title: Voltage-sensitive dye mapping in Langendorff-perfused rat hearts.
abstract: An imaging system suitable for recordings from Langendorff-perfused rat hearts using the voltage-sensitive dye 4-[beta-[2-(di-n-butylamino)-6-naphthyl]vinyl]pyridinium (di-4-ANEPPS) has been developed. Conduction velocity was measured under hyper- and hypokalemic conditions, as well as at physiological and reduced temperature. Elevation of extracellular [K(+)] to 9 mM from 5.9 mM caused a slowing of conduction velocity from 0.66 +/- 0.08 to 0.43 +/- 0.07 mm/ms (35%), and reduction of the temperature to 32 degrees C from 37 degrees C caused a slowing from 0.64 +/- 0.07 to 0.46 +/- 0.05 mm/ms (28%). Ventricular activation patterns in sinus rhythm showed areas of early activation (breakthrough) in both the right and left ventricle, with breakthrough at a site near the apex of the right ventricle usually occurring first. The effects of mechanically immobilizing the preparation to reduce motion artifact were also characterized. Activation patterns in epicardially paced rhythm were insensitive to this procedure over the range of applied force tested. In sinus rhythm, however, a relatively large immobilizing force caused prolonged PQ intervals as well as altered ventricular activation patterns. The time-dependent effects of the dye on the rat heart were characterized and include 1) a transient vasodilation at the onset of dye perfusion and 2) a long-lasting prolongation of the PQ interval of the electrocardiogram, frequently resulting in brief episodes of atrioventricular block.
authors.affiliation: Department of Physiology and Biophysics, University of Calgary, Calgary, Canada T2N 4N1.
authors.forename: A
authors.initials: A
authors.lastname: Nygren
authors.forename: C
authors.initials: C
authors.lastname: Kondo
authors.forename: R B
authors.initials: RB
authors.lastname: Clark
authors.forename: W R
authors.initials: WR
authors.lastname: Giles
mesh_terms: D000818:Animals; D018780:Body Surface Potential Mapping; D002304:Cardiac Pacing, Artificial; D004396:Coloring Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D004562:Electrocardiography / Q000187:drug effects; D022062:Electrophysiologic Techniques, Cardiac / Q000295:instrumentation / Q000379:methods; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006329:Heart Conduction System / Q000187:drug effects / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D010477:Perfusion; D011188:Potassium / Q000378:metabolism / Q000494:pharmacology; D011312:Pressure; D011726:Pyridinium Compounds / Q000493:pharmacokinetics / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012849:Sinoatrial Node / Q000502:physiology; D013696:Temperature
chemical_list: D004396:Coloring Agents; D011726:Pyridinium Compounds; C050019:1-(3-sulfonatopropyl)-4-(beta)(2-(di-n-butylamino)-6-naphthylvinyl)pyridinium betaine; D011188:Potassium