1. Pediatric Cardioplegia Strategy Results in Enhanced Calcium Metabolism and Lower Serum Troponin T 
J. Darcy O'Brien, MS, Susan E. Howlett, PhD, Hayley J. Burton, RN, Stacey B. O'Blenes, MD, D. Sharon Litz, MD, Camille L. Hancock Friesen, MD 
The Annals of Thoracic Surgery 
Volume 87, Issue 5, Pages (May 2009)
DOI: /j.athoracsur
Copyright © 2009 The Society of Thoracic Surgeons Terms and Conditions

2. Fig 1
Contractions in myocytes exposed to pediatric cardioplegia (group PC) or adult cardioplegia (group AC). (A) Representative examples of contraction recordings throughout an experiment in group PC and group AC myocytes. (CP = cardioplegia; RF = reperfusion.) (B) Group AC (white circles) but not group PC myocytes (black circles) were contractile when stimulated. There was an overshoot in contraction upon reperfusion in group AC but not in group PC. Arrows indicate field-stimulation during cardioplegia. (Data are presented with the standard error; 7 to 9 myocytes/group; *p < 0.05.)
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2009 The Society of Thoracic Surgeons Terms and Conditions

3. Fig 2
Changes in Ca2+ levels in myocytes exposed to pediatric (group PC) or adult cardioplegia (group AC). (A) Examples of intracellular Ca2+ levels in group PC and group AC myocytes. (B) Ca2+ transients were elicited by stimulation in group AC (white circles) but not group PC (black circles) myocytes. An overshoot in Ca2+ transients occurred in group AC, but Ca2+ transients recovered slowly in group PC. (C) Throughout cardioplegia, diastolic Ca2+ was lower in group PC (black circles) than in group AC (white circles). Diastolic Ca2+ rose during stimulation in group AC but not in group PC. Diastolic Ca2+ levels recovered rapidly in early reperfusion in group AC but recovered slowly in group PC. Arrows indicate stimulation during cardioplegia. (Data are presented with the standard error; n = 7 to 9 myocytes/group, *p < 0.05).
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2009 The Society of Thoracic Surgeons Terms and Conditions

4. Fig 3
Changes in resting membrane potential in myocytes exposed to pediatric (group PC) or adult cardioplegia (group AC). (A) Cardioplegia caused depolarization of the resting membrane potential in both groups. (B) Resting membrane potential was near –80 mV before cardioplegia. Myocytes depolarized to similar levels during cardioplegia in group PC (black bars) and in group AC (white bars). Dashed line represents –50 mV. Recordings were made from 3 to 4 myocytes in each group. (Data are presented with the standard error; *p < 0.05 vs control values).
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2009 The Society of Thoracic Surgeons Terms and Conditions

5. Fig 4
Subgroup serum troponin T after cardiotomy. (A) In both infants and noninfants, pediatric cardioplegia (group PC) resulted in significantly lower serum troponin T levels at time 1 and time 2 (data not shown) than adult cardioplegia (group AC). (B) In both cyanotic and acyanotic cohorts, group PC had lower serum troponin T levels than group AC at time 1, whereas only the acyanotic group was significantly different between groups at time 1 (data not shown). (C) Serum troponin T levels were similar between groups for tetralogy patients (p = 0.12), but levels in group PC were significantly lower than group AC in the nontetralogy patients, indicating that when muscle incision is excluded as a source of troponin T, the difference in serum troponin T correlates with the cardioplegia strategy used.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2009 The Society of Thoracic Surgeons Terms and Conditions