Biomedical subjects

Samir Saha

Publications and source records attributed to Samir Saha.

5 recordsLinked to original sources

PubMed2006

Impaired myocardial functional reserve in hypertension and diabetes mellitus without coronary artery disease: Searching for the possible link with congestive heart failure in the myocardial Doppler in diabetes (MYDID) study II.

BACKGROUND: Although the impact of type 2 diabetes mellitus (DM) and hypertension (HTN) on myocardial function has recently been studied using tissue Doppler echocardiography (TDE), the independent role of both conditions, and the influence of other risk factors on myocardial function has not been completely defined, particularly in absence of coronary artery disease (CAD). The aim of this study was to assess the myocardial functional reserve in patients with DM or HTN with apparently normal left ventricular (LV) systolic function. METHODS: Standard and dobutamine stress echocardiography using TDE was performed in 128 subjects: 59 had DM, 20 had HTN, 27 had both DM and HTN (HTN + DM), and 22 subjects were controls (C). Subjects with known CAD and depressed LV function were excluded. In addition, standard two-dimensional and Doppler measurements, LV regional peak systolic (PSV), early (E') and late (A') diastolic velocities, strain (S%) and strain rate (SR), were assessed at rest and peak stress. RESULTS: The LV mass did not differ, although relative wall thickness was significantly higher in subjects with HTN + DM and HTN. The PSV did not differ at rest but was lowest in subjects with HTN + DM at peak stress. The E' wave velocity was significantly lower in subjects with HTN + DM both at rest and during peak stress, as were S% and SR. CONCLUSIONS: The addition of DM to HTN has a negative effect on LV systolic and diastolic functions. A depressed myocardial functional reserve might be postulated as one of the pathophysiologic mechanisms for the excessive occurrence of congestive heart failure in patients with DM or HTN.

Coronary Artery Disease↗

PubMed2005

Isolated type 2 diabetes mellitus causes myocardial dysfunction that becomes worse in the presence of cardiovascular diseases: results of the myocardial doppler in diabetes (MYDID) study 1.

AIMS: Patients with type 2 diabetes mellitus (DM) often suffer disproportionately and have a worse outcome when burdened with cardiovascular complications compared with those without DM. A specific heart muscle disease reportedly caused by DM per se may explain this. We sought to investigate whether an echo Doppler diagnosis of such a myocardial disease is clinically relevant in DM with or without coexistent coronary artery disease (CAD) and/or hypertension (HTN). SUBJECTS AND METHODS: Two hundred subjects (127 males, 73 females, 56 +/- 10 years) including controls (n = 23), patients with HTN (n = 20), CAD (n = 35), uncomplicated DM (n = 59), DM+HTN (n = 27), DM+CAD (n = 16) and DM+CAD+HTN (n = 20) underwent tissue Doppler-enhanced dobutamine stress echocardiography. Myocardial function was assessed by measuring left ventricular myocardial peak systolic velocity (PSV) and early diastolic velocity at rest and during peak stress, besides measurements of standard Doppler variables. RESULTS: Average left ventricular PSV at rest was significantly lower in CAD (4.7 +/- 1.5) compared with controls (5.7 +/- 1.2) and in DM+CAD+HTN (4.6 +/- 1.4) compared with DM (5.6 +/- 1.3; all p < 0.05). During peak stress, lower PSV persisted in CAD (9.5 +/- 3.1) and DM+CAD+HTN (8.1 +/- 2.7), while appearing de novo in DM (11.3 +/- 2.6) and HTN (11.0 +/- 2.3) unlike in the controls (12.5 +/- 2.5; all p < 0.001). When pooled together, DM subjects with CAD and/or HTN or both had significantly lower PSV (9.1 +/- 2.7) than those without (10.0 +/- 2.8; p < 0.001). Early diastolic velocity response was equally lower in both groups compared with the controls. CONCLUSION: The results suggest that dobutamine stress unmasks myocardial functional disturbances caused by uncomplicated DM. The discrete disturbances become quantitatively more pronounced in the presence of coexistent cardiovascular diseases.

Adult↗

PubMed2005

Functional diagnosis of coronary stenosis using tissue tracking provides best sensitivity and specificity for left circumflex disease: experience from the MYDISE (myocardial Doppler in stress echocardiography) study.

