When Is Heart Attack Most Harmful?

Heart attack, also known as myocardial infarction (MI), is a condition in which interruption of blood supply to heart occurs and causes heart cells to die. This is commonly due to blockage of a coronary artery.

A study recently reported that the size of a heart attack and the harm it can cause depends on what time it strikes. Researchers from the Minneapolis Heart Institute at Abbott Northwestern Hospital found that the greatest injury that a heart attack causes to the heart is when it takes place between 1am and 5am. This is because key restrictions occur in humans' blood supply according to the time of day, according to their findings published online on November 17, 2011 in the medical journal ‘Circulation Research’.

Studies had found that infarct size after ischemia or reperfusion exhibits a circadian dependence on the time of coronary occlusion in rodents. In order to find out whether a similar circadian dependence of infarct size occurs in humans, researchers analyzed 1,031 patients of acute heart attack referred for primary percutaneous coronary intervention with known ischemic times between 1 and 6 hours.

165 patients, who had their first heart attack because of blocked arteries, were identified. They all had well-defined ischemic times and data on size of heart attack, and area-at-risk were recorded. It was observed that the extent of infarct size was significantly associated with time of day onset of infarction.

The ability of heart to protect itself against more severe damage varies over a 24-hour cycle. It is important for scientists to identify those protective changes since this would help pharmaceutical manufacturers develop medications to prevent cardiovascular disease.

Meanwhile, it is known that sleep consists of different phases. Early morning sleep is known as rapid eye movement sleep during which people dream. While the body is asleep, the mind is still awake. The autonomous nervous system is stimulated and releases hormones like adrenaline, noradrenaline and cortisol. These hormones increase the activity of the heart that beats and works harder but the hormones constrict the blood supply to the heart.

One main reason why heart attack are worst at night is that people tend to wait till morning to go and get examination or treatment from doctors. Most people might just think that it was indigestion and simply took some antacids.

What Can Chocolate Do To Cut Cardiovascular Disease Risk?

Chocolate is something that most people hard to resist. It is estimated that a typical American consumes over 10 pounds of chocolate annually. This leads to an interesting question: Would chocolate pose any threat to our health?

According to scientists, chocolate contains compounds called "flavanols" that is a naturally occurring antioxidant and has anti-inflammatory properties. Many large-scale studies have linked consumption of flavanol to lower risk of cardiovascular disease. Nevertheless, only few studies have tested the direct effect of chocolate consumption.

That is why researchers from San Diego State University intend to find out whether chocolate, particularly dark chocolate, might protect against the risk of cardiovascular disease (including heart disease and stroke) by lowering blood pressure, blood flow, and improving blood lipid levels.

31 participants were randomly assigned to consume for 15 days a daily serving (50 grams) of regular dark chocolate (containing 70 percent of cocoa), dark chocolate (containing 70 percent of cocoa) that had been overheated or bloomed, or white chocolate (containing 0 percent of cocoa).

At the outset of the study, researchers recorded these participants’ readings on blood pressure, forearm skin blood flow, circulating lipid profiles, and blood glucose levels.

With reference to participants assigned to white chocolate group, those consuming either form of dark chocolate had lower blood glucose and low-density lipoprotein cholesterol (LDL or the bad cholesterol) levels coupled with higher high-density lipoprotein cholesterol (HDL or the good cholesterol).

The findings, which were presented on April 24, 2012 at the Experimental Biology 2012 meeting in San Diego, CA, indicated that dark chocolate might reduce the risk of cardiovascular disease by reducing the glucose levels and lipid profiles.

Meanwhile, the researchers warned that people should consume dark chocolate in moderation because chocolate can easily raise daily amounts of saturated fat and calories. Remember this, the study participants were allowed to consume not more than 50 grams of chocolate a day.

The researchers are planning follow-up studies involving more participants and a longer duration of chocolate consumption.

Will Cardiovascular Risk Decline For Older Folks With Hypertension?

The blood pressure of a person is considered as normal when the reading does not exceed 120/80 mmHg. ‘120’ is the so-called systolic pressure and ‘80’ is the diastolic pressure. When this person’s systolic reading reaches 140 mmHg or higher, or diastolic pressure reaches 90 mmHg or higher, he or she is said to have hypertension (high blood pressure).

Hypertension is known to be a preventable risk factor for cardiovascular disease (CVD) and coronary heart disease (CHD). It contributes to about 50 percent of all CVD and for every 10-point in diastolic blood pressure, the risk of getting CVD doubles.

A recent study, however, claimed that high blood pressure becomes less of a risk factor for incident cardiovascular disease (CVD) and coronary heart disease (CHD) with age. The findings were presented by researchers from Prevention of Metabolic Disorders Research Center, Tehran, Iran at the World Congress of Cardiology on April 23, 2012.

