Malignant Hypertension

The word malignant, when applied to hypertension, describes a syndrome in which organ malfunction and damage to the tissue happens in widespread areas of the body. If malignant hypertension is not treated aggressively, it can progress to a catastrophic event that nearly always has a fatal outcome (Oczek, 1976).

Hypertension is another name for high blood pressure, there are a number of factors that contribute to people developing hypertension. An individual is considered hypertensive when their systolic blood pressure is over 180 mmHg.  Hypertension can be caused by stress, atherosclerosis, kidney disease and vascular diseases to name a few. Hypertensive emergencies happen when the systolic blood pressure is over 180 mmHg systolic and 120 mmHg diastolic over a period of time.

Constant elevation of blood pressure will cause hypertrophy of the left side of the heart, the left side of the heart is responsible for supplying blood to the body’s tissues and organs. Increased systemic vascular resistance, increased vascular stiffness and increased responsiveness to stimuli are central to the pathophysiology of hypertension.

Malignant hypertension is the most severe form of arterial hypertension. Clinically it is characterised by high blood pressure associated with lesions of the retinal fundus (flame-shaped haemorrhages, exudate or cotton wool spots with or without papilledema). Current literature indicates that malignant hypertension is caused by activation of the renin-angiotensin-aldosterone system, endothelial dysfunction and more recently the immune system may play a part in MHT (Foëx & Sear, 2004)

Patients with malignant hypertension are characterised by pronounced targeted organ damage including structural and functional cardiac abnormalities. It is frequently complicated by renal insufficiency and end-stage renal disease. End-stage kidney disease and renal insufficiency remain a major cause of morbidity and mortality in individuals who suffer from MHT.

Signs and Symptoms 

  • Bleeding in the retina
  • Papilledema must be presented before the diagnosis of malignant hypertension
  • The brain shows the manifestation of Increased Intracranial pressure such as a headache, nausea and vomiting.
  • Chest pain may be present, due to the increased workload of the heart.
  • People may suffer from ventricular dysfunction as a result of a mismatch in oxygen demand and supply.
  • Dyspnea
  • Anxiety
  • Agitation
  • Altered Mental state

Management 

Current best practice guidelines indicate that if malignant hypertension is suspected, it should be treated aggressively without waiting for further tests. The initial goal for therapy is to reduce mean arterial BP by no more than 25% within the first minute to an hour using parenteral means in emergency department or ICU.

The drug of choice is dependant on the type of hypertension and what is available in the healthcare facility.

Nitrates  – Nitro – vasodilators such as nitroprusside and nitroglycerin, nitrates work by providing nitric oxide that induces vasodilation of through the generation of GMP which the produces calcium-sensitive potassium ion channels in the cell’s membrane.

Nitroprusside –  When administered via IV infusion, begins to act within one minute or less and once it is ceased its effect disappears with 10 minutes or less. Close monitoring of patients on this drug is required because this drug can produce a sudden and drastic drop in blood pressure. 

Other classes of drugs used in the management of hypertensive emergencies include

If the patient remains stable, further reduce the blood pressure to 160 mmHg systolic with 2 to 6 hours. Normal BP may be targeted over the next 24 to 48 hours. Excessive fall in BP may perpetuate renal, cerebral or coronary ischemia and should be avoided.

Exceptions to the general rule are patients with aortic dissection (120 mmHg), pheochromocytoma crisis and severe preeclampsia or eclampsia. In these patients, BP should be reduced to 140 mmHg with the first hour.

The side effects of treatment depend on the type of medication that was used, GTN infusion may induce hypotension, diuretics can cause dehydration and salt imbalance, and calcium channel blockers can induce swelling in the legs as well as heart attack and congestive heart failure. ACE inhibitors can cause chronic dry cough.

If it is not treated, it can cause 

  • Damage to the kidneys, Brain and Heart
  • Blood vessel damage to the eye and loss of vision
  • Narrowing of the arteries
  • Stroke
  • Heart attack
  • Chronic renal failure requiring dialysis
  • Irregular heartbeats

After treatment in the hospital, an individual needs to take medication as prescribed by the doctor. BP may return back to normal with a diet low in sodium, weight loss, increase in physical activity and reduction in alcohol intake. In most cases, individual with malignant hypertension have to take medication for life.

Sources 

Oczek, W. J. (1976). The Rational Use of Diuretics in the Treatment of Arterial Hypertension. Angiology, 27(6), 358-369. doi:10.1177/000331977602700604

Foëx, P., & Sear, J. W. (2004). Hypertension: pathophysiology and treatment. Continuing Education in Anaesthesia Critical Care & Pain, 4(3), 71-75. doi:10.1093/bjaceaccp/mkh020

 

 

Disclaimer: This is should not be used as a diagnostic tool if malignant hypertension is suspected seek medical help immediately.
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