Clinical application of pulsed Doppler tissue imaging for assessing abnormal left ventricular relaxation

The pathophysiology of heart failure with normal ejection fraction: exercise echocardiography reveals complex abnormalities of both systolic and diastolic ventricular function involving torsion, untwist, and longitudinal motion

OBJECTIVES

The purpose of this study was to test the hypothesis that in heart failure with normal ejection fraction (HFNEF) exercise limitation is due to combined systolic and diastolic abnormalities, particularly involving ventricular twist and deformation (strain) leading to reduced ventricular suction, delayed untwisting, and impaired early diastolic filling.

BACKGROUND

A substantial proportion of patients with heart failure have a normal left ventricular ejection fraction. Currently the pathophysiology is considered to be due to abnormal myocardial stiffness and relaxation.

METHODS

Patients with a diagnosis of HFNEF and proven cardiac limitation by cardiopulmonary exercise testing were studied by standard, tissue Doppler, and speckle tracking echocardiography at rest and on submaximal exercise.

RESULTS

Fifty-six patients (39 women; mean age 72 +/- 7 years) with a clinical diagnosis of HFNEF and 27 age-matched healthy control subjects (19 women; mean age 70 +/- 7 years) had rest and exercise images of sufficient quality for analysis. At rest, systolic longitudinal and radial strain, systolic mitral annular velocities, and apical rotation were lower in patients, and all failed to rise normally on exercise. Systolic longitudinal functional reserve was also significantly lower in patients (p < 0.001). In diastole, patients had reduced and delayed untwisting, reduced left ventricular suction at rest and on exercise, and higher end-diastolic pressures. Mitral annular systolic and diastolic velocities, systolic left ventricular rotation, and early diastolic untwist on exercise correlated with peak VO(2)max.

CONCLUSIONS

In HFNEF there are widespread abnormalities of both systolic and diastolic function that become more apparent on exercise. HFNEF is not an isolated disorder of diastole.

Tissue Doppler imaging of the left ventricle in healthy elderly females does not support the concept of “isolated” diastolic dysfunction

The concept of "isolated" left ventricular diastolic dysfunction has recently been challenged, since left ventricular contraction abnormalities can be demonstrated in subjects with normal left ventricular ejection fraction (EF). In this study of 35 healthy females (aged 65--80 years) with EF>50%, the ratio of peak early transmitral flow velocity to peak early diastolic myocardial velocity (E/Em) correlated significantly with peak systolic myocardial longitudinal velocity (Sm) (r=-0.57, p<0.0001), assessed as an average in six basal left ventricular segments. E/Em correlated also with age (r=0.51, p<0.002), but not significantly with ambulatory daytime systolic blood pressure (r=0.32, p=0.06), nor with left ventricular mass. In conclusion, there is a significant correlation between left ventricular diastolic and systolic function also in an apparently healthy population when adequately sensitive methods are used, in terms of tissue Doppler assessment of the left ventricular longitudinal motion. Although age may influence left ventricular longitudinal motion, an influence of arterial blood pressures is unclear.

Atrial and ventricular function in thalassemic patients with supra-ventricular arrhythmias

The aims of this study were to evaluate through Color Doppler Myocardial Imaging (CDMI) echocardiography if atrial or ventricular myocardial alterations could be detectable in patients with thalassemia major (THAL) and if these alterations could be considered as predictive elements for supra-ventricular arrhythmic events. Twenty-three patients with THAL underwent clinical and electrocardiographic evaluation; patients were grouped in THAL1 (9 with supra-ventricular arrhythmias) and THAL2 (14 without arrhythmias); 12 healthy subjects were considered as control group (C). We examined through conventional 2D Color Doppler echocardiography some morphological and functional parameters regarding left ventricular (LV) systolic and diastolic function, and through CDMI the velocities at mitral annulus level, the regional LV and left atrial (LA) strain and strain rate. All THAL patients had LV dimension (p<0.05), LA area (p<0.01) and E/Em ratio (p<0.001) to be significantly higher than controls. The mitral annulus longitudinal velocities were significantly lower in THAL1 than in THAL2 (p<0.001); the E/Em ratio was higher in THAL1 than THAL2 (p<0.001). The THAL1 showed a lower systolic strain rate of atrial wall than THAL2 and C (p<0.05). The multiple regression highlighted a significantly inverse correlation among E/Em and atrial strain (p<0.02). CDMI showed both THAL subgroups had subtle systolic and diastolic left ventricular myocardial alterations, which could represent the onset of developing "iron cardiomyopathy" and are related to supra-ventricular arrhythmia. Monitoring these parameters in the THAL patients could contribute to decisions about follow-up and therapy.

Is the aging heart similar to the diabetic heart? Evaluation of LV function of the aging heart with Tissue Doppler Imaging

BACKGROUND AND AIMS

Left ventricular (LV) function in the healthy aging heart is modified by biochemical changes with advancing age. We employed for the first time Tissue Doppler Imaging (TDI), to identify which phase of the cardiac cycle is involved.

