1. Volume 7, Issue 4, Pages 251-261 (March 2001)
Alterations in electrical and mechanical activity in Langendorff-perfused guinea pig hearts exposed to decreased external sodium concentration with or without hypotonic insult 
Nobuhito Yanagi, Toru Maruyama, Makoto Arita, Yoshikazu Kaji, Yoshiyuki Niho 
Pathophysiology 
Volume 7, Issue 4, Pages (March 2001)
DOI: /S (00)

2. Fig. 1
Effects of isotonic [NaCl]0-reduction on the LV isovolumetric contraction in the perfusion study. (A) Actual traces of the LVDP recorded under conditions of isotonic [NaCl]0-reduction, where [NaCl]0 was decreased from the control (140 mEq/l) to a certain lower level during the periods as indicated. Preparations differed among the three recordings. (B) Time-dependent effects of isotonic [NaCl]0-reduction on percent changes in LVDP. Stepwise reduction of [NaCl]0 from 140 to 120 (○; n=3), 100 (□; n=3) and 80 mEq/l (▵; n=3) was imposed. Symbols and bars indicate mean±S.D.
Pathophysiology 2001 7, DOI: ( /S (00) )

3. Fig. 2
Comparison of effects of hypotonic [NaCl]0-reduction with those of isotonic [NaCl]0-reduction. (A) Changes in LVDP recorded during hypotonic [NaCl]0-reduction, as indicated by respective numerals and arrows. The hypotonic [NaCl]0-reduction was discontinued and reverted to normal [NaCl]0 after evolution of AV conduction block (*). (B) Changes in LVDP recorded during isotonic [NaCl]0-reduction. Preparations in (A) and (B) are different. (C) Summarized data of LVDP as a function of [NaCl]0, from experiments of panels (A) and (B). LVDP is expressed as percentage. Symbols and bars indicate mean±S.D. (n=9). *P<0.05 vs. control LVDP at 140 mEq/l [NaCl]0 (100%).
Pathophysiology 2001 7, DOI: ( /S (00) )

4. Fig. 3
Comparison of effects of hypotonic [NaCl]0-reduction with those of isotonic [NaCl]0-reduction on the electrical parameters of the heart. (A) Changes in PQ interval as a function of [NaCl]0. Abrupt prolongation of PQ interval at 80 mEq/l in hypotonic [NaCl]0-reduction is due to the advanced AV conduction disturbance preceding complete AV block. Preparations presenting complete AV block were not included in the analyses of PQ interval. Symbols and bars indicate mean±S.D. (n=7, 4 and 2 in [NaCl]0, of 100, 90 and 80 mEq/l, respectively). *P<0.05 vs. respective PQ interval at 140 mEq/l [NaCl]0. (B) The incidence (%) of complete AV block and/or AV dissociation observed in hypotonic and isotonic [NaCl]0-reduction. Progressive decrease in [NaCl]0 led to an increased incidence of complete AV block and/or dissociation, with more prominent effects in the case of hypotonic than isotonic [NaCl]0-reduction. (C) Changes in QRS duration as a function of [NaCl]0. Symbols and bars indicate mean±S.D. *P<0.05 vs. respective QRS duration at 140 mEq/l [NaCl]0.
Pathophysiology 2001 7, DOI: ( /S (00) )

5. Fig. 4
Effects of [Na+]0-reduction (solid lines) on LVDP (panel A), PQ interval (panel B) and QRS duration (panel C) where the concomitant reduction in [Cl−]0 was compensated for by adding an appropriate amount of tetraethylammonium chloride to the perfusate. In all panels, open circles and bars indicate mean±S.D. *P<0.05 vs. respective LVDP, PQ interval and QRS duration at 140 mEq/l [Na+]0 (n=4). Dotted lines were re-drawn, for comparison, from graphs showing the effect of isotonic [NaCl]0-reduction in Fig. 2C (panel A), Fig. 3A (panel B) and Fig. 3C (panel C), respectively.
Pathophysiology 2001 7, DOI: ( /S (00) )

6. Fig. 5
Effects of Gd3+ (solid lines) on LVDP (panel A), PQ interval (panel B) and QRS duration (panel C), recorded under conditions of hypotonic [NaCl]0-reduction. The Gd3+ concentrations tested are: 1 μM (○; n=5), 5 μM (□; n=5) and 10 μM Gd3+ (▵; n=3). In all panels, symbols and bars indicate mean±S.D. Dotted lines were re-drawn from graphs illustrating the effect of hypotonic [NaCl]0-reduction in the absence of Gd3+ (i.e. from 2C, 3A and C), respectively. *P<0.05 vs. the values at 140 mEq/l [NaCl]0. †P<0.05 vs. the values in the absence of Gd3+ (dotted lines) at a particular [NaCl]0.
Pathophysiology 2001 7, DOI: ( /S (00) )

7. Fig. 6
Effects of KB-R7943 (solid lines), an inhibitor of Na+/Ca2+-exchange, on LVDP (panel A), PQ interval (panel B) and QRS duration (panel C) recorded under conditions of isotonic [NaCl]0-reduction. In all panels, open circles and bars indicate mean±S.D. Dotted lines were re-drawn from graphs illustrating the effect of isotonic [NaCl]0-reduction in the absence of KB-R7943 (i.e. 2C, 3A and C), respectively. *P<0.05 vs. the values at 140 mEq/l [NaCl]0 (n=5). †P<0.05 vs. LVDP in the absence of no. KB-R 7943 (dotted lines) at a particular [NaCl]0.
Pathophysiology 2001 7, DOI: ( /S (00) )