PubMed Health⌕ Search

Biomedical subjects

John Lekakis

Publications and source records attributed to John Lekakis.

At least 19 recordsLinked to original sources
PubMed2007

High anticipatory stress plasma cortisol levels and sensitivity to glucocorticoids predict severity of coronary artery disease in subjects undergoing coronary angiography.

Hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis and/or increased sensitivity of peripheral tissues to glucocorticoids may be associated with the dysmetabolic syndrome and its cardiovascular sequelae. In this prospective pilot clinical study, we examined possible associations between HPA axis activity and severity of cardiovascular disease. We measured morning serum cortisol and intima media thickness (IMT) of carotid and femoral arteries in 105 subjects before undergoing coronary angiography for suspected coronary artery disease (CAD). In a randomly selected 46 of these subjects, we obtained late afternoon and morning cortisol levels (after ultralow-dose dexamethasone [0.25 mg] treatment) and determined their genotype for the Bcl1 polymorphism of the glucocorticoid receptor gene, which has been associated with increased sensitivity to glucocorticoids. There was significant association between morning preangiography cortisol levels and the number of vessels with severe stenosis in the angiography, independently of age or sex (P = .002), and a trend for a positive correlation between morning cortisol and the IMT of the femoral artery (P = .057). Bcl1 G allele homozygotes had a significantly higher carotid IMT (P = .005) and a nonsignificant tendency for higher waist-hip ratio (P = .059). Hyperactivity of the HPA axis in anticipation of a stressful procedure, such as angiography, may be an index of CAD severity. Chronic HPA axis hyperreactivity combined with tissue hypersensitivity to glucocorticoids may contribute to more severe atherosclerosis and CAD.

Adult↗
PubMed2007

Weight loss after bariatric surgery improves aortic elastic properties and left ventricular function in individuals with morbid obesity: a 3-year follow-up study.

OBJECTIVE: To investigate whether weight loss after bariatric surgery (gastric bypass) is associated with changes in aortic function (an important determinant of left ventricular function) and in left ventricular function, in morbidly obese individuals 3 and 36 months after surgery. METHODS: We used echocardiography to evaluate 60 obese individuals [body mass index (BMI) > 40 kg/m2] who underwent surgery and 20 obese individuals who neither underwent surgery nor lost weight, at baseline and at 3 and 36 months of follow-up, and 40 lean individuals (BMI < 25 kg/m2) of similar age, sex and risk factors, at baseline. We measured aortic strain, distensibility, stiffness index, pressure-strain modulus and Doppler indices of left ventricular diastolic dysfunction (ratio of peak early to peak atrial flow velocities, isovolumic relaxation time and deceleration time). RESULTS: Baseline aortic function and Doppler diastolic indices were impaired in obese individuals compared with those who were lean (P < 0.05). During 3 and 36 months of follow-up, BMI and left ventricular diastolic diameter, volume, mass and wall thickness were reduced, and indices of aortic function and left ventricular diastolic function were normalized, in obese individuals after surgery [aortic distensibility (cm2 x dyn(-1) x 10(-6)): 1.9 before surgery, 3.4 at 3 months after surgery and 4.3 at 3 years after surgery, compared with 3.36 in lean controls; P < 0.01], but not in those who did not lose weight. The reduction in BMI after surgery was related to the concomitant improvement in indices of aortic function (P < 0.01) and isovolumic relaxation time (P < 0.05) after adjustment for age, sex and concomitant reduction in blood pressure, lipids and glucose concentrations. CONCLUSION: Weight reduction after bariatric surgery normalizes aortic function, reduces left ventricular hypertrophy and, thus, improves left ventricular diastolic function in morbidly obese individuals over a 3-year period of follow-up.

Adult↗
PubMed2006

Acute smoke-induced endothelial dysfunction is more prolonged in smokers than in non-smokers.

BACKGROUND: The aim of the study was to compare acute endothelial dysfunction caused by smoking one cigarette between smokers and non-smokers. METHODS: Thirty volunteers, 15 smokers and 15 non-smokers, were asked to smoke the same type of cigarette and endothelial function was assessed by FMD (flow mediated dilatation) at fast, 30, 60 and 90 min post-smoking. RESULTS: Overall response of FMD after smoking was significantly different between smokers and non-smokers (p=0.011). Endothelial dysfunction after smoking remained significant for 1-h in smokers (p=0.002), but only for 30 min in non-smokers (p=<0.001). FMD 1-h after smoking was significantly higher in non-smokers than in smokers (p=0.002). CONCLUSIONS: Smokers seem to have sustained and more intensive unfavourable effects in endothelial function than non-smokers after smoking one cigarette. It is possible that long-term smoking diminishes the capacity of endothelium to counterbalance external factors that cause endothelial dysfunction.

