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Biomedical subjects

E Lipp

Publications and source records attributed to E Lipp.

7 recordsLinked to original sources

Regional left ventricular function during transient coronary occlusion: relation with coronary collateral flow.

OBJECTIVE: To test the hypothesis that regional left ventricular (LV) function during balloon angioplasty is related to the amount of collateral flow to the ischaemic region. DESIGN: Prospective study. SETTING: Tertiary referral centre. METHODS: In 50 patients with coronary artery disease and without myocardial infarction, regional systolic and diastolic LV function was determined using tissue Doppler ultrasound (TD) before and at the end of a 60 second occlusion of a stenotic lesion undergoing percutaneous transluminal coronary angioplasty (PTCA) through a pressure guidewire. The study population was subdivided into a group with collaterals insufficient (n = 33) and one with collaterals sufficient (n = 17) to prevent ECG ST shifts suggestive of myocardial ischaemia during PTCA. Pulsed TD was performed from an apical window in the myocardial region supplied by the vessel being treated by PTCA. Pressure derived collateral flow index (CFI) was determined by simultaneous measurement of mean aortic (P(ao)) and distal intracoronary occlusive pressures (P(occl)), where CFI = (P(occl) - 8)/(P(ao) - 8). RESULTS: At 60 seconds of occlusion, several parameters of systolic and diastolic TD derived LV long axis function were significantly different between the groups. Also, there was a significant correlation between regional systolic excursion velocity, early diastolic excursion velocity, regional isovolumetric relaxation time, and CFI. CONCLUSION: During brief coronary artery occlusions, regional systolic and diastolic LV function is directly related to the amount of collateral flow to this territory.

Angioplasty, Balloon, Coronary↗

Gender differences in coronary artery size per 100 g of left ventricular mass in a population without cardiac disease.

OBJECTIVES: To determine whether there is a gender difference in coronary artery size normalised for left ventricular (LV) mass. BACKGROUND: Small coronary artery caliber may play a role as a risk factor for coronary artery disease in women. However, the existence of a gender difference in coronary artery size is controversial. Furthermore, coronary artery size ought to be normalised for LV mass, since there is a theoretical relation of coronary artery size to LV mass according to the law of minimum viscous energy loss for the transport of blood in the coronary circulation. METHODS: In 200 individuals (100 women) without cardiac disease and with normal Doppler echocardiography, left main (LCA) and right coronary artery (RCA) size were determined using transoesophageal echocardiography. LV mass was assessed by transgastric M-mode echocardiography. RESULTS: Age (44 +/- 15 years in women; 41 +/- 16 years in men), the presence of non-cardiac diseases, cardiovascular risk factors and medication were similar in women and men. LV mass in women was lower than in men (148 +/- 36 g, 189 +/- 45 g; p < 0.0001). LCA and RCA cross-sectional areas in women were smaller than those in men (LCA: 10 +/- 3 and 16 +/- 5 mm2, p < 0.0001; RCA: 4 +/- 2 and 7 +/- 3 mm2, p < 0.0001, respectively). LCA and RCA cross-sectional areas of women were smaller even after normalisation for LV mass (LCA: 7 +/- 3 and 9 +/- 3 mm2/100 g LV mass, p < 0.0001; RCA: 3 +/- 1 and 4 +/- 1 mm2/100 g LV mass, p = 0.002, respectively). LCA caliber of women ranged below the theoretically expected size according to the law of minimum viscous energy loss for the transport of blood in the coronary circulation, whereas those of men tended to be above it. CONCLUSIONS: In a population without cardiac disease, women have smaller coronary artery size even after normalisation for left ventricular mass.

Adult↗

Relation between directly detected patent foramen ovale and ischemic brain lesions in sport divers.

BACKGROUND: In divers, the significance of a patent foramen ovale and its potential relation to paradoxical gas emboli remain uncertain. OBJECTIVE: To assess the prevalence of symptoms of decompression illness and ischemic brain lesions in divers with regard to the presence of a patent foramen ovale. DESIGN: Retrospective cohort study. SETTING: University hospital and three diving clubs in Switzerland. PARTICIPANTS: 52 sport divers and 52 nondiving controls. MEASUREMENTS: Prevalence of self-reported decompression events, patent foramen ovale on contrast transesophageal echocardiography, and ischemic brain lesions on magnetic resonance imaging. RESULTS: The risk for decompression illness events was 4.5-fold greater in divers with patent foramen ovale than in divers without patent foramen ovale (risk ratio, 4.5 [95% CI, 1.2 to 18.0]; P = 0.03). Among divers, 1.23 +/- 2.0 and 0.64 +/- 1.22 ischemic brain lesions per person (mean +/- SD) were detected in those with and those without patent foramen ovale, respectively. Among controls, 0.22 +/- 0.44 and 0.12 +/- 0.63 lesion per person were detected (P < 0.001 for all groups). CONCLUSIONS: Regardless of whether a diver has a patent foramen ovale, diving is associated with ischemic brain lesions.

Adult↗

Doppler tissue imaging for assessing left ventricular diastolic dysfunction in heart transplant rejection.

