Hypertension

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Guidelines

  • See [1]
  • Diagnosis: See diagram
  • Lab Tests (Repeat as needed):
    • Urinalysis
    • Blood chemistry (potassium, sodium and creatinine)
    • Fasting glucose
    • Fasting total cholesterol and HDL-C, LDL-C, and triglycerides
    • Standard 12-leads EKG
  • Therapy with compelling indications: [2]
Hypertension is a hidden disease. Does this man look like he has hypertension? Well he doesn't. He's just a model.

The definition of hypertension is somewhat arbitrary and usually taken as that level of blood pressure associated with a doubling of long-term risk. Perhaps the best operational definition is "the level at which the benefits (minus the risks and costs) of action exceed the risks and costs (minus the benefits) of inaction".

There is evidence that higher blood pressures are truly associated with increased cardiovascular risk – the correlation is strong and positive, with exponentially greater risk of a cardiac event as blood pressure increases. There is also evidence that treating this high blood pressure decreases cardiovascular risk.

By far the majority of hypertension patients have essential hypertension (90-95%), which is probably idiopathic.

Etiology

Approximately 30-60% of hypertension patients are thought to have a genetic component, which is most often polygenic, though there are at least three cases in which hypertension can be monogenic (aldosteronism, liddle syndrome, and ...)

Investigation

A good clinical approach is to assume that the patient has primary hypertension, which is the pretest probability. As such, end-organ damage should be investigated, and routine laboratory tests run to assess other comorbid conditions such as kidney disease or diabetes. These should be done with the goal of assessing how close to a hypertensive emergency the patient is – how much cardiovascular risk exists.

Screening should also happen for hyperaldosteronism.

Grades

According to the World Health Organization (WHO), hypertension is divided into three grades: mild hypertension (S=140-159,D=90-99); moderate hypertension (S=160-179,D=100-109); and severe (S>180,D>110).

In Canada, 22% of Canadians between 18 and 70 have hypertension, and 50% of Canadians >65 have hypertension. Of these, almost half (43%) are unaware that they are hypertensive.

Management

As per the North American society, one of the primary managements for hypertension is pharmacological. There are several main classes involved:

  1. Alpha adrenergic antagonists
  2. Beta adrenergic antagonists
  3. Centrally acting agents
  4. Diuretics
  5. Direct vasodialators
  6. Calcium channel blockers
  7. ACE inhibitors
  8. Angiotensin receptor blockers

Resources