Biomedical subjects

Marta Sitges

Publications and source records attributed to Marta Sitges.

24 records · Page 2Linked to original sources

PubMed2002

Left ventricular outflow tract mean systolic acceleration as a surrogate for the slope of the left ventricular end-systolic pressure-volume relationship.

OBJECTIVE: The goal of this study was to analyze left ventricular outflow tract systolic acceleration (LVOT(Acc)) during alterations in left ventricular (LV) contractility and LV filling. BACKGROUND: Most indexes described to quantify LV systolic function, such as LV ejection fraction and cardiac output, are dependent on loading conditions. METHODS: In 18 sheep (4 normal, 6 with aortic regurgitation, and 8 with old myocardial infarction), blood flow velocities through the LVOT were recorded using conventional pulsed Doppler. The LVOT(Acc) was calculated as the aortic peak velocity divided by the time to peak flow; LVOT(Acc) was compared with LV maximal elastance (E(m)) acquired by conductance catheter under different loading conditions, including volume and pressure overload during an acute coronary occlusion (n = 10). In addition, a clinically validated lumped-parameter numerical model of the cardiovascular system was used to support our findings. RESULTS: Left ventricular E(m) and LVOT(Acc) decreased during ischemia (1.67 +/- 0.67 mm Hg.ml(-1) before vs. 0.93 +/- 0.41 mm Hg.ml(-1) during acute coronary occlusion [p < 0.05] and 7.9 +/- 3.1 m.s(-2) before vs. 4.4 +/- 1.0 m.s(-2) during coronary occlusion [p < 0.05], respectively). Left ventricular outflow tract systolic acceleration showed a strong linear correlation with LV E(m) (y = 3.84x + 1.87, r = 0.85, p < 0.001). Similar findings were obtained with the numerical modeling, which demonstrated a strong correlation between predicted and actual LV E(m) (predicted = 0.98 [actual] -0.01, r = 0.86). By analysis of variance, there was no statistically significant difference in LVOT(Acc) under different loading conditions. CONCLUSIONS: For a variety of hemodynamic conditions, LVOT(Acc) was linearly related to the LV contractility index LV E(m) and was independent of loading conditions. These findings were consistent with numerical modeling. Thus, this Doppler index may serve as a good noninvasive index of LV contractility.

Acceleration↗

PubMed2002

Impact of left ventricular outflow tract area on systolic outflow velocity in hypertrophic cardiomyopathy: a real-time three-dimensional echocardiographic study.

OBJECTIVES: The aim of this study was to use real-time three-dimensional echocardiography (3DE) to investigate the quantitative relation between minimal left ventricular (LV) outflow tract area (A(LVOT)) and maximal LV outflow tract (LVOT) velocity in patients with hypertrophic obstructive cardiomyopathy (HCM). BACKGROUND: In patients with HCM, LVOT velocity should change inversely with minimal A(LVOT) unless LVOT obstruction reduces the pumping capacity of the ventricle. METHODS: A total of 25 patients with HCM with systolic anterior motion (SAM) of the mitral valve leaflets underwent real-time 3DE. The smallest A(LVOT) during systole was measured using anatomically oriented two-dimensional "C-planes" within the pyramidal 3DE volume. Maximal velocity across LVOT was evaluated by two-dimensional Doppler echocardiography (2DE). For comparison with 3DE A(LVOT), the SAM-septal distance was determined by 2DE. RESULTS: Real-time 3DE provided unique information about the dynamic SAM-septal relation during systole, with A(LVOT) ranging from 0.6 to 5.2 cm(2) (mean: 2.2 +/- 1.4 cm(2)). Maximal velocity (v) correlated inversely with A(LVOT) (v = 496 A(LVOT)(-0.80), r = -0.95, p < 0.001), but the exponent (-0.80) was significantly different from -1.0 (95% confidence interval: -0.67 to -0.92), indicating a significant impact of small A(LVOT) on the peak LVOT flow rate. By comparison, the best correlation between velocity and 2DE SAM-septal distance was significantly (p < 0.01) poorer at -0.83, indicating the superiority of 3DE for assessing A(LVOT). CONCLUSIONS: Three-dimensional echocardiography-measured A(LVOT) provides an assessment of HCM geometry that is superior to 2DE methods. These data indicate that the peak LVOT flow rate appears to be significantly decreased by reduced A(LVOT). Real-time 3DE is a potentially valuable clinical tool for assessing patients with HCM.

