Novel ultrasound contrast agent dilution method for the assessment of ventricular ejection fraction

Aims: Left ventricular (LV) ejection fraction is an important determinant of prognosis in heart failure. We evaluated the accuracy of a novel algorithm for LV ejection fraction quantification based on indicator dilution curve (IDC) principles using ultrasound contrast as indicator, and compared the results with contrast enhanced biplane LV ejection fraction assessment. Method: A diluted ultrasound contrast bolus (SonoVue®) was injected intravenously in 31 patients (19 male, age 65 ± 11) with known or suspected heart disease. A total of 68 recordings were made. The developed algorithm used the left atrium and LV IDC for LV ejection fraction measurement. Biplane enhanced LV ejection fraction measurements with pure ultrasound contrast (SonoVue®) were determined in multiple four- and two-chamber recordings as reference. Results: The mean LV ejection fraction measured by biplane and IDC method was 33 ± 17% and 35 ± 18%, respectively. A correlation coefficient r = 0.93 was observed between the two methods. Bland–Altman analysis demonstrated a slight LV ejection fraction overestimation with IDC (mean 1.9 ± 6.3%). Conclusion: A new fast method for LV ejection fraction assessment based on IDC principles is described and comparison with contrast enhanced biplane LV ejection fraction quantification shows accurate results

Novel ultrasound-contrast-agent dilution method for assessment of left ventricular ejection faction

Background: Left ventricular ejection fraction (LVEF) is an important determinant of prognosis. We evaluated the accuracy of a novel fast method for LVEF quantification based on indicator dilution curve (IDC) principles (figure 1) and compared the results with contrast-enhanced biplane LVEF assessment. Method: a 10 ml diluted (1:100) ultrasound-contrast bolus (SonoVue ®) was injected intravenously in thirty patients (pts) (20 male, age 65 ± 10) with known or suspected heart disease. In 22 pts multiple recordings were made and in 12 pts injections were repeated after implantation of a biventricular pacemaker, leading to 68 measurements. The developed algorithm used the left atrium and LV IDC for the LVEF measurement. For the biplane enhanced LVEF measurements a 0.5 ml pure ultrasound-contrast bolus (SonoVue ®) was administered to obtain multiple four- and two-chamber recordings. Results: according to contrast enhanced biplane assessments, the LVEF ranged from 10 to 75 % while the LV end-diastolic volume ranged from 80 to 521 ml. The mean LVEF measured by the biplane and the IDC method was 33 ± 17 % and 35 ± 18 %, respectively. A correlation coefficient r=0.91 was observed between the two methods (figure 2). Conclusion: A new fast method for LVEF assessment based on IDC principles is described and comparison with contrast enhanced biplane LVEF quantification shows accurate results. The proposed method also allows simultaneous quantification of right ventricular EF based on the same IDC principles

Effect of a nurse-coordinated prevention programme on cardiovascular risk after an acute coronary syndrome: main results of the RESPONSE randomised trial

Objective To quantify the impact of a practical, hospital-based nurse-coordinated prevention programme on cardiovascular risk, integrated into the routine clinical care of patients discharged after an acute coronary syndrome, as compared with usual care only. Design RESPONSE (Randomised Evaluation of Secondary Prevention by Outpatient Nurse SpEcialists) was a randomised clinical trial. Setting Multicentre trial in secondary and tertiary healthcare settings. Participants 754 patients admitted for acute coronary syndrome. Intervention A nurse-coordinated prevention programme, consisting of four outpatient nurse clinic visits, focusing on healthy lifestyles, biometric risk factors and medication adherence, in addition to usual care. Main outcome measures The main outcome was 10-year cardiovascular mortality risk as estimated by Systematic Coronary Risk Evaluation at 12 months follow-up. Secondary outcomes included Framingham Coronary Risk Score at 12 months, in addition to changes in individual risk factors. Risk factor control was classified as ‘poor’ if 0 to 3 factors were on target, ‘fair’ if 4 to 6 factors were on target, and ‘good’ if 7 to 9 were on target. Results The mean Systematic Coronary Risk Evaluation at 12 months was 4.4 per cent (SD 4.5) in the intervention group and 5.4 per cent (SD 6.2) in the control group (p=0.021), representing a 17.4% relative risk reduction. At 12 months, risk factor control classified as ‘good’ was achieved in 35% of patients in the intervention group compared with 25% in the control group (p=0.003). Attendance to the nurse-coordinated prevention programme was 92%. In the intervention group, 86 rehospitalisations were observed against 132 in the control group (relative risk reduction 34.8%, p=0.023). Conclusions The nurse-coordinated hospital-based prevention programme in addition to usual care is a practical, yet effective method for reduction of cardiovascular risk in patients with coronary disease. Our data suggest that the counselling component of the programme may lead to a reduction in hospital readmissions

Large enhancement of deuteron polarization with frequency modulated microwaves

We report a large enhancement of 1.7 in deuteron polarization up to values of 0.6 due to frequency modulation of the polarizing microwaves in a two liters polarized target using the method of dynamic nuclear polarization. This target was used during a deep inelastic polarized muon-deuteron scattering experiment at CERN. Measurements of the electron paramagnetic resonance absorption spectra show that frequency modulation gives rise to additional microwave absorption in the spectral wings. Although these results are not understood theoretically, they may provide a useful testing ground for the deeper understanding of dynamic nuclear polarization.Comment: 10 pages, including the figures coming in uuencoded compressed tar files in poltar.uu, which also brings cernart.sty and crna12.sty files neede

Study of large hemispherical photomultiplier tubes for the ANTARES neutrino telescope

The ANTARES neutrino telescope, to be immersed depth in the Mediterranean Sea, will consist of a 3 dimensional matrix of 900 large area photomultiplier tubes housed in pressure resistant glass spheres. The selection of the optimal photomultiplier was a critical step for the project and required an intensive phase of tests and developments carried out in close collaboration with the main manufacturers worldwide. This paper provides an overview of the tests performed by the collaboration and describes in detail the features of the PMT chosen for ANTARES