Hypertension Part 1: A Brief Overview
Author: Dr. Sukheshni Nand
“Blood pressure is the force exerted by circulating blood against the walls of the body’s arteries, the major blood vessels in the body". When the pressure is too high, hypertension occurs [1]. Blood pressure is written as two numbers [1]:
The first (systolic) number – the pressure in blood vessels when the heart contracts or beats.
The second (diastolic) number-the pressure in the vessels when the heart rests between beats.
Hypertension is only diagnosed when (it is measured on two different days), the systolic blood pressure readings on both days is ≥140 mmHg and/or the diastolic blood pressure readings on both days is ≥90 mmHg [1]. Whenever possible, the diagnosis should not be made on a single office visit. Usually, 2–3 office visits at 1–4-week intervals (depending on the BP level) are required to confirm the diagnosis of hypertension [2]. The diagnosis might be made on a single visit if BP is ≥180/110 mm Hg and there is evidence of cardiovascular disease (CVD) [2].
Furthermore, isolated systolic hypertension defined as elevated SBP (≥140 mm Hg) and low DBP (<90 mm Hg) is common in young and in elderly people [2]. In young individuals, including children, adolescents, and young adults, isolated systolic hypertension is the most common form of essential hypertension. However, it is also particularly common in the elderly, in whom it reflects stiffening of the large arteries with an increase in pulse pressure (the difference between SBP and DBP) [2].
Unfortunately, hypertension has no warning signs or symptoms which is why most people with hypertension are unaware of the problem [1]. "This is why hypertension is known as the silent killer. For this reason, it is essential that blood pressure is measured regularly" [1].
Symptoms/signs of hypertension/coexisting illnesses [2]:
Chest pain, shortness of breath, palpitations, claudication, peripheral edema, headaches, blurred vision, nocturia, hematuria, dizziness.
Symptoms suggestive of secondary hypertension; muscle weakness/tetany, cramps, arrhythmias (hypokalemia/primary aldosteronism), flash pulmonary edema (renal artery stenosis), sweating, palpitations, frequent headaches (pheochromocytoma), snoring, daytime sleepiness (obstructive sleep apnea), symptoms suggestive of thyroid disease.
"Among other complications, hypertension can cause serious damage to the heart. Excessive pressure can harden arteries, decreasing the flow of blood and oxygen to the heart [1]. Hypertension can also burst or block arteries that supply blood and oxygen to the brain, causing a stroke. In addition, hypertension can cause kidney damage, leading to kidney failure" [1]. Prevention [1]
Reducing salt intake (to less than 5g daily)
Eating more fruits and vegetables
Being physically active on a regular basis
Avoid the use of tobacco
Reducing alcohol consumption
Limiting the intake of foods high in saturated fats
Eliminating/reducing trans fats in the diet
Management
Reducing and managing mental stress
Regularly checking blood pressure
Treating high blood pressure
Managing other medical conditions
According to the new ACC and American Heart Association (AHA) guidelines for the detection, prevention, management, and treatment of high blood pressure- High blood pressure should be treated earlier with lifestyle changes and in some patients with medication – at 130/80 mm Hg rather than 140/90 [3]. "You've already doubled your risk of cardiovascular complications compared to those with a normal level of blood pressure," said Paul K. Whelton, MB, MD, MSc, FACC, lead author of the guidelines [3]. "We want to be straight with people – if you already have a doubling of risk, you need to know about it. It doesn't mean you need medication, but it's a yellow light that you need to be lowering your blood pressure, mainly with non-drug approaches" [3].
Blood pressure categories in the 2017 guideline are [3]:
Normal: Less than 120/80 mm Hg;
Elevated: Systolic between 120-129 and diastolic less than 80;
Stage 1: Systolic between 130-139 or diastolic between 80-89 Stage 2: Systolic at least 140 or diastolic at least 90 mm Hg
Hypertensive crisis: Systolic over 180 and/or diastolic over 120, with patients needing prompt changes in medication if there are no other indications of problems, or immediate hospitalization if there are signs of organ damage
The 2017 guidelines eliminate the category of prehypertension. Now only categorizing patients as having either Elevated (120-129 and less than 80) or Stage I hypertension (130-139 or 80-89) [3]. While previous guidelines classified 140/90 mm Hg as Stage 1 hypertension (this level is classified as Stage 2 hypertension under the new guidelines) [3]. Other changes include:
Prescribing medication only for Stage I hypertension if a patient has already had a cardiovascular event such as a heart attack or stroke, or is at high risk of heart attack or stroke based on age, the presence of diabetes mellitus, chronic kidney disease or calculation of atherosclerotic risk (using the same risk calculator used in evaluating high cholesterol) [3].
