Cardiovascular Flashcards
What is an abdominal aortic aneurysm?
An unruptured AAA is > 3cm across.
What are aneurysms of the arteries?
An artery with a dilatation >50% of it’s original diameter .
True aneurysms are abnormal dilatations that involve all layers of the arterial wall.
What are the causes of an abdominal aortic aneurysm?
- Atheroma
- Trauma
- Infection, e.g. mycotic aneurysm in endocarditis, tertiary syphillis
- Connective tissue disorders (e.g. Marfan’s, Ehler’s-Danlos)
- Inflammatory e.g. Takayasu’s aortitis
What are the complications of an abdominal aortic aneurysm?
- Rupture
- Thrombosis
- Embolism
- Fistulae
- Pressure on other structures
What are the symptoms of a ruptured abdominal aortic aneurysm?
- Intermittent or continuous abdominal pain (radiates to the back, iliac fossae or groans)
- Collapse
- Expansile abdominal mass (expands and contracts)
- Shock
What are the symptoms of an unruptured aortic aneurysm?
Often none
- Might cause abdominal/back pain, often discovered incidentally on abdominal examination
What tests help identify the size, and rate of growth of an aneurysm?
- Abdominal ultrasound
- CT
- Echocardiogram
- Angiogram
What is an aortic dissection?
A condition where a tear in the aortic intima allows blood to surge into the aortic wall, causing a split between the inner and outer tunica media which creates a false lumen
What is the aetiology of aortic dissection?
Degenerative changes in the smooth muscle of the aortic media are the predisposing event
What are the risk factors of aortic dissection?
- Hypertension
- Aortic atherosclerosis
- Connective tissue disease (e.g. SLE, Marfan’s, Ehlers-Danlos)
- Congenital cardiac abnormalities (e.g. aortic coarctation)
Aortisis - Iatrogenic
- Trauma
- Crack Cocaine
How does the Stanford classification categorise aortic dissection?
Type A= ascending aortic tear (most common)
Type B= descending aorta tear distal to the left subclavian artery
What is the epidemiology of aortic dissection?
Most common in males between 40 and 60 years
What are the presenting symptoms of aortic dissection?
Sudden central ‘tearing’ pain which may radiate to the back (might mimic an MI)
Aortic dissection can lead to occlusion of the aorta and its branches
What are the symptoms of aortic dissection when the carotid is obstructed?
- Hemiparesis
- Dysphasia
- Blackout
What are the symptoms of aortic dissection when the coronary artery is obstructed?
Chest pain (angina or MI)
What are the symptoms of aortic dissection when the subclavian is obstructed?
- Ataxia
- Loss of consciousness
What are the symptoms of aortic dissection when the anterior spinal artery is obstructed?
Paraplegia
What are the symptoms of aortic dissection when the coeliac is obstructed?
Severe abdominal pain (ischaemic bowel)
What are the symptoms of aortic dissection when the renal artery is obstructed?
- Anuria
- Renal failure
What are the signs of aortic dissection of physical examination?
Murmur on the back below left scapula, descending to abdomen
BP: Hypertension (discrepancy between arms of >20mmHg), wide pulse pressure. If hypotensive, may signify tamponade, check for pulsus paradoxus
Aortic insufficiency: Collapsing pulse, early diastolic murmur over aortic area.
Unequal arm pulses
Might be palpable abdominal mass
What are the investigations for aortic dissection?
Bloods: FBC, U&E , clotting
CXR: Widened mediastinum, localised bulge in aortic arch
ECG: Often normal, signs of ventricular hypertrophy or inferior MI if dissection compromises the ostia of the right coronary artery
CT-Thorac: False lumen of dissection may be visualsed
Echocardiography: transoesopharangeal is highly specific
Cardiac Catheterization and aortography
What is aortic regurgitation?
Reflux of blood from aorta into left ventricle during diastole.
Also called aortic insufficiency
What is the aetiology of aortic regurgitation?
- Aortic valve leaflet abnormalities or damage
- Aortic root/ascending aorta dilation
What causes aortic valve leaflet abnormalities or damage leading to aortic regurgitation?
