EACH year on May 17, World Hypertension Day — an initiative of the World Hypertension League — is observed. The aim is to increase awareness about this often undiagnosed silent killer.

According to the World Hypertension League, hypertension is the leading risk factor for disease burden worldwide, with approximately four in 10 adults having raised blood pressure. The Jamaica Healthy Lifestyles survey done in 2008 reports that one in four Jamaicans in the age group 15-74 have hypertension.

WHAT IS HYPERTENSION?

Hypertension, commonly known as high blood pressure, occurs when the systolic blood pressure exceeds 140 mmHG and the diastolic exceeds 90 mmHG. The normal range for blood pressure is 90/60 to 140/90.

Contrary to popular belief, hypertension does not cause any symptoms. Particularly in Jamaica, many Jamaicans are of the belief that they will feel dizzy or have headaches when their blood pressure is high. Whenever these symptoms are observed and associated with a high blood pressure reading, it is usually because the brain has suffered acute injury from a severely elevated blood pressure. This is a true emergency, requiring hospitalisation and measures to get the blood pressure down by at least 20 per cent within 24 hours.

WHY DO WE TREAT HYPERTENSION?

We treat hypertension because of the potential for significant long-term damage to the body’s major organs, namely heart, kidney and brain. Because hypertension affects the blood vessels and blood vessels are everywhere, the ravaging effects of hypertension can affect any organ of the body.

It can lead to kidney failure, requiring dialysis, stroke and heart attack. It may also affect the eyes, leading to bleeding at the back of the eyes and loss of vision.

For these many effects, we treat hypertension, aiming to keep the blood pressure within the normal range. Over the years, research has shown that keeping the blood pressure within the normal range through lifestyle modification such as diet and exercise, as well as use of medications, can prevent or delay the onset of some of these complications.

HYPERTENSION AND THE HEART

Hypertension causes the heart to work harder, this leads to increased thickness of the heart muscle. This is akin to a bodybuilder lifting weights for many years. During this time, the patient may not experience any symptoms. Some people may notice chest pain when they exert themselves, such as doing a brisk walk or running, and some may have chest pain during these activities.

These are signs that the pressure inside the heart is high, and that the heart muscle is so thick, that even with normal circulation, it cannot get enough nutrients and oxygen when there is an increased demand.

If this goes unchecked, it will eventually lead to the heart becoming enlarged and weak, and symptoms of heart failure.

The good news is that if we catch it before the heart starts to enlarge or get weak, with good treatment of the hypertension, the damage can be halted or in some cases reversed.

HOW CAN YOUR DOCTOR TELL IF YOU HAVE HYPERTENSIVE HEART DISEASE?

This may be diagnosed on the basis of an electrocardiography (ECG) and confirmed using an echocardiogram. The ECG gives information about the electrical activity of the heart and there are some signs we can pick up, such as high voltage, which tells us that maybe your heart muscle is thicker than it should be.

This test is not 100 per cent accurate, but can give an idea.

So, if you have symptoms such as shortness of breath or chest pain with long-standing hypertension, even if your ECG is normal, your doctor should recommend an echocardiogram. The echocardiogram is an ultrasound test of the heart during which we measure the sizes of all the heart chambers, the pressures in the various chambers, have detailed look at heart valves etc. The echocardiogram gives more details about the structure and function of the heart which cannot be obtained on ECG alone.

Dr Claudine Lewis is an adult cardiologist and medical director at Heart Smart Centre in Montego Bay. She is also a cardiologist at the Cornwall Regional Hospital and an associate lecturer with the University of the West Indies. Questions may be sent to questions@heartsmartcentre.com and for additional information call 684-9989 or visit the website www.heartsmartcentre.com