* Premature atrial contractions. These are early extra beats that originate in the atria (upper chambers of the heart). They are harmless and do not require treatment.
* Premature ventricular contractions (PVCs). These are among the most common arrhythmias and occur in people with and without heart disease. This is the skipped heartbeat we all occasionally experience. In some people, it can be related to stress, too much caffeine or nicotine, or too much exercise. But sometimes, PVCs can be caused by heart disease or electrolyte imbalance. People who have a lot of PVCs, and/or symptoms associated with them, should be evaluated by a heart doctor. However, in most people, PVCs are usually harmless and rarely need treatment.
* Atrial fibrillation. AF is a very common irregular heart rhythm that causes the atria, the upper chambers of the heart to contract abnormally.
* Atrial flutter. This is an arrhythmia caused by one or more rapid circuits in the atrium. Atrial flutter is usually more organized and regular than atrial fibrillation. This arrhythmia occurs most often in people with heart disease, and in the first week after heart surgery. It often converts to atrial fibrillation.
* Paroxysmal supraventricular tachycardia (PSVT). A rapid heart rate, usually with a regular rhythm, originating from above the ventricles. PSVT begins and ends suddenly. There are two main types: accessory path tachycardias and AV nodal reentrant tachycardias (see below).
* Accessory pathway tachycardias. A rapid heart rate due to an extra abnormal pathway or connection between the atria and the ventricles. The impulses travel through the extra pathways as well as through the usual route. This allows the impulses to travel around the heart very quickly, causing the heart to beat unusually fast.
* AV nodal reentrant tachycardia. A rapid heart rate due to more than one pathway through the AV node. It can cause heart palpitations, fainting or heart failure. In many cases, it can be terminated using a simple maneuver performed by a trained medical professional, medications or a pacemaker.
* Ventricular tachycardia (V-tach). A rapid heart rhythm originating from the lower chambers (or ventricles) of the heart. The rapid rate prevents the heart from filling adequately with blood; therefore, less blood is able to pump through the body. This can be a serious arrhythmia, especially in people with heart disease, and may be associated with more symptoms. A heart doctor should evaluate this arrhythmia.
* Ventricular fibrillation. An erratic, disorganized firing of impulses from the ventricles. The ventricles quiver and are unable to contract or pump blood to the body. This is a medical emergency that must be treated with cardiopulmonary resuscitation (CPR) and defibrillation as soon as possible.
* Long QT syndrome. The QT interval is the area on the electrocardiogram (ECG) that represents the time it takes for the heart muscle to contract and then recover, or for the electrical impulse to fire impulses and then recharge. When the QT interval is longer than normal, it increases the risk for “torsade de pointes,” a life-threatening form of ventricular tachycardia. Long QT syndrome is an inherited condition that can cause sudden death in young people. It can be treated with antiarrhythmic drugs, pacemaker, electrical cardioversion, defibrillation, implanted cardioverter/defibrillator or ablation therapy.
* Bradyarrhythmias. These are slow heart rhythms, which may arise from disease in the heart’s electrical conduction system. Examples include sinus node dysfunction and heart block.
* Sinus node dysfunction. A slow heart rhythm due to an abnormal SA (sinus) node. Sinus node dysfunction is treated with a pacemaker.
* Heart block. A delay or complete block of the electrical impulse as it travels from the sinus node to the ventricles. The level of the block or delay may occur in the AV node or HIS-Purkinje system. The heart may beat irregularly and, often, more slowly. If serious, heart block is treated with a pacemaker.
What are the types of arrhythmias?
November 29th, 2009Health Tip: Choosing a Backpack
November 24th, 2009Along with pens, paper and notebooks, for many youngsters, a backpack is a back-to-school necessity.
The U.S. National Safety Council offers these safety guidelines for selecting a backpack:
-Look for features that offer better support, comfort and safety.
-Choose a backpack with padding in the back to minimize pressure.
-Opt for a backpack that has belts around the hip and chest to more evenly distribute the contents.