It took 9.3 years to complete the study that evaluated the risk of different blood pressure categories among 6,273 participants who aged 30 years old and above.

Analysis of results showed that the risk of developing incident CVD and CHD was significantly higher among people with high normal blood pressure during middle-age (between 30 and 60 years old) than for those with the same high normal blood pressure aged 60 and above. But incident CVD and CHD risk were found to be similarly high in people with diagnosed high blood pressure across all age-groups.

While the findings did reinforce the fact that hypertension is a serious risk factor for CVD in all age groups, they also suggested that people managing high normal blood pressure resources should direct their focus to those individuals who are in middle age.

Treating high blood pressure is important. A previous study showed that it was linked to a 35 percent cut in the risk of stroke and at least 16 percent reduction in the risk of myocardial infarction (heart attack).

What Is The Chance Of Having A Baby Girl?

Ideally, the sex ratio at birth should be 1 boy to 1 girl. However, the practice of sex selection might determine the ratio in any given country. For instance, about 105 boys are born for every 100 girls in Iran. The current global sex ratio is 107 boys to 100 girls.

It seems that the ratio is going to change and the number of women in population is likely to rise in coming years with increasing number of heart disease cases.

Researchers from Tabriz University in Iran reported on April 20, 2012 at the World Congress of Cardiology in Dubai that pregnant women with heart disease were more likely to give birth to girls.

Their study involved 200 pregnant women who had heart disease and were referred to a heart center for delivery. They gave birth to a total of 216 babies, of which 75 percent were girls, or 32 boys were born for every 100 girls. The average age of the women was 29.

Among these women, 64 percent had a form of heart disease that involves problems with the heart valve, 19 percent had dilated cardiomyopathy (a condition in which the heart becomes weakened and enlarged and is not able to pump blood efficiently), and 14 percent had a problem with their heart's structure and function that was present since birth.

It has been known that the chromosomes in a man’s sperm determine the sex of a baby. Sperm carry either an X or Y chromosome, while eggs carry only an X chromosome. A sperm cell with an X chromosome unites with an egg will give birth to a girl. On the other hand, a sperm with a Y chromosome unites with an egg will give birth to a boy.

The researchers admitted that the reason for the skewed sex ratio among babies born to women with heart disease is not known. But the study did suggest the health status of the mother might be related to the sex of the babies she is able to carry to full-term.

Would Glucose Stop Heart Attack?

Heart attack is something that people cannot take it lightly. If a person having a heart attack does not receive medical care within the shortest period, the person might experience severe damage to heart tissue or in some serious cases, even end up dead. Unfortunately, timely medical help does not always available to save a heart attack victim.

According to the many studies carried out previously on acute cardiac care in emergency departments and hospitals, more people die of heart attack outside the hospital than inside the hospital.

Laboratory studies had suggested that in the setting of cardiac ischemia, immediate intravenous a mixture of glucose, insulin and potassium (GIK) could reduce ischemia-related arrhythmias and myocardial injury. The potential benefit of GIK is supposed to be related to timeliness of administration after cardiac ischemia begins, especially to prevent cardiac arrest. The risk for cardiac arrest is believed to be the highest during the first hour of acute coronary syndromes (ACS).

In order to test out-of hospital emergency medical service (EMS) administration of GIK in the first hours of suspected ACS, researchers from Tufts Medical Center started a study on 911 patients in 13 United States cities, between December 2006 and July 31, 2011 involving trained paramedics, who used electrocardiograph (ECG)-based instruments to determine if a patient was likely having a heart attack.

The findings showed that GIK given to patients showing heart attack symptoms had not reduced their risk of progressing to a heart attack and no improve 30-day survival though GIK was associated with lower rate of cardiac arrests or in-hospital deaths.

Funded by the National Institutes of Health, the study was presented in March 2012 at a meeting of the American College of Cardiology in Chicago, and was subsequently published on May 9, 2012 in ‘The Journal of the American Medical Association’ (JAMA).

Researchers felt that there is a need to carry out further studies to assess out-of-hospital use of GIK as therapy for patients with ACS.

Why Too Much Vitamin-D Bad For Heart?

While small amounts of Vitamin-D can be found in foods including fatty fish (mackerel, sardines and tuna), 80 to 90 percent of what the body requires can get from exposure to sunlight. But during winter season or in cold northern climates where there is a lack of sunlight, people are often encouraged to take supplements.

This is because a deficiency in Vitamin-D would lead to many medical disorders including osteoporosis, heart disease, stroke and hypertension, diabetes and metabolic syndrome, and cancer.

However, people who take too much supplement in Vitamin-D might get into troubles too. Researchers from Intermountain Medical Center in Murray, Utah reported in November 2011 at the annual meeting of the American Heart Association that higher than normal levels of Vitamin-D could make the heart beat too fast and out of rhythm (atrial fibrillation).

