Ultrasonic tissue characterization and Doppler tissue imaging in the analysis of left ventricular function in essential arterial hypertension: a preliminary study

S, A.K. A, A.K. D, Garg B, Goel A. Impact of prehypertension on left ventricular structure, function and geometry

BACKGROUND

Awareness of prevalence, determinants, and prognosis of asymptomatic untreated prehypertension is still lacking especially in India and subcontinent. The present study was to assess the effects of prehypertension on structure, function and geometrical pattern of left ventricle on the basis of left ventricular mass (LVM), left ventricular mass indexed to height (LVMI/Ht), and relative wall thickness (RWT) recorded by echocardiography based on the American society of echocardiography (ASE) convention.

METHODS

The study population included prehypertensives (n 61; 31 M, 30 F) and normotensives (n 38; 19 M, 19 F) between age 25 and 65 years, and were assessed by echocardiography.

RESULTS

It was observed that the stroke volume (SV), cardiac output (CO), cardiac index (CI), body mass index (BMI), body surface area (BSA), were found to be little elevated but was not significant in hypertensive females compared to normotensives. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), pulse pressure (PP), mean arterial pressure (MAP), end systolic stress (ESS), and end isovolumetric systolic stress (EISS) were significantly elevated (p<0.001) in female prehypertensives compared to normotensives. Left ventricular mass (LVM) was significantly (p< 0.05) elevated, indicating alterations in cardiac morphology and functions even during prehypertensive stage. However, in prehypertensive males, SBP, DBP, HR, PP, MAP, ESS, and EISS were significantly (<0.001) raised; ejection fraction (EF%) and fractional fibre shortening (FS%) were noted to be within normal range in both sexes. Prehypertensive males showed changes in left ventricular geometry in the form of concentric remodeling (CR-3.44%), eccentric hypertrophy (EH-3.44%) and concentric hypertrophy (CH-13.79%). Prehypertensive females showed (CR-6.45%), (EH-3.22%) and (CH-6.4%).

CONCLUSION

Such findings carry prognostic implication and require further population survey involving a larger group. Early diagnosis of prehypertension will help to take necessary preventive measures to reduce mainly the future cardiovascular complications. The care of prehypertensive subjects should include, to reduce the afterload in order to improve the left ventricular contractile state as early as possible. So it is advisable to do routine echocardiography after the age of 40 years.

Pulsed tissue Doppler imaging of the left ventricular septal mitral annulus in healthy dogs

This study evaluated pulsed TDI variables including the isovolumic time interval and duration of the major wave in a population of large healthy dogs. Longitudinal myocardial motion at the septal mitral annulus was evaluated with pulsed TDI in 45 healthy adult dogs. Maximal myocardial velocities, isovolumic time intervals, and duration of the myocardial waves were measured. The correlation between time intervals and velocity variables was also investigated. The mean maximal systolic velocity was 6.92 ± 1.78 cm/sec, the mean early diastolic velocity (Em) was 6.58 ± 1.81 cm/sec, the mean late diastolic velocity (Am) was 5.10 ± 2.00 cm/sec, the mean isovolumic contraction time (IVCT) was 53.61 ± 95.13 msec, and the mean isovolumic relaxation time (IVRT) was 26.74 ± 57.24 msec. The early diastolic mitral inflow velocity (E)/Em ratio was 10.94 ± 3.27 while the Em/Am ratio was 1.40 ± 0.40. There was a negative correlation between Am duration and Am amplitude, and a positive correlation between the IVRT and Em/Am ratio (p < 0.05). The normal LV parameter using pulsed TDI method could be used as the reference range for identifying myocardial dysfunction in dogs.

Early left ventricular mechanics abnormalities in prehypertension: a two-dimensional strain echocardiography study

BACKGROUND

Prehypertension predicts established hypertension. In this study, the aim was to analyze left ventricular (LV) mechanics in borderline prehypertensive (pre-HT) and hypertensive (HT) subjects through two-dimensional (2D)-strain echocardiography and then evaluate possible relations between cardiac parameters and insulin metabolism (homeostasis model assessment of insulin resistance (HOMA(IR)).

METHODS

Seventy-four consecutive newly diagnosed, untreated HT were divided, on the basis of their office blood pressure (BP) measurements, confirmed by ambulatory BP monitoring (ABPM), in 41 borderline pre-HT (ABPM: 122.5 +/- 6.7/76.2 +/- 5.2 mm Hg) and 33 never-treated mild HT (ABPM: 138.3 +/- 7.3/87.6 +/- 7.1 mm Hg). Thirty-three healthy normotensive (NT) controls (ABPM: 114.8 +/- 6.3/73.1 +/- 6.1 mm Hg) (P < 0.0001) were also studied (NT). All subjects performed 2D color Doppler and pulsed-wave tissue Doppler imaging (PW-TDI).

