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Transfer entropy is a better indicator of changes in AV coupling than standard measures of AV conduction
Author(s) -
Rhodes Samhita S,
Ropella Kristina M,
Camara Amadou KS,
Heinen Andre,
Aldakkak Mohammed,
Heisner James S,
Stowe David F
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a321-a
Subject(s) - atropine , reserpine , perfusion , chemistry , medicine , coefficient of variation , cardiology , anesthesia , chromatography
We tested if transfer entropy (TE, au), a dynamic measure of directional information transfer, better quantifies atrioventricular (AV) coupling than conduction time (CT, ms) and variability (% coefficient of variation in CT, COV). Denervated (+ and ‐ atropine) and catecholamine‐depleted (reserpinized) isolated guinea pig hearts were crystalloid perfused at 37 °C. After baseline (BL) 18 hearts were placed in 3 groups: control, reserpine (2 mg/kg/day ip twice), or 1 μM atropine perfused continuously. Hearts were subjected to 30 min global ischemia and 2 h reperfusion (RP). We recorded simultaneous bipolar right A and V electrograms for 4 min during BL, atropine perfusion and at RP10, and RP120 min. All data ± SEM and p<0.05 vs. BL. We found: a) COV was higher at RP10 in control and atropine but not reserpine. b) For control, CT (BL 76±9) was higher at RP120 (123±24), and TE (BL 2.3±0.1) was lower at RP10 (2.0±0.1) and higher at RP120 (3.1±0.4). c) During atropine perfusion, CT (BL 62±3) was higher at RP10 (93±14) and RP120 (80±8), and TE (BL 2.5±0.1) was high (3.1±0.2) and remained high at RP10 (3.0±0.2) and RP120 (3.1±0.2). e) For reserpine TE (BL 2.2±0.3) was lower at RP10 (1.4±0.1). We conclude: 1) TE, but not CT or COV, is an event‐independent measure of AV coupling. 2) In control hearts, COV and TE at RP10 indicate weak AV coupling; and, TE at RP120 indicates improved AV coupling despite unchanged COV. 3) In reserpinized hearts, COV did not change, but TE at RP10 indicates weak AV coupling. 4) In atropine treated hearts, COV indicates weak AV coupling while TE indicates strong AV coupling at RP10. These apparent contradictory results are together predictive of AV dissociation. (NIH, AHA)