cardiomyopathy: usefulness of tissue Doppler imaging

OBJECTIVE

The aim of the study was to evaluate whether tissue Doppler imaging (TDI) detects a pre-clinical impairment of diastolic function in subjects with Type 2 diabetes with short duration of disease and normal cardiac function with conventional echocardiography (CE), and whether echocardiographic parameters are related to metabolic abnormalities.

PATIENTS AND METHODS

We studied 40 non-obese, normotensive, uncomplicated Type 2 diabetic subjects with short duration of disease and 20 control subjects. All participants underwent both CE and TDI echocardiography. With TDI, early velocity (Ea), atrial velocity (Aa), their ratio (Ea/Aa) and systolic velocity (Sa) were measured at the lateral corner of mitral annulus. Glycosylated haemoglobin, fasting plasma glucose and insulin were determined and homeostasis model assessment (HOMA-IR), as an index of insulin resistance, was calculated.

RESULTS

Cardiac function with CE was similar in the two groups. Using TDI, diabetic subjects showed a lower Ea velocity (15.5+/-3.9 vs. 19.4+/-3.5 cm/s, P<0.0001), an increased Aa velocity (15.5+/-2.4 vs. 14.1+/-2.4 cm/s, P<0.05) and a reduced Ea/Aa ratio (1.00+/-0.2 vs. 1.39+/-0.3, P<0.0001), compared with control subjects. Linear regression analysis in the diabetic group showed that only HOMA-IR was negatively associated with Ea/Aa ratio (P=0.026). No significant association was observed with other metabolic variables.

CONCLUSION

An early stage of diabetic cardiomyopathy can be evidenced by TDI in Type 2 diabetic subjects even in the presence of a normal cardiac function with CE. This abnormality is associated with insulin resistance.