RESULTS

Left ventricular mass (LVM) was significantly higher in pre-HT (39.2 +/- 8.7 g/m(2.7)) and in HT (43.6 +/- 8.5 g/m(2.7)) compared with NT (30.9 +/- 7.4 g/m(2.7)) (P < 0.0001). A mild LV diastolic dysfunction was found both with Doppler mitral flow velocity and PW-TDI at mitral annulus level analysis. Longitudinal 2D strain in pre-HT (-18.9% +/- 3.4) and in HT (-18.0% +/- 3.3) was significantly lower than in NT (-23.9% +/- 3.0) (P < 0.002). These LV abnormalities were associated with systolic ABPM, LVM, and HOMA(IR).

CONCLUSIONS

Early abnormalities of LV longitudinal systolic deformation were found both in pre-HT and HT, together with a mild LV diastolic dysfunction. In both groups this early cardiac systolic and diastolic dysfunction is associated to insulin resistance, systolic pressure load, and cardiac remodeling.

Is echo-determined left ventricular geometry associated with ventricular filling and midwall shortening in hypertensive ventricular hypertrophy?

BACKGROUND

The correlation between left ventricular (LV) geometry, mass, diastolic function, and midwall fractional shortening (MFS) in hypertensive patients with left ventricular hypertrophy (LVH) is not well established owing to limited diffusion of MFS evaluation. The aim of the study was to evaluate this correlation in 1887 consecutive hypertensive patients, all affected by LVH (mean age 66 years, 924 males), with LV ejection fraction (LVEF) >45% for early detection of ventricular dysfunction rather than LVEF and diastolic function impairment.

METHODS AND RESULTS

All patients underwent M-B mode echocardiography and PW-Doppler evaluation. LV geometry and mass were compared with Doppler-determined mitral flow and tissue velocities. LV geometry was eccentric (E) for 1018 subjects (53.9%) and concentric (C) for 869 (46.1%). There was no difference concerning LV diastolic dysfunction (P: n.s.) between 576 (30.6%) of the ELVH and 368 (19.4%) of the CLVH patients. The following parameters showed significant statistical differences: LV MFS impairment (P < 0.01) between 86 (4.6%) of the ELVH and 177 (9.4%) of the CLVH patients. LV MFS impairment rate was higher in 171 patients without LV diastolic dysfunction (9.1%), than in 92 patients affected (4.9%, P < 0.02). In CLVH patients, a higher prevalence of LV MFS impairment was observed in 143 without LV diastolic dysfunction (7.6%), than in 34 patients affected (1.8%, P < 0.01). In ELVH patients, a lower prevalence of LV MFS impairment was observed in 28 without diastolic dysfunction (1.5%), than in 58 patients affected (3.1%, P < 0,03).

CONCLUSION

Midwall LV impairment, an independent predictor of cardiac death and morbidity in hypertensive patients, can allow early identification of patients with LV dysfunction even when LVEF or assessment of diastolic function are normal. LV MFS impairment rate is higher in CLVH patients, and even higher when considering only those CLVH patients with no diastolic dysfunction. These results suggest that the ventricular dysfunction with normal LVEF is not always due to diastolic dysfunction, but often to systolic dysfunction as assessed by MFS impairment, an important early sign of ventricular dysfunction in hypertensive patients, even when diastolic function is normal.

Acoustic videodensitometric parameters correlate with abnormalities of left ventricular filling in hypertensive patients assessed via Doppler Tissue Imaging

PURPOSE

Using a videodensitometric technique developed in our center we investigated whether the amplitude of variation of gray levels in the interventricular septum was related to functional parameters, especially ventricular filling as studied by doppler tissue imaging (DTI) in hypertensive patients.

METHODS AND RESULTS

We included 35 hypertensive patients from whom we recorded a two dimensional sequence of the left ventricle from the short axis parasternal view and a doppler tissue scan of the mitral ring. Two-dimensional sections were then analyzed with Iodp software to measure variations in levels of gray in the septum. We observed significant correlations between these variations and the velocity of the Ea wave on DTI of the lateral wall (r = 0.49, p < 0.002). On dividing this population into three sub-groups according to the Appleton classification of ventricular filling, we noted a tendency to a reduction in amplitude of variations of gray of the septum in cases with abnormalities of relaxation. This was even more marked in cases with a restrictive or pseudo-normal profile.

