Hypertension Clinic
The Hypertension Clinic has been operating at the University of Ottawa Heart Institute for the past 15 years under the directorship of Dr. Frans Leenen. The clinic works on a referral basis from family doctors and other specialists. Typically, new patients are seen each morning, with follow-ups being seen in the afternoon.
High Blood Pressure
If your blood pressure is 140 mm Hg or greater, then you need to get it down. One in 10 Canadians aged 65 to 75 years old is hospitalized with a stroke, and the number climbs dramatically for people older than 75. There is a strong connection between high blood pressure and stroke. Normalizing blood pressure through lifestyle changes and medication dramatically lowers the risks for stroke, heart attack, and congestive heart failure, particularly in patients with diabetes. Patient with diabetes and kidney disease should have their blood pressure lowered to less than 130/85 mm Hg.
The Initial Meeting
The initial visit consists of approximately 45 minutes mainly with the clinical nurse. During this time, the nurse checks your height and weight to calculate your body mass index (BMI), and the nurse also measures your abdominal circumference. Blood pressure measurements are done after you rest for five minutes without talking. Blood pressure measurements are done in both arms to detect possible differences between the two arms. In some people, one arm may have a higher reading and the nurse will then tell you that you should use that arm to have your blood pressure measured.
The size of your arm will be measured to ensure that the proper monitor cuff size is used when measuring your blood pressure. If the cuff is too small, the readings will be higher than what your true measurement is. This is very important because many people have larger arm sizes. Several readings are obtained in the sitting and standing positions.
A medical history is then documented. New patients are asked to bring all their current medications in their original containers to their appointment. The doctor will discuss a plan of action and will invite you to return for a follow-up appointment. At the follow-up visits, lifestyle modifications are discussed and medications are added or modified depending on the blood pressure measurements.
Tests and Investigations
Common tests that may be ordered include blood tests to measure your electrolytes, blood sugar, lipids, and kidney function. Urine is tested to detect the presence of blood, sugar, or protein in your urine. An ECG (electrocardiogram) or echocardiogram (ultrasound of the heart) may be requested to check for evidence of a previous heart attack or for damage to your heart from high blood pressure.
There are several different methods to assess blood pressure for diagnosis and for treatment. The most common way is the office blood pressure measurement; however, it is not the best indicator of what the true blood pressure is. Twenty-four-hour ambulatory blood pressure values and home blood pressure values more accurately reflect the overall level of blood pressure and risk for future cardiovascular disease.
Twenty-Four-Hour Blood Pressure Monitoring
Twenty-four-hour monitoring of blood pressure is done for our patients as well as for patients referred to the Heart Institute from their doctor's offices. The cost of this procedure is $100 (cash or cheque). The blood pressure monitor is an excellent diagnostic tool that assists the physicians in determining the patient's blood pressure in normal daily life. This blood pressure monitor is put on at the Heart Institute and is worn for 24 hours.
The machine automatically takes the blood pressure every 20 minutes from 6:00 a.m. to 10:00 p.m., and hourly from 10:00 p.m. to 6:00 a.m. The patient is asked to keep a diary detailing time at work, time of meals, medication, type and time of activities, and times when one has felt under stress. The monitor is returned to the clinic and is read by the attending physician.
There are four patterns seen:
- White coat hypertension: Blood pressure is primarily elevated in the doctor's office from the anxiety of a clinical visit and is lower or not elevated with normal activities.
- Sustained hypertension: Blood pressure is consistently above 135/85 mm Hg.
- Masked hypertension: Blood pressure is more elevated when measured at home or at work than in the doctor’s office.
- Non-dipping: Blood pressure does not decrease during the night.
Home Blood Pressure Monitoring
Before a diagnosis is made, a patient may be asked by the doctor to measure blood pressure at home. The patient takes a reading twice a day, morning and night, for seven days. Once a diagnosis is made, the patient may be asked to take blood pressure measurements two to three times a week. Patients should always try to have a quiet environment, sit for at least five minutes, and have their arms supported at heart level.
Recorded numbers should be brought to the next appointment with the doctor. If the reading is very high, then the doctor must repeat the measurement again, after the patient has relaxed for five minutes. If possible, it is also a good idea to measure blood pressure at work. For home blood pressure machines, we advise using either a Omron or LifeSource equipment. It is recommended that patients buy an arm cuff model and avoid the finger and wrist models, as they tend not to be accurate. It is important to note that patients need to buy the proper size cuff, especially if they have big arms.
A number of factors influence blood pressure; for example, pain, stress and anxiety; a full bladder or bowel; smoking; coffee; and some over-the-counter medications (particularly NSAIDs). It is advisable not to measure blood pressure under these circumstances.