-A backpack with lots of compartments is better, as it also helps evenly distribute the weight of school supplies.
-Look for compression straps at the bottom or side of the backpack to bring the contents closer to the back.
-Look for reflective material so your child is easier to see if walking in the dark.
What causes an arrhythmia?
November 19th, 2009Arrhythmias may be caused by many different factors, including:
-Coronary artery disease
-Electrolyte imbalances in your blood (such as sodium or potassium).
-Changes in your heart muscle.
-Injury from a heart attack
-Healing process after heart surgery.
Irregular heart rhythms can also occur in “normal, healthy” hearts.
Health Tip: Staying Healthy
November 18th, 2009Your lifestyle choices really can make a difference in whether you’re healthy or frequently sick, the American Academy of Family Physicians says.
The academy offers these suggestions to help prevent chronic health problems:
-Avoid smoking and any other use of tobacco.
-Limit your alcohol intake. For women, that’s no more than one drink per day, or no more than two drinks per day for men.
-Stick to a healthy diet, maintain a healthy body weight and get regular exercise.
-Protect your skin from the sun. Wear sunscreen, and avoid sunbathing and using tanning beds.
-Be safe when it comes to choosing sexual partners and having sex. Always use condoms and -spermicide.
-Keep blood pressure and cholesterol under control.
-Make regular appointments for vaccinations and screenings, such as mammograms, Pap smears, cancer screenings and physical exams.
It’s Back to Basics to Save a Life
November 13th, 2009Medics and doctors are used to participating in a flurry of activity when trying to save a person who’s had a cardiac arrest — inserting IVs, placing a breathing tube, performing defibrillation to restart the heart.
But studies now show that none of those advanced techniques saves lives as well as ordinary cardiopulmonary resuscitation, or CPR. And what’s more, those studies have also found that a truncated version of CPR that tosses out mouth-to-mouth in favor of simple and sustained chest compressions increases survival rates dramatically.
“It’s been shown to work, while these other things have not been shown to improve survival,” said Dr. Alex Garza, an associate professor of emergency medicine at the Washington Hospital Center and Georgetown University School of Medicine in Washington, D.C. “They were just things we thought would be good.”
“The important thing now is to step back, do chest compressions and proceed methodically,” he said.
Both the American Red Cross and the American Heart Association have endorsed chest compressions as an acceptable alternative for people who witness a cardiac arrest but aren’t trained in CPR.
By simplifying the process, they hope to get more bystanders to step in and perform chest compressions on the ailing person until help arrives. The American Heart Association estimates that fewer than a third of those who suffer cardiac arrest in a public place receive any form of CPR.
Bystanders simply are “worried about making an error, and they forget a lot of the steps,” said Dr. Marc Eckstein, associate professor of emergency medicine at the Keck School of Medicine at the University of Southern California and medical director of the Los Angeles Fire Department. “Mouth-to-mouth is complex, and many people are reluctant to perform it. Performing compression only, the results are comparable to full CPR — and you can teach someone to do it in a matter of minutes.”
The compressions need to be applied in the center of the chest at a rate of about 100 a minute — ironically, about the same rhythm as the Bee Gees’ song “Stayin’ Alive.” One study has found that performing chest compressions while listening to that song improved the CPR technique of physicians and medical students.
“Laypersons with no formal training in CPR, when they’re presented with someone in cardiac arrest, can do a pretty decent job with chest compressions,” Garza said.
Garza and Eckstein go further than the American Red Cross or the American Heart Association, however, saying that even trained rescuers should focus on uninterrupted chest compressions rather than trying to juggle compressions with mouth-to-mouth or other treatments.
It takes many repeated chest compressions to increase pressure enough to begin driving blood into heart tissue, Garza said. “By the time you got to your 15th chest compression, you’d just gotten to where you were doing some good, and then you’d stop to perform mouth-to-mouth, and it went back to zero,” he said.
