3. Definition
Hypertension is the persistent elevation of blood pressure
Hypertension is defined as a systolic blood pressure (SBP) of 140 mm Hg or more, or
a diastolic blood pressure (DBP) of 90 mm Hg or more.
4. Classification
The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and
Treatment of High Blood Pressure (JNC 7), classifies BP for adults aged 18 years or older as
follows:
Normal: Systolic lower than or equal to 120 mm Hg, diastolic lower than or equal to 80 mm Hg
Prehypertension: Systolic 120-139 mm Hg, diastolic 80-89 mm Hg
Stage 1: Systolic 140-159 mm Hg, diastolic 90-99 mm Hg
Stage 2: Systolic 160 mm Hg or greater, diastolic 100 mm Hg or greater
HTN is an important modifiable risk factor for cardiovascular disease (stroke, myocardial
infarction). The risk of cardiovascular disease doubles for every 20/10 mmHg rise in blood
pressure.
5. Normal Regulation of blood pressure
Mean blood pressure = cardiac output X total peripheral resistance
Usually hypertension is a resultant of increased peripheral resistance that is caused
by constriction of small arterioles
Homeostatic reflexes
Baroreceptor reflex (regulate minute to minute change in blood pressure)
Renin-angiotensin-aldosterone system (regulates blood pressure in longer term)
Other substances that control blood pressure includes: atrial natriuretic peptide,
bradykinin and antidiuretic hormone.
6. Pathophysiology
Hypertension may result from a specific cause (secondary hypertension) or from an unknown etiology
(primary or essential hypertension).
Secondary hypertension (<10% of cases) is usually caused by chronic kidney disease (CKD) or renovascular
disease.
Other conditions are Cushing syndrome, primary aldosteronism and hyperthyroidism etc.
Factors contribute in primary hypertension are :
Humoral abnormality involving renin-angiotensin-aldosterone system (RAAS).
Abnormality in renal or tissue autoregulatory process for sodium excretion, plasma volume and arteriolar
constriction.
Deficiency in synthesis of vasodilating substances in vascular endothelium (prostacyclin, bradykinin, and
nitric oxide.
High intake of sodium.
7. Hypertensive crisis
a BP of more than 180/120 mm Hg, can either be a hypertensive emergency or urgency.
hypertensive emergency is characterized by evidence of impending or progressive target organ
dysfunction.
hypertensive urgencies are those situations without progressive target organ dysfunction.
Acute end-organ damage in the setting of a hypertensive emergency may include the following:
Neurologic: hypertensive encephalopathy, cerebral vascular accident/cerebral infarction, subarachnoid
hemorrhage, intracranial hemorrhage.
Cardiovascular: myocardial ischemia/infarction, acute left ventricular dysfunction, acute pulmonary edema,
aortic dissection, unstable angina.
Other: acute renal failure/insufficiency, retinopathy, eclampsia, microangiopathic hemolytic anemia
8. Clinical presentation
Patients with uncomplicated primary hypertension are usually asymptomatic
initially.
Patients with secondary hypertension may have symptoms of underlying disorder
like in pheochromocytoma, patient have
Headache
Visual disturbances
Target organ damage (stroke, ischemic heart disease or renal failure)
9. Diagnosis
Evaluated hypertension can be diagnosed through :
Accurate measurement of patient’s blood pressure through blood pressure metre
Medical history and physical examination
Routine laboratory tests
12-lead electrocardiogram
These studies help in determining the possible cause of hypertension,
cardiovascular risk factors and baseline values for judging biochemical effects of
therapy.
10. Management (lifestyle modifications)
Weight loss (The DASH eating plan)
Limit alcohol consumption
Reduce sodium intake
Maintain adequate intake of dietary potassium, calcium and magnesium.
Stop smoking
Reduce intake of dietary saturated fat and cholesterol for overall cardiovascular
health
Aerobic exercise
11. Management (Pharmacological)
If lifestyle modifications are insufficient to achieve the goal of BP, there are several drug options for
treating and managing hypertension.
Diuretics, an angiotensin-converting enzyme inhibitor (ACEI) , angiotensin receptor
blocker (ARB), or calcium channel blocker (CCB) are the preferred agents.
