Ann Thorac Surg 2008;85:2078. doi:10.1016/j.athoracsur.2008.03.051
© 2008 The Society of Thoracic Surgeons
Original Articles: Pediatric Cardiac
Invited Commentary
Hideki Uemura, MD, FRCS
Department of Cardiothoracic Surgery, Royal Brompton Hospital, Sydney St, London SW3 6NP, United Kingdom
(Email: huemura-cvs{at}umin.ac.jp).
The authors [1] are to be congratulated for their invaluable report regarding the post-Ross rhythm issue. There has been enthusiasm for this particular procedure, but we can not deny that this is extensive surgery. Whenever choosing this attractive procedure, clinicians should precisely know the scientific truth. Apart from huge benefits, there are downsides. Regarding rhythms, several pairs of underlying factors are relevant. These include atrial versus ventricular arrhythmias, influence of surgical incisions versus functional and myocardial impediments, and excitation abnormalities related to scars versus visceral denervation.
A circular scar, inevitably located at the right ventricular outflow tract, potentially supports a re-entrant circuit causing ventricular tachycardia, particularly when the outflow tract grows or when it is elongated by a septal incision. On the other hand, myocardium (whether damaged functionally in a natural course of aortic valve disease or affected by surgical ischemia) can serve as a locus for deleterious ventricular excitation. These points were clearly mentioned in the discussion by the authors. Visceral denervation also may have relevance, although minor, to ventricular arrhythmia. Coronary flow reserve could be less than normal and cause functional ischemia as a result of cutting efferent autonomic fibers. Division of afferent fibers may lead to impairment in sensing an arrhythmia or feeling angina pain. Regarding visceral nerves, the authors focused on sinus nodal function. The nerve plexus on the great arteries probably terminates more in the ventricular mass, but atrial tissues including the sinus and the atrioventricular nodes are likely regulated by pulmonary and caval venous nerve plexuses. It remains unclear how much crossover is present between the plexuses across the atrioventricular junction. One possible hypothesis is that chronotropic regulation is in balance between these plexuses. Injury to the arterial plexus could make a situation in which the venous plexus becomes dominant and suppresses the nodes. The condition subsequent to cardiac transplantation seems slightly different from the hypothesis. The post-arterial switch circumstance (in which both of the great arteries are entirely transected and the venous plexus remains intact) may be more analogous. Complete transection of the great arteries may be used in some patients undergoing the Norwood-type procedure or other complex procedures. Because rhythm disturbances produce morbidity and impaired quality of life at any stage of life, we should keep this crucial issue of cardiac rhythm in mind during extensive surgery of the great arteries.
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References
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- Pasquali SK, Marino BS, Kaltman JR, et al. Rhythm and conduction disturbances at midterm follow-up after the Ross procedure in infants, children, and young adults Ann Thorac Surg 2008;85:2072-2078.[Abstract/Free Full Text]
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Rhythm and Conduction Disturbances at Midterm Follow-up After the Ross Procedure in Infants, Children, and Young Adults
- Sara K. Pasquali, Bradley S. Marino, Jonathan R. Kaltman, Andrew J. Schissler, Gil Wernovsky, Meryl S. Cohen, Thomas L. Spray, and Ronn E. Tanel
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