Adult↗
PubMed2006

ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death).

Explore the source record for details and available documents.

Anti-Arrhythmia Agents↗
PubMed2006

ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death) developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society.

Explore the source record for details and available documents.

Arrhythmias, Cardiac↗
PubMed2006

ACC/AHA/ESC 2006 Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: a report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (writing committee to develop Guidelines for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society.

Explore the source record for details and available documents.

American Heart Association↗
PubMed2006

ACC/AHA/ESC 2006 Guidelines for the Management of Patients with Atrial Fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Revise the 2001 Guidelines for the Management of Patients With Atrial Fibrillation): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society.

Explore the source record for details and available documents.

Algorithms↗
PubMed2006

Gender influence on metabolic syndrome's effects on arterial stiffness and pressure wave reflections in treated hypertensive subjects.

BACKGROUND: In hypertensive subjects, aortic stiffness, an independent predictor of cardiovascular (CV) risk, measured from pulse wave velocity (PWV), contributes to enhance augmentation index (AI), a marker of the timing and amplitude of wave reflections. Whether PWV and AI are correlated and reflect CV risk in hypertensive men and women with metabolic syndrome (MS) remains unknown. METHODS: In a cohort of 613 (364 males) treated hypertensive subjects with and without MS (41% MS) pulse wave analysis was used to determine aortic PWV and carotid AI. CV risk was estimated from standard Framingham equations. RESULTS: In females, but not in males, aortic PWV was higher in subjects with MS, when compared with those without MS (12.7+/-0.3m/s versus 11.1+/-0.4m/s, p<0.001). This result was independent of age and blood pressure. Only in females AI was independently related to the presence of MS; AI did not differ between subjects with or without MS, both males and females. AI did not correlate with PWV, except in males without MS. The overall CV risk was strongly associated to PWV independently of MS and gender, but AI was associated to CV risk only in males. CONCLUSION: In treated hypertensive subjects, the effect of MS on PWV and AI is modulated by gender. The dissociation between PWV and AI observed in women with MS was due to "blunted" wave reflections. This finding is associated with the fact that PWV, but not AI, was a constant marker of CV risk in subjects with MS, whether men and women.

Antihypertensive Agents↗
PubMed2006

Pressure wave reflections, central blood pressure, and aortic stiffness in patients with Adamantiades-Behcet's disease: a cross-sectional case-control study underlining the role of chronic corticosteroid treatment.

BACKGROUND: Adamantiades-Behcet's disease (ABD) is a multisystemic inflammatory/autoimmune disease involving both microcirculation and macrocirculation. Aortic stiffness index and aortic augmentation index (AI) are indices for the estimation of arterial stiffness and pressure wave reflections, respectively. The effect of anti-inflammatory and immunosuppressive drugs used in ABD on these indices is unknown. METHODS: In this cross-sectional study we examined 74 subjects with ABD (aged 40.1 +/- 12.5 years, 24 men) and 24 control subjects by using the noninvasive technique of radial artery applanation tonometry and pulse wave analysis for assessment of aortic AI by application of transfer functions. Echocardiography was used for assessment of aortic stiffness index. Classic cardiovascular (CV) risk factors, left ventricular and endothelial function of the brachial artery, as well as intima-media thickness of carotid artery, were also assessed. RESULTS: Corticosteroids were the only drug having a negative and independent effect on aortic AI, but not on aortic stiffness. Patients taking corticosteroids had lower aortic AI and central systolic blood pressure (BP), but not aortic stiffness and peripheral systolic BP, when compared to those without corticosteroids (21+/-14% v 12+/-14%, P < .050). Medication, traditional CV risk factors, and functional or structural CV parameters were all comparable among the two groups. The AI was similar between the control group and patients with ABD taking corticosteroids. CONCLUSIONS: The AI, but not aortic stiffness, is lower in patients with ABD taking corticosteroids compared to patients not taking corticosteroids and similar to the control group. These results imply a role of inflammation or immunomodulatory mechanisms in the regulation of pressure wave reflections.

Adrenal Cortex Hormones↗
PubMed2006

Arterial wave reflections are associated with left ventricular diastolic dysfunction in Adamantiades-Behçet's disease.