- Bicuspid aortic valve
- Infective endocarditis
- Rheumatic fever
- Trauma
What causes aortic root/ascending aorta dilation leading to aortic regurgitation?
- Systemic hypertension
- Aortic dissection
- Aortitis
- Arthritides
- Marfan’s syndrome
- Ehler’s-Danlos syndrome
- Osteogenesis imperfecta
What is the epidemiology of aortic regurgitation?
Chronic AR often begins in the late 50s, documented frequently over 80 years
What are the presenting symptoms of aortic regurgitation?
Chronic AR:
Initially asymptomatic. Later, symptoms of heart failure: exertional dyspnoea, orthopnoea, fatigue. Occasionally angina
Severe acute AR:
Sudden cardiovascular collapse
Symptoms related to the aetiology:
E.g. chest or back pain in patients with aortic dissection
What are signs of aortic regurgitation on examination?
Collapsing ‘water-hammer’ pulse and wide pulse pressure. Thrusting and heaving (volume-loaded) displaced apex beat.
How is an early diastolic murmur heard in AR?
At lower left sternal edge.
Better head with the patient sitting forward with the breath held in expiration
An ejection systolic murmur is often heard because of increase flow across the valve
How is an Austin Flint- mid-diastolic murmur head in AR?
Over the apex, from turbulent reflux hitting the anterior cusp of the mitral valve and causing physiological mitral stenosis
What rare signs are associated with a hyperdynamic pulse in AR?
- Quincke’s sign: Visible pulsations on nail-bed
- de Musset’s sign: Head nodding in time with pulse
- Becker’s sign: Visible pulsation of the pupils and retinal arteries
- Muller’s sign: Visible pulsations of the uvula
- Corrigan’s sign: Visible pulsations in the neck
- Traube’s sing: ‘Pistol shot’’ heard on auscultation of the femoral arteries
- Duroziez’s sign: a systolic and diastolic bruit heard on partial compression of femoral artery with a stethoscope
- Rosenbach’s sign: Systolic pulsations of the liver
Gerhard’s sign: Systolic pulsations of the spleen
Hill’s sign: Popliteal cuff systolic pressure exceeding brachial pressure by more than 60mmg
What are the investigations for aortic regurgitation?
CXR: Cardimegaly, dilatation of ascending aorta, signs of pulmonary oedema may be seen with left heart failure
ECG: May show signs of left ventricular hypertrophy (Deep S wave is in V1-2, tall R wave in V5-6, Inverted T waves in I, aVL, V5-6 and left axis deviation)
Echo:
Cardiac catheterization with angigraphy
What is aortic stenosis?
Narrowing of the left ventricular outflow at the level of the aortic valve
What is the aetiology of aortic stenosis?
1) Stenosis secondary to rheumatic heart disease (commonest worldwide)
2) Calcification of a congenital bicuspid aortic valve
3) Calcification/degeneration of a tricuspid aortic valve in the elderly
What is the epidemiology of aortic stenosis?
- Prevalence in 3% of 75 year olds. Affects males more then females.
- Those with bicuspid aortic valve may present earlier (as young adults)
What are the presenting symptoms of aortic stenosis?
May be asymptomatic initially.
- Angina (because increased oxygen demand of the hypertrophies ventricles)
- Syncope or dizziness on exercise
- Symptoms of heart failure (e.g. dyspnoea)
What are the signs of aortic stenosis of physical examination?
BP: Narrow pulse pressure
Pulse: Slow-rising
Palpation: Thrill in aortic area (if severe). Forceful sustained thrusting undisplaced apex beat
Auscultation: Harsh ejection systolic murmur at aortic area, radiating to carotid artery and apex. Second heart sound may be softened or absent. Bicuspid valve may produce ejection click.
What are the investigations for aortic stenosis?
ECG: signs of left ventricular hypertrophy, LBBB
CXR: Enlargement of ascending aorta, calcification of aortic valve
Echo
Cardiac angiography: allows differentiation from other causes of angina
What are arterial ulcers?
- Caused by poor perfusion to the lower extremities.