Both doctors have studied what happens when paramedics change their cardiac protocols to focus more on chest compressions, Garza in Kansas City and Eckstein in Los Angeles. They both found that survival rates improved when paramedics delayed intubating patients, administering medications or performing defibrillation in favor of consistent compressions.
Chest compression CPR is more valuable than defibrillation because rescuers often arrive too late for effective defibrillation, which needs to occur within five minutes of cardiac arrest, Garza said.
“The problem is, most paramedics don’t arrive in the first five minutes,” he said. By the time rescuers arrive, the body’s tissues are starved for oxygen and the heart cells are depleted of energy. “If you attempt a defibrillation at that time, it’s less likely to be successful,” Garza said. “They’re more likely to flat-line.”
Airports and casinos boast excellent heart attack survival rates “because there’s always a defibrillator within a five-minute walk,” Garza said. Security guards are trained in the use of defibrillators, and both types of facilities have excellent closed-circuit monitoring.
If defibrillation isn’t available, it’s best for bystanders to start providing chest compressions, the experts say. That way, the stores of oxygen still in the blood will continue to circulate and feed the body’s tissues, keeping the person’s body and brain alive.
“When the heart stops, it’s not a problem of not having oxygen in the blood,” Eckstein said. “It’s a pump problem. You have to circulate that oxygen.”
Irregular heartbeat
November 11th, 2009An irregular heartbeat is an arrhythmia (also called dysrhythmia). Heart rates can also be irregular. A normal heart rate is 50 to 100 beats per minute. Arrhythmias and abnormal heart rates don’t necessarily occur together. Arrhythmias can occur with a normal heart rate, or with heart rates that are slow (called bradyarrhythmias — less than 60 beats per minute). arrhythmias can also occur with rapid heart rates (called tachyarrhythmias — faster than 100 beats per minute). In the United States more than 850,000 people are hospitalized for an arrhythmia each year.
Even modest fitness may extend lifespan
November 10th, 2009People who stay even moderately fit as they age may live longer than those who are out-of-shape, a new study suggests.
The study, of nearly 4,400 healthy U.S. adults, found that the roughly 20 percent with the lowest physical fitness levels were twice as likely to die over the next nine years as the 20 percent with the next-lowest fitness levels.
That was with factors like obesity, high blood pressure and diabetes taken into account — underscoring the importance of physical fitness itself, researchers report in the journal Medicine and Science in Sports and Exercise.
“Our findings suggest that sedentary lifestyle, rather than differences in cardiovascular risk factors or age, may explain (the) two-fold higher mortality rates in the least-fit versus slightly more fit healthy individuals,” lead researcher Dr. Sandra Mandic, of the University of Otago in Dunedin, New Zealand, noted in an email to Reuters Health.
She pointed out that nearly two-thirds of the least-fit study participants were not getting the minimum recommended amount of exercise — at least 30 minutes of moderate activity, like brisk walking, on five or more days a week.
“These results emphasize the importance of improving and maintaining high fitness levels by engaging in regular physical activity,” Mandic said, “particularly in poorly fit individuals.”
The study included 4,384 middle-aged and older adults whose fitness levels were assessed during exercise treadmill tests sometime between 1986 and 2006; they were then followed for an average of about nine years.
When Mandic’s team separated the participants into five groups based on fitness levels, they found that one-quarter of the least-fit men and women had died during the study period, versus 13 percent of those who were slightly more in shape.
Among adults in the most-fit group, only 6 percent died during the follow-up period.
Overall, the five groups showed little difference in their reported exercise habits over their adult lives. Where they did differ was their activity levels in recent years.
“Since it is recent physical activity that offers protection,” Mandic said, “it is important to maintain regular physical activity throughout life.”
And since fitness is linked to longevity regardless of weight and health conditions like high blood pressure and high cholesterol, exercise is important for all, according to Mandic.
That, she said, includes people who are thin and in generally good health.
Fetal Surgery May Treat Heart Defect
October 24th, 2009Infants born with a rare heart defect may have better outcomes when surgery to repair the heart is done while the infant is still in the womb, Harvard University researchers say.
