In what is believed to be the first, large-scale analysis of racial or ethnic differences in certain kinds of heart function, a team of Johns Hopkins cardiologists found that muscle contraction in three main regions of the heart was on average weaker by 1 percent to 3 percent in African Americans, regardless of age, gender or existing risk factors, such as high blood pressure.
The Hopkins findings are among the first conclusions to emerge from the long-term Multiethnic Study of Atherosclerosis, or MESA for short. MESA is monitoring nearly 7,000 men and women, age 45 to 84, of different ethnic backgrounds and with no existing symptoms of heart disease to determine who develops heart failure and dies from it, and who does not.
In the study the team also found that Chinese Americans’ hearts had a consistently, if mildly stronger squeezing function, of a similar magnitude than those of other racial or ethnic groups. Researchers say that heart disease among Chinese Americans is less of a problem than in African Americans, although there is yet no direct evidence of a protective effect of stronger contraction in Chinese Americans.
Another surprise finding was that hearts in Chinese Americans contract more quickly than those of other ethnic groups. Three of four heart walls were fully squeezed on average 20 milliseconds to 30 milliseconds faster than in Hispanics, and were more than 10 milliseconds faster than in either African Americans or Caucasians.
According to senior study investigator and cardiologist João Lima, M.D., M.B.A., “our results show that genetic and racial factors are clues that can be used in early identification of those more vulnerable to coronary artery disease, heart failure, arrhythmias and sudden cardiac death, or those in more need of early treatment - or those at less risk and less likely to need early intervention.”
MEDICA.de; Source: Johns Hopkins Medical Institutions