CONCLUSION

These observations point to the interest of sonographic videodensitometry in the evaluation of hypertensive cardiopathy. Further studies will be required to determine whether it can define the extent of the abnormalities of myocardial structure and the degree of fibrosis.

Assessment of the relationship between functional capacity and right ventricular ultrasound tissue characterization by integrated backscatter in patients with isolated mitral stenosis

AIM

The aim of the present study was to investigate right ventricular (RV) myocardial textural properties in asymptomatic and symptomatic mitral stenosis (MS) patients with normal RV systolic function using integrated backscatter (IBS).

METHODS

The study included 40 patients with MS of moderate or severe degree. Patients were classified into 2 groups according to NYHA class (asymptomatic group, NYHA class I, symptomatic group, NYHA class II-III). RV pulsed-wave tissue Doppler imaging (TDI) and IBS analyses were performed in all patients. Isovolumic contraction time (IVCT), systolic wave velocity (S), isovolumic relaxation time (IVRT), early diastolic wave velocity (E), and late diastolic wave velocity (A) were measured by TDI. IBS amplitude (IB) and cyclic variation (CV) of the RV lateral wall in the parasternal long-axis view were measured by IBS. CV was calculated by subtracting systolic IB from diastolic IB.

RESULTS

IVRT (54.2 +/- 11.9 ms versus 86.2 +/- 16.2 ms, P < 0.001) and A wave amplitude (10.2 +/- 2.1 cm/s versus 13.6 +/- 1.8 cm/s, P < 0.05) were higher whereas E wave amplitude (11.7 +/- 1.6 cm/s and 10.3 +/- 1.5 cm/s, P < 0.05) and E/A ratio (1.3 +/- 0.3 versus 0.7 +/- 0.1, P < 0.001) were lower in group 2. Symptomatic patients had a lower CV value of RV (9.5 +/- 3.4 dB versus 6.7 +/- 1.9 dB, P = 0.004). There was a positive correlation between CV and E/A (r = 0.964, P < 0.001)

CONCLUSION

Symptomatic isolated MS patients had RV echo texture changes and diastolic dysfunction in comparison to asymptomatic ones with similar mitral valve areas in the presence of normal RV systolic function. In isolated MS, both pulsed-wave TDI and IBS may aid in the detection of RV diastolic pathology.

Early abnormalities of left ventricular myocardial characteristics associated with subclinical hyperthyroidism

The aim of the present study was to analyze heart function in subclinical hyperthyroidism (sHT) in otherwise healthy subjects by new methods using intramyocardial ultrasonic techniques. Twenty-four newly diagnosed and untreated sHT patients (20 women, 4 men; mean age: 42+/-4 yr) and 24 sex- and age-matched healthy volunteers were studied. All subjects were submitted to conventional 2D color-Doppler echocardiography, pulsed wave tissue Doppler imaging (PWTDI) for the analysis of diastolic function, color Doppler myocardial imaging (CDMI) for the analysis of regional strain and strain rate (SR) expression of regional myocardial deformability, and to integrated backscatter (IBS) for the evaluation of intrinsic contractility and tissue characterization. Regional myocardial systolic strain findings were significantly higher in sHT patients when compared with controls (p<0.001). Considering diastolic SR, the early phase of diastolic SR was compromised in sHT subjects as compared with controls (p<0.001). Cyclic variation index (CVI), expression of intrinsic contractility, was significantly higher in sHT subjects in comparison with controls (p<0.0001). IBS values were comparable between the 2 study groups. In conclusion, the present study suggests that in patients with sHT early systolic hyperdeformability and hypercontractility are present, together with impairment of both active and passive phases of diastole. On the contrary, no left ventricular hypertrophy or other structural alterations are documented.

Myocardial Functional and Textural Findings of the Right and Left Ventricles and Their Association with Cellular Adhesion Molecules in Behçet's Disease

AIM

This study was designed to assess whether ultrasonic reflectivity, evaluated by integrated backscatter analysis was associated with the severity of inflammation and diastolic dysfunction of the left (LV) and right ventricles (RV) in Behçet's disease (BD).

METHODS

The study consisted of 20 patients with BD and 18 healthy controls. The expression of CD11b and CD63 on the surface of granulocytes and monocytes were measured by flow cytometry. RV and LV diastolic functions were assessed by tricuspid and mitral annular tissue Doppler recordings, respectively. Backscatter cyclic variation (CV) and maximal intensity (IB) were measured in RV lateral wall, interventricular septum, and posterior LV wall from parasternal long-axis view, apex from apical four-chamber view, anterior, inferior, and lateral LV walls from parasternal short axis view.

