Non-diabetic hyperglycaemia correlates with angiographic coronary artery disease prevalence and severity.

AIM: The role of glycaemia as a coronary artery disease (CAD) risk factor is controversial, and the optimal glucose level is still a matter of debate. For this reason, we assessed the prevalence and severity of angiographic CAD across hyperglycaemia categories and in relation to haemoglobin A(1c) (HbA(1c)) levels. METHODS: We studied 273 consecutive patients without prior revascularization undergoing coronary angiography for suspected ischaemic pain. CAD severity was assessed using three angiographic scores: the Gensini's score; extent score; and arbitrary index. Patients were grouped, according to 2003 American Diabetes Association criteria, into those with normal fasting glucose (NFG), impaired fasting glucose (IFG) and diabetes mellitus (DM). RESULTS: CAD prevalence was 2.5-fold higher in both the IFG and DM groups compared with the NFG group. Deterioration of glycaemic profile was a multivariate predictor of angiographic CAD severity (extent score: P=0.027; arbitrary index: P=0.007). HbA(1c) levels were significantly higher among CAD patients (P=0.016) and in those with two or more diseased vessels (P=0.023) compared with the non-CAD group. HbA(1c) levels remained predictive of CAD prevalence even after adjusting for conventional risk factors, including DM (adjusted OR: 1.853; 95% CI: 1.269-2.704). CONCLUSION: Non-diabetic hyperglycaemia, assessed either categorically by fasting glucose categories or continuously by HbA(1c) levels, correlates with the poorest angiographic outcomes.

Systems biology in heart diseases.

Systems biology based on integrative computational analysis and high technology is in a position to construct networks, to study the interactions between molecular components and to develop models of cardiac function and anatomy. Clinical cardiology gets an integrated picture of parameters that are addressed to ventricular and vessel mechanics, cardiac metabolism and electrical activation. The achievement of clinical objectives is based on the interaction between modern technology and clinical phenotype. In this review the need for more sophisticated realization of the structure and function of the cardiovascular system is emphasized while the incorporation of the systems biology concept in predicting clinical phenotypes is a promising strategy that optimize diagnosis and treatment in cardiovascular disease.

Usefulness of colour tissue Doppler imaging in assessing aortic elastic properties in Type 1 diabetic patients.

AIMS: Diabetes mellitus (DM) is associated with macrovascular disease and impaired aortic function. We hypothesized that the change in aortic elastic properties could be investigated with colour tissue Doppler imaging (CTDI) in Type 1 diabetic patients and that these findings could be related to the aortic stiffness index. METHODS: We examined by echocardiography 66 patients with Type 1 DM (mean age 35 +/- 10 years, mean duration of disease 20 +/- 9 years) without a history of arterial hypertension or coronary artery disease (negative thallium-201 stress test) and 66 age- and sex-matched normal subjects. Arterial pressure was measured before echocardiography was performed. Internal aortic systolic and diastolic diameters by M-mode echocardiography and aortic systolic upper wall tissue velocity (Sao, cm/s) by CTDI were measured 3 cm above the aortic valve. Aortic distensibility and aortic stiffness index were calculated using accepted formulae. RESULTS: Aortic stiffness, distensibility and Sao velocity differed significantly between the studied groups. In the diabetic group, duration of diabetes correlated with aortic stiffness (r = 0.53, P < 0.001), distensibility (r = -0.61, P < 0.001) and Sao velocity (r = -0.48, P < 0.001). There was a negative correlation between aortic stiffness and Sao velocity (r = -0.49, P < 0.001). Multiple stepwise linear regression analysis in the diabetic group revealed that aortic S velocity (beta = 0.30, P = 0.005) and duration of diabetes (beta = -0.49, P = 0.001) were the main predictors of aortic distensibility (overall R(2) = 0.48). CONCLUSIONS: Aortic elastic properties can be directly assessed by measuring the movements in the upper aortic wall. Reduced aortic S velocity is associated with increased aortic stiffness in Type 1 diabetic patients.

Haemodynamic factors and the important role of local low static pressure in coronary wall thickening.