Often, patients require several antihypertensive agents to achieve adequate BP control.
Choosing a specific antihypertensive agent include considerations of comorbidities (heart failure,
ischemic heart disease, chronic kidney disease, and diabetes), drug intolerability or
contraindications.
12. Management (Pharmacological)
Following are drug class recommendations for compelling indications based on
various clinical trials:
Heart failure: Diuretic, beta-blocker, ACE inhibitor, ARB, aldosterone antagonist
Myocardial infarction: Beta-blocker, ACE inhibitor
Diabetes: ACE inhibitor, ARB
Chronic kidney disease: ACE inhibitor, ARB
13. Management (Pharmacological)
Diuretics generally potentiate the effects of other antihypertensive drugs.
Specifically, the use of a thiazide diuretic in conjunction with a beta-blocker or
an ACEI has an additive effect, controlling BPin up to 85% of patients.
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18. Special population (HTN & Diabetes)
The JNC 8, recommends a goal BP below 140/90 mmHg in hypertensive patients with diabetes.
In general, patients with diabetes type 1 or type 2 and hypertension have shown clinical improvement
with diuretics, angiotensin-converting enzyme inhibitors (ACEIs), beta-blockers, angiotensin
receptor blockers (ARBs), and calcium antagonists. Most studies, however, have shown superiority
of ACEIs or ARBs over calcium antagonists in diabeticpatients.
Two or more antihypertensive drugs at maximal doses should be used to achieve optimal BP targets
in patients with diabetes and hypertension.
19. Special population (HTN emergencies)
Initial treatment goals are to reduce the mean arterial BP by no more than 25% within minutes to 1
hour. If the patient is stable, reduce the BP to 160/100-110 mm Hg within the next 2-6 hours. Several
parenteral and oral therapies can be used to treat hypertensive emergencies, such as nitroprusside
sodium, hydralazine, nicardipine, fenoldopam, nitroglycerin, or enalapril. Other agents that may be
used include labetalol, esmolol, and phentolamine. Avoid using short-acting nifedipine in the initial
treatment of this condition because of the risk of rapid, unpredictable hypotension and the
possibility of precipitating ischemic events. Once the patient’s condition is stabilized, the patient’s
BP may be gradually reduced over the next 24-48 hours.
20. Special population (HTN in Pregnancy)
In patients who are pregnant, the goal of antihypertensive treatment is to minimize the risk of maternal
cardiovascular or cerebrovascularevents.
Antihypertensive therapy should be started in pregnant women if the systolic BP >160 mm Hg or the
diastolic BP is >100-105 mm Hg.
Although reducing maternal risk is the goal of treating chronic hypertension in pregnancy, it is fetal
safety that largely directs the choice of antihypertensive agent. Methyldopa is generally the preferred
first-line agent because of its safety profile. Other drugs that may be considered include labetalol,
other beta-blockers, and diuretics.
Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor (ARB) antagonists
should be avoided because of the risk of fetal toxicity and death.
21. Special population (HTN in Pediatrics)
An angiotensin-converting enzyme inhibitor (ACEI), angiotensin receptor blocker (ARB), long- acting
calcium channel blocker (CCB), or thiazide diuretic are the recommended pharmacological options
in pediatric hypertensive patients.
In general, the selection of antihypertensive agents in children is similar to that in adults, but the doses
are smaller and must be closely titrated. Extreme cautions are necessary with antihypertensive
therapy in sexually active teenage girls and in those who are pregnant; ACEI and ARBs should not
be used.
22. Special population (HTN in Geriatrics)
Clinicians should initiate treatment in patients aged 60 years or older who have persistent systolic blood
pressure (SBP) at or above 150 mm Hg to achieve a target of below 150 mm Hg to reduce the risk for
stroke, cardiac events, and death.
Angiotensin-converting enzyme inhibitor (ACEI), angiotensin receptor blocker (ARB), calcium
antagonists and thiazide-type diuretics are proven beneficial in hypertensive patients aged >55 yrs.
Beta-blockers may not be as effective as other first-line agents in patients aged 60 years and older,
especially for stroke prevention, and should probably be used when other indications are present, such
as heart failure, previous myocardial infarction, and angina.