Heart and Cardiovascular System

 


High blood pressure and exercise, weight loss:


Regular exercise and weight loss may help overweight people with moderately high blood pressure avoid the need for anti-hypertensive drugs, a new study indicates.

The 99 people who completed the 6-month study were divided into three groups: 

  1. those who combined exercise with a calorie- and fat-restricted weight-loss diet,

  2. those who exercised but didn't follow the weight-loss program, and 

  3. a control group that did neither.

All were moderately overweight people ages 29 or older with sedentary lifestyles and blood pressures ranging from 130 to 180 systolic (the upper figure in blood pressure readings) and 85 to 105 diastolic (the lower figure).

By the end of the study, published in the August issue of Hypertension: Journal of the American Heart Association, the systolic pressure of those in the exercise/weight loss group dropped an average of 8 points. Their diastolic pressure declined by an average of 6 points.

In the exercise-only group, the average systolic reading dropped by 3.5 points and the average diastolic reading by 5 points. The control group showed a decrease of 2 points in the average systolic reading, while the diastolic pressure remained unchanged.

Reducing blood pressure through exercise and weight loss could move many people from Stage 1 hypertension into the "high normal" category and many others from "high normal" to "normal," according to study author Anastasia Georgiades, Ph.D., of the Duke University Medical Center.

Normal blood pressure is a systolic pressure less than or up to 130 millimeters of mercury (mmHg) and a diastolic pressure up to 85 mmHg. A blood pressure reading of 130-139 systolic over 85-89 diastolic is in the "high normal" range. A person with systolic pressure between 140-159, and diastolic pressure from 90-99 mmHg, is said to have Stage 1 hypertension.

"This study shows that exercise in combination with weight loss is an effective drug-free treatment for elevated blood pressure in mild to moderately obese individuals," Dr. Georgiades concludes.

Sheldon G. Sheps, M.D., a hypertension specialist at Mayo Clinic, Rochester, Minn., agrees.

"This study adds to the weight of evidence that a healthier lifestyle lowers blood pressure," says Dr. Sheps. "Lifestyle measures should be part of the management of every person with higher-than-desired blood pressure, even if drugs also are needed to achieve goal blood pressures."

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Cardiac arrest and CPR:


The American Heart Association (AHA) has revised and streamlined its guidelines for resuscitation of people whose hearts have stopped (cardiac arrest).

People will no longer be taught to check the pulse of a collapsed person before starting chest compressions and breaths, according to the AHA. Instead, the new guidelines advise checking for normal breathing, movement, and response to touch or questions when deciding whether cardiopulmonary resuscitation (CPR) is necessary.

Studies have shown that people who perform CPR are incorrect in their judgment about the presence of a pulse at least 35 percent of the time, according to Vinay Nadkarni, M.D., chairman-elect of the AHA committee that sets guidelines for emergency cardiac care.

Each year in the United States, an estimated 225,000 episodes of sudden cardiac arrest occur outside a hospital, according to AHA president Rosemarie Robertson, M.D., and only 5 percent of people survive.

Sudden cardiac arrest occurs when the heart's electrical signals are disrupted. The heart stops beating, or it starts to quiver (ventricular fibrillation). Blood is not pumped to the brain or other vital organs, resulting in collapse and, without prompt treatment, death.

A heart attack is not the same as sudden cardiac arrest. A heart attack is the death of heart muscle. Sudden cardiac arrest may be brought on by a heart attack or a drug overdose, or it may result from an accident such as electrical shock or near drowning.

The AHA guidelines simplify CPR. Previous instructions varied the ratio of chest compressions and breaths according to the number of rescuers. The new guidelines say that people giving CPR to adults should perform 15 chest compressions for every 2 breaths regardless of the number of rescuers present.

The guidelines also call for widespread distribution of portable devices called external defibrillators in ambulances, fire trucks, police cars, public buildings, sports arenas, theaters, airports and airplanes. These computerized units quickly sense whether the heart has stopped and deliver a jolt of electricity to restore the heart's natural rhythm.

CPR followed by defibrillation within 2 to 3 minutes of collapse has produced survival rates of up to 50 percent in some studies, Dr. Nadkarni says. With each minute of delay, chance of survival decreases by 7 percent to 10 percent.

The guidelines are published in the Aug. 22 issue of Circulation: Journal of the American Heart Association.

For more information on the heart and resuscitation, see:

         Interactive heart tour

         American Heart Association - Emergency cardiovascular care programs

         Circulation: Journal of the American Heart Association

 

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