METHODS

TDI was performed in 175 aging subjects, free of cardiovascular and/or respiratory disease (group II), and in 182 healthy adults enrolled as the control group (group I), to calculate the Myocardial Performance Index (MPI). The index derives from the values of Isovolumetric Contraction Time (ICT), Isovolumetric Relaxation Time (IRT) and Left Ventricular Ejection Time (LVET) measured in ms, according to the formula: (ICT+IRT)/LVET.

RESULTS

An increase in MPI in group II was shown, with significant lengthening of IRT in comparison with the same value obtained in the control group (group I), ICT and LVET were unchanged.

CONCLUSIONS

The rise in IRT in the aging healthy heart is dependent on diastolic LV dysfunction consequent upon the formation of Advanced Glycosilation End-product (AGE) crosslinks with connectival proteins of interstitial myocardial tissue. Agerelated increase in oxidative stress also modifies some interstitial compounds, favoring hardening of ventricular walls. These changes are similar to those happening in the diabetic heart, and TDI seems to be able to define non-invasively which phase of the cardiac cycle is impaired.

Myocardial and aortic stiffening in the early course of primary aldosteronism

BACKGROUND

Primary aldosteronism (PA) has been experimentally and clinically linked to myocardial and vascular fibrosis, and it has been further associated with left ventricular (LV) structural adaptations.

HYPOTHESIS

Functional cardiovascular adaptations in hypertensive patients with PA precede structural alterations in the early stages of the disease.

METHODS

We studied 17 hypertensive subjects with a recent diagnosis of PA (10 male patients, aged approximately 55 y, with office blood pressure [BP] of 137/88 mm Hg), and 30 essential hypertensives matched for age, sex, office BP levels, treatment status, and LV mass index (LVMI). Apart from standard 2-Dimensional (2-D) and conventional Doppler parameters, tissue Doppler imaging (TDI) methodology was used to assess LV diastolic function; averaging early and late diastolic mitral annular peak velocities (Emav/, Amav, Emav/Amav ratio) from 4 separate sites of measurement (septal, lateral, anterior, and inferior walls). Aortic stiffness was evaluated by means of carotid-femoral pulse wave velocity (cf-PWV) measurements.

RESULTS

Although transmitral E/A ratio was similar in both groups (0.95+/-0.26 versus 0.98+/-0.24, p=0.66), hypertensive subjects with PA compared with essential hypertensives are characterized by significantly higher relative wall thickness (0.50+/-0.07 versus 0.41+/-0.06, p<or=0.001), decreased values of Emav (7+/-1.7 versus 8.1+/-1.8 cm/s, p=0.048), and Emav/Amav ratio (0.63+/-0.16 versus 0.77+/-0.17, p=0.015). The higher PWV in the PA population failed to reach statistical significance (8.5+/-1.6 versus 7.9+/-0.9 msec, p=0.19).

CONCLUSION

Our study demonstrates altered LV geometry and TDI-revealed diastolic dysfunction in hypertensives with PA compared with demographically- and LVMI-matched essential hypertensives. Furthermore, the increased aortic stiffening in PA patients failed to reach statistical significance.

Advances in the cardiovascular assessment of patients with chronic kidney disease

Cardiovascular mortality is grossly elevated in patients with chronic kidney disease (CKD), and is associated with a wide variety of structural and functional abnormalities. These issues have driven additional attempts to further characterise these abnormalities to elucidate the pathophysiology involved, assess individual risk and/or target and monitor therapies specifically directed at the cardiovascular (CV) system. This review aims to assess the techniques that are currently available for the study of the CV system. This includes conventional assessments of the whole CV system from heart to peripheral microcirculation (although not deal with VC assessment), as well as the key functional consequences relating to stress induced cardiovascular reserve, perfusion and vasoregulation. In addition this review will introduce a variety of techniques aiming to expand the envelope of conventional measurements.

New Echocardiographic Techniques for Evaluating Left Ventricular Myocardial Function

Ultrasound imaging of the heart continues to play an important role in diagnosis and management of patients with cardiovascular diseases. Recent advances in ultrasound technology and introduction of newer imaging modalities have enabled improved assessment of left ventricular myocardial function. Tissue Doppler imaging and 2-dimensional speckle tracking allow more objective quantification of myocardial function in the form of tissue velocities, displacement, strain, and strain rate. Similarly, contrast-enhanced echocardiography and 3-dimensional echocardiography have provided a unique insight into left ventricular form and function that was not possible by unenhanced 2-dimensional echocardiography. In this review, the authors discuss the clinical application of these new imaging techniques in the assessment of left ventricular myocardial function.

