Hypertension Flashcards
What is hypertension?
https://www.youtube.com/watch?v=9CKihqqIokI&vl=en-US
The blood pressure above which the benefits of treatment outweigh the risks in terms of morbidity and mortality.
What are risk factors for the development of hypertension?
- Cigarette smoking (adds 20/10 mmHg)
- Diabetes Mellitus (5-30x increased risk of MI)
- Renal Disease
- Male
- Hyperlipidaemia
- Previous MI or Stroke
- LVH
- Family history
- Low birth weight
What are the different types of hypertension?
- Primary/Essential hypertension
- Secondary hypertension
- Malignant hypertension
- White coat hypertension
What is primary hypertension?
This is hypertension of unknown cause. It accounts for the vast majority (> 95%) of cases. In these cases, hypertension is due to a combination of genetic, lifestyle and environmental factors.
What is secondary hypertension?
Present when blood pressure is raised due to an identifiable and potentially treatable cause; examples include renal, renovascular and endocrine disorders, certain drugs (such as steroids or the oral contraceptive pill), coarctation of the aorta and pregnancy.
What is malignant hypertension?
An acute rise in blood pressure (usually to > 180/110mmHg) with papilloedema (optic disc swelling) and/or retinal haemorrhage. Malignant hypertension is a medical emergency and may be associated with heart failure, cerebral oedema and renal failure.
What is white coat hypertension?
Present when blood pressure is normal other than when checked during a medical consultation; 24-hour blood pressure monitoring may help decide whether the patient is truly hypertensive.
What is benign hypertension?
Any stage 1 or stage 2 hypertension
What are the criteria for stage 1 hypertension?
Clinic blood pressure = 140/90 mmHg or higher
+
ABPM or HBPM average BP = 135/85 mmHg or higher.
What are the criteria for the diagnosis of stage 2 hypertension?
Clinic blood pressure = 160/100 mmHg or higher
+
ABPM or HBPM average BP = 150/95 mmHg or higher
What are the criteria for the diagnosis of severe/Stage 3 hypertension?
Clinic systolic blood pressure = 180 mmHg or higher
Clinic diastolic blood pressure = 110 mmHg or higher
What factors play a role in the development of primary hypertension?
- Genetic
- Age
- Foetal factors
- Obesity
- Alcohol intake
- Sodium intake
- Stress
- Humoral mechanisms
- Insulin resistance
- Race
Why does age play a role in the development of hypertension?
Reduced arterial compliance
What foetal factors play a role in the development of hypertension?
Low birth weight
How does sodium intake influence blood pressure?
Sodium acts osmotically to pull more fluid into the vascular space
What are cardivascular causes of secondary hypertension?
Coarctation of the Aorta
What condition in pregnancy can cause secondary hypertension?
Pre-eclampsia
What are endocrine causes of secondary hypertension?
- Cushing’s syndrome
- Acromegaly
- Thyroid disease
- Hyperparathyroid disease
- Conn’s syndrome
- Phaeochromocytoma
- Adrenal hyperplasia
What are adrenal causes of hypertension?
- Conn’s syndrome
- Adrenal hyperplasia
- Phaeochromocytoma
What are renal causes of secondary hypertension?
- Diabetic nephropathy
- Chronic GN
- Adult Polycystic disease
- Chronic tubulointersitial nephritis
- Renovascular disease
What drugs can cause secondary hypertension?
- NSAIDs
- MAOIs
- Oral contraceptives
- Vasopressin
- Sympathomimetics
What respiratory problems can cause secondary hypertension?
Sleep apnoea
What are the features of hypertensive retinopathy?
- AV nipping
- Copper and Silver wiring
- Cotton wool spots
- Microaneurysms
- Retinal haemorrhages
What is the following?
AV nipping - An enlarged retinal arteriole that crosses a vein can press down and cause swelling distal to the crossing. The vein will have an hourglass appearance on either side of the intersection.
What is the following and what is it a sign of?
Cotton wool spots - Small areas of yellow-white discolouration on the retina, often described as puffy white patches.
Diabetes and hypertension
What is the following, and what is it a sign of?
Retinal haemorrhage - Bleeding that occurs in or spills onto the retina. Can be ‘dot and blot’ or ‘streaking’ in appearance.
Sign of diabetes, hypertension or trauma
What are retinal microaneurysms?
Small, round, dark red dots on the retinal surface that are smaller than the diameter of major optic veins They often herald a progression to the exudative phase of hypertensive retinopathy.
As progression of hypertensive retinopathy occurs, there is capillary occlusion ischaemia and degeneration of the vascular smooth muscle, endothelial cell necrosis and formation of tiny aneurysms.
What is the mechanism behind the following?
AV nipping - Persistently elevated blood pressure causes hyperplasia of the arteriolar media and intimal thickening. The enlarged vessel impinges on the underlying vein, giving it a ‘nipped in’ appearance.
What is the mechanism behind the following?
Cotton wool spots - Principally due to damage and swelling of the nerve fibres. Prolonged hypertension results in distortion and blocking of retinal arterioles, blockage of axoplasmic flow (of proteins, lipids etc along the axon of the neuron) and a build-up of intracellular nerve debris in the nerve fibre layer. These insults result in swelling of the layer.
What is the mechanism of the following?
Retinal haemorrhage - Prolonged hypertension leads to intimal thickening and ischaemia. This causes degeneration of retinal blood vessels to the point where they leak plasma and bleed onto the retina.
What are features of end organ damage in hypertension?
- Blindness - hypertensive retinopathy
- Cardiac failure - LVH, MI, Pulmonary oedema
- Vascular disease - Atherosclerosis/Aneurysms/Dissections
- CKD - proteinuria, uraemia
- Stroke/TIA - Haemorrhage, seizure, Vascular dementia
What signs would indicate that coarctation of the Aorta could be causing hypertension?
- Radio-femoral delay
- Radial-radial delay
- Hypertension
- Scapular bruit
- Systolic murmur - over scapula
What is the mechanism behind the sign of radiofermoral delay?
Reduced amplitude and delayed timing of the pulses in the lower body with respect to the pulses in the upper body are classic features of aortic coarctation
Coarctation causes a decrease in the rate of ejection of blood because of vessel narrowing and the Venturi effect sucking the walls inwards, creating a reduction in the flow and amplitude of the pulse distal to the occlusion.
What is the mechanism behind radial-radial delay?
A disparity between the timing of pulses felt when simultaneously palpating the left and right radial pulse.
A coarctation or narrowing of the aorta occurs before the origin of the left subclavian artery, limiting the blood flow and causing a pressure drop distal to the narrowing. The pulse wave will arrive later in the left arm and the amplitudes of the left and right pulses will be different.