What is blood pressure?
(Today’s column was contributed by our expert consultant, Celine T. Aquino, M.D., cardiologist at Cebu Cardiovascular Center, Cebu Doctors’ Hospital. The management of high blood pressure is one of her specialty interests.---PSC)
Blood pressure (resulting from the heart pumping action) is the force exerted by the circulating blood against the walls of the arteries, much like automobile tire pressure, where the air inside the inner tube exerts certain amount of force against the walls of the tube to keep the tire “properly inflated” and not flat.
What is hypertension?
Hypertension is the medical term for high blood pressure ("hyper" meaning high, and "tension" meaning pressure). There is no specific demarcation between "normal blood pressure" and hypertension. However, medical statistics show that a systolic pressure (top figure in a blood pressure reading) equal to or greater than 140, and a diastolic pressure (the bottom figure) equal to or greater than 90 carries with it a higher risk of developing cardiovascular health problems. For this reason, a blood pressure of 140/90 has been designated cut-off for hypertension. When the diastolic pressure (bottom figure) is equal to or higher than 90, a diagnosis of hypertension is made regardless of the systolic (top figure), and if the diastolic pressure is lower than 90, a systolic reading of 140 or greater constitutes hypertension
Is there more than one kind of hypertension?
Yes, primary and secondary. Nearly 50 million Americans and about 10 million Filipinos, are hypertensives. Primary hypertension accounts for more than 90% of cases, popularly known even in medical circles as benign or essential, two terms that are a gross misnomer, since it is neither benign nor essential. Essential refers to the fact that no one particular organ system is responsible for the high blood pressure. The secondary form is one which is caused by a derangement in an organ system, like Renal Hypertension (about 8%), where the destruction or disease of the both kidneys causes the high blood pressure, or Acromegally (gigantism) where the pituitary gland in the brain malfunctions, causing hypertension as one of its symptoms. Only about 1-2% of cases are due to potentially curable condition.
What happens in untreated hypertension?Bluntly put, untreated hypertensive people die prematurely, from heart disease (the most common), stroke or kidney failure. A significant number develop eye complication called retinopathy, which could progress to blindness. Compared to a decade ago, the physician today has a more comprehensive, more sophisticated and more effective regimen in the management of hypertension. There is really no justifiable reason why someone with high blood pressure should suffer and risk life by not seeing a physician for the treatment of hypertension. Those under early and effective management of high blood pressure could lead a normal life, with some lifestyle modification.
How is hypertension diagnosed?The majority of patients will not have symptoms from high blood pressure and only discovered as hypertensives on routine physical examination. A single "high" reading does not constitute hypertension. The blood pressure should be consistently high (systolic higher than 140 and or diastolic higher than 90) over a period of 2-4 weeks. The readings should be taken at least five minutes apart after the patient has been sitting quietly, and various readings taken at different times of the day. A history of hypertension in the family helps make the diagnosis easier.
What is "white-coat" hypertension?This is phenomenon of elevated blood pressure when the patient is examined in a doctor's office, where the physician or nurse are usually wearing white lab coats. It is obviously a psychological effect brought on by some nervousness or anxiety. This may be amusing but this occurs in as much as 35% of cases, including physician patients!
What other factors can affect blood pressure reading?Smoking within 30 minutes of a blood pressure reading could raise the blood pressure by as much as 20 mm Hg. Nervousness, a recent meal, extremes of room temperature, aggravating or nagging emotional stress, etc. can affect the readings.
Do salty foods affect blood pressure?Most definitely so, since ingestion of salt (Sodium Chloride) leads to a higher level of Sodium in the blood stream, which leads to fluid retention in the body, increasing the circulating blood volume resulting in an elevated pressure. Other mechanisms come into play to raise the blood pressure following intake of salty foods. High blood pressure may also be associated with excessive alcohol intake, contraceptives, licorice, cocaine, symphatomimetics (nasal decongestants, etc.) and steroids.
Must high blood pressure be treated immediately?As soon as the diagnosis is made, hypertension should be treated without delay. Because of the inevitability of end organ damage if high blood pressure is left untreated, even the mild form of the hypertension must be treated as early as it is detected.
Do all cases of hypertension need to be treated with drugs?After ruling out the cases of secondary hypertension which will benefit from surgery, all hypertensives need drug therapy. Some of the general measures include stress management, regular aerobic exercises, dietary restriction of salt, total caloric intake, cholesterol and saturated fats, abstinence from cigarettes and alcohol. Lifestyle changes are essential but not enough. On top of these, drug therapy is a must, in order to reduce the risk for cardiovascular morbidity and mortality.
What drugs are used to treat hypertension?Today, there are 6 major classes of drugs prescribed for high blood pressure: 1. Diuretics (water pills); 2. Anti-adrenergic agents (central, alpha and beta- blockers); 3. Vasoldilators; 4. Calcium Channel Blockers; 5. Angiotensin Converting Enzyme (ACE) Inhibitors; and, 6. Angiotensin II receptor blockers (All blockers). The attending physician will evaluate the patient and tailor the choice of drugs and management according to the individual situation and concomitant conditions the patient may have. None of these medications should be taken without the supervision of a physician, since these drugs, like any others, have potential side effects (and interaction with other medications) which could be serious or even lethal. Once a hypertensive, always a hypertensive, so the therapy is for life.
Do anti-hypertension drugs cause impotence?All drugs used to treat high blood pressure, by their very nature, have some potential to lessen libido and cause male erectile dysfunction. The effect varies among different persons, some more affected than others. The side-effect is not permanent. Discontinuance of the medications leads to the pre-treatment sexual potency. But the power of suggestion has a lot to do with most psychic side-effects. A symphatetic doctor-patient relationship will achieve much to alleviate any anxiety that may arise (pardon the pun) from the knowledge of the potential side-effects of these drugs.
Our readers are invited to send in their medical questions for possible inclusion in future issues of this column. Mail your questions to the author at Heart to Heart Talk, c/o Cebu Cardiovascular Center, Cebu Doctors' Hospital, Osmena Boulevard, Cebu City, Philippines, or e-mail them to philip@chua.net
Philip S. Chua, M.D. is Chairman of Cardiovascular Surgery of Cebu Cardiovascular Center at Cebu Doctors' Hospital, where he and his team do open-heart and coronary bypass surgery. He is Cardiac Surgeon Emeritus in Northwest Indiana, U.S.A. and shuttles to Cebu every other month to do cardiac surgery with his team. He was a Denton A. Cooley Cardiac Surgery Fellow at the Texas Heart Institute in Houston. Dr. Chua is a weekly columnist of Cebu Daily News, MALAYA Philippine national daily, Southern Leyte Times, HealthNEWS Magazine of the Manila Times, Essence Magazine-Cebu, The Filipino Reporter of New York, The Philippine News of California (national edition), and the Pinoy Monthly of Chicago. He is past president of the American Heart Association (NWI), the Association of Philippine Physicians in America (APPA) and the Society of Philippine Surgeons in America (SPSA). His email address is philip@chua.net.