Usefulness of systolic time intervals in the identification of abnormal ventriculo-arterial coupling in stable heart failure patients

BACKGROUND

The ratio of effective arterial elastance (Ea) to ventricular end-systolic elastance (Ees) indicates the status of ventriculo-arterial coupling.

AIMS

We investigated if systolic time intervals (pre-ejection period, PEP; ejection time, ET; and their ratio, PEP/ET) can be used to identify heart failure patients with abnormal ventriculo-arterial coupling.

METHODS

Age and sex-matched study subjects included 54 apparently healthy subjects with normal left ventricular (LV) function, and stable patients with LV diastolic (n=54) and systolic dysfunction (n=54). Ees and Ea were estimated non-invasively by echocardiography, and abnormal ventriculo-arterial coupling was defined as Ea/Ees>1.2. PEP, ET, and PEP/ET were measured automatically using electrocardiography, phonocardiography, and brachial pulse volume recording.

RESULTS

Ea/Ees>1.2 was present in 48.1% of subjects with systolic dysfunction. The PEP/ET was significantly associated with most parameters of LV structure and function, and Ea/Ees (r=0.67, p<0.001). Using PEP/ET> or =0.423 as cut point, the sensitivity and specificity to identify patients with Ea/Ees>1.2 were 85.7% and 84.3%, respectively for the whole population, and 84.6% and 78.6%, for patients with systolic dysfunction.

CONCLUSION

Abnormal ventriculo-arterial coupling was present in almost half of stable patients with systolic dysfunction. PEP/ET was useful in identifying such patients.

Prognostic value of pulse-wave tissue Doppler parameters in patients with systolic heart failure

The aim was to study the prognostic value of left ventricular (LV) function using pulse-wave tissue Doppler imaging (TDI) in an ordinary population with heart failure (HF). One hundred fifty-six patients hospitalized for HF and LV ejection fraction < or =40% were examined using conventional echocardiography and pulse-wave TDI for the assessment of longitudinal LV function. Mitral annular systolic and early diastolic (e') velocities were recorded from a mean of 4 annular sites from the apical 2- and 4-chamber views. Noninvasive LV filling pressure was calculated from the ratio between transmitral early inflow velocity (E) and e'. All patients were followed up for 2 years, and data from the National Registry of Deaths were collected. Mean LV ejection fraction was 24.7 +/- 7.2%. TDI recordings showed a mean mitral annular systolic velocity of 5.0 +/- 1.0 cm/s and e' velocity of 6.2 +/- 1.9 cm/s. E/e' ratio was 14.1 +/- 4.8. Thirty patients (19%) had atrial fibrillation. During follow-up, 27 patients (17%) died of a cardiovascular cause. Multivariate analysis showed that only E/e' ratio and age were predictors of cardiovascular mortality. A cut-off value for E/e' ratio >13 had sensitivity of 84% and specificity of 45% to identify patients who died within 2 years of cardiac reasons. In conclusion, in the acute stage of HF, E/e' ratio is a strong independent predictor of long-term cardiovascular mortality in an ordinary population with HF and systolic dysfunction. Systolic and diastolic velocities had no independent prognostic value.

Left ventricular diastolic function evaluated with tissue Doppler imaging in children with familial Mediterranean fever

The aim of this study was to assess the left ventricular diastolic function using conventional echocardiography and tissue Doppler imaging in children with familial Mediterranean fever. This study included 29 (13 males and 16 females) patients and 30 healthy subjects as controls. Body mass index was calculated and arterial blood pressure was monitored. After an overnight fast, venous blood samples were taken and serum amyloid A protein, C-reactive protein, serum-fasting glucose, total cholesterol, triglycerides, high-density lipoprotein cholesterol, very low density lipoprotein cholesterol, and serum low-density lipoprotein cholesterol levels were measured. A complete 2-dimensional, M-mode, pulse wave Doppler, and pulse wave tissue Doppler echocardiographic examination was performed. There were no significant differences between the groups regarding age, body mass index values, systolic and diastolic blood pressures, heart rates, serum-fasting glucose, total cholesterol, triglycerides, high-density lipoprotein cholesterol, very low density lipoprotein cholesterol, and serum low-density lipoprotein cholesterol. Serum levels of inflammatory markers were higher in patients' group (C-reactive protein and serum amyloid A protein levels were 10.84 mg/dl, 22.32 mg/l in patients' group, respectively, and 4.11 mg/dl, 3.65 mg/l, respectively, in the healthy controls.) Peak mitral A wave, E and A wave ratio differed significantly in both groups. There were statistically significant differences regarding parameters observed by tissue Doppler imaging such as E'm, A'm, E'm, and A'm ratio between patients' group and controls. Tissue Doppler imaging provided additional information on left ventricular diastolic function. While systolic functions were in normal range, some of the diastolic function parameters were impaired in patients with familial Mediterranean fever during childhood.

