Background Female patients with atrial fibrillation （AF） experience increased risk of thromboembolism compared to males, an observation that is reflected by its inclusion in the CHA2DS2VASc score. New onset AF （oft...Background Female patients with atrial fibrillation （AF） experience increased risk of thromboembolism compared to males, an observation that is reflected by its inclusion in the CHA2DS2VASc score. New onset AF （often associated with tachycardia） also confers upon patients increased thromboembolic risk. The mechanisms underlying this risk are uncertain, but new onset AF is associated with profound impairment of platelet nitric oxide （NO） signalling. Given that cardiovascular responses to catecholamines are gender-dependent, and that the presence of tachycardia in new onset AF may represent a response to catecholaminergic stimulation, we explored the potential impact of gender and tachycardia on platelet aggregation and NO signalling. Methods Interactions were sought in 87 AF patients between the extent of adenosine diphosphate （ADP）-induced platelet aggregation, the anti-aggregatory effects of the NO donor, sodium nitroprusside, gender, and admission heart rate. The potential impact of platelet expression of thioredoxin-interacting protein （Txnip） was also evaluated. Results Analysis ofcovariance confLrmed the presence of physiological antagonism between platelet ADP and NO responses [F （1, 74） = 12.212, P 〈 0.01 ], while female sex correlated with impaired NO responses independent of platelet aggregability [F （2, 74） = 8.313, P 〈 0.01]. Admission heart rate correlated directly with platelet aggregation （r = 0.235, P 〈 0.05）, and inversely with NO response （r = -0.331, P 〈 0.01）. Txnip expression varied neither with gender nor with heart rate. Conclusions These results indicate, that gender and heart rate are independent determinants of platelet fimction. Prospective studies of the putative benefit of reversal of tachycardia on restoration of normal platelet function are therefore a priority.展开更多
Coronary artery disease(CAD) screening and diagnosis are core cardiac specialty services.From symptoms,autopsy correlations supported reductions in coronary blood flow and dynamic epicardial and microcirculatory coron...Coronary artery disease(CAD) screening and diagnosis are core cardiac specialty services.From symptoms,autopsy correlations supported reductions in coronary blood flow and dynamic epicardial and microcirculatory coronaries artery disease as etiologies.While angina remains a clinical diagnosis,most cases require correlation with a diagnostic modality.At the onset of the evidence building process much research,now factored into guidelines were conducted among population and demographics that were homogenous and often prior to newer technologies being available.Today we see a more diverse multi-ethnic population whose characteristics and risks may not consistently match the populations from which guideline evidence is derived.While it would seem veryunlikely that for the majority,scientific arguments against guidelines would differ,however from a translational perspective,there will be populations who differ and importantly there are cost-efficacy questions,e.g.,the most suitable first-line tests or what parameters equate to an adequate test.This article reviews non-invasive diagnosis of CAD within the context of multi-ethnic patient populations.展开更多
文摘Background Female patients with atrial fibrillation （AF） experience increased risk of thromboembolism compared to males, an observation that is reflected by its inclusion in the CHA2DS2VASc score. New onset AF （often associated with tachycardia） also confers upon patients increased thromboembolic risk. The mechanisms underlying this risk are uncertain, but new onset AF is associated with profound impairment of platelet nitric oxide （NO） signalling. Given that cardiovascular responses to catecholamines are gender-dependent, and that the presence of tachycardia in new onset AF may represent a response to catecholaminergic stimulation, we explored the potential impact of gender and tachycardia on platelet aggregation and NO signalling. Methods Interactions were sought in 87 AF patients between the extent of adenosine diphosphate （ADP）-induced platelet aggregation, the anti-aggregatory effects of the NO donor, sodium nitroprusside, gender, and admission heart rate. The potential impact of platelet expression of thioredoxin-interacting protein （Txnip） was also evaluated. Results Analysis ofcovariance confLrmed the presence of physiological antagonism between platelet ADP and NO responses [F （1, 74） = 12.212, P 〈 0.01 ], while female sex correlated with impaired NO responses independent of platelet aggregability [F （2, 74） = 8.313, P 〈 0.01]. Admission heart rate correlated directly with platelet aggregation （r = 0.235, P 〈 0.05）, and inversely with NO response （r = -0.331, P 〈 0.01）. Txnip expression varied neither with gender nor with heart rate. Conclusions These results indicate, that gender and heart rate are independent determinants of platelet fimction. Prospective studies of the putative benefit of reversal of tachycardia on restoration of normal platelet function are therefore a priority.
文摘Coronary artery disease(CAD) screening and diagnosis are core cardiac specialty services.From symptoms,autopsy correlations supported reductions in coronary blood flow and dynamic epicardial and microcirculatory coronaries artery disease as etiologies.While angina remains a clinical diagnosis,most cases require correlation with a diagnostic modality.At the onset of the evidence building process much research,now factored into guidelines were conducted among population and demographics that were homogenous and often prior to newer technologies being available.Today we see a more diverse multi-ethnic population whose characteristics and risks may not consistently match the populations from which guideline evidence is derived.While it would seem veryunlikely that for the majority,scientific arguments against guidelines would differ,however from a translational perspective,there will be populations who differ and importantly there are cost-efficacy questions,e.g.,the most suitable first-line tests or what parameters equate to an adequate test.This article reviews non-invasive diagnosis of CAD within the context of multi-ethnic patient populations.
