Impact of stent implantation on endothelial shear stress.

BACKGROUND: Endothelial shear stress (ESS) may play a key role in the pathobiology of stent restenosis (SR). Nevertheless, limited data are available about ESS and its relation to SR. PATIENTS AND METHODS: We enrolled 14 patients who underwent successful percutaneous coronary intervention (PCI) in this study. Three-dimensional (3D) reconstruction of 14 coronary arteries before and after stent implantation was performed. Using computational fluid dynamics, mean ESS was calculated proximally, in tertiles within and distal to the stent, both before and after stent implantation. RESULTS: Stent implantation resulted in a significant ESS decrease in the entire atherosclerotic lesion (1.83 vs. 1.26 Pa, p = 0.02). Regarding the five territories in which the entire lesion was divided, ESS decrease was marginally significant in the area of the second in-stent tertile, and in the area 5 mm distal to the stent, whereas ESS decrease was not significant in the area 5 mm proximal to the stent, and in the area of the first and third in-stent tertile. At 12 months, two patients had SR, but restenosis was not related to ESS decrease. CONCLUSION: ESS decreases after stent implantation but not uniformly, with the major reduction being in the middle tertile of the stent, and distal to the stent. In-stent ESS decrease may create local hemodynamic conditions leading to in-stent and in-segment restenosis.

In-hospital and long-term prognostic value of fibrinogen, CRP, and IL-6 levels in patients with acute myocardial infarction treated with thrombolysis.

Plasma fibrinogen, C-reactive protein (CRP), and interleukin-6 (IL-6) levels in patients with acute myocardial infarction (AMI) receiving thrombolysis have been related to prognosis. The aim of this study was to investigate the time course of plasma fibrinogen, CRP, and IL-6 levels during the in-hospital phase in patients with AMI receiving thrombolysis, and their relationship to in-hospital and prognosis after 12-months follow-up. In 40 patients presenting with AMI within 6 hours of symptom onset and treated with thrombolysis, plasma fibrinogen, CRP, and IL-6 levels were measured on admission and after 6, 12, 24, 48, and 72 hours; 7 days; and 6 months. Patients with other diseases that can alter fibrinogen, CRP, or IL-6 levels were excluded. Patients had a clinical follow-up at 6 and 12 months, and the following cardiac events were recorded: cardiac death, recurrent angina, recurrent AMI, and heart failure. Plasma fibrinogen concentrations decreased significantly (p <0.01 vs admission levels) at 12 hours (425 +/-94 vs 322 +/-132 mg/dL), started to increase at 24 hours, reached peak value at 72 hours (602 +/-209 mg/dL), remained elevated at 7 days, and were back to admission levels at 6 months (375 +/-79 mg/dL). CRP levels increased significantly at 12 hours (0.73 +/-0.43 vs 0.23 +/-0.11 mg/dL, p <0.01), reached peak value at 72 hours (7.66 +/-3.28 mg/dL), decreased significantly on day 7 (2.32 +/-1.17 mg/dL), and at 6 months were within normal limits (0.49 +/-0.29 mg/dL). IL-6 levels increased significantly at 6 hours (14.03 +/-8.13 vs 6.37 +/-3.88 pg/mL, p <0.05), reached peak value at 24 hours (59.49 +/-23.57 pg/mL), started to decrease at 48 hours, and at 6 months were within normal limits (2.25 +/-1.24 pg/mL). During the in-hospital phase 33 patients had an uneventful course and 7 patients had complications (3 post-AMI angina; 4 heart failure). During the 12-month follow-up period 28 patients had an uneventful course, and 12 patients had complications (1 cardiac death, 5 recurrent angina, 2 recurrent AMI, and 4 heart failure). Regarding the in-hospital prognosis, fibrinogen, CRP, and IL-6 levels were significantly higher (p <0.05) in patients with complications from 48 to 72 hours, from 12 hours until day 7, and from 6 hours until day 7, respectively. During the 12-month follow-up period fibrinogen, CRP, and IL-6 levels were significantly higher in patients with complications (at 48, 24, and 24 hours, respectively) only in the subgroup of patients who had complications within the first 6 months following AMI. Multivariate analysis showed that CRP at 48 hours was the most important factor related to in-hospital prognosis (p = 0.02), and ejection fraction followed by CRP at 24 hours (p = 0.02) to 6-month prognosis (p = 0.018). Fibrinogen, CRP, and IL-6 levels alter in patients with AMI receiving thrombolysis, and are related both to in-hospital and to 6-month follow-up prognosis.

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.

Complete left bundle branch block with left QRS axis deviation: defining its clinical importance.

Aim of this study was to elucidate the diagnostic significance of left axis deviation (LAD) in patients (pts) with chronic (> 6 months) left bundle branch block (LBBB). We retrospectively studied 2094 consecutive pts who underwent cardiac catheterization. All pts had left heart catheterization and coronary angiography, whereas right heart catheterization or endomyocardial biopsy were performed on indication. Our study group consisted of 43 pts with LBBB (29 men, 14 women, mean age 60.3 +/- 7.9 years). Pts with acute myocardial infarction or prior high degree AV-block were excluded. Initial evaluation included history, physical examination, chest X-ray, serial ECGs, 2D-echo and Doppler studies. ECG-criteria for LBBB were a QRS duration of > 0.12 secs, a predominantly negative QRS deflection in V1 and a widened R-wave in V6. LAD was considered present when the mean frontal QRS axis was between -30 degrees and -90 degrees. The mean frontal QRS axis was considered normal if it was between -29 degrees and +90 degrees. Twenty-nine pts had normal axis and 14 had LAD. According to angiographic data, among coronary disease pts, 12 (31.48%) had normal axis and 4 (28.57%) LAD (p = 0.041). Among mitral valve disease pts, 3 (10.35%) had normal axis and none LAD. Among pts with aortic valve disease, I (3.45%) had normal axis and 8 (57.15%) LAD (p = 0.0001). Among pts with dilated cardiomyopathy, 2 (6.9%) had normal axis and 1 (7.14%) LAD. Among pts with no organic heart disease, 11 (37.93%) had normal axis and 1 (7.14%) LAD (p = 0.035). The presence of LAD had a 41.9% sensitivity and a 91.6% specificity for the presence of organic heart disease. These findings point towards a statistically significant difference in the presence of organic heart disease in LBBB pts with LAD compared to normals. Aortic valve disease in LBBB pts seems to be frequently accompanied by LAD.

Correlation study of arterial blood pressure level to the amplitude of the pressure pulse waveform.

Automated blood pressure measurements are usually characterized by poor operational reliability and a considerable degree of complexity in performing the measurement. This paper introduces a new technique for the indirect measurement of the systolic and diastolic blood pressure of an individual. The technique is based upon a statistically consistent relationship between the amplitude of the pulsative pressure waveform at the systolic and diastolic points, and the amplitude of pulse signals detected when the artery is fully occluded. Clinical testing and statistical analysis techniques are used to derive appropriate numerical values for these relationship. The proposed procedure thus incorporates an adaptive measurement philosophy achieving minimum observer involvement and consequently high instrument accuracy. Overall measurement errors are maintained well within proposed standards for automated sphygmomanometers.

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.