High blood pressure

What Is High Blood Pressure?

High blood pressure (HBP) is a serious condition that can lead to coronary heart disease, heart failure, stroke, kidney failure, and other health problems.

“Blood pressure” is the force of blood pushing against the walls of the arteries as the heart pumps out blood. If this pressure rises and stays high over time, it can damage the body in many ways.

About 1 in 3 adults in the United States has HBP. HBP itself usually has no symptoms. You can have it for years without knowing it. During this time, though, it can damage the heart, blood vessels, kidneys, and other parts of your body.

This is why knowing your blood pressure numbers is important, even when you’re feeling fine. If your blood pressure is normal, you can work with your health care team to keep it that way. If your blood pressure is too high, you need treatment to prevent damage to your body’s organs.

Blood Pressure Numbers

Blood pressure numbers include systolic (sis-TOL-ik) and diastolic (di-a-STOL-ik) pressures. Systolic blood pressure is the pressure when the heart beats while pumping blood. Diastolic blood pressure is the pressure when the heart is at rest between beats.

You will most often see blood pressure numbers written with the systolic number above or before the diastolic, such as 120/80 mmHg. (The mmHg is millimeters of mercury—the units used to measure blood pressure.)

Blood pressure tends to rise with age. Following a healthy lifestyle helps some people delay or prevent this rise in blood pressure.

People who have HBP can take steps to control it and reduce their risks for related health problems. Key steps include following a healthy lifestyle, having ongoing medical care, and following the treatment plan that your doctor prescribes.

Genetic and environmental influences

An international research team has identified common genetic variants associated with systolic blood pressure, diastolic blood pressure, and high blood pressure (hypertension), suggesting potential avenues of investigation for the prevention or treatment of high blood pressure.

About 1 in 3 adults (approximately 72 million people) in the United States has high blood pressure. High blood pressure can lead to coronary heart disease, heart failure, stroke, kidney failure, and other health problems, and causes over 7 million deaths worldwide each year.

While the environment (diet, physical activity, stress, etc.) affects blood pressure, genetics also plays a substantial role and may increase some people’s risk of developing high blood pressure under specific environmental exposures; however, many genes involved in blood pressure regulation remain unknown.

To identify genes involved in blood pressure maintenance and high blood pressure, the researchers analyzed differences in the genomes of nearly 30,000 people of European descent whose average systolic blood pressures ranged from 118 mm Hg to 143 mm Hg and average diastolic blood pressures ranged from 72 mm Hg to 83 mm Hg. These individuals were part of a long-term study of cardiovascular health and disease supported by the National Institutes of Health called ARIC (Atherosclerosis Risk in Communities). The researchers looked for genetic differences that correlated with high blood pressure and found 11 variations or changes in DNA sequence that appear to regulate blood pressure levels.

Blood pressure is measured in millimeters of mercury (mm Hg), and expressed with two numbers, for example, 120/80 mm Hg. The first number (systolic pressure) is the pressure when the heart beats while pumping blood. The second number (diastolic pressure) is the pressure in large arteries when the heart is at rest between beats.

The researchers found that the top 10 gene variants for systolic and diastolic blood pressure were each associated with around a 1 and 0.5 mm Hg increase in systolic and diastolic blood pressure, respectively. The prevalence of high blood pressure increased as the number of variants increased.

People who carry very few blood pressure genetic risk variants have blood pressure levels that are several mm Hg lower than those who carry multiple risk variants. In practical terms this is enough to increase the risk for cardiovascular disease. A prolonged increase in diastolic blood pressure of only 5 mm Hg is associated with a 34 percent increase in risk for stroke and a 21 percent increase of coronary heart disease. The new insight into how the kidneys govern the balance of salt in the body, a crucial task for regulating blood pressure. And, it reveals how a gene already linked to behavior and mental health can play a role in the body, as well as the brain.

Take a Blood Pressure at Home

Knowing your blood pressure is a good idea because it shows how at least in part how healthy your lifestyle is. Some people have high BP genetically but good exercise and diet habits can help lower it. First, you need to know the normal healthy ranges of an adult blood pressure. The standard healthy B/P as of now is 120 systolic / 80 diastolic. The systolic pressure measures how hard the left ventricle pumps during systole (contraction phase) and the diastolic pressure measures how much the heart relaxes during diastole (relaxation phase). To take a blood pressure, you’ll need a blood pressure cuff and a stethoscope. In order to get an accurate reading, you must make sure that the edge of the cuff is 40% of the circumference of the person’s arm between the inner elbow and the shoulder. If this isn’t the case, the reading can be a false high or a false low.