By following 132,000 patients at a Utah based medical center, researchers found that the risk of newly developed atrial fibrillation jumped almost 3-fold when blood levels of Vitamin-D were high. The normal range for Vitamin-D is between 41 and 80 nanograms per deciliter (ng/dl). But the patients in the study had readings above 100 ng/dl.

People who are diagnosed with atrial fibrillation and are taking Vitamin-D supplements are advised to have their blood levels checked to ensure they are not taking excessive amount of Vitamin-D. According to researchers, the effects of high Vitamin-D on heart rhythms are reversible. The arrhythmias would also improve simply by cutting down the consumption.

As recommended by National Institute of Health, the daily intake of Vitamin-D for people age between 1 and 70 years old is 600 IUs (International Units), based on what is sufficient for bone health.

Vitamin-D can be obtained from several natural food sources include oily fish such as tuna or salmon. For instance, 3 ounces of cooked salmon contains 447 IUs of Vitamin-D per serving. Small amounts of Vitamin-D can also be found in cheese and egg yolks. The Department of Agriculture provides a comprehensive list of foods containing Vitamin-D.

Instead of assuming supplements sold over the counter are safe, people should check their blood level to make sure they are in the safe range simply because people absorb supplement differently.

Be Happy To Prevent Heart Disease!

It has been known that people who are chronically angry, anxious or depressed would have a higher risk of heart attack. The reason quoted by scientists is that the stress associated with these people can lead to damage of arteries and the heart.

On the other hand, people who are upbeat and optimistic might prevent them from getting heart disease. This is what the researchers from Harvard School of Public Health found. After reviewing dozens of studies examining a positive outlook on heart health, they discovered that the most optimistic people had half the risk of a first heart attack comparing to the least optimistic.

The study, which were funded by the Robert Wood Johnson Foundation, showed that people who are more optimistic tend to have healthier blood pressure, cholesterol level and weight, and more likely to exercise, eat healthier, get enough sleep and avoid smoking. The findings were published on April 17, 2012 in the ‘Psychological Bulletin’.

However, more research is still needed to confirm whether a positive outlook makes people feel more willingly to take heart-healthy steps or living healthier helps people feel more positive.

In 2010, researchers from Columbia University Medical Center reported in the February issue of the European Society of Cardiology’s European Heart Journal that people with positive emotions could possibly prevent heart disease.

According to the findings, positive emotions might prevent heart disease by influencing on heart-rate variability, sleeping patterns and smoking cessation. The reasons behind the argument are positive affect might have longer periods of rest or relaxation physiologically and those with positive emotion might recover more quickly from stressors and might not spend too much time ‘re-living’ them, which in turn could cause physiological damage.

Some heart specialists noticed that those patients who feel they can have some control over their lives and are invested in their care have better outcomes. But the problem is that not all people are optimistic. Some people are just pessimistic by nature.

While it is not always easy for people to be happy, especially in the present tough economic situation, taking a moment to just relax and enjoy a sunny day might be just good for the heart!

You Might Be At Risk of Heart Disease Even Before You Are Born!

When we talk about heart disease, we will usually associate it with unhealthy diet and lifestyle, which can trigger many risk factors including high blood pressure, obesity, and diabetes. Of course, family history of heart disease might play a role, too.

But a study conducted by researchers from Leiden University Medical Center in The Netherlands found that a woman’s risk of getting a heart attack might begin to rise even before she is born. The risk could be increased by more than 8 times if the woman had changes in certain genes. These changes, as found previously, could be brought on by stress experienced in the womb like not getting enough nutrients.

The new findings, which were published on November 17, 2011 in the ‘International Journal of Epidemiology’, supported the belief of scientists that conditions during early life, such as habits of a pregnant mother, might affect her baby’s risk of later getting heart disease.

1,654 participants, who aged between 70 and 82 and had not had a heart attack before the study’s start, were involved in the study. After 3 years, 122 people were found to have a heart attack. Their DNA was compared with 126 participants who had not experienced a heart attack and were similar in age and other characteristics.

The researchers looked for epigenetic changes in 6 genes, known to be influenced by in the utero environment. A chemical ‘tag’ was added to a section of DNA during such a change.

It was found that epigenetic changes in 2 of the genes were linked to an increased risk of heart attack. Women with a tag on one gene were 2.8 times more likely to have a heart attack while women with a tag on both genes were 8.6 times more likely to have a heart attack, comparing to those who did not have these changes.

As the study was conducted in adults, the researchers do not know exactly what the participants had experienced during the prenatal period. Also the study was small, so they insisted that larger studies including a wider range of age groups should be carried out to determine more accurate risk estimates.

For men, there is no link found between changes in the genes and heart attack. This could be due to the fact that men tend to have heart attacks at earlier ages than the participants in the study, masking the effect of the gene changes in the study group.