Impact of statin therapy on left ventricular function and carotid arterial stiffness in patients with hypercholesterolemia

BACKGROUND

Hypercholesterolemia is a well-established risk factor for the development of vascular events. Statins have pleiotropic effects beyond reducing the low-density lipoprotein-cholesterol (LDL-C) concentration. This study sought to determine whether treatment with pitavastatin affects latent regional left ventricular (LV) systolic and diastolic dysfunction and carotid arterial stiffness in patients with hypercholesterolemia and preserved LV ejection fraction (LVEF), using newly developed ultrasonic strain imaging and carotid ultrasonography.

METHODS AND RESULTS

A total of 30 patients with hypercholesterolemia (>or=220 mg/dl for serum total cholesterol, and/or >or=140 mg/dl for LDL-C) were randomized to either administration of pitavastatin (1 or 2 mg/day; n=15) or no statin therapy (n=15) for 12 months. LV systolic and diastolic functions were evaluated by measuring transmitral flow velocity, mitral annular motion velocity, and the myocardial strain and strain rate profiles using pulsed Doppler, tissue velocity, and ultrasonic strain imaging. Subclinical atherosclerosis also was determined by measuring the intima - media thickness (IMT) and stiffness beta of the left and right common carotid arteries using B- and M-mode ultrasonography. During the follow-up period, the mean peak systolic strains of the LV posterior and inferior walls increased from 39.2+/-15.9% to 51.5+/-17.7% (p<0.01) and 46.0+/-12.2% to 57.5+/-10.3% (p<0.01), respectively, in the pitavastatin group compared with the no statin group. The mean peak early diastolic strain rates of the LV posterior and inferior walls also increased from -6.5+/-2.9 s(-1) to -9.5+/-2.8 s(-1) (p<0.01) and -6.5+/-2.5 s(-1) to -9.1+/-2.7 s(-1) (p<0.01), respectively, in the pitavastatin group. The stiffness beta decreased from 5.6+/-2.5 to 4.1+/-0.8 (p<0.05) in the pitavastatin group, whereas there was no significant change in IMT.

CONCLUSIONS

One year of pitavastatin treatment improved not only carotid arterial stiffness but also regional LV systolic and diastolic function in patients with hypercholesterolemia and preserved LVEF. Ultrasonic strain imaging has the potential to become a sensitive tool for detecting the effects of early medical intervention on latent regional LV myocardial dysfunction in this patient population.

Tissue Doppler-derived diastolic myocardial velocities are abnormal in pediatric cardiac transplant recipients in the absence of endomyocardial rejection

The aim of this study was to evaluate diastolic function in pediatric cardiac transplant recipients free of acute rejection using tissue Doppler. E' and A' velocities at the mitral, septal, and tricuspid annuli in 31 pediatric heart transplant recipients free of acute rejection were compared with 28 controls and with previously published pediatric normative data. E' velocities were lower in the transplant group at the mitral (0.13 +/- 0.04 vs. 0.2 +/- 0.04 m/s, p < 0.0001), septal (0.1 +/- 0.03 vs. 0.14 +/- 0.03 m/s, p = 0.001), and tricuspid annuli (0.1 +/- 0.04 vs. 0.17 +/- 0.04 m/s, p < 0.0001). A' velocities were also lower in the transplant group at the septal (0.04 +/- 0.01 vs. 0.06 +/- 0.01 m/s, p = 0.001) and tricuspid annuli (0.06 +/- 0.02 vs. 0.1 +/- 0.03 m/s, p < 0.00001). E' and A' were abnormally low at the mitral annulus in 31% and 13%, septal annulus in 50% and 21%, and tricuspid annulus in 63% and 36% of the subjects, respectively. Abnormalities in tissue Doppler-derived diastolic myocardial velocities are common in pediatric cardiac transplant recipients free of acute rejection.

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.

Impact of myocardial geometry on left ventricular performance in healthy black and white young adults

Racial differences in left ventricular (LV) structure are suggested by clinical and experimental studies. This study evaluates if racial differences in LV performance exist comparing black to white young males, by tissue Doppler echocardiography and myocardial performance index (MPI). We examined 40 healthy males, 20 blacks (mean age 27.6 +/- 4.4 years) and 20 whites (mean age 26.5 +/- 6.7 years). All subjects underwent conventional echocardiography, tissue Doppler echocardiography, and MPI assessment. No differences were found in LV diameters, volumes, mass, and hemodynamic measurements. Septal and posterior wall thicknesses were significantly increased in black subjects as well as the relative wall thickness. Systolic and diastolic functions estimated by conventional parameters were superimposable in the two groups. In black subjects, a significant increase of septal S-wave, peak velocity, and time-velocity integral were found. MPI was significantly higher in black compared to white subjects (0.46 +/- 0.05 vs 0.40 +/- 0.06, P < 0.002). A significant correlation between MPI and relative wall thickness (r = 0.54) was demonstrated. Besides, MPI correlated with S(pv) (r = 0.55) and S(tvi) (r = 0.38) at the septal site. In conclusion our data show a higher MPI in black subjects that seems to be geometry-dependent. Correlations between MPI and tissue Doppler echocardiography systolic indexes were found. Our findings suggest that racial differences in LV performance exist, especially, in the systolic function, even in the absence of other conventional echocardiographic changes.