UNLABELLED: BACKGROUND/STUDY OBJECTIVES: The purpose of our study was to investigate the possible correlation between blood flow physical parameters and the wall thickening in typical human coronary arteries. METHODS: Digitized images of seven transparent arterial segments prepared post-mortem were adopted from a previous study in order to extract the geometry for numerical analysis. Using the exterior outline, reconstructed forms of the vessel geometries were used for subsequent computational fluid dynamic analysis. Data was input to a pre-processing code for unstructured mesh generation. The flow was assumed to be two-dimensional, steady, laminar with parabolic inlet velocity profile. The vessel walls were assumed to be smooth, inelastic and impermeable. Non-Newtonian power law was applied to model blood rheology. The arterial wall thickening was measured and correlated to the wall shear stress, static pressure, molecular viscosity, and near wall blood flow velocity. RESULTS: Wall shear stress, static pressure and near wall velocity magnitude exhibit negative correlation to wall thickening, while molecular viscosity exhibits positive correlation to wall thickening. CONCLUSION: There is a strong correlation between the development of vessel wall thickening and the blood flow physical parameters. Amongst these parameters the role of local low wall static pressure is predominant.

Doppler echocardiographic evaluation of right ventricular diastolic function in hypertrophic cardiomyopathy.

AIMS: Left ventricular diastolic function in patients with hypertrophic cardiomyopathy has been adequately studied. In contrast there are few studies concerning right ventricular diastolic function in hypertrophic cardiomyopathy. We studied right ventricular diastolic function in patients with hypertrophic cardiomyopathy using Doppler echocardiography. METHODS AND RESULTS: We studied 20 patients with hypertrophic cardiomyopathy (mean age 43.6+/-13.8 years) and 20 healthy volunteers (control group, mean age 43+/-13.8 years). We calculated left ventricular and right ventricular diastolic indices using pulsed Doppler echocardiography. Hypertrophic cardiomyopathy patients compared with controls had significantly lower right ventricular-E/A ratio (1.01+/-0.40 vs 1.30+/-0.28, P<0.04), significantly prolonged right ventricular isovolumic relaxation time (170+/-72 vs 32+/-23 ms, P<0.001), and also significantly prolonged right ventricular deceleration time (160+/-58 vs 118+/-35 ms, P<0.01). There was also strong significant correlation between right ventricular deceleration time and left ventricular deceleration time (r=0.78), right ventricular-E/A ratio and left atrial filling fraction (r=-0.55) and between right atrial filling fraction and left atrial filling fraction (r=0.75). CONCLUSIONS: Right ventricular diastolic function in patients with hypertrophic cardiomyopathy is impaired, reflecting abnormal relaxation. Right ventricular diastolic indices correlate well with those of left ventricle.

An angiotensin-converting enzyme inhibitor improves left ventricular systolic and diastolic function in transfusion-dependent patients with beta-thalassemia major.

BACKGROUND: Cardiac complications are the major cause of death in patients with beta-thalassemia major. The purpose of this study was to assess the impact of long-term treatment with the angiotensin-converting enzyme inhibitor enalapril on left ventricular (LV) performance, with an emphasis on diastolic LV function because diastolic dysfunction has been found to be an early event in an asymptomatic thalassemic population with only mild impairment of LV systolic function. METHODS: We used echocardiography to study the impact of treatment with oral enalapril on the evolution of standard M-mode and Doppler indices, along with a recently introduced Doppler index of combined systolic and diastolic LV performance. RESULTS: Patients were found to have significantly increased LV end-diastolic dimensions (LVEDD), LV end-systolic dimensions (LVESD), and left atrial dimensions and decreased LV fractional shortening (LVFS) compared with controls. After treatment with enalapril, LVESD decreased from 3.58 +/- 0.3 cm to 3.23 +/- 0.4 cm (P <.01) and LVFS increased from 32.6% +/- 4.0% to 38.0% +/- 3.1% (P <.001). Patients at baseline were found to have a significantly higher E-wave velocity, E/A ratio, and Doppler index compared with controls. The E-wave deceleration time was significantly shorter compared with that of controls. After treatment with enalapril, the E/A ratio decreased from 2.10 +/- 0.42 to 1.50 +/- 0.30 (P <.05), E-wave deceleration time increased from 0.12 +/- 0.02 seconds to 0.15 +/- 0.03 seconds (P <.01), and the Doppler index decreased from 0.46 +/- 0.10 to 0.37 +/- 0.14 (P <.05). CONCLUSIONS: Enalapril was well tolerated in asymptomatic or minimally symptomatic patients with LV dysfunction resulting from beta-thalassemia major. Echocardiographically we demonstrated significant improvement in LV systolic and diastolic function. Whether this translates to improved long-term prognosis and survival remains to be further evaluated.