RESULTS

The mean fluorescence intensity (MFI) of CD11b on granulocytes and CD63 on monocytes in BD patients was higher than those of controls. Patients with BD had smaller mitral and tricuspid annular early diastolic wave velocities and early/late diastolic wave velocity ratios (E/A) than controls. MFI of CD11b and CD63 was inversely correlated with tricuspid and mitral annular E/A in BD patients. CV of RV and global CV of LV were found to be diminished in BD patients than controls. CV of RV and global CV of LV showed a direct correlation with tricuspid and mitral annular E/A ratio, respectively.

CONCLUSION

There is an association between the levels of cellular adhesion molecules, deterioration of diastolic function, and altered myocardial ultrasonic reflectivity in BD.

Obesity cardiomyopathy: is it a reality? An ultrasonic tissue characterization study

Obesity is a well-established risk factor for congestive heart failure. Evidence has been provided indicating that insulin resistance could be the mediator between obesity and congestive heart failure, but the pathogenic mechanisms leading to myocardial alterations remain unclear. The aim of this study was to investigate, by ultrasonic integrated backscatter (IBS) analysis, subclinical alterations of left ventricular (LV) structure and function in severe obesity. Sixty consecutive, severely obese people, who were otherwise healthy (15 men, 45 women; mean age +/- SD = 31.8 +/- 7 years), were enrolled. A total of 48 sex- and age-matched nonobese healthy participants were recruited as control subjects. All participants underwent conventional 2-dimensional color Doppler echocardiography, pulsed wave Doppler tissue imaging at mitral annulus level, and IBS. The homeostasis model assessment insulin resistance index was used to assess insulin resistance; the index values in the obese group were significantly higher (mean +/- SD = 4.9 +/- 1.4) than in the control group (0.92 +/- 0.5, P < .0001). Obese patients had a greater LV mass index by height (58.5 +/- 14 g/m(2.7)) than did control subjects (37 +/- 8 g/m(2.7), P < .0001) because of compensation response to volume overload caused by a greater cardiac output (P < .02). Preload reserve was increased in obese patients, as demonstrated by the significant increase in left atrial dimension (P < .0001). This volumetric increase activated the Frank-Starling mechanism, and determined a significantly higher LV ejection fraction (P < .03) in obese patients as compared with control subjects. A slightly reduced LV diastolic function was demonstrated in obese patients (transmitral early to late peak diastolic transmitral flow velocities ratio = 1.1 +/- 0.7) as compared with control subjects (1.5 +/- 0.5, P < .02). Pulsed wave Doppler tissue imaging showed an impairment of diastolic LV longitudinal function and increased LV diastolic filling pressure. The IBS values at septum level, indexed by pericardium interface, were significantly higher for septum in the obese group (57.8 +/- 8%) than in the control group (42.3 +/- 9%, P < .0001). Additional IBS alterations were observed in the obese group, with a significantly lower cyclic variation index both at septum (P < .0001) and at posterior wall (P < .001) levels. A significant association was found between insulin resistance index and both the IBS index of myocardial reflectivity at septum level (expression of increased myocardial collagen content) or LV mass. In conclusion, this study demonstrates that obese patients exhibit myocardial structural and functional alterations related to insulin resistance and to LV volume overload, which could be considered the very early stage of incipient obesity cardiomyopathy.

Myocardial systolic strain abnormalities in patients with acromegaly: a prospective color Doppler imaging study

BACKGROUND

Heart abnormalities are frequent findings in patients with acromegaly: systolic abnormalities are considered to be secondary to diastolic changes.

AIM

The aim of the study was to evaluate whether early systolic abnormalities might be revealed in acromegalic patients using the high sensitive color Doppler myocardial imaging (CDMI) technique.

PATIENTS AND METHODS

Twenty-two consecutive acromegalic patients with active untreated disease (ACROUNTR) were evaluated at baseline and after a 6-month course with SS analogs (SSa) (ACROSSa); 25 healthy subjects served as controls. All subjects underwent conventional 2D-color Doppler echocardiography, pulse wave tissue Doppler imaging (PW-TDI) and CDMI.

