It seems like pacemakers and other implanted devices like ICD's have been in the news a lot lately, for different reasons. Here is some good news that is somewhat related, and may mean that in the future some people will get to avoid surgery: scientists have discovered an enzyme that works to put the brakes on a racing heartbeat. A person's heart rate is set by a single cell within the heart, called the pacemaker cell, and a naturally occurring enzyme called Pak 1 has been found to interact specifically with that cell -- telling it to slow things down.

This discovery will obviously have a potentially huge effect on treatments, drugs, and the lives of people living with heart disease.

Scientists have found a way for mice to eat whatever kind and however much fat in their diets and still not run any risk of getting heart disease. They deleted the gene that produces the enzyme ACAT2, which usually works in the body by converting cholesterol and other fats into forms that stick more easily and sometimes end up causing blocked vessels.

Of course, like all studies based on mice, there's no word yet if the same principles will hold true in people. The hope is obviously that it does, and that a drug can be developed to inhibit the enzyme in humans, therefore reducing or maybe even eliminating a person's risk for developing heart disease.

Here's to hoping! That would big.

I recently saw an ad that featured a very old man, wrinkled and feeble looking, holding an infant. The editorial in the ad read something like this: "You're born small and weak and you die small and weak. How you look in between is up to you." Again, I'm paraphrasing here, but that's the gist of it. My first reaction was that the ad agency was really going for the hard sell with this one. I also found the ad to be a bit morbid. And, perhaps worst of all, I can't say I remember what the product they were selling was -- although I think it was for a nutritional supplement of some kind. Then again, I seem to remember that ad over the hundreds of other I read in the same publication, so maybe it served its intended purpose. Either way, I was reminded of this imagery after learning of some new research involving the important discovery of a fetal heart-cell enzyme, and how it relates to the onset of heart failure.

Evidently, in all forms of heart failure, the heart begins to express genes that are normally only expressed in the fetal heart. While scientists have long known that this fetal-gene reactivation occurs, they really haven't known why it happens. But, researchers from U. Penn School of Medicine may have found the missing piece; the every-elusive "Why?"

In the online publication of the journal Nature Medicine, the researchers explain that an enzyme crucial in fetal-heart development regulates the enlargement of heart cells (known as cardiac hypertrophy), which is a precursor to many forms of congestive heart failure.

By inhibiting the enzyme HDAC (an enzyme switch of sorts that regulates how DNA is packaged inside the cell, and therefore how large groups of related genes are turned off an on) in adult mice, it was discovered that the fetal-gene program can be prevented from restarting. In essence, HDAC's inhibition "prevented the beginning of the downward slide to progressive heart failure," as one of the researchers put it.

This is a big step toward understanding heart disease at the cellular level. That's a much better ad if you ask me.

New research has revealed information as to why shift workers; people who suffer jet-lag; people with sleep disorders or people advancing in age seem to have more heart disease compared to people in other groups.

Researchers have discovered there is an internal body clock that regulates enzyme production in the liver. These enzymes determine how the liver handles the food we eat and potentially toxic metabolites. The problem is the enzymes function at different levels depending on the time of day.

According to Dr Michael Hastings, who led the research, "Circadian rhythms or our internal body clock adapt us to the solar and social 24 hour world by driving our daily rhythms of behaviour, physiology and metabolism. When these natural cycles go awry we perform less well and feel dreadful. In particular, when our body clocks are disturbed so as to cause a mismatch between when and what we eat and what the body is able to process at meal times, nutrients are handled less effectively, for example fats will not be cleared from the blood stream and blood sugar levels will not be regulated appropriately." This research is published in the journal Current Biology.

There might be good news for grapefruit lovers who have been told to avoid the fruit because of the drugs they need to take to maintain heart health. People who take cholesterol and blood pressure medications are warned not to eat grapefruit because the tart orb can increase the rate at which these drugs enter the bloodstream. Until now, scientists believed that flavonoids in grapefruit were the cause of the problem, but recent research indicates that furanocoumarins are the true culprit.

According to an explanation by the researchers, the drugs affected by grapefruit juice usually have some difficulty entering the body after they are consumed because an intestinal enzyme partially destroys them as they are absorbed. Other fruit juices do not create this same problem. As a result, grapefruit juice needs to be avoided by some patients.

If additional studies support the initial findings that it is furanocoumarins and not flavonoids that make grapefruit a forbidden fruit for those on cholesterol and blood pressure medications, furanocoumarin-free grapefruit juice is a possible solution to the problem.