The overlying skin and tissues are deprived oxygen, kill the tissues and causing the area to form an open wound.
The lack of blood supply can result in minor scrapes or cutes, failing to heal and eventually developing into ulcers - Also known as ischaemic ulcers
What is aetiology of arterial ulcers?
- Restrictions to blood vessels due to peripheral vascular disease
- Chronic vascular insufficiency
- Vasculitis
- Diabetes mellitus
- Renal failure
- High blood pressure
- Arteriosclerosis
- Atherosclerosis
- Trauma
- Limited joint mobility
- Increased age
What are the risk factors for arterial ulcers?
- Diabetes mellitus
- Foot deformity and callus formation resulting in focal areas of high pressure
- Poor footwear that inadequately protects against high pressure and shear
- Obesity
- Absence of protective sensation due to peripheral neuropathy
- Limited joint mobility
What are the signs of arterial ulcers on examination?
- Ulcer with punched out appearance
- Intensely painful
- Gray or yellow fibrotic base and undermining skin margins
- Pulses not palpable
- Most common on distal ends of limbs
What is Curling’s ulcer?
Special type of ischaemic ulcer developing in duodenum after sever burns
What symptoms do arterial ulcers present with?
- Pain in the extremity at rest and increased pain with elevation of the extremity and activity
- Relief of symptoms with the extremity in a dependent position
- Characteristic dependent rubor may be seen
What is the epidemiology of arterial ulcers?
- Difficult to heal by basic would care and require advanced therapy
- IF not taken care of in time, high chances that these may become infected and may need amputation
- Individuals with history of previous ulcerations are 36 more likely to develop another ulcer
What investigations are used to diagnose arterial ulcers?
- Arterial doppler
- Pulse volume recordings
- Radiographs to rule out osteomyelitis
What is atrial fibrillation?
Characterised by rapid, chaotic and ineffective atrial electrical conduction. Often subdivided into: ‘permanent’, ‘persistent’ and ‘paroxysmal’
What is the aetiology of atrial fibrillation?
May be no identifiable cause in ‘lone’ atrial fibrillation. Secondary causes lead to abnormal atrial electrical pathways that results in AF?
What are the systemic causes of atrial fibrillation?
- Thyrotoxicosis
- Hypertension
- Pneumonia
- Alcohol
What are the risk factors in the heart of atrial fibrillation?
- Mitral valve disease
- Ischaemic heart disease
- Rheumatic heart disease
- Cardiomyopathy
- Pericarditis
- Sick sinus syndrome
- Atrial myxoma
What are the risk factors in the heart of atrial fibrillation?
- Bronchial carcinoma
- Pulmonary embolism
What is epidemiology of atrial fibrillation?
Very common in the elderly (approx 5% of those more than 65)
May be paroxysmal
What are the presenting symptoms of atrial fibrillation?
- Often asymptomatic
- Some patients experience palpitations or syncope
- Symptoms of the cause of the AF
What are the signs of atrial fibrillation on examination?
- Irregularly irregular pulse
- Difference in apical beat and radial pulse
- Look for thyroid disease and valvular heart disease
What are investigations for atrial fibrillation?
ECG: Uneven baseline with absent P waves, irregular QRS complexes. If saw-tooth baseline, consider if atrial flutter
Blood: Cardiac enzymes, TFT, lipid profile, U&E, Mg2+, Ca2+
Echo: To assess for mitral valve disease, left atrial dilation, left ventricular dysfunction of structural abnormalities
What is the management plan for atrial fibrillation?
Treat any reversible cause.
1) Rhythm control
2) Rate control
3) Stroke risk stratification
How is rhythm controlled for atrial fibrillation?
If the AF is over 48h from onset, anticoagulate (at least 3-4 weeks) before attempting cardioversion
DC cardioversion: synchronised DC shock
Chemical cardioversion: Flecainide (contraindicated if there is history of ischaemic heart disease) or amiodarone
Prophylaxis against AF: Sotalol, amioadarone or flecainide. Also consider providing ‘pill in the pocket’ strategy for suitable patients
How is rate controlled for atrial fibrillation?