OBJECTIVE: To test the hypothesis that diastolic mitral annular motion velocity, as determined by Doppler tissue imaging and left ventricular diastolic flow propagation velocity, is related to the histological degree of heart transplant rejection according to the International Society of Heart and Lung Transplantation (ISHLT). METHODS: In 41 heart transplant recipients undergoing 151 myocardial biopsies, the following Doppler echocardiographic measurements were performed within one hour of biopsy: transmitral and pulmonary vein flow indices; mitral annular motion velocity indices; left ventricular diastolic flow propagation velocity. RESULTS: Late diastolic mitral annular motion velocity (A(DTI)) and mitral annular systolic contraction velocity (SC(DTI)) were higher in patients with ISHLT < IIIA than in those with ISHLT >/= IIIA (A(DTI), 8.8 cm/s v 7.7 cm/s (p = 0.03); SC(DTI), 19.3 cm/s v 9.3 cm/s (p < 0.05)). Sensitivity and specificity of A(DTI) < 8.7 cm/s (the best cut off value) in predicting significant heart transplant rejection were 82% and 53%, respectively. Early diastolic mitral annular motion velocity (E(DTI)) and flow propagation velocity were not related to the histological degree of heart transplant rejection. CONCLUSIONS: Doppler tissue imaging of the mitral annulus is useful in diagnosing heart transplant rejection because a high late diastolic mitral annular motion velocity can reliably exclude severe rejection. However, a reduced late diastolic mitral annular motion velocity cannot predict severe rejection reliably because it is not specific enough.

Blood Flow Velocity↗

Antibodies against platelet glycoproteins and antiphospholipid antibodies in autoimmune thrombocytopenia.

Autoantibodies against platelet glycoproteins (anti-GP) are found in the majority of patients with autoimmune thrombocytopenia (AITP) as well as in thrombocytopenia associated with systemic lupus erythematosus (SLE). Some of these patients may have anti-phospholipid antibodies (anti-PL). To evaluate the pathogenetic significance of anti-PL and anti-GP antibodies in AITP and SLE patients, we investigated anti-cardiolipin (anti-CL), anti-phosphatidylserine (anti-PS) and anti-GP antibodies (anti-GPIIb-IIIa and anti-GPIb-IX) in 71 patients with AITP and 3 thrombocytopenic patients with SLE. Anti-GP antibodies were detected in 52 (70%) patients. Fifty-six (73%) patients showed anti-PL antibodies. Seven patients (6 AITP, 1 SLE) with both anti-GPIIb-IIIa and IgG anti-PL antibodies were followed during treatment with corticosteroids. Antibodies were measured before treatment and at the time of platelet-peak. Anti-GPIIb-IIIa antibodies decreased in all or became undetectable in five. In contrast, IgG anti-PS and IgG anti-CL antibodies decreased only moderately or remained positive. Adsorption experiments, using gelfiltered platelets, erythrocyte (Ec)-inside-out-vesicles and purified GPIIb-IIIa, showed that anti-GP and anti-PL antibodies have distinct specificities and do not crossreact. We conclude that anti-PL and anti-GP antibodies may be present simultaneously in some patients with immune mediated thrombocytopenia. Although anti-PS as well as anti-CL antibodies may be responsible for thrombocytopenia, we speculate that anti-GPIIb-IIIa antibodies are more related to the severity of thrombocytopenia.

Adolescent↗

International study to compare antigen-specific methods used for the measurement of antiplatelet autoantibodies.

Platelet-associated and plasma autoantibodies against platelet glycoproteins (GP) have been demonstrated in patients with autoimmune thrombocytopenia (AITP) using various methods. Eight laboratories in seven countries participated in this international study to evaluate the interlaboratory agreement using glycoprotein-specific immunoassays for these autoantibodies. The participating laboratories received blind samples of frozen washed platelets and plasma from 22 normal donors and 22 AITP patients. Platelet-associated and plasma autoantibodies against GPIIb-IIIa and GPIb-IX were measured by MAIPA, immunobead assay or modified antigen capture assay. Of the control samples, 96.0% and 97.2% of all results for platelet-associated and plasma autoantibodies to GPIIb-IIIa/ GPIb-IX, respectively, were negative. The mean variation coefficient of the control samples of platelet-associated and plasma autoantibodies was 89.5% (range 11.1-272.9%) and 46.5% (range 21.0-78.0%), respectively. In 20/22 patient samples, platelet-associated autoantibodies to either glycoprotein were noted by at least two laboratories. The mean degree of agreement in these samples was 74.0%. There was a significant correlation in the individual antibody measurements between all laboratories (Kendall coefficient of concordance 0.60 and 0.38, P < 0.001; Spearman rank order test, range of correlation coefficient 52.3-94.0% and 42.2-85.0%, P < 0.05, for anti-GPIIb-IIIa and anti-GPIb-IX, respectively). In contrast, plasma autoantibodies to either glycoprotein were noted by at least two laboratories in only 13/22 patient samples. Moreover, the degree of agreement was poor (50.1%) and a significant correlation was noted between only six pairs of laboratories. We conclude that methods used in this study yield good interlaboratory agreement in measuring platelet-associated autoantibodies against GPIIb-IIIa and GPIb-IX. In contrast, poor agreement was found in detecting plasma autoantibodies to the same glycoproteins.

Autoantibodies↗