Adult↗

PubMed2002

[Long-term prognosis of women with non-ST-segment elevation acute coronary syndromes. a case-control study].

BACKGROUND AND OBJECTIVES: Women with ST-segment-elevation myocardial infarction have a worse prognosis than men. However, information about the prognosis of women with non-ST-segment-elevation acute coronary syndromes (NSTEACS) is scarce. The aim of this study was to determine if the long-term prognosis of men and women with NSTEACS differs. PATIENTS AND METHOD: Case-control study. In a consecutive series of 300 patients admitted for a NSTEACS and ischemic ECG changes, we compared the clinical characteristics, in-hospital and long-term follow-up of 95 women and 95 men matched for age, presence of diabetes, and past history of hypertension. RESULTS: The median age of patients was 69 years, 36% had diabetes, and 65% had a history of hypertension. There were no gender differences in the history of angina or hypercholesterolemia, clinical presentation, number of patients with ST-segment depression, and CK-MB elevation. However, smoking, coronary artery disease, and peripheral vascular disease were less frequent in women. Treatment at admission and at discharge was similar in men and women, as was the use of in-hospital diagnostic and therapeutic procedures (echocardiography: 80 vs 88%; coronary angiography: 57 vs 59%; percutaneous coronary intervention: 17 vs 14%; coronary surgery 13 vs. 11%). Women had a better mean ejection fraction (55 13 vs 49 14%; p < 0.01) and fewer stenosed coronary vessels (1.4 1.1 vs 2.2 0.9; p < 0.01). There were no differences in the frequency of recurrent angina (28 vs 25%), death, or infarction (both 3.2%) during hospitalization. However, during a 30-month follow-up the incidence of death, myocardial infarction, or a new episode of NSTEACS was significantly lower in women with a relative risk (RR) of 0.53 (95% CI: 0.33-0.86; p < 0.01). This apparently better prognosis persisted after adjusting for clinical data and ejection fraction (RR: 0.57 (0.33-0.98); p < 0.05), but disappeared after adjusting for the number of diseased coronary vessels (RR: 0.71 (0.35-1.47); p = 0.36). CONCLUSIONS: Women with NSTEACS had a better long-term prognosis than men. This better prognosis was independent of the patients' clinical characteristics and treatment, and could be explained by a less severe and less extensive coronary artery disease.

Aged↗

PubMed2002

Elevation of serum levels of the anti-inflammatory cytokine interleukin-10 and decreased risk of coronary events in patients with unstable angina.

BACKGROUND: Inflammation is an important phenomenon in atherosclerotic plaque growth and in plaque instability. Cytokines are nuclear mediators in the inflammatory response; some have proinflammatory and others anti-inflammatory roles. Proinflammatory cytokines have been associated with worse outcomes in unstable angina. The aims of this study were to determine the role of the anti-inflammatory cytokine interleukin (IL)-10 and the proinflammatory to anti-inflammatory ratios in the short-term prognosis of patients with unstable angina. METHODS: Serum levels of proinflammatory cytokines IL-1beta, IL-6, and IL-8, and of the anti-inflammatory cytokine IL-10 were determined on admission in 127 consecutive patients with severe unstable angina, and comparisons were made between patients who had cardiovascular events (death, nonfatal myocardial infarction, readmission for refractory angina) (n = 20) and patients without coronary events (n = 107) during a follow-up period of 3 months. RESULTS: IL-10 levels were lower (0.67 +/- 1.13 vs 1.33 +/- 1.67 pg/mL, P =.04) and IL-8 levels were higher (3.6 +/- 2.41 vs 2.23 +/- 2.47 pg/mL, P =.029) in patients in whom cardiovascular events subsequently developed compared with those without events, with resulting higher proinflammatory to anti-inflammatory cytokine ratios in the former group, whereas no significant differences were seen in IL-1beta or IL-6 levels between the groups, except for the subgroup of patients with prolonged rest angina and persistent electrocardiographic changes. A greater ratio of IL-8 to IL-10 serum levels was observed in patients who had coronary events (28 +/- 25 vs 12 +/- 21, P =.007). The risk of subsequent coronary events increased in patients in the highest quartile of proinflammatory to anti-inflammatory cytokine ratio (IL-8/IL-10). Patients in the highest quartile had a relative risk 3.8 times higher than those in the lowest quartile (P =.01). CONCLUSIONS: Lower levels of IL-10, with higher proinflammatory to anti-inflammatory cytokine ratios, were observed on admission in patients with unstable angina who subsequently had cardiovascular events. Higher levels of the anti-inflammatory cytokine IL-10 may be needed to provide protection in unstable angina.