Chronic ‘permanent’ AF: Ventricular rate control with digoxin, verapamil and/or beta-blockers. Aim for rate of 90/min
How is stroke risk stratification carried out in atrial fibrillation?
Low-risk patients can be managed with aspirin, and high risk-patients require anticoagulation with warfarin. Risk factors indicating high risk are previous thromboembolic event, age >75 years with hyppertension, diabetes or vascular disease, and/or clinical evidence of valve disease, heart failure or impaired left ventricular function
What are the possible complications of atrial fibrillation?
- Thromboembolism (e.g. embolic stroke 4% risk per year, increased risk with left atrial enlargement or left ventricular dysfunction)
- Worsens any existing heart failure
What is the prognosis of atrial fibrillation?
Chronic AF in diseased heart does not usually return to sinus rhythm
What is cardiac arrest?
Acute cessation of cardiac function
What is the aetiology of cardiac arrest?
4 H’s & 4 T’s
Hypoxia, Hypothermia, Hypovolaemia, Hypo- or hyperkalaemia
Tamponade, Tension pneumothorax, Thromboembolism, Toxins and other metabolic disorders (drugs, therapeutic agents and sepsis)
What are the signs of cardiac arrest on examination?
- Unconscious
- Patient is not breathing
- Absent carotid pulses
What are the investigations for cardiac arrest?
Cardiac monitor: Classification of rhythm directs management
Bloods: ABG, U&E, FBC, cross-match, clotting, toxicology screen, glucose
What is a management plan for cardiac arrest?
- Safety
- BLS
- ALS
- Treatment of reversible causes
How are the reversible causes of cardiac arrest treated?
Hypothermia: warm slowly
Hypo-hyperkalaemia: correction of electrolytes
Hypovolaemia: IV colloids, crystalloids or blood products
Tamponade: Pericardiocentesis under xiphisternum up and leftwards
Tension pneumothorac: Needle into second intercostal space, mid-clavicular line
- Thromboembolism
- Toxins
What are the possible complications of cardiac arrest?
- Irreversible hypoxic brain damage
- Death
What is the prognosis of cardiac arrest?
- Resuscitation is less successful in the arrests that occur outside hispital
- Duration of inadequate effective cardiac output is associate with poor prognosis
What is cardiac failure?
Inability of the cardiac output to meet the body’s demands despite normal venous pressures
What is the aetiology of cardiac failure?
Low output High output (increased demand)
What are the low output causes of cardiac failure?
- Left heart failure: Ischaemic heart disease, hypertension, cardiomyopathy, aortic valve disease, mitral regurgitation
- Right heart failure: Secondary to left heart failure, infarction, cardiomyopathy, pulmonary hypertension/embolus/valve disease, chronic lung disease, tricuspid regurgitation constrictive pericarditis/pericardial tamponade
Biventricular failure: Arrhythmia, cardiomyopathy (dilated or restrictive), myocarditis, drug toxicity
What are the high output causes of cardiac failure?
- Anaemia
- Berberi
- Pregnancy
- Paget’s disease
- Hyperthyroidism
- Arteriovenous malformation
What is the epidemiology of cardiac failure?
10% of over 65 year olds
What are the signs on examination for left cardiac failure?
- Tachycardia
- Tachypnoea
- Displaced apex beat
- Bilateral basal crackles
- Third heart sound (‘gallop’ rhythm: rapid ventricular filling), pansystolic murmur (functional mitral regurgitation)
What are the signs on examination for right cardiac failure?
- Raised JVP
- Hepatomegaly
- Ascites
- Ankle/sacral pitting
- Oedema
- Signs of functional tricuspid regurgitation
What are the presenting symptoms of left cardiac failure?
Symptoms caused by pulmonary congestion
Dyspnoea, Othropnoea, paroxysmal nocturnal dyspnoea, fatigue
What are the presenting symptoms of right cardiac failure?
- Swollen ankes
- Fatigue
- Increased weight (resulting from oedema)
- Reduced exercise tolerance
- Anorexia
- Nausea
What are the investigations for cardiac failure?
