|
E-mail this page to a friend!
Senior Citizen Health & Medicine
Some High Blood Pressure Treatments May Increase
Heart Attack Risk
'Failure of calcium channels as we age has
flagged up a warning sign'
 March 15, 2007 - Some treatments for high blood
pressure could be increasing the risk of heart attacks and causing more
people to need cardiac pacemakers, according to new research findings
published today in the journal of the American Heart Association,
Circulation.
High blood pressure is sometimes treated by calcium
channel blockers to reduce the heart beat, as the channels which allow
calcium into the cells are linked to muscle contraction. But the
channels are also fundamental to the electrical currents which create
the heartbeat.
University of Leeds scientists Dr. Matthew Lancaster
and Dr. Sandra Jones have discovered that the channels gradually fail as
we age and this failure is a likely factor in arrythmia and heart
attacks in the elderly.
By blocking the channels to treat high blood
pressure, clinicians may unwittingly be increasing the likelihood of
other problems developing.
Dr. Lancaster said: "Many people suffer from an
irregular heartbeat as they grow older and large numbers have pacemakers
fitted. Making the link between these heart problems and the failure of
the calcium channels as we age has flagged up a warning sign that some
common medical treatments may be making the condition worse.
"Clinicians
should think carefully before prescribing calcium channel blockers and
ensure that, in treating one heart condition, they arent exacerbating
others."
The beating of the heart is caused by an electrical
signal, which starts at the top of the heart in the sinoatrial (SA) node
and is transmitted down to cause consecutive muscle contraction of the
different chambers. The electrical signal is generated through an influx
of calcium into the cells in the SA node, causing a change in voltage
which creates the current.
Calcium enters the cells through channels so
these are fundamental to a steady heart beat. If the calcium channels
are reduced, the heartbeat becomes irregular leading to a fall in blood
pressure, fainting, and potentially, if untreated, death. These are the
symptoms which can mean a patient needs a cardiac pacemaker fitted but
they may be exacerbated by treatment for high blood pressure which
blocks the calcium channels.
The link between age and loss of calcium channels
opens up new possibilities of treating heart conditions.
Dr. Jones said:
"It may be possible to mitigate the effects of the loss of calcium
channels through gene therapy, as the treatment would only be required
in one specific area the sinoatrial node so should be fairly easy to
administer."
The researchers also think exercise may also be a
factor. As members of the sports science group in Leeds Faculty of
Biological Sciences, Lancaster and Jones are now looking at whether
exercise training is able to reduce the loss of the calcium channels in
the SA node.
Click to More Senior News on the
Front Page
Copyright: SeniorJournal.com |
