کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2925180 1175933 2006 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Low osmolarity transforms ventricular fibrillation from complex to highly organized, with a dominant high-frequency source
موضوعات مرتبط
علوم پزشکی و سلامت پزشکی و دندانپزشکی کاردیولوژی و پزشکی قلب و عروق
پیش نمایش صفحه اول مقاله
Low osmolarity transforms ventricular fibrillation from complex to highly organized, with a dominant high-frequency source
چکیده انگلیسی

BackgroundAn osmotic challenge activates volume-regulated chloride currents (ICl,vol), resulting in depolarization of the resting membrane potential and shortening of action potential duration (APD). ICl,vol is activated in ischemia/reperfusion, but the effects of osmotic challenges and ICl,vol on ventricular fibrillation (VF) are unknown.ObjectivesThe purpose of this study was to investigate the influence of hypo-osmotic and hypotonic stress and ICl,vol activation on VF dynamics.MethodsGuinea pig hearts were isolated, stained with di-4 ANEPPS to optically map action potentials (APs) from epicardium using a photodiode array, and perfused with iso-osmotic (low NaCl Ringer plus 45 mM mannitol) or hypo-osmotic (low NaCl Ringer) solution.ResultsHypo-osmotic solution shortened APDs (143 ± 5 ms → 115 ± 10 ms) and increased APD gradients between right and left ventricles (21 ± 7 ms → 41 ± 10 ms, n = 4). In VF induced by burst stimulation, switching to hypo-osmotic solution increased VF frequencies (15.3 ± 1.2 Hz to 28.9 ± 3.6 Hz, n = 11), transforming complex fast Fourier transformation spectra to a single dominant high frequency on the left but not the right ventricle. Perfusion with the ICl,vol blocker indanyloxyacetic acid-94 (10 μM) reversed organized VF to complex VF with lower (13.5 ± 3.7 Hz in left ventricle) frequencies (n = 8), indicating that ICl,vol underlies the changes in VF dynamics. Consistent with this interpretation, the levels of ClC-3 channel protein were 27% greater on left than right ventricles (n = 10), and computer simulations showed that insertion of ICl,vol transformed complex VF to a stable spiral.ConclusionActivation of ICl,vol by decreasing osmolarity (45 mOsm) has a major impact on VF dynamics by transforming random multiple wavelets to a highly organized VF with a single dominant frequency.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Heart Rhythm - Volume 3, Issue 10, October 2006, Pages 1210–1220
نویسندگان
, , , , ,