Hartritme en risico op overlijden.*

Mannen van middelbare leeftijd wiens polsslag, in rust, de laatste vijf jaar is toegenomen, hebben een veel hogere kans op overlijden de komende 20 jaar dan mannen wiens polsslag onveranderd is gebleven of gedaald is, zo zegt een Franse studie.
De polsslag in rust is een indicator van de arbeid die het hart moet leveren om een goede doorbloeding te onderhouden. Normaal is deze 60-80 slagen per minuut, bij sportbeoefenaars of mensen met een heel goede lichamelijke conditie kan die wel 40-50 bedragen volgens de onderzoekers. In eerdere onderzoeken is reeds gebleken dat een hogere polsslag een hogere kans op overlijden geeft, maar dit onderzoek is het eerste dat de betekenis van een verandering in polsslag over meerdere jaren heeft onderzocht.
Ruim 4.000 Fransen in de leeftijd van 42-53 jaar werden 20 jaar gevolgd en iedere 5 jaar onderzocht. Mannen wiens polsslag in rust met 7 slagen of meer toenam hadden bijna 50% meer kans op overlijden in die 20 jarige periode, terwijl mannen wiens polsslag met 7 slagen of meer daalden hun kans op overlijden met 20% zagen afnemen. Op basis van dit onderzoek zou iedereen met een stijging van de hartfrequentie in rust gedurende verschillende jaren zich moeten laten onderzoeken om na te gaan wat de oorzaak kan zijn.
Long-term rise in resting heart rate linked to higher risk of death in men

Abstract 4203 (This release contains updated information from the abstract)

— Middle-aged men whose resting heart rate (HR) increased over five years had a much higher risk of death over a 20-year span than men whose resting HR remained unchanged or decreased, researchers reported at the American Heart Association’s Scientific Sessions 2006.

A long-term rise in resting HR increased the risk of death in middle-aged men by almost 50 percent, while a long-term decrease in resting HR reduced the risk by almost 20 percent, according to the French study.

Resting HR, measured in beats per minute (bpm), is routinely checked during medical appointments.  Resting HR is one indicator of how hard the heart is working to maintain adequate blood flow.  A resting HR of 60–80 bpm is considered normal.  Athletes or people in excellent physical condition typically have a resting HR in the range of 40–50 bpm, researchers said.

Other studies have shown that a high resting HR is associated with a higher risk of death, but the study by the French team is the first to investigate the significance of changes in resting HR over years.

Researchers examined the health histories of 4,320 native Frenchmen ages 42 to 53.  The men were recruited between 1967 and 1972 and had yearly examinations during the next five years in the same standardized conditions.  The participants underwent electrocardiograms and physical examinations, provided blood samples for laboratory tests, and answered questionnaires administered by trained interviewers.  Resting HR was determined by measuring the radial (wrist) pulse during a one-minute recording, after a five-minute rest lying down.

During the follow-up of more than 20 years, 1,018 men died from various causes, including cardiovascular disease.  The researchers examined the individual HR trends over five years, and categorized the men into groups based on the degree of change in resting HR and baseline HR.

After adjusting for other risk factors, such as age, physical activity, tobacco consumption, body mass index, systolic blood pressure, blood sugar and total cholesterol, the researchers found that the men whose resting HR increased by more than 7 bpm had an increase in mortality of 47 percent, while men whose resting HR decreased by more than 7 bpm had a decrease in mortality of 18 percent.

The researchers concluded that resting HR and its changes may be independent risk factors of mortality in the general population.  The study’s lead author, Xavier P. Jouven, M.D., Ph.D., of Hopital Européen Georges Pompidou INSERM, Paris, said the findings raise several questions.

“We don’t know why resting HR goes down or up over time,” Jouven said.  “It might be related to lifestyle changes, such as less activity.  We also cannot say for sure whether the increase in resting HR is only a marker for some other disease process or whether it is directly associated with mortality.”  

Jouven also noted that when the original study was designed in 1965, it was thought that men were mainly at risk for heart disease, so the study included only middle-aged men.   A separate study should be done on middle-aged women, he said.

Based on this study, clinicians should adopt a standard method for measuring resting HR that is tracked over time, Jouven said.  Patients who have an increase in resting HR over several years should be examined and tested further to determine what might be causing it.

“The clinician has to test for the cause of the increase in resting HR and not assume that it’s only related to a cardiovascular condition,” Jouven said.

Though there is no international standard, the optimal method for measuring resting HR in a doctor’s office or clinic, he said, is for the patient to rest lying down for about five minutes before the resting HR is measured.   He said that to ensure accuracy, the radial pulse should be counted for a full minute, rather than 15 seconds as is common.

“The role of and measurement of resting HR has been underestimated as a health indicator,” Jouven said.  “We have to devote more scientific attention to resting HR.”

Co-authors are Jean Philippe Empana, M.D., Ph.D.; Jean François Buyck, M.D.; Florence Canoui Poitrine, M.D.; Awa Kane, M.Sc.; Christine Mouries, Ph.D.; Dominique Courbon, M.Sc.; and Pierre Ducimetiere, Ph.D.

The study was funded by INSERM and Mairie de Paris.

Statements and conclusions of study authors that are published in the American Heart Association scientific journals are solely those of the study authors and do not necessarily reflect association policy or position.  The American Heart Association makes no representation or warranty as to their accuracy or reliability.

NR06-1098 (SS06/Jouven)  (Jan. 2007)