The condition, hypoplastic left heart syndrome, occurs when the fetus’s left ventricle is underdeveloped and the heart cannot pump enough blood to sustain life. It affects about 1 in 10,000 newborns, and without open-heart surgery within a week of birth, these infants face death. Even with the heart repair, the children lead restricted lives and need at least one heart transplant, researchers say.
“Using the new procedure, in about 30 percent of the fetuses [with technically successful operations], there was an outcome of a two-ventricle circulation after birth,” said Dr. Doff B. McElhinney, an assistant professor of pediatrics at Harvard Medical School and an associate in cardiology at Children’s Hospital Boston.
The findings appear online Sept. 28 in Circulation.
How well the infants in the study will fare over the long term isn’t known, but the researchers intend to follow them as they grow up, McElhinney said.
In fetuses, aortic stenosis usually progresses to hypoplastic left heart syndrome, the study explains. Prenatal intervention could reduce the total number of surgeries required over a lifetime, eliminate the need for a heart transplant and possibly improve the children’s quality of life, he said.
According to the study, 51 of 68 procedures were considered technically successful, and 17 infants (33 percent of the 51) were born with a fully functioning heart.
The operation involves threading a catheter through the mother’s abdomen into the fetus’s heart. A balloon at the end of the catheter enlarges the aortic valve that controls blood flow from the left ventricle into the aorta and then into the body, McElhinney explained.
Over seven years, the researchers were able to establish criteria to determine which infants were likely to benefit from the procedure, which would not and when the operation would be most likely to succeed, McElhinney said. “This enables us to focus it more, and expose fewer mothers and fetuses to the risks of the procedure,” he said.
The window for performing the procedure is narrow — at around 20 to 21 weeks of pregnancy, McElhinney said. With time, experience and better technology, the success rate will get better, he added.
McElhinney is cautious about the impact of the new procedure and doesn’t want to oversell its benefits.
“By no means is this revolutionizing the care for all fetuses with hypoplastic left heart syndrome,” he said. “It’s applicable only in a small subset of those with this disease, and it’s working in a relatively small percentage of those in whom we attempt it,” he said. And even infants who had a successful procedure needed additional procedures after birth, he noted.
Still, while not a “ringing success,” he said it reinforces the belief that prenatal intervention can be used to change the development of serious forms of heart disease.
Dr. Steven E. Lipshultz, chairman of pediatrics at the Leonard M. Miller School of Medicine at the University of Miami, said that the study points the way to better treatment and outcomes for youngsters with this heart problem.
“This is a landmark study,” Lipshultz said. Without this procedure, “every one of these kids would have needed open heart surgery in the first few days after birth,” he said. Additional surgeries and multiple heart transplants are almost always necessary, he added.
Parents whose doctors think their baby might have hypoplastic left heart syndrome should act fast to find a program that will consider their child for a fetal operation, he said.
Dr. Ruben A. Quintero, professor and director of maternal-fetal medicine at the Miller School of Medicine, said he thinks that much more needs to be done to improve the procedure and increase the success rate before embracing the operation.
“What needs to happen now is that other centers use the experience of the Boston group to share their outcomes and try to improve on the limitations that the Boston group has outlined,” he said. “This has happened in other areas of fetal therapy.”
Once the surgical technique is ironed out, clinical trials should compare the outcomes of those undergoing the procedure with those who don’t have it, Quintero said.
Mini-Stroke Found to Precede 1 in 8 Strokes
October 12th, 2009Just one of every eight strokes is preceded by a milder interruption of blood flow to the brain, called a transient ischemic attack (TIA), a new Canadian study shows.
And because of that, the researchers conclude, such an attack is not the crucial warning sign that physicians need.
“The clinical implication of this study is that we cannot rely on the TIA as a warning signal to tell us to intervene to prevent a stroke because it is seen before only one of every eight strokes,” said Dr. Daniel G. Hackam, an assistant professor of medicine in neurology at the University of Western Ontario in Canada and lead author of a report in the Sept. 29 issue of Neurology.