Left ventricular filling pressure by Doppler echocardiography in patients with end-stage renal disease

Left ventricular hypertrophy and systolic dysfunction predict mortality in patients with end-stage renal disease. However, the prognostic value of left ventricular filling pressure has remained uncertain in this population. We evaluated whether the early mitral inflow velocity to peak mitral annulus velocity (E/Em) ratio, an estimate of left ventricular filling pressure by tissue Doppler imaging, has significant additional prognostic value to conventional echocardiographic parameters and other clinical and biochemical parameters in 220 patients with end-stage renal disease. The E/Em ratio was elevated (>15) in 62% of the patients. Multivariate analysis showed that an elevated E/Em ratio had the highest correlation with left ventricular volume index, followed by loss of residual glomerular filtration rate, increasing age, worsening ejection fraction, and diabetes. During the median follow-up of 48 months, the E/Em ratio emerged as an independent predictor of all-cause mortality (adjusted hazard ratio: 1.027; 95% CI: 1.003 to 1.051; P=0.026) and cardiovascular death (adjusted hazard ratio: 1.033; 95% CI: 1.002 to 1.065; P=0.035) in the multivariable Cox regression analysis. In addition, the E/Em ratio added significant incremental prognostic value for all-cause mortality (P=0.035) and cardiovascular death (P=0.035) beyond the standard clinical, biochemical, and dialysis parameters and echocardiographic measurements. In conclusion, the E/Em ratio displayed important additional long-term prognostic information above and beyond that of left ventricular mass and systolic function. Our data suggest that left ventricular filling pressure should be estimated during echocardiographic examination for additional prognostication in patients with end-stage renal disease.

Myocardial Radial Strain in Early Diastole is Useful for Assessing Left Ventricular Early Diastolic Function: Comparison with Invasive Parameters

BACKGROUND

Peak myocardial systolic strain determined using myocardial strain imaging is a useful index of left ventricular (LV) myocardial systolic function. We investigated the relationship between peak myocardial radial strain during early diastole and LV early diastolic function.

METHODS

A total of 85 patients without localized LV wall-motion abnormality underwent myocardial strain imaging and diagnostic cardiac catheterization. Peak myocardial radial strain during early diastole was obtained at the LV posterior-sided wall in the short-axis image. Invasive parameters of LV function were determined during cardiac catheterization.

RESULTS

Peak myocardial radial strain during early diastole significantly correlated with both the time constant tau (r = 0.80, P < .0001) and the peak negative dP/dt (r = -0.64, P < .0001). Although it correlated with the LV ejection fraction, LV end-diastolic pressure, LV end-systolic volume index, and mean pulmonary capillary wedge pressure, the time constant tau was the prime determinant of peak myocardial radial strain during early diastole.

CONCLUSION

Peak myocardial radial strain during early diastole could be used to evaluate LV early diastolic function. Myocardial strain imaging is a promising noninvasive tool for assessing LV function in systole and early diastole.

Progressive diastolic dysfunction in the female mRen(2). Lewis rat: influence of salt and ovarian hormones

This study determined the contribution of chronic salt loading and early loss of ovarian hormones on diastolic function in the hypertensive female mRen(2). Lewis rat, a monogenetic strain that expresses the mouse renin-2 gene in various tissues. Estrogen-intact mRen2 rats fed a high salt (HS) (8% sodium chloride) diet exhibited early diastolic dysfunction when compared to normal salt-fed (NS) (1% sodium chloride) rats. In contrast, ovariectomized (OVX) rats on either NS or HS diets showed impaired relaxation with evidence of elevated left ventricular filling pressures (E/e') or pseudonormalization. This more advanced stage of diastolic dysfunction was associated with increases in interstitial cardiac fibrosis and high circulating levels of aldosterone, two factors leading to reduced ventricular compliance. These findings may explain the preponderance of diastolic dysfunction and diastolic heart failure in postmenopausal women and provide a potential animal model for evaluating prevention and treatment interventions for this disorder.

Atrium-driven Mitral Annulus Motion Velocity Reflects Global Left Ventricular Function and Pulmonary Congestion During Acute Biventricular Pacing

BACKGROUND

The short-term effect of acute biventricular pacing on cardiac function in patients with chronic heart failure undergoing heart surgery is widely unknown. The present study was designed to determine whether mitral annular tissue Doppler imaging (TDI) is useful to predict acute changes in global systolic function determined by the continuous cardiac output method that was measured postoperatively during various pacing configurations in patients with depressed left ventricular (LV) function.

