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    Previous data showed that PFOs not detected by high-quality transthoracic echocardiography are smaller and associated with small right-to-left shunts (4); therefore, they are far less likely to be associated with embolic stroke features (5)

    Quantification of Myocardial Perfusion in Human Subjects Using 82Rb and Wavelet-Based Noise Reduction

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    Quantification of myocardial perfusion with 82Rb has been difficult to achieve because of the low signal-to-noise ratio of the dynamic data curves. This study evaluated the accuracy of flow estimates after the application of a novel multidimensional wavelet-based noise-reduction protocol. Methods: Myocardial perfusion was estimated using 82Rb and a two-compartment model from dynamic PET scans on 11 healthy volunteers at rest and after hyperemic stress with dipyridamole. Midventricular planes were divided into eight regions of interest, and a wavelet transform protocol was applied to images and time–activity curves. Flow estimates without and with the wavelet approach were compared with those obtained using H215O. Results: Over a wide flow range (0.45–2.75 mL/g/min), flow achieved with the wavelet approach correlated extremely closely with values obtained with H215O (y = 1.03 x -0.12; n = 23 studies, r = 0.94, P < 0.001). If the wavelet noise-reduction technique was not used, the correlation was less strong (y = 1.11 x + 0.24; n = 23 studies, r = 0.79, P < 0.001). In addition, the wavelet approach reduced the regional variation from 75% to 12% and from 62% to 11% (P < 0.001 for each comparison) for resting and stress studies, respectively. Conclusion: The use of a wavelet protocol allows near-optimal noise reduction, markedly enhances the physiologic flow signal within the PET images, and enables accurate measurement of myocardial perfusion with 82Rb in human subjects over a wide range of flows

    Absolute quantitation of coronary steal induced by intravenous dipyridamole

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    AbstractOBJECTIVESThe study was done to determine whether coronary steal (defined as an absolute decrease in perfusion from resting blood flow) is induced by intravenous (IV) dipyridamole in patients with severe coronary artery disease (CAD).BACKGROUNDMyocardial ischemia during coronary vasodilation is usually attributed to coronary steal. However, there is limited data on the absolute magnitude of coronary steal in humans.METHODSEighteen patients with multivessel CAD underwent dynamic positron emission tomography (PET) imaging with 13NH3at rest and after infusion of IV dipyridamole. Eight myocardial sectors were analyzed per short axis slice and myocardial blood flow calculated with a two-compartment model in absolute terms.RESULTSCoronary steal occurred in 8 of the 18 patients. In the 8 patients with coronary steal, myocardial blood flow decreased from 90 ± 18 ml/100 g/min at rest to 68 ± 27 ml/100 g/min following dipyridamole in the segments with steal, and increased from 87 ± 19 to 138 ± 16 ml/100 g/min following dipyridamole in the segments without steal. Significant clinical correlates of coronary steal were either ST elevation or the combination of ST depression and angina.CONCLUSIONSCoronary vasodilation with IV dipyridamole is associated with significant reductions in blood flow to collateral-dependent myocardium consistent with coronary steal in about 45% of patients with severe CAD

    Relationship Between Cardiovascular Disease Knowledge and Race/Ethnicity, Education, and Weight Status

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    Background: Inadequate cardiovascular disease (CVD) knowledge has been cited to account for the imperfect decline in CVD among women over the last 2 decades. Hypothesis: Due to concerns that at-risk women might not know the leading cause of death or symptoms of a heart attack, our goal was to assess the relationship between CVD knowledge race/ethnicity, education, and body mass index (BMI). Methods: Using a structured questionnaire, CVD knowledge, socio-demographics, risk factors, and BMI were evaluated in 681 women. Results: Participants included Hispanic, 42.1% (n = 287); non-Hispanic white (NHW), 40.2% (n = 274); non-Hispanic black (NHB), 7.3% (n = 50); and Asian/Pacific Islander (A/PI), 8.7% (n = 59). Average BMI was 26.3 ± 6.1 kg/m2. Hypertension was more frequent among overweight (45%) and obese (62%) than normal weight (24%) (P 12 years (both P < 0.0001). Conclusions: Effective prevention strategies for at-risk populations need to escalate CVD knowledge and awareness among the undereducated and minority women

    Endothelial dysfunction is associated with carotid plaque: a cross-sectional study from the population based Northern Manhattan Study

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    BACKGROUND: Impaired vascular function occurs early in atherogenesis. Brachial flow mediated dilatation (FMD) is a non-invasive measure of vascular function and may be an important marker of preclinical atherosclerosis. Data on the association between FMD and carotid plaque in multi-ethnic populations are limited. The objective of this study was to determine whether endothelial dysfunction is independently associated with carotid plaque in a community of northern Manhattan. METHODS: In the population-based Northern Manhattan Study (NOMAS), high-resolution B-mode ultrasound images of the brachial and carotid arteries were obtained in 643 stroke-free subjects (mean age 66 years; 55% women; 65% Caribbean-Hispanic, 17% African-American, 16% Caucasian). Brachial FMD was measured during reactive hyperemia. Maximum carotid plaque thickness (MCPT) was measured at the peak plaque prominence. RESULTS: The mean brachial FMD was 5.78 ± 3.83 %. Carotid plaque was present in 339 (53%) subjects. The mean MCPT was 1.68 ± 0.82 mm, and the 75(th )percentile was 2.0 mm. Reduced FMD was significantly associated with increased MCPT. After adjusting for demographics, vascular risk factors, and education, each percent of FMD decrease was associated with a significant 0.02 mm increase in MCPT (p = 0.028). In a dichotomous adjusted model, blunted FMD was associated with an increased risk of MCPT ≥ 2.0 mm (OR, 1.11 for every 1% decrease in FMD; 95% CI, 1.03–1.19). CONCLUSION: Decreased brachial FMD is independently associated with carotid plaque. Non-invasive evaluation of endothelial dysfunction may be a useful marker of preclinical atherosclerosis and help to individualize cardiovascular risk assessment beyond traditional risk factors

    Rizik neželjenih događaja kod bolesnika s otvorenim foramen ovale liječenih lijekovima: pregled literature

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    Patent foramen ovale is associated with stroke. However, the rate of recurrent events in medically treated patients with patent foramen ovale remains undefined. Estimates differ by the studies. In order to provide a more accurate estimate of the recurrent adverse event rates in medically treated patients with patent foramen ovale, we reviewed the literature and analyzed the results from a total of 1,108 patients combining 12 studies. We found the annual rate of stroke or death to be 3.12% (95% CI, 2.32-4.11%). This estimate will provide a valuable guideline for any future study to compare the efficacy of other modalities such as percutaneous device closure of patent foramen ovale with medical treatment.Otvoreni foramen ovale (OFO) udružen je s moždanim udarom. Međutim, učestalost rekurentnih neželjenih događaja u bolesnika liječenih lijekovima s otvorenim foramen ovale nije poznata, a procjene iz različitih studija se razlikuju. Stoga smo obavili pregled literature i analizirali rezultate za ukupno 1.108 bolesnika iz 12 studija, kako bismo dobili točniju procjenu učestalosti neželjenih događaja u bolesnika s otvorenim foramen ovale liječenih lijekovima. Utvrdili smo godišnju stopu moždanog udara ili smrti od 3,12% (95% CI, 2,32-4,11%). Ova će procjena poslužiti kao vrijedna smjernica za buduća ispitivanja u kojima će se uspoređivati učinkovitost drugih načina liječenja, primjerice, zatvaranje otvorenog foramen ovale pomoću perkutanog uređaja uz medikamentno liječenje
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