“We need better risk profiles to predict a patient who will have that first stroke,” Hackam said. “This study is highlighting a gap in our knowledge base. If we know a stroke is impending, we can intervene to prevent that stroke.”
In the study, Hackam and his colleagues found that, of the 16,409 people diagnosed with stroke over a four-year period in Ontario hospitals, 2,032 — or 12.4 percent of them — had a TIA in the weeks before the stroke.
A TIA, he said, does not have enough predictive power to warrant intensive preventive measures.
“We need better tools,” Hackam said. “That is really the main message of our paper.”
A TIA, which some refer to as a mini-stroke, occurs when a clot briefly blocks a brain artery. Symptoms of a TIA are the same as those of a stroke — sudden onset of weakness or numbness in an arm or leg, loss of vision or double vision, speech difficulty, dizziness, loss of balance — but they go away, often in a few minutes. Many people ignore the symptoms, but they are clear signs of possible trouble, Hackam said.
The numbers in the new study are similar to those about TIA and subsequent stroke that have been reported for decades, said Dr. Larry B. Goldstein, director of the Duke Stroke Center. But he disagrees with Hackam’s interpretation of the predictive importance of TIAs.
“They predict 10 to 15 percent of strokes,” Goldstein said. “This is not a small number, so it is an opportunity to prevent stroke that you don’t want to miss when it happens.”
Better predictive tools are available, Hackam said. He prefers carotid ultrasound, an inexpensive way to listen to blood flow in the main artery to the brain. “It’s fairly inexpensive, and I do it for everyone I see in the clinic,” Hackam noted.
His patients have been referred to the stroke clinic because they have the risk factors for stroke, which include old age, smoking, high blood pressure, obesity and high cholesterol, Hackam said. Results of a carotid ultrasound test can confirm the need for treatment not only with medications to control blood pressure and blood fats but also with lifestyle changes such as more exercise, no smoking and a less-fatty diet, Hackam said.
Goldstein, though, said that detailed tests such as carotid ultrasound are not needed to recommend such measures for people who have the risk factors for stroke. Those tests tend to measure not the specific risk of stroke but the risk of all cardiovascular problems, including heart attacks, he said.
“The more tests you do, the more chance there is to make a mistake,” Goldstein said. “The standard risk factors can lead to recommending basic lifestyle changes. People who don’t smoke, who drink moderately, who keep their blood pressure low, are less likely to have strokes.”
And anyone who experiences a TIA should report it to a doctor immediately, Goldstein said. “It only matters if you are going to do something about it,” he said. “A TIA identifies someone who is at high risk of having a stroke in a short period of time.”
More Retinal Detachment Seen With Higher Income Status
October 6th, 2009Wealthy people are twice as likely to suffer retinal detachment as poorer people, according to Scottish researchers who said they couldn’t identify the reason for the disparity.
Retinal detachment — the separation of the retina from its connection at the back of the eye — usually occurs as a result of a tear in the retina. If patients don’t receive immediate treatment, retinal detachment can lead to permanent vision loss.
The new study included 572 patients diagnosed with primary retinal detachment in Scotland over a one-year period between 2007 and 2008. The rate of retinal detachment was 15.4 per 100,000 population among the most affluent patients, compared with 13.6 per 100,000 for the second-most affluent patients, 9.3 per 100,000 for the third-most affluent patients, and 6.9 per 100,000 among the least affluent patients.
This was a surprising finding that’s never been reported before, said Dr. David Yorston of Gartnavel General Hospital in Glasgow, and colleagues.
“We have not found any satisfactory explanation for the greater incidence of [retinal detachment] in less deprived patients. It is possible that a combination of small differences in known risk factors, such as myopia [short-sightedness] and previous cataract surgery account for the difference,” they wrote. “However, we cannot exclude the possibility that affluence is associated with some other, hitherto, unknown risk factor.”