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This lecture on hypertension explains the mechanism of development, risk factors, diagnosis, laboratory investigations, management, follow up and other related aspects of the topic.

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Outline of Lecture

Hypertension Defined

“Hypertension (HTN) is defined as sustained abnormal elevation of the arterial blood pressure

Physiology of Blood Pressure

Blood Pressure  =

Cardiac Output (CO)    X

Peripheral Vascular Resistance

Components of Blood Pressure

Systolic Pressure

Diastolic Pressure

Pulse Pressure


The Seventh Report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC VII) uses the following guidelines to define HTN in adults


The most common primary diagnosis in the United States, 50 million American affected.

Only 70% are aware they have HTN

Of those aware of their HTN, only 50% are being treated.

Only 25% of all hypertensive patients have their BP under control

HTN is a risk factor for coronary artery disease (CAD), congestive heart failure (CHF), stroke, and renal failure

Cardiovascular risk increases two-fold for each 20mm/Hg rise in systolic pressure or each 10mm/Hg rise in diastolic pressure

Risk factors in all populations include age, obesity, sedentary life-style, family history, smoking, alcohol, high sodium intake, low potassium or magnesium intake, and the use of NSAIDS


Primary Hypertension

  • Genetics
  • Environment
  • Neurohormonal mediators

Contributing factors for Primary HTN:

Increased activity of:

  • sympathetic nervous system (SNS)
  • Renin-angiotensin-aldosterone system (RAA)

Defects in natriuretic hormone function



Endothelial dysfunction

Insulin resistance

Primary90-95% of cases – also termed “essential” of “idiopathic”

Secondary about 5% of cases

Renal or renovascular disease

Endocrine disease


Cushings syndrome

Conn’s syndrome

Acromegaly and hypothyroidism

Coarctation of the aorta


Hormonal / oral contraceptive


Other forms of HTN

Complicated HTN

Malignant HTN

Hypertensive Crisis

Differential Diagnosis

  • Rule out isolated incident of increased blood pressure.
  • Rule out secondary hypertension related to:
  • Renal disease
  • Cushing’s disease
  • Pheochromocytoma
  • Hyperthyroidism

Clinical Manifestations

Physical exam:







Lab tests:


Blood Chemistry


Renal ultrasound


Vascular studies
“…properly measured…”

Cuff size


Confirm with manual

No recent caffeine or smoking

Evaluation Of Hypertension
Hypertension is evaluated by a four-step process:

Blood pressure is classified

A diagnostic workup is performed

The patient is then assessed for:

Major cardiovascular disease (CVD) risk factors; and

Identifiable causes of hypertension

Diagnostic workup

Assess risk factors and comorbidities

Find identifiable causes

Assess target organ damage

History /physicial exam

Lab tests


Assess CVS risk factors



Cigarette smoking


Physical inactivity

Age >55 male,>65 female

Premature family history of CVD

Clinical clues to renal vascular disease

Hypertension under 40 Yrs of age.

Generalised vascular (esp peripheral) disease.

Mild – moderate renal dysfunction.

Sudden onset pulmonary oedema.


Left ventricular hypertrophy(Voltage criteria)

Limb leads

R wave in lead 1 plus S wave in lead III >25 mm

R wave in lead aVL >11 mm

R wave in lead aVF >20 mm

S wave in lead aVR >14 mm

Precordial leads

R wave in leads V4, V5, or V6 > 26 mm

R wave in leads V5 or 6 plus S wave in lead V1 > 35 mm

Largest R wave plus largest S wave in precordial leads > 45 mm

    Non-voltage criteria

ST segment depression and T wave inversion in the left precordial leads

Hypertension: Reason to Treat
Reduced incidence of stroke (35-40%)

Reduced incidence of MI (20-25%)

Reduced incidence of heart failure (50%)

Reduced incidence of renal  failure

Therapeutic targets


Primary goal is to reduce cardiovascular and renal morbidity and mortality.

Other keys to management are:


Patient education

Life-style modification



Diuretics– Thiazides (HCTZ), Loop (Furosemide), Potassium-sparing (Spironolactone)

Beta-Blockers– Atenolol, Nadolol, Propranolol

ACE Inhibitors– Benezapril, Captopril, Cilizapril

Ca+ Channel Blockers– Nifedipine, Verapamil

Alpha blockers- Prazosin, Terazosin

ARBs- Losartan, Valsartan

Vasodilators- Apresoline

Hypertension in elderly

Hypertension is very common, occuring in over 50% of older people, and is a major risk factor for stroke and ischaemic heart disease.

Drug treatment of hypertension in older people saves lives and prevents unnecessary morbidity.

Treating isolated systolic hypertension also saves lives.
Hypertension in the Elderly

Medications to use with caution


Alpha-blockers (i.e. terazosin)

Preferred first line medications



Calcium channel blockers

Recognizing Hypertensive Emergency
Signs of end-organ involvement

Severe Headache

Neurologic symptoms

Chest pain


When to suspect Secondary Hypertension

HTN refractory to multiple medications

Unexplained hypokalemia

Symptoms consistent with:Pheochromocytoma

Cushing’s syndrome




Follow up

Frequent monitoring is necessary until BP is under control.  Once under control office visits can be decreases, with limited laboratory tests.

Lipids should be checked yearly.

ECG every 2-4 years, as indicated by initial ECG


Complications as a result of HTN include:



Myocardial Infarction

Congestive Heart Failure

Retinal Vasculopathy

Aortic Dissection

Renal Disease or Failure


Hospitalization should be considered if:

Very high BP

Severe headache

Chest pain

Neurologic symptoms

Altered mental status

Acutely worsening renal failure

S & S of hypertensive emergency

Hypertensive crisis

Acute or ongoing vital target organ damage, such as damage to the brain, kidney, or heart, in the setting of severe hypertension is considered a hypertensive emergency

It requires a prompt reduction in blood pressure within minutes or hours

Hypertensive urgency

The absence of target organ damage in the presence of severe elevation of blood pressure with diastolic blood pressure frequently greater than 120 mm Hg is considered hypertensive urgency, and it requires reduction in blood pressure within 24-48 hours

A continuum exists between the clinical syndrome of hypertensive urgency and emergency; hence, their distinction may not always be clear and precise

Hypertensive encephalopathy

Accelerated hypertension is associated with group 3 Keith-Wagener-Barker retinopathy, which is characterized by retinal hemorrhages and exudates on funduscopic examination

Malignant hypertension is associated with group 4 Keith-Wagener-Barker retinopathy, which is characterized by the presence of papilledema, heralding the neurologic impairment from an elevated intracranial pressure.

Labetalol: 20 mg IV bolus, then 20-80 mg IV bolus q10min; not to exceed 300 mg; 2 mg/min IV infusion alternatively, titrate to desired BP; not to exceed 300 mg




Hypertension in Pregnancy

JNC Guidelines



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