Blood: FBC, U&Es, LFTs, CRP, glucose, lipids, TFTs
CXR: Cardiomegaly, prominent upper lobe vessels, pleural effusion, interstitial oedema (Kerley B lines), perihilar shadowing (bat’s wings), fluid in fissures
ECG: may be normal, may have ischaemic changes, arrhythmia, lvh
Echo: Assess ventricular contraction
Swan-Ganz catheter:
How is acute left ventricular failure managed?
Cardiogenic shock: severe cardiac failure with low BP requires the use of inotropes
Pulmonary oedema: sit up patient, 60-100% 02 and consider CPAP.
How is chronic left ventricular failure managed?
Treat the cause e.g. hypertension. Treat exacerbating factors e.g. anaemia. ACE-inhibitors B-blockers Loop Diuretics Aldosterone antagonists Angiotensin receptor blockers Digoxin
What are the complications of cardiac failure?
- Respiratory failure
- Cardiogenic shock
- Death
What is the prognosis of cardiac failure?
50% of patients with severe heart failure die within 2 years
What is cardiomyopathy?
Primary disease of the myocardium
- Cardiomyopathy may be dilated, hypertrophic or restrictive
What is the aetiology for dilated cardiomyopathy?
- Post-viral myocarditis
- Alcohol
- Drugs (doxorubicin, cocaine)
- Familial
- Thyrotoxicosis
- Haemochromatosis
- Peripartum
What is the aetiology for hypertrophic cardiomyopathy?
- Up to 50% of cases are genetic with mutations in B-myosin, troponin T or a-tropomyosin (components of the contractile apparatus)
What is the aetiology for restrictive cardiomyopathy?
- Amyloidosis
- Sarcoidosis
- Haemochromatosis
What is the epidemiology of cardiomyopathy?
Prevalence of dilated and hypertrophic is 0.05-0.2%.
Restrictive is rare
What are the presenting symptoms of dilated cardiomyopathy?
- Symptoms of heart failure
- Arrhythmias
- Thromboembolism
- Family of sudden death
What are the presenting symptoms of hypertrophic cardiomyopathy?
- Usually none
- Syncope
- Angine
- Arrhythmia
- Family history of sudden death
What are the presenting symptoms of restrictive cardiomyopathy?
- Dyspnoea
- Fatigue
- Arrhythmia
- Ankle
- Abdominal swelling
Enquire about family history of sudden death
What are the signs on examination of dilated cardiomyopathy?
- Raised JVP
- Displaced apex beat
- Functional mitral and tricuspid regurgitations
- Third heart sound
What are the signs on examination of hypertrophic cardiomyopathy?
- Jerky carotid pulse
- Double apex beat
- Ejection systolic murmur
What are the signs on examination of restrictive cardiomyopathy?
- Raised JVP (Kussmaul’s sign: further increase on inspiration)
- Palpable apex beat
- Third heart sound
- Ascites
- Ankle oedema
- Hepatomegaly
What are the investigations for cardiomyopathy?
CXR: may show cardiomegaly, and signs of heart failure ECG Echo Cardiac catheterization Endomyocardial biopsy Pedigree or genetic analysis
What is seen on an ECG for cardiomyopathy?
All types: Non-specific St changed, conduction defects, arrhythmias
Hypertrophic: Left axis-deviation, signs of left ventricular hypertrophy, Q waves in inferior and lateral leads
Restrictive: Low voltage complexes
What is seen on an Echocardiogram for cardiomyopathy?
Dilated: Dilated ventricles with global hypokinesia
Hypertrophic: Ventricular hypertrophy
Restrictive: Non-dilated non-hypoertrophied ventricles. Atrial enlargement.
What is constrictive pericarditis?
Medical condition characterised by a thickened, fibrotic pericardium limiting the heart’s ability to function normally.
What are the causes of constrictive pericarditis?
- Tuberculosis
- Incomplete drainage of purulent pericarditis
- Fungal and parasitic infections
- Chronic pericarditis
- Postviral pericarditis
- Postsurgical
- Following MI, post-myocardial infarction
What are the presenting symptoms of constrictive pericarditis?
