7 research outputs found
Przezsk贸rna ablacja opornego na farmakologiczne leczenie ustawicznego migotania kom贸r w przebiegu ostrego incydentu wie艅cowego
M臋偶czyzn臋 w wieku 77 lat przyj臋to do szpitala z powodu ostrego incydentu wie艅cowego, ci臋偶kiej
niewydolno艣ci serca oraz nawracaj膮cych epizod贸w migotania kom贸r. Pojedyncze przedwczesne
skurcze komorowe wywo艂ywa艂y cz臋stoskurcz komorowy, kt贸ry powtarzalnie przechodzi艂 w migotanie
kom贸r. W wyniku zastosowania ablacji tylno-przegrodowej cz臋艣ci lewej komory, gdzie
poprzednio rejestrowano podw贸jne potencja艂y pochodz膮ce z w艂贸kien Purkinjego, wyeliminowano
dodatkowe przedwczesne skurcze komorowe. Po zabiegu ust膮pi艂y objawy „burzy elektrycznej”
serca, a podczas wykonywanej po ablacji programowanej stymulacji kom贸r nie wywo艂ano
偶adnej tachyarytmii. Dodatkowe przedwczesne skurcze komorowe sta艂y si臋 mechanizmem wyzwalaj膮cym,
a zarazem r贸wnie偶 substratem dla powstania cz臋stoskurczu komorowego oraz
migotania kom贸r w przebiegu ostrego incydentu wie艅cowego wsp贸艂istniej膮cego z niewydolno艣ci膮
serca. (Folia Cardiologica Excerpta 2006; 1: 492-496
Distribution of ultrasonic radiofrequency signal amplitude detects lipids in atherosclerotic plaque of coronary arteries: an ex-vivo study
Distribution of ultrasonic radiofrequency signal amplitude detects lipids in atherosclerotic plaque of coronary arteries: an ex-vivo study
Abstract Background Accumulation of lipids within coronary plaques is an important process in disease progression. However, gray-scale intravascular ultrasound images cannot detect plaque lipids effectively. Radiofrequency signal analysis could provide more accurate information on preclinical coronary plaques. Methods We analyzed 29 zones of mild atheroma in human coronary arteries acquired at autopsy. Two histologic groups, i.e., plaques with a lipid core (group L) and plaques without a lipid core (group N), were analyzed by automatic calculation of integrated backscatter. One hundred regions of interest were set on the target zone. Radiofrequency signals from a 50 MHz transducer were digitized at 240 MHz with 12-bit resolution. The intensity of integrated backscatter and its distribution within each plaque were compared between the two groups. Results Although the mean backscatter was similar between the groups, intraplaque variation of backscatter and backscatter in the axial direction were larger in group L than in group N (p = 0.02). Conventional intravascular ultrasound showed extremely low sensitivity for lipid detection, despite a high specificity. In contrast, a cut-off value>32 for the total variance of integrated backscatter identified lipid-containing plaque with a high sensitivity (85%) and specificity (75%). Conclusion Compared with conventional imaging, assessment of the intraplaque distribution of integrated backscatter is more effective for detecting lipid. As coronary atheroma progresses, its composition becomes heterogeneous and multi-layered. This radiofrequency technique can portray complex plaque histology and can detect the early stage of plaque progression.</p
Comparison of Diagnostic Accuracy between Pulse Volume Recording Parameters and Exercise-Ankle-Brachial Pressure Index in Patients with Ankle-Brachial Pressure Index above 0.91
Distribution of ultrasonic radiofrequency signal amplitude detects lipids in atherosclerotic plaque of coronary arteries: an ex-vivo study-0
<p><b>Copyright information:</b></p><p>Taken from "Distribution of ultrasonic radiofrequency signal amplitude detects lipids in atherosclerotic plaque of coronary arteries: an ex-vivo study"</p><p>http://www.cardiovascularultrasound.com/content/6/1/18</p><p>Cardiovascular Ultrasound 2008;6():18-18.</p><p>Published online 9 May 2008</p><p>PMCID:PMC2391144.</p><p></p