Doppler echocardiographic evaluation of right ventricular diastolic function in isolated valvular aortic stenosis.

BACKGROUND AND AIM OF THE STUDY: Left ventricular diastolic function (LVDF) in patients with aortic stenosis (AS) has been adequately studied, in contrast to right ventricular diastolic function (RVDF). In this study, RVDF in patients with AS was evaluated using pulsed-wave Doppler echocardiography. METHODS: The study population comprised 20 patients with isolated AS (mean age 53.7 +/- 6.5 years) and 20 healthy volunteers (control group, mean age 52.6 +/- 8.8 years). The diastolic indices of right ventricular (RV) function were calculated using transtricuspid and transpulmonary Doppler flow velocities. Statistical analysis was performed using Student's t-test. There was no statistically significant difference between patients and controls with regard to age, height, bodyweight, heart rate, systolic and diastolic blood pressures, end-diastolic and end-systolic left ventricular (LV) diameter, LV fractional shortening and RV end-diastolic diameter. RESULTS: RV diastolic indices in patients (versus controls) were as follows: E/A ratio of transtricuspid flow waves was significantly lower (0.88 +/- 0.20 versus 1.25 +/- 0.33, p < 0.001); deceleration time of E wave was significantly longer (184 +/- 3 versus 127 +/- 3 ms, p < 0.001); atrial filling fraction was significantly augmented (43.1 +/- 7.7 versus 33.6 +/- 7.6%, p < 0.001); and isovolumic relaxation time was significantly prolonged (116 +/- 73 versus 31 +/- 15 ms, p < 0.001). There was no statistically significant correlation between diastolic indices and interventricular septum thickness and LV mass index. CONCLUSIONS: RVDF in AS patients is impaired, reflecting abnormal relaxation.

Control of breathing in patients with chronic obstructive lung diseases and secondary polycythemia after venesection.

Using the mouth occlusion pressure technique, we have studied the control of breathing in 10 hypercapnic patients with chronic obstructive pulmonary diseases and polycythemia before and after venesection. The mean hematocrit value was 59.9 +/- 5.5% which, following venesection (approximately 1,200-1,600 cm3 of blood was removed from each patient over three consecutive days), fell to 44.4 +/- 2.2%. Respiratory drive, expressed as P0.1 (mouth occlusion pressure 0.1 s after the onset of occluded inspiration at functional residual capacity) and as mean inspired flow (VT/TI), was diminished after venesection (p less than 0.001 and p less than 0.05); in contrast to that, we found no changes in respiratory timing (TI and TI/Ttot). The arterial PCO2 was decreased (p less than 0.001) and arterial PO2 was increased after venesection, these improvements are mainly attributed to decreased dead space ventilation (p less than 0.05). It seems that the improvements of blood gases after venesection is probably responsible for the decrease in respiratory drive.

Airway function in stage I and stage II pulmonary sarcoidosis.

Airway function was studied in 39 patients with stage I sarcoidosis and in 20 patients with stage II sarcoidosis. All of our patients were nonsmokers. Characteristic functional changes of restrictive lung disease was observed in 4 patients with stage II sarcoidosis. Specific airway conductance and % FEV1 were abnormal in 3 patients with stage II sarcoidosis. Abnormal small airway function was demonstrated in several patients with stage I and stage II sarcoidosis, always by multiple tests. Frequency dependence of dynamic compliance was demonstrated in 40% of stage I and 50% of stage II sarcoidosis. Maximal flow (Vmax50, Vmax25) was decreased respectively in 36 and 30% of patients of stage I sarcoidosis and in 56 and 62% of patients with stage II sarcoidosis. The ratio of closing volume to vital capacity was increased above corrected predictions in 30% of stage I and 44% of stage II sarcoidosis. delta Vmax25 decreased and Visov/VC (%) increased in more than 50% of patients. Upstream airway resistance was abnormally increased in 50% of patients with stage I and in 73% with stage II sarcoidosis. These results suggest that small airway dysfunction is common in early sarcoidosis without restrictive defect.