METHODS

TDI peak velocities of systolic (Sm), early diastolic (Em), and late diastolic (Am) mitral annular motion waves were measured in 17 patients (age 67 +/- 8 years, 10 male) with depressed LV systolic function (LV ejection fraction < or = 35%) and QRS duration > 120 ms undergoing temporary epicardial biventricular pacing after aortocoronary bypass and valve surgery. TDI velocities, QRS duration on surface electrocardiogram, cardiac index (CI), right atrial pressure, pulmonary artery pressure, and pulmonary capillary wedge (PCW) pressure were measured simultaneously during various pacing configurations (right atrial-biventricular, right atrial-LV, right atrial-right ventricular, atrial inhibited, and no pacing).

RESULTS

Univariate linear regression analysis showed a good correlation between Am and CI (r = 0.53, P = .0001) determined in all pacing modes, a weak correlation between Sm and CI (r = 0.31, P = .017), and no correlation between Em and CI (r = 0.21, P = .074). Am > 6 cm/s predicted a CI of 2.5 L/min/m(2) or more with a sensitivity of 95% and a specificity of 30%. All TDI values correlated negatively with PCW (r = -0.53, P = .0001 for Sm; r = -0.34, P = .01 for Em; r = -0.50, P = .0001 for Am). Am greater than 6 cm/s predicted a PCW of 16 mm Hg or less with a specificity of 100% and a sensitivity of 34%. Mean values of TDI velocities and hemodynamic parameters were not significantly different between each pacing configuration.

CONCLUSIONS

Peak Am mitral annular velocity correlates well with CI and PCW, respectively, thus providing an easy means to assess LV systolic function and pulmonary congestion during cardiac pacing in chronic heart failure.

Contribution of the Pericardium to Left Ventricular Torsion and Regional Myocardial Function in Patients with Total Absence of the Left Pericardium

OBJECTIVE

The relationship between left ventricular (LV) torsional deformation and myocardial function has recently been recognized. However, little is known about whether the pericardium affects this relationship. Our aim was to identify the contribution of the pericardium to LV torsion and regional myocardial function in the clinical setting.

METHODS

We examined LV torsion in basal and apical LV short-axis views, and regional LV myocardial function, such as longitudinal strain in apical 4-chamber view, and circumferential and radial strains in parasternal LV short-axis views using 2-dimensional speckle-tracking imaging method in 5 patients with congenital total absence of the left pericardium and systolic paradoxical ventricular septal motion on M-mode echocardiogram and in 10 control subjects. Diagnosis of the pericardial defect was based on chest radiograph, computed tomography, jugular phlebogram, and M-mode and 2-dimensional echocardiogram. LV torsion was defined as the net difference in LV rotation in the basal and apical planes.

RESULTS

There was no significant difference in LV ejection fraction determined by 2-dimensional echocardiography between the pericardial defect and control groups. LV torsion was markedly decreased in the pericardial defect group compared with the control group. There were no significant differences in longitudinal, radial, and circumferential systolic strains and systolic and early diastolic strain rates in the LV walls and in longitudinal systolic strains and systolic and early diastolic strain rates in the left atrial walls between the two groups.

CONCLUSIONS

Pericardial defects cause a lack of LV torsion while maintaining LV regional myocardial function in patients with systolic paradoxical ventricular septal motion. Therefore, pericardium plays an important role in LV torsion.

Physical activity, height, and left atrial size are independent risk factors for lone atrial fibrillation in middle-aged healthy individuals

AIMS

The aetiology of atrial fibrillation (AF) remains unknown in some patients. The aim of the study was to identify new risk factors for developing lone AF (LAF).

METHODS AND RESULTS

A series of 107 consecutive patients younger than 65, seen in the emergency room for an episode of LAF of <48 h duration were included in the study. A group of 107 healthy volunteers matched for age and sex were recruited as controls. All subjects answered a validated questionnaire concerning leisure and occupational activities performed throughout their lifetimes to estimate accumulated hours of physical effort, classified in four levels of intensity. Demographic and echocardiographic measurements were also recorded. There were 69% of males and mean age was 48 +/- 11 years. AF was paroxysmal in 57% and persistent in the remaining 43%. Patients with AF performed more hours of both moderate and heavy intensity physical activity. They also were taller, and had a larger left atria, ventricle, and body surface area. At the multivariable analysis, only moderate and heavy physical activity, height, and anteroposterior atrial diameter were independently associated with LAF.

CONCLUSIONS

Accumulated lifetime physical activity, height, and left atrial size are risk factors for LAF in healthy middle-aged individuals.

The relationship between tissue Doppler imaging and seric NTproBNP levels in sinus rhythm patients: a prospective study

N-terminal pro-brain natriuretic peptide (NTproBNP) correlates with left ventricular (LV) filling pressure. The ratio between early diastolic transmitral velocity and early mitral annular diastolic velocity (E/Ea) reflects LV filling pressure in a variety of cardiac diseases. However this relationship was not validated in some categories of patients. Our aim was to evaluate the correlation between tissue Doppler velocities of the mitral annulus and NTproBNP levels in sinus rhythm patients.

