Background: There is concern about whether cardiac damage occurs as a result of prolonged strenuous exercise. Objective: To investigate whether competing in a triathlon is associated with cardiac damage based on a sustained increase in cardiac troponin T (cTnT), and whether such an increase correlates with echocardiographic changes Methods: cTnT and echocardiographic measurements were made in 38 participants in the 2001 Australian ironman triathlon. cTnT was measured the day before, immediately after, and the day following the race. Echocardiography was done the day before, immediately after, and two to six weeks later for measurement of ejection fraction, stroke volume, cardiac output, wall motion analysis, and global left ventricular function (LVF). Results: No subject had detectable cTnT in the pre-race sample. Following the race, 32 subjects (86.5%) had detectable levels of cTnT (.0.01 ng/ml), with six (16.2%) having .0.10 ng/ml. The day after the race, nine subjects (23.7%) still had detectable cTnT, with two recording a level .0.10 ng/ml. Previously described echocardiographic changes of ''cardiac fatigue'' were observed in the whole cohort. There was a modest but significant correlation between change in ejection fraction and peak cTnT level (p = 0.02, r = 0.39). Athletes with a post-race cTnT .0.10 ng/ml had a greater decrease in global LVF (p = 0.02) and a trend toward a greater fall in ejection fraction and stroke volume than athletes with cTnT levels ,0.10 ng/ml. Cardiac output fell in the group with cTnT .0.10 ng/ml (p.0.05). Conclusions: Participation in ironman triathlon often resulted in persistently raised cTnT levels, and the troponin rise was associated with echocardiographic evidence of abnormal left ventricular function. The clinical significance and long term sequelae of such damage remains to be determined.

The human genome has two linked alpha-globin genes on chromosome 16. Deletion of one or more of them, as occurs in alpha-thalassaemia, leads to a reduced output of alpha-globin mRNA in proportion to the number of alpha-globin genes lost. In some racial groups deletion of one of the pair of alpha-globin genes may result from unequal crossing over between the genes on homologous chromosomes by a mechanism resembling that postulated for the formation of the delta beta fusion genes of the Lepore haemoglobins. By analogy, the opposite chromosome in this cross-over should have three alpha-globin genes just as the 'anti-Lepore chromosome has three non-alpha chain genes. We describe here a Welsh family in which three members have five alpha-globn increased alpha mRNA output and it may therefore produce the phenotype of mild beta-thalassaemia.

ObjectiveSurvival of patients with repaired tetralogy of Fallot (rToF) into young adulthood is very good. Concerns exist, however, over long-term morbidity and mortality as these subjects reach middle age. We aimed to assess survival and the prevalence of complications in patients with rToF seen in our Adult Congenital Heart Disease (ACHD) service.MethodsOne hundred and sixty-eight consecutive patients with ‘simple rToF’, aged over 16 years, followed up at our tertiary-level ACHD service in Sydney, Australia since 2000, were included. We documented mortality and analysed the prospectively defined composite end points of (a) ‘Serious adverse events’, including death, heart failure hospitalisation and/or documented ventricular arrhythmia and (b) ‘Adverse events’ inclusive of the above and endocarditis, atrial arrhythmia, defibrillator and/or pacemaker implantation.ResultsMean age at the last follow-up was 34±12 years, and 55% were men. There were 10 (6%) deaths, and 26 patients (16%) experienced a ‘serious adverse event’. Fifty-one patients (30%) experienced an ‘adverse event’ and 29 patients had atrial arrhythmias. One hundred and one (61%) patients had at least one pulmonary valve replacement. By age 40 years, 93% were free of serious adverse events, and 83% were free of any adverse event. By age 50 years, only 56% had not had an adverse event. Older age and history of atrial arrhythmia were predictive of serious adverse events.ConclusionSurvival into mid-adulthood in patients with rToF is very good; however, a substantial number of survivors have adverse events by the age of 50 years.

We studied 11 families with alpha-thalassemia from the Qatif population of eastern Saudi Arabia to determine the genetic and molecular basis of hemoglobin-H disease, which is being encountered in this area with increasing frequency. The results show that there are two common alpha-thalassemia haplotypes, a deletion (-alpha/) determinant and a nondeletion (alpha alpha T/) determinant, which interact to produce a series of overlapping phenotypes. The most severe, hemoglobin-H disease, results from the homozygous state for the nondeletion determinant--a pattern of inheritance not previously recognized for this condition. Its molecular and genetic properties are thus different from those that produce the condition in Oriental or Mediterranean populations.

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