This study reports on a cohort of competitive cross country skiers 28-30 years after an initial evaluation. There is no control group. The initial evaluation was in 1976 and included 122 participants classified into 3 age groups at baseline: group I 26-33; group II 43-50; group III 58-64.
At follow-up in 2004-2006, 37 had died (most in the older age group) and 11 were lost to follow-up. Among the 78 remaining ones, 17% had AF and 13% lone AF. Broken down by age group, the AF prevalence was 18% in group I, 14% in group II and 25% in group III.
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As expected, the subjects with AF had larger atrial sizes when measured at follow-up. LV mass was not measured (the less sensitive wall thickness was similar among AF and non-AF subjects).
The baseline data were limited to physical examination, PFT’s, ECG at rest and with exercise, as well as VO2 max measurement.
A slow heart rate and prolonged PQ interval, both indicators of vagal tone, were strong discriminant of the future risk of AF in the younger age group (HR 44 ± 5 for LAF and 53 ± 9 for sinus subjects; PQ 0.17 ± 0.05 for LAF and 0.17 ± 0.02 for sinus subjects). A similar pattern was found for the overall cohort, although the effect was not as strong.
Intensity and duration of training, height (at follow-up), thyroid tests and HgA1c (at follow-up) were not associated with AF status.
Take-home: This supports the hypothesis that AF in endurance athletes may be significantly impacted by autonomic tone. A speaker at this year’s ACC meeting emphasized the same point.
The wheels of French bureaucratic justice are grinding slowly by surely, and this time, it is a regulatory agency that is on the receiving end of the guillotine…
I previously reported on the very unusual story that broke out a year ago about the French pharmaceutical regulator being potentially the subject of criminal investigation for allowing the continuing sales of the anorectic drug Mediator despite the publication of data suggesting it could be harmful.
I commented that the scientific data with which the agency is getting indicted is incredibly meager, but the criminal aspect of the conduct may not be so much that AFFSAPS allowed a harmful drug to be sold on the market, but that it allowed it on the market longer than the other EC countries.
With bureaucratic principles and legal doctrine becoming more similar among Western nations subjecting themselves to the oversight of supranational organizations, I suspect US trial lawyers will be watching this development with great interest.
The release of the latest report from the Joint National Committee on Hypertension (JNC-8) has been delayed for several years. It’s already been a decade since the prior report was issued.
Until recently the reason for the delay was obscure, but in the March issue of Cardiology News inside information is provided by cardiologist Sidney Smith. The UNC professor of medicine, who has made a career out of writing practice guidelines for the American Heart Association, is a senior writer on the JNC-8 panel and this is what he had to say:
The delay has been due in large part to an unprecedented degree of prerelease review by numerous government agencies at a multitude of levels. This extensive and time-consuming advance scrutiny was instituted mainly because many health officials felt blindsided by the publication of the U.S. Preventive Health Services Task Force controversial mammography guidelines, which kicked up a hornet’s nest of criticism in the breast cancer and public health communities. Government officials don’t ever want to be caught by surprise like that again, explained Dr. Smith, professor of medicine at the University of North Carolina, Chapel Hill.
That’s right. There is nothing more frustrating for a government official than to be caught by surprise by a body of medical experts sifting through scientific data for the benefit of practitioners. The report must first be approved by the authorities!
This paper is yet another report from the Physician’s Health Study, a very large and very old clinical trial/prospective cohort study that followed some 22,000 physicians by questionnaire administered at various time points. One initial aim of the study was to test any mortality benefit of some primary prevention measures (daily aspirin, beta-carotene), but enough data was collected that numerous other associations (or lack of) have been reported over the years. This particular report looked at the association between responses to exercise questionnaires administered at the 3-year and 9-year time points in the study, and subsequent development of atrial fibrillation (self-reported). Continue Reading »
A young woman who collapsed and died during the 2012 London Marathon was found to have detectable levels of DMAA in her bloodstream. She had apparently obtained this “nutritional supplement” online. The story is reported in theheart.org and elsewhere in the press.
The coroner Philip Barlow (not to be confused with Philip Marlowe!) is decidedly non-committal:
She had taken a supplement containing DMAA, which on a balance of probability, in combination [with] extreme exertion, caused cardiac failure, which resulted in her death.
I had overlooked this earlier article published in 2006. Heidbuchel and colleagues have written extensively on right ventricular problems in athletes, and I may review that literature in due time.
For this particular study they looked at outcomes after consecutive cases of atrial flutter ablation performed between 1999 and 2003. Their EP center happened to routinely administer an exercise questionnaire to all ablation patients as part of another study on cardiac risk factors. The questionnaire was apparently reasonably detailed. Continue Reading »
From the same Barcelona group, this study by Mont et al. did not focus on endurance athletes but simply identified all new cases of lone AF coming to the Emergency Department during a 4.5-year period (2001-2005) and compared them to a group of age and sex-matched healthy controls, who were solicited from among visitors and relatives of patients in the ambulatory cardiology clinic.
Subjects in both groups (n=107 in each) were asked to respond to an activity questionnaire and were subjected to a physical and echocardiographic examination. The questionnaire was fairly detailed and tried to capture years of activity as well as intensity, both in terms of occupational and sports activity. As we know, such methods do have important limitations. Continue Reading »
Thanks to John Mandrola for reporting on the buzz being created by Dr. James O’Keefe from the Mid-America Heart Institute. Besides the recent WSJ article that cites a yet to be published paper by O’Keefe, this recently posted 18-minute TED-x talk by Dr. O’Keefe informs us of the gist of his claims:
This next study is from the same Barcelona group that published the Mont et al. paper and the Elosua et al. one. This, however, is an entirely different cohort of subjects.
Participants in the 1990 Barcelona marathons were invited to participate in a health survey (unrelated to the topic of atrial fibrillation). A total of 252 runners agreed. Age range at entry was 20-60. Of these, 183 agreed to participate in a follow-up examination in 2002-03, on average 11 years after the initial marathon.
The controls were selected from a near contemporaneous, unrelated study of 802 subjects (age range 25-74) performed in the Barcelona region. All subjects who were sedentary (< 305 kcal/day of leisure activity) were selected. That made up a group of 305 subjects. Of these, 290 agreed to respond at the 2003-03 follow-up. The study design is below: Continue Reading »