METHODS

Echocardiography was performed in 111 consecutive patients simultaneously with NTproBNP measurement. E/Ea and E/(Ea x Sa) were calculated (Sa is the maximal systolic velocity of mitral annulus); the average of the velocities of septal and lateral mitral annulus was used.

RESULTS

Simple regression analysis demonstrated a significant linear correlation between E/(Ea x Sa) and NTproBNP (r = 0.71, P < 0.0001), superior to E/Ea correlation (r = 0.58, P < 0.0001). Significant but weaker correlations were found between NTproBNP and Sa, pulmonary artery systolic pressure, Ea, mitral E/A (early/late diastolic transmitral velocity), E wave, mitral E deceleration time and LV ejection fraction (LVEF). The optimal E/(Ea x Sa) cut-off for prediction of NTproBNP levels > 900 pg/ml was 1.5 (sensitivity = 81%, specificity = 70%). Among analyzed parameters, E/(Ea x Sa) was best correlated with NTproBNP levels in patients with LVEF >or= 50% (r = 0.80, P < 0.0001), with depressed LVEF (<50%) (r = 0.66, P < 0.0001), with regional wall motion abnormalities (r = 0.75, P < 0.0001), and with E/Ea 8 to 15 (r = 0.58, P < 0.0001).

CONCLUSIONS

E/(Ea x Sa) strongly correlates with NTproBNP, regardless of LVEF, and can be a simple and accurate echocardiographic index in patients in sinus rhythm, particularly in those with regional wall motion abnormalities or intermediate E/Ea.

The assessment of cardiac functions by tissue Doppler-derived myocardial performance index in patients with Behcet’s disease

Vascular involvement is one of the major characteristics of Behcet's disease (BD). However, there are controversial findings regarding cardiac involvement in BD. Although early reports demonstrated that there is diastolic dysfunction in BD, conflicting results were found in the following trials. Hence, a new method for more objectively estimating the cardiac functions is needed. For this aim, we used high-usefulness tissue Doppler echocardiography for detailed analysis of cardiac changes in BD patients because this method was superior to other conventional echocardiographic techniques. The study population included 42 patients with BD (19 men, 23 women; mean age, 35 +/- 10 years, mean disease duration, 2.7 +/- 1.6 years) and 30 healthy subjects (14 men, 16 women; mean age, 38 +/- 7 years). Cardiac functions were determined using echocardiography, comprising standard two-dimensional and conventional Doppler and tissue Doppler imaging (TDI). Peak systolic myocardial velocity at mitral annulus, early diastolic mitral annular velocity (Em), late diastolic mitral annular velocity (Am), Em/Am, and myocardial performance index (MPI) were calculated by TDI. The conventional echocardiographic parameters and tissue Doppler measurements were similar between the groups. Tissue Doppler derived mitral relaxation time was longer (75 +/- 13 vs 63 +/- 16 msn, p = 0.021) in patients with BD. There was statistically significant difference between the two groups regarding left ventricular MPI (0.458 +/- 0.072 vs 0.416 +/- 0.068%, p = 0.016), which were calculated from tissue Doppler systolic time intervals. There was also significant correlation between the disease duration and MPI (r = 0.38, p = 0.017). We have demonstrated that tissue Doppler-derived myocardial left ventricular relaxation time and MPI were impaired in BD patients, although systolic and diastolic function parameters were comparable in the patients and controls.

The detailed assessment of left and right ventricular functions by tissue Doppler imaging in patients with familial Mediterranean fever

In the contrary to other rheumatologic disorders, there have been limited numbers of studies investigating the cardiac involvement in patients with familial Mediterranean fever (FMF), although the disease may carry a potential for cardiovascular disorders because of sustained inflammation during its course. In the present study, we used high usefulness tissue Doppler echocardiography for detailed analysis of cardiac changes in FMF patients. The study population included 30 patients with FMF (11 men, 19 women; mean age, 35 +/- 7 years, mean disease duration, 15.4 +/- 7.6 years) and 30 healthy subjects as controls (12 men, 18 women; mean age, 33 +/- 7 years). The diagnosis of FMF was established according to the Tell-Hashomer criteria. Left and right ventricular functions were measured using echocardiography comprising standard two-dimensional, M-mode, and conventional Doppler as well as tissue Doppler imaging. The conventional echocardiographic paratemeters were similar apart from left ventricular relaxation time was longer (107 +/- 25 vs 85 +/- 10 ms, p < 0.001, respectively) in patients with FMF. According to the tissue Doppler measurements, while systolic velocities of both ventricles were not different, diastolic filling velocities of left ventricle including E'(m) (12.6 +/- 3.4 vs 14.7 +/- 3.3 cm/s, p = 0.04), A'(m) (10.1 +/- 2.6 vs 8.6 +/- 2.0 cm/s, p = 0.015), and E'(m)/ A'(m) (1.24 +/- 0.4 vs 1.71 +/- 0.5 cm/s, p = 0.012) values were statistically different between the groups. Left ventricular myocardial performance indices and right ventricular diastolic functions were found similar between two groups. In addition, there were no significant correlations between the disease duration, clinical features, and echocardiographic parameters. In conclusion, we have demonstrated that although systolic functions were comparable in the patients and controls, left ventricular diastolic function indices were impaired in FMF patients by using tissue Doppler analysis.