AIMS: To evaluate the diagnostic capacity of quantitative analysis of segmental longitudinal myocardial displacement images (tissue tracking, TT) during dobutamine stress echocardiography for the detection of patients with coronary artery disease (CAD). METHODS AND RESULTS: TT-generated colour-coded maps of systolic segmental longitudinal displacement were obtained by post-processing of echocardiographic data from 105 patients with CAD and 90 low risk individuals selected from MYDISE database. Quantitative analysis of the distribution pattern of segmental displacement during dobutamine stress was most successful when a ratio of basal (high amplitude) to apical (low amplitude) colour-coded displacement bands (B/A ratio) was employed. Applied in four different left ventricular sectors, the B/A ratio provided a significant discrimination of patients with CAD (p<0.05 in the anterior and p<0.001 in the inferior wall) as assessed by receiver operating characteristic analysis. The procedure was most sensitive when applied in inferior wall for the detection of left circumflex coronary artery disease, the B/A ratio of 0.8 giving the best combination of sensitivity (77+/-8%) and specificity (77+/-5%) values. CONCLUSION: Quantification of dobutamine stress echocardiography using TT is an efficient diagnostic approach and a valuable additional modality in functional cardiac imaging for the initial identification of patients suspected for CAD.

Adrenergic beta-Agonists↗

PubMed2004

Improvement of cardiac function after haemodialysis. Quantitative evaluation by colour tissue velocity imaging.

BACKGROUND: Overhydration and accumulation of uraemic toxins may influence the myocardial function in haemodialysis (HD) patients. To evaluate cardiac function and the effects of fluid and solute removal during a single session of HD, colour tissue velocity imaging (TVI) was used. This new technique, which is less load dependent than conventional echocardiography, allows an objective quantitative assessment of myocardial contractility, contraction and relaxation. METHODS: Conventional echocardiographic and TVI images were recorded before and after a single HD session in 13 clinically stable HD patients (62+/-10 years, six males) and in 13 sex- and age-matched healthy controls. Myocardial tissue velocities (v; cm/s) for isovolumetric contraction (IVC), peak systole (PS), early (E') and late (A') diastolic filling and strain rate (SR) were measured. RESULTS: Left ventricular hypertrophy (LVH) was present in 12 patients. TVI gave additional information in comparison with conventional echocardiography. Before HD, PS (5.0+/-0.8 vs 6.0+/-1.2 cm/s, P<0.05), E' (5.7+/-1.7 vs 7.3+/-2.0 cm/s, P<0.05) and A' (6.6+/-1.7 vs. 8.3+/-2.9 cm/s, P<0.05) velocities were lower in the patients than in the controls, indicating systolic and diastolic dysfunction. The HD session increased IVCv (4.0+/-1.7 to 5.5+/-1.9 cm/s; P<0.001), PSv (5.0+/-0.8 to 5.7+/-0.8 cm/s; P<0.05) and SR (0.7+/-0.2 to 0.9+/-0.2 1/s; P < 0.05) and decreased E/E' (16.7+/-7.7 to 12.2+/-4.0, P<0.05), indicating improved systolic function and decreased LV filling pressure, respectively. Linear regression analysis demonstrated a dependency of systolic contraction (PSv) and contractility (IVCv) upon plasma levels of phosphate (r(2) = 0.70, P<0.005, r(2) = 0.33, P<0.01). CONCLUSIONS: Using TVI, HD patients demonstrate myocardial dysfunction, which is found less frequently when using conventional echocardiography. The systolic function seems to be impaired by high plasma levels of phosphate and an increased Ca x P product. One single session of HD improved systolic function as indicated by increases in IVCv, PSv and SR. Further studies are needed to clarify if this effect of HD is due to the acute removal of fluid, the removal of solutes or both.

Aged↗

PubMed2004

Electromechanical coupling, uncoupling, and ventricular function in patients with bundle branch block: a tissue-Doppler echocardiographic study.

BACKGROUND: Left bundle branch block (LBBB) is associated with impaired left ventricular (LV) function and increased morbidity and mortality, especially in patients with structural heart diseases. The mechanisms are poorly understood. SUBJECTS AND METHODS: Subjects with isolated LBBB (n=20), right bundle branch block (RBBB, n=20), and controls (C, n=20) were studied with standard two-dimensional (2D), and color-encoded tissue-Doppler echocardiography (TDE). Inter- and intraventricular systolic and diastolic coordination were assessed from the TDE velocity profiles. LV function was assessed by 2D echocardiography, by TDE-derived peak systolic velocities, and the atrioventricular (AV) plane displacement. RESULTS: Subjects with LBBB had longer electromechanical delays and longer isovolumic relaxation times than did the C and RBBB groups (P <0.001). For the LBBB subjects compared with the RBBB and C groups, ejection times were shorter, peak systolic velocities and AV plane displacements were lower, they had larger LV end-systolic volumes and lower LV ejection fraction (all P <0.001), and the atrial contribution to A-V plane displacement was higher (P <0.01). There were no differences in diastolic or filling times among the groups. CONCLUSIONS: In patients with LBBB, delayed regional electromechanical coupling and uncoupling leads to generalized intra- and interventricular asynchrony, thereby explaining the depressed regional and global LV functions. Assessment of the electromechanical coupling and uncoupling processes and their consequences on cardiac function in patients with BBB and structural heart diseases may be possible using TDE.

Analysis of Variance↗