Acknowledging that many people will need two or more types of medications to control their blood pressure and that people may take their pills more consistently if multiple medications are combined into a single pill [3].
"Identifying socioeconomic status and psychosocial stress as risk factors for high blood pressure that should be considered in a patient's plan of care" [3].
A corresponding analysis of the guidelines' impact, Paul Muntner, Ph.D., et al., suggests "the 2017 ACC/AHA hypertension guideline has the potential to increase hypertension awareness, encourage lifestyle modification and focus antihypertensive medication initiation and intensification on US adults with high CVD risk" [3].
Individuals identified with confirmed hypertension (grade 1 and grade 2) should receive appropriate pharmacological treatment [2]. BP should be lowered if ≥140/90 mm Hg and treated to a target <130/80 mm Hg (<140/80 in elderly patients) [2].
In addition, hypertension in pregnancy is a condition affecting 5%–10% of pregnancies worldwide. Maternal risks include placental abruption, stroke, multiple organ failure (liver, kidney), disseminated vascular coagulation. Fetal risks include intrauterine growth retardation, preterm birth, intrauterine death [2]. Hypertension in pregnancy includes the following conditions: Preexisting hypertension; starts before pregnancy or <20 weeks of gestation, and lasts >6 weeks postpartum with proteinuria [2]. Gestational hypertension; starts >20 weeks of gestation, and lasts <6 weeks postpartum.
A variety of lifestyle modifications have been shown to lower blood pressure and to reduce the prevalence of hypertension. These include reduction of dietary sodium intake, weight loss in people who are overweight, physical activity, increased dietary potassium intake, and a diet with increased fresh fruit and vegetables, and reduced saturated fat intake. As part of the community approach to primary prevention of hypertension, primary health care professionals should measure blood pressure regularly in all persons above 40 years of age, even if they are normotensive, at least once every 2 years and advise patients with mild hypertension on lifestyle modifications, such as increasing physical exercise, and reducing salt and saturated fat intake. Hypertension, hyperlipidemia, hyperglycemia, obesity, and smoking are interlinked risks for ill health. The risk of coronary heart disease multiplies with additional cardiovascular risk factors. Reducing salt intake from 12 g per day to 3 g per day reduces strokes by 33% and coronary heart disease by 25%. Although antihypertensive drug therapy represents one of the major success stories in the prevention of cardiovascular disease, the pharmacological approach to management has limitations if used in isolation.
A range of lifestyle modifications has been shown to reduce blood pressure and to lower the prevalence of hypertension. "These include reduction of dietary sodium intake, weight loss in people who are overweight, physical activity, increased dietary potassium intake and a diet with increased fresh fruit and vegetables and reduced saturated fat intake". As part of the community approach to primary prevention of hypertension, health care professionals should measure blood pressure regularly in all persons above 30 to 40 years of age, at least once every 2 years, and advise patients with mild hypertension on lifestyle modification. Hypertension, hyperlipidemia, hyperglycemia, obesity, and smoking are interlinked risks for ill health. The risk of coronary heart disease multiplies with additional cardiovascular risk factors. Although antihypertensive drug therapy represents one of the major success stories in the prevention of cardiovascular disease, the pharmacological approach to management has limitations if used in isolation.
Reference:
1. World Health Organisation. Hypertension. Available at:https://www.who.int/news-room/fact-sheets/detail/hypertension. 2019
2. Journals. 2020 International Society of Hypertension Global Hypertension Practice Guidelines Thomas Unger, et al. 2020
3. American College of Cardiology. New ACC/AHA High Blood Pressure Guidelines Lower Definition of Hypertension. 2017