Lymphatic vessels transition to state of summation above a critical contraction frequency

Although behavior of lymphatic vessels is analogous to that of ventricles, which completely relax between contractions, and blood vessels, which maintain a tonic constriction, the mixture of contractile properties can yield behavior unique to lymphatic vessels. In particular, because of their limited refractory period and slow rate of relaxation, lymphatic vessels lack the contractile properties that minimize summation in ventricles. We, therefore, hypothesized that lymphatic vessels transition to a state of summation when lymphatic vessel contraction frequency exceeds a critical value. We used an isovolumic, controlled-flow preparation to compare the time required for full relaxation with the time available to relax during diastole. We measured transmural pressure and diameter on segments of spontaneously contracting bovine mesenteric lymphatic vessels during 10 isovolumic volume steps. We found that beat-to-beat period (frequency−1) decreased with increases in diameter and that total contraction time was constant or slightly increased with diameter. We further found that the convergence of beat-to-beat period and contraction cycle duration predicted a critical transition value, beyond which the vessel does not have time to fully relax. This incomplete relaxation and resulting mechanical summation significantly increase active tension in diastole. Because this transition occurs within a physiological range, contraction summation may represent a fundamental feature of lymphatic vessel function.

Predictive Value of Associations Between Carotid Arterial Sclerosis and Left Ventricular Diastolic Dysfunction in Patients with Cardiovascular Risk Factors

It is well known that arterial stiffness affects the morbidity and mortality associated with cardiovascular disease. However, there are limited data addressing the relationship between arterial stiffness and left ventricular (LV) diastolic function in patients with cardiovascular risk factors. Subclinical atherosclerosis was determined by measuring the intima-media thickness and stiffness (beta) of the left and right common carotid arteries using B- and M-mode ultrasonography in 30 patients with one or more cardiovascular risk factors. LV systolic and diastolic function were also determined by measuring transmitral flow velocity, mitral annular motion velocity, and myocardial strain and strain rate profiles using pulsed Doppler, tissue velocity, and ultrasonic strain imaging. The carotid stiffness beta was greater and the peak early diastolic strain rates of the LV posterior and inferior walls were lower in these patients than in the age-matched control group. The carotid intima-media thickness correlated only with body mass index and LV wall thickness. The carotid stiffness beta correlated with age, peak early diastolic velocity and deceleration time of the transmitral flow, peak early diastolic mitral annular motion velocity, and peak early diastolic strain rates of the LV walls. Multiple linear regression analysis revealed that early diastolic strain rates of the LV walls are strongly related to carotid stiffness beta. In conclusion, LV relaxation is significantly associated with carotid arterial atherosclerosis, particularly sclerosis, in patients with cardiovascular risk factors. These results support the importance of screening using ultrasonic strain imaging and early intervention in this patient population.

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.

Evaluation of hypertensive cardiac abnormalities using the Cornell product

BACKGROUND

The Cornell product (CP) improved identification of left ventricular hypertrophy (LVH) in the LIFE study, although its clinical significance is still unknown in Japanese hypertensive (HT) patients.

METHODS AND RESULTS

A standard 12-lead ECG was recorded in 265 HT and 363 normotensive cases (N). All ECGs were digitized, and a simple product was calculated by multiplying the Cornell voltage (CV) by the QRS duration. In 147 of the 265 HT cases, the standard 12-lead ECG and transthoracic Doppler echocardiography were examined in the same period. The mean value of CP increased in the following order: 1,426+/-673 mm x ms in N, 1,989+/-900 mm x ms in HT with treatment, 2,137+/-976 mm x ms in HT without treatment. The correlation with left ventricular mass index (LVMI) measured by echocardiography was improved by CP with the simple CV. With use of a partition of 2,440 mm x ms in CP, LVMI and relative wall thickness were significantly higher in HT with > or =2,440 mm x ms of CP compared with <2,440 mm x ms. Early diastolic wave in tissue Doppler imaging was significantly lower in HT with > or =2,440 mm x ms of CP compared with <2,440 mm x ms.

CONCLUSION

The Cornell product is a useful ECG marker, reflecting not only left ventricular (LV) mass but also LV geometry and diastolic function in Japanese HT patients.