Prevalence of and variables associated with silent myocardial ischemia on exercise thallium-201 stress testing

AbstractThe prevalence of silent myocardial ischemia was prospectively assessed in a group of 103 consecutive patients (mean age 59 ± 10 years, 79% male) undergoing symptom-limited exercise thallium-201 scintigraphy. Variables that best correlated with the occurance of patients ischemia by quantitative scintigraphic criteria were examined. Fifty-nine patients (57%) had no angina on exercise testing. A significantly greater persent of patients with silent ischemia than of patients with angina had a recent myocardial infarction (31% versus 7%, P < 0.01), had no prior angina (91% versus 64%, p < 0.01), had dyspnea as an exercise test end point (56% versus 35%, p < 0.05) and exhibited redistribution defects in the supply regions of the right and circumflex coronary arteries (50% versus 35%, p < 0.05). The group with exercise angina had more ST depression (64% versus 41%, p < 0.05) and more patients with four or more redistribution defects.However, there was no difference between the two groups with respect to mean total thallium-201 perfusion score, number of redistribution defects per patient, multivessel thallium redistribution pattern or extent of angiographic coronary artery disease. There was also no difference between the silent ischemia and angina groups with respect to antianginal drug, usage, prevalence of diabetes mellitus, exercise duration, peak exercise heart rate, peak work load, peak double (rate-pressure) product and percent of patients achieving ≥85% of maximal predicted heart rate for age.Thus, in this study group, there was a rather high prevalence rate of silent ischemia (57%) by exercise thallium-201 criteria. Patients with silent ischemia and those with exercise angina had comparable 1) exercise tolerance and hemodynamics, 2) extent of angiographic coronary artery disease, and 3) extent of exercise-induced hypoperfusion. Finally, more patients with recent infarction had silent ischemia than had exercise angina

Stable population structure in Europe since the Iron Age, despite high mobility

Ancient DNA research in the past decade has revealed that European population structure changed dramatically in the prehistoric period (14,000–3000 years before present, YBP), reflecting the widespread introduction of Neolithic farmer and Bronze Age Steppe ancestries. However, little is known about how population structure changed from the historical period onward (3000 YBP - present). To address this, we collected whole genomes from 204 individuals from Europe and the Mediterranean, many of which are the first historical period genomes from their region (e.g. Armenia and France). We found that most regions show remarkable inter-individual heterogeneity. At least 7% of historical individuals carry ancestry uncommon in the region where they were sampled, some indicating cross-Mediterranean contacts. Despite this high level of mobility, overall population structure across western Eurasia is relatively stable through the historical period up to the present, mirroring geography. We show that, under standard population genetics models with local panmixia, the observed level of dispersal would lead to a collapse of population structure. Persistent population structure thus suggests a lower effective migration rate than indicated by the observed dispersal. We hypothesize that this phenomenon can be explained by extensive transient dispersal arising from drastically improved transportation networks and the Roman Empire’s mobilization of people for trade, labor, and military. This work highlights the utility of ancient DNA in elucidating finer scale human population dynamics in recent history

Stable population structure in Europe since the Iron Age, despite high mobility

International audienceAncient DNA research in the past decade has revealed that European populationstructure changed dramatically in the prehistoric period (14,000–3000 years before present, YBP),reflecting the widespread introduction of Neolithic farmer and Bronze Age Steppe ancestries.However, little is known about how population structure changed from the historical period onward(3000 YBP - present). To address this, we collected whole genomes from 204 individuals fromEurope and the Mediterranean, many of which are the first historical period genomes from theirregion (e.g. Armenia and France). We found that most regions show remarkable inter-individualheterogeneity. At least 7% of historical individuals carry ancestry uncommon in the region wherethey were sampled, some indicating cross-Mediterranean contacts. Despite this high level ofmobility, overall population structure across western Eurasia is relatively stable through the historicalperiod up to the present, mirroring geography. We show that, under standard population geneticsmodels with local panmixia, the observed level of dispersal would lead to a collapse of populationstructure. Persistent population structure thus suggests a lower effective migration rate than indi-cated by the observed dispersal. We hypothesize that this phenomenon can be explained by exten-sive transient dispersal arising from drastically improved transportation networks and the RomanEmpire’s mobilization of people for trade, labor, and military. This work highlights the utility ofancient DNA in elucidating finer scale human population dynamics in recent history