RESULTS

Mean left ventricular (LV) ejection fraction did not differ in ACROUNTR and in controls; at variance, ACROUNTR patients had reduced mean LV diastolic function (E/A ratio: 0.96+/-0.3 vs controls: 1.6+/-0.3; p<0.002). Impairment of global LV diastolic function was confirmed by PW-TDI in ACROUNTR patients having a normal systolic function. Regional myocardial systolic strain (epsilon) and strain rate (SR) values, indices of regional systolic heart deformation, were lower in ACROUNTR [epsilonsys (S) -19.8+/-2.9 and epsilonsys (L): -17.7+/-2.2] than in controls [epsilonsys (S): -27.9+/-3.8; p<0.001 and epsilonsys (L): -25.3+/-2.6; p<0.001]. In addition, the early phase of diastolic function, evaluated using SR parameters, was impaired in acromegalic patients (p<0.005 vs controls). Strain and SR values were related to serum GH and IGF-I levels (p<0.02) and greatly improved after a 6-month course with SSa [epsilonsys (S) improved to -23.8+/-3.8 (p<0.05) and epsilonsys (L) improved to -24.7+/-2.4 (p<0.03)].

CONCLUSIONS

Our study confirms that ACROUNTR patients have impaired diastolic function. More important, our study clearly shows that ACROUNTR patients have an impairment of regional myocardial systolic function, which is not secondary to diastolic changes. These intramyocardial functional abnormalities improved during medical treatment of acromegaly. It is conceivable that GH-IGF-I excess has detrimental effects either on the diastolic or the systolic phases of heart function.

Value of tissue Doppler imaging to predict left ventricular filling pressure in patients with coronary artery disease

Assessment of left ventricular (LV) diastolic filling pressure provides important information on the hemodynamic status in the general population. The aim of our study was to investigate the reliability of tissue Doppler imaging (TDI) in estimating left ventricular filling pressure in patients with coronary artery disease (CAD). We prospectively studied 32 consecutive CAD-patients, mean age 64 +/- 12 years, in sinus rhythm. All patients underwent cardiac catheterization and echocardiography within the same hour. Catheterization investigated pre-A-wave pressure (preA) and LV ejection fraction (LVEF). Echocardiographic LVEF was calculated using wall motion indexes (WMI) with segmental division of LV wall. The following Doppler parameters were assessed: (1) PW Doppler signals from the mitral inflow (E), (2) PW TDI of the mitral annulus (E'), thus allowing to obtain the mitral inflow to annulus ratio (E/E'). The best correlation between invasive and echocardiographic LVEF was observed using WMI (r = 0.91). The correlations between preA and E, E', and E/E' were significant (r = 0.36, r = 0.38, and r = 0.60, respectively). In patients with LVEF >50%, no correlation between E/E' and preA was found (r = 0.18, P = 0.44), whereas with LVEF <50%, this correlation was strong (r = 0.76, P < 0.001). In patients with myocardial infarction, the correlation between E/E' and preA was significant whatever the localization of myocardial infarction (r > 0.71, P < 0.05). ROC curve analysis identified an E/E'>9 to be the best cut-off value related to preA > 15 mmHg. We conclude that the mitral inflow-to-annulus ratio is a reliable method in CAD patients and allows determination of LV filling pressure when LVEF <50%.

Ultrasonic backscatter and diastolic function in hypertensive patients

This study was designed to assess whether ultrasonic reflectivity, evaluated by a real-time integrated backscatter analysis, was related to the severity of diastolic dysfunction, as studied by Doppler echocardiography in patients with essential hypertension. One hundred nine subjects were included in the study. Diastolic function was assessed by mitral-inflow Doppler ultrasound recordings. Backscatter cyclic variation and maximal intensity were measured in 6 regions throughout the left ventricle. The subjects were classified in 5 groups according to blood pressure and diastolic function: 29 normotensives with normal diastolic function (group 1), 18 hypertensives with normal diastolic function (group 2), 47 hypertensives with a delayed relaxation pattern (group 3), 11 hypertensives with a pseudonormal filling pattern (group 4), and 4 hypertensives with a restrictive filling pattern (group 5). The highest cyclic variation was found in groups 1 and 2, the lowest in groups 4 and 5 (5.7+/-0.2 dB in group 1 and 5.7+/-0.2 dB in group 2 versus 2.9+/-0.3 dB in group 4 and 2.1+/-0.4 dB in group 5; P<0.001), with intermediate values in group 3 (5.2+/-0.2 dB). Cyclic variation was inversely correlated with left ventricular chamber stiffness (P<0.05) and directly correlated with midwall fractional shortening (P<0.02) in all hypertensives. No differences in maximal intensity were found among the 5 groups of subjects. These results show an association between diminished cyclic variation of backscatter and deterioration of diastolic function in hypertensive patients. Thus, alterations in this parameter may be useful for the assessment of diastolic dysfunction in hypertension.