Adult↗

PubMed2002

Pulmonary venous flow determinants of left atrial pressure under different loading conditions in a chronic animal model with mitral regurgitation.

BACKGROUND: The aim of our study was to quantitatively compare the changes and correlations between pulmonary venous flow variables and mean left atrial pressure (mLAP) under different loading conditions in animals with chronic mitral regurgitation (MR) and without MR. METHODS: A total of 85 hemodynamic conditions were studied in 22 sheep, 12 without MR as control (NO-MR group) and 10 with MR (MR group). We obtained pulmonary venous flow systolic velocity (Sv) and diastolic velocity (Dv), Sv and Dv time integrals, their ratios (Sv/Dv and Sv/Dv time integral), mLAP, left ventricular end-diastolic pressure, and MR stroke volume. We also measured left atrial a, x, v, and y pressures and calculated the difference between v and y pressures. RESULTS: Average MR stroke volume was 10.6 +/- 4.3 mL/beat. There were good correlations between Sv (r = -0.64 and r = -0.59, P <.01), Sv/Dv (r = -0.62 and r = -0.74, P <.01), and mLAP in the MR and NO-MR groups, respectively. Correlations were also observed between Dv time integral (r = 0.61 and r = 0.57, P <.01) and left ventricular end-diastolic pressure in the MR and NO-MR groups. In velocity variables, Sv (r = -0.79, P <.001) was the best predictor of mLAP in both groups. The sensitivity and specificity of Sv = 0 in predicting mLAP 15 mm Hg or greater were 86% and 85%, respectively. CONCLUSION: Pulmonary venous flow variables correlated well with mLAP under altered loading conditions in the MR and NO-MR groups. They may be applied clinically as substitutes for invasively acquired indexes of mLAP to assess left atrial and left ventricular functional status.

Animals↗

PubMed2002

Recombinant soluble P-selectin glycoprotein ligand-Ig (rPSGL-Ig) attenuates infarct size and myeloperoxidase activity in a canine model of ischemia-reperfusion.

The role of P-selectin in the process of reperfusion injury was evaluated using a recombinant soluble P-selectin glycoprotein ligand-Ig (rPSGL-Ig) in a canine coronary artery balloon occlusion model. rPSGL-Ig (1 mg/kg) or saline was given as an intravenous bolus 15 min before balloon deflation. Balloon occlusion time was 90 min followed by either 120 min or 7 days reperfusion. Infarct size was significantly reduced in the treatment group when expressed either as percentage of the area at risk or as absolute infarct size. Histological analysis showed that extensive myocardial injury and neutrophil infiltration were reduced by rPSGL-Ig. Myeloperoxidase activity (MPO) was significantly reduced in the risk area in the rPSGL-Ig group. Left ventricular ejection fraction was significantly less impaired during the first 24 h after reperfusion in the rPSGL-Ig group, although there was no difference by 7-day follow-up. Thus, administration of rPSGL-Ig decreases myocardial injury and inflammatory response for at least 7 days after reperfusion of ischemic myocardium.

Animals↗