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Egred M, Al-Mohammad A, Waiter GD, Redpath TW, Semple SK, Norton M, Welch A, Walton S.Egred M, et al.Heart. 2003 Jul;89(7):738-44. doi: 10.1136/heart.89.7.738.Heart. 2003.PMID: 12807845Free PMC article.