Michael Jacson Dies: Sudden Cardiac Arrest (Sudden Cardiac Death)

Singer Michael Jackson died on June 25, 2009, after being rushed to a hospital suffering from cardiac arrest.
Cardiac arrest is the sudden loss of cardiac function, when the heart abruptly stops beating. A person whose heart has stopped will lose consciousness and stop normal breathing, and their pulse and blood pressure will be absent. Unless resuscitative efforts are begun immediately, cardiac arrest leads to death within a few minutes. This is often referred to by doctors as “sudden death” or “sudden cardiac death (SCD).”
Ventricular fibrillation is the most common cause of cardiac arrest. Ventricular fibrillation occurs when the normal, regular, electrical activation of heart muscle contraction is replaced by chaotic electrical activity that causes the heart to stop beating and pumping blood to the brain and other parts of the body. Permanent brain damage and death can occur unless the flow of blood to the brain is restored within five minutes. Heart attack is the most common cause of ventricular fibrillation. Less common causes of cardiac arrest include respiratory arrest (loss of breathing function), choking, trauma, electrocution, and drowning.

Introduction to sudden cardiac arrest
A natural disaster hits, the power goes off and the lights go out. It’s a common scene that plays out during hurricane and tornado seasons, and it’s very similar in trying to explain sudden cardiac arrest. The heart sustains an insult, the electricity is short circuited, the heart can’t pump, and the body dies.
The heart is an electrical pump, where the electricity is generated in special pacemaker cells in the upper chamber, or atrium, of the heart. This electrical spark is carried through pathways in the heart so that all the muscle cells contract at once and produce a heart beat. This pumps blood through the heart valves and into all the organs of the body so that they can do their work.
This mechanism can break down in a variety of ways, but the final pathway in sudden death is the same: the electrical system is irritated and fails to produce electrical activity that causes the heart to beat. The heart muscle can’t supply blood to the body, particularly the brain, and the body dies. Ventricular fibrillation (V Fib) is the most common reason for sudden death in patients. Without a coordinated electrical signal, the bottom chambers of the heart (ventricles) stop beating and instead, jiggle like Jello. Ventricular Fibrillation is treated with electrical shock, but for it to be effective, the shock usually needs to happen within less than four to six minutes, not only for it to be effective, but also to minimize brain damage from lack of blood and oxygen supply. Automatic external defibrillators (AEDs) are commonly available in public places to allow almost anybody to treat sudden death. Less commonly, the heart can just stop beating. The absence of a heart beat is known as asystole (asystole: a=no + systole=beat).
What are the causes of sudden cardiac arrest?
Sudden death is most often caused by heart disease. When blood vessels narrow, the heart muscle can become irritated because of lack of blood supply. In heart attack (acute myocardial infarction), a blood vessel becomes completely blocked by a blood clot, and there is enough irritability of the muscle to cause ventricular fibrillation. In fact, the reason many people with chest pain are admitted to the hospital is to monitor their heart rate and rhythm for signs that might lead to ventricular fibrillation. Sudden death may also be the first presentation of heart disease.
Congestive heart failure and heart valve problems, like aortic stenosis (narrowing of the aortic valve) also increase the risk of sudden cardiac arrest.
Cardiomyopathy is a broad category of heart disease where the heart muscle does not contract properly for whatever reason. Often it is ischemic, where part of the heart muscle doesn’t get an adequate blood supply for a prolonged period of time and no longer can efficiently pump blood. People whose ejection fractions (the amount of blood pumped out of the heart with each heart beat) is less than 30% are at greater risk for sudden death (a normal ejection fraction is above 50%). In some people, cardiomyopathy may develop in the absence of ischemic heart disease.
Inflammation of the heart muscle, known as myocarditis (myo=muscle + card=heart + itis= inflammation), can also cause rhythm disturbances. Diseases like sarcoidosis, amyloidosis, and infections can cause inflammation of the heart muscle.
Some people are born with electrical conducting systems that are faulty, which place them at higher risk for rhythm disturbances. Some are due to the wiring, or electrical conduction system, like Wolff-Parkinson-White syndrome, while others are due to the structural basic structural problems within the heart, like Marfan syndrome.
Pulmonary embolus, a blood clot to the lung, can also cause sudden death. Clots form in the leg or arm and may break off and flow to the lung where they decrease the lung’s ability to get oxygen from the air to the body. Risk factors for blood clots include surgery, prolonged immobilization (for example, hospitalization, long car rides or plane trips), trauma, or certain diseases like cancer.
Blunt chest trauma, such is in a motor vehicle accident, may result in ventricular fibrillation.