title: L-Type Calcium Channels Do Not Play a Critical Role in Chest Blow Induced Ventricular Fibrillation: Commotio Cordis.
abstract: Background. In a commotio cordis swine model, ventricular fibrillation (VF) can be induced by a ball blow to the chest believed secondary to activation of mechanosensitive ion channels. The purpose of the current study is to evaluate whether stretch induced activation of the L-type calcium channel may cause intracellular calcium overload and underlie the VF in commotio cordis. Method and Results. Anesthetized juvenile swine received 6 chest wall strikes with a 17.9 m/s lacrosse ball timed to the vulnerable period for VF induction. Animals were randomized to IV verapamil (n = 6) or placebo (n = 6). There was no difference in the observed frequency of VF between verapamil (19/26: 73%) and placebo (20/36: 56%) treated animals (p = 0.16). There was also no significant difference in the combined endpoint of VF or nonsustained VF (21/26: 81% in verapamil versus 24/36: 67% in controls, p = 0.22). Conclusions. In this experimental model of commotio cordis, verapamil did not prevent VF induction. Thus, in commotio cordis it is unlikely that stretch activation of the L-type calcium channel with resultant intracellular calcium overload plays a prominent role.
authors.affiliation: Cardiac Electrophysiology Service, Section of Cardiology, Rush University Medical Center, Chicago, IL, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Madias
authors.affiliation: Cardiac Arrhythmia Center, Division of Cardiology, Tufts Medical Center (TMC), P.O. Box 197, 800 Washington Street, Boston, MA 02111, USA.
authors.forename: Ann C
authors.initials: AC
authors.lastname: Garlitski
authors.affiliation: Cardiac Arrhythmia Center, Division of Cardiology, Tufts Medical Center (TMC), P.O. Box 197, 800 Washington Street, Boston, MA 02111, USA.
authors.forename: John
authors.initials: J
authors.lastname: Kalin
authors.affiliation: Cardiac Arrhythmia Center, Division of Cardiology, Tufts Medical Center (TMC), P.O. Box 197, 800 Washington Street, Boston, MA 02111, USA.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Link