BACKGROUND: Adamantiades-Behçet's disease (ABD) is characterized by systemic vasculitis. We investigated whether aortic distensibility and arterial wave reflections are linked to left ventricular (LV) diastolic dysfunction in ABD. METHODS AND RESULTS: Eighty-two patients and 40 controls with similar atherosclerotic risk factors were examined by applanation tonometry of the radial artery (SphygmoCor) and echocardiography. Augmentation index (AI%) and arrival time (Deltat, ms) of reflected arterial waves as well as aortic distensibility (AoD) assessed by echocardiography were estimated. Doppler diastolic abnormalities were defined as proposed by the European Study Group on Diastolic Heart Failure by measurement of E/A ratio, isovolumic relaxation time, deceleration time, and flow propagation velocity. Patients had impaired central augmentation index (CAI), Deltat, and AoD compared with controls (P > .05). After adjusting for age, atherosclerotic risk factors, left ventricular mass, and medication the odds-ratio of AoD and CAI for left ventricular diastolic dysfunction was 0.664 (95%CI 0.449-0.982), P = .04, and 1.073 (95% CI 1.014-1.140), P = .001, respectively. The addition of CAI to the multivariable model including AoD significantly increased the power of the model for prediction of left ventricular diastolic dysfunction (-2 Log likelihood change = 18.8, P for change > .01). CONCLUSION: Augmentation index has a complementary value to aortic distensibility in the assessment of left ventricular diastolic dysfunction in ABD.

Adult↗
PubMed2006

Arterial stiffness and Chlamydia pneumoniae infection in coronary artery disease. Is there a link?

BACKGROUND: We investigated the possible association between antichlamydial antibodies and pulse wave analysis (PWA) parameters in a cohort of patients with coronary artery disease (CAD). METHODS: The augmentation index (AI), the reflection time index (RTI) and the time to the beginning of the reflected wave (CT-1) were estimated (Sphygmocor ATCOR Medical). IgA titers >or= 40 and IgG >or=80 were considered as positive (microimmunofluorescence test). Patients also underwent coronary angiography, ultrasound carotid measurements and 24 h ambulatory blood pressure (BP) measurements. RESULTS: No differences existed in the traditional risk factors for CAD between the seronegative and seropositive IgA/ IgG groups. IgA seropositive subjects had higher values of AI (p < 0.01) comparing to seronegatives whilst the levels of CT-1 and RTI were lower (p < 0.011 and p < 0.02 respectively). No differences in AI, CT-1 and RTI values were found between IgG seropositive/ seronegatives patients. CONCLUSIONS: An association was indicated between IgA antichlamydial titers and PWA parameters in patients with CAD, supporting that the connecting link between arterial stiffness and CAD might include this microorganism.

Adult↗
PubMed2006

ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death--executive summary: A report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death) Developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society.

Explore the source record for details and available documents.

Anti-Arrhythmia Agents↗
PubMed2006

ACC/AHA/ESC 2006 guidelines for the management of patients with atrial fibrillation: full text: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Revise the 2001 guidelines for the management of patients with atrial fibrillation) developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society.

Explore the source record for details and available documents.

Atrial Fibrillation↗
PubMed2006

Combined acute effects of red wine consumption and cigarette smoking on haemodynamics of young smokers.

OBJECTIVE: Red wine seems to improve haemodynamic variables, while smoking provokes adverse effects. The haemodynamic effects of their combined use is unknown. The purpose of the present study was to examine the acute effects of red wine and its constituents, in combination with the smoking of one cigarette, on haemodynamic parameters, such as blood pressure and wave reflections, in a group of smokers. METHODS: Twenty smokers (12 males, eight females) participated in a double-blind, crossover study comprised of 3 study days. All subjects either smoked one cigarette, or smoked and drank 250 ml of red wine, or 250 ml of de-alcoholized red wine (containing the same type and similar concentration of antioxidants). Applanation tonometry and generalized transfer functions were used to estimate aortic pressure waveforms at baseline and 30, 60 and 90 min after each trial. The augmentation index (AIx) was used to express wave reflections. RESULTS: Smoking increased peripheral systolic blood pressure (P < 0.005) 30 min later, but simultaneous consumption of either type of red wine caused no such effect. Additionally, smoking caused no overall effect on AIx, while smoking and drinking either regular or de-alcoholized red wine reduced AIx (P < 0.001). The reduction of AIx after red wine consumption was significantly greater than the respective reduction after de-alcoholized red wine (P = 0.004). CONCLUSION: Antioxidant substances in red wine counteracted the smoking-induced increase in peripheral systolic blood pressure. Both alcohol and antioxidants in red wine decrease wave reflections in uncomplicated habitual smokers postprandially, indicating an additional favourable effect of red wine.

Adult↗