- Fatigue
- Swollen abdomen
- Dyspnoea
- Swelling of legs
- General weakness
What are the signs of constrictive pericarditis on examination?
- Raised JVP with inspiration (Kussmaul’s sign)
- Pulsus paradoxus
- Hepatomegaly
- Ascites
- Oedema
- Pericardial knock (rapid ventricular filling
- AF
What investigates are used for constrictive pericarditis?
- CXR: pericardial calcification, pleural effusions
- Echo
- ECG
What is percutaneous coronary intervention and coronary angiography?
Non-surgical procedure used to treat the stenotic coronary arteries of the heart found in coronary heart disease.
A cardiologists feeds a deflated balloon on a catheter from the inguinal femoral artery or radial artery through blood vessels until the sit of blockage in the heart is reached.
Angioplasty involves inflating a balloon to open the artery and allow blood flow
What are the indications for coronary angiography and PCI?
- Acute ST-elevation myocardial infarction
- Non-ST elevation acute coronary syndrome
- Unstable angina
- Stable angine
- Anginal equivalent (e.g. dyspnoea, arrhythmia, dizziness or syncope)
- High risk stress test findings
What are the possible complications of coronary angiography and PCI?
- Intramural haematoma
- Perforation
- Distal embolisation
- Side branch occlusion
- Access site bleeding
- Atheroembolism
- AKI
- Stroke
- Infection
- Arrhythmia
- Peripheral artery disease
What is a coronary artery bypass graft?
A surgical procedure aiming to restore normal blood flow to an obstructed coronary artery
The procedure involves the construction of one or more grafts between the arterial and coronary circulations
What are the indications for a coronary artery bypass graft?
- Disease of the left main coronary artery
- Disease of all three coronary vessels
- Diffuse disease not amenable to treatment with a PCI
What are the possible complications of a coronary artery bypass graft?
- Postperfusion syndrome
- Myocardial infarction
- Acute renal failure
- Vasoplegic sundrome
- Pneumothorax
- Haemothorax
- Pleural effusion
- Pericarditis
- Post-operative atrial fibrillation and atrial flutter
What is DC cardioversion?
A medical procedure by which an abnormally fast heart rate (tachycardia) or cardiac arrythmia is converted to a normal rhythm using electricity or drugs
What are the indications for cardioversion?
- Indicated in patients with disabling symptoms. In haemodynamically stable patients with preserved left ventricular function and no evident of hypokalaemia or hypomagnasaemia.
- Atrial fibrillation, atrial flutter
- Emergency situations to correct an abnormal rhythm when it is accompanied by faintness, low blood pressure, chest pain, difficulty breathing or loss of consciousness
What are the possible complications of cardioversion?
- Dislodged blood clots: electric cardioversion can cause clots in the heart to move could result in a stroke. May need anticoagulation for several weeks beforehand to reduce risk.
- Abnormal heart rhythm
- Low blood pressure
- Skin burns: from where the electrodes were placed
What is deep vein thrombosis?
The development of a blood clot in a major deep vein in the leg, thigh, pelvis or abdomen, which may result in impaired venous blood flow and consequent leg swelling and pain. DVT may also occur in the upper extremities or the brain.
What are the risk factors of deep vein thrombosis?
- Medical hospitalisation within the past 2 months
- Major surgery within 3 months
- Active cancer
- Lower-extremity trauma
- Increasing age
- Pregnancy
- Obesity
- Factory V Leiden
- Protein C or S deficiency
- Antithrombin deficiency
- Antiphospholipid antibody syndrome
- Medical comorbidity
- Recent long-distance air travel
What is the epidemiology of deep vein thrombosis?
- Incidence increased with age
- Comparable in men and women with a slight female dominance in people under the age of 35 years
- Incidence 10-15% higher in black people.
- Hospital acquired DVT (DVT that occurs during hospitalisation or within 90 days of discharge) is common
What are the presenting symptoms of deep vein thrombosis?
- Pain
- Tenderness
- Swelling
- Warmth
- Redness
- Discolouration
What are the signs of deep vein thrombosis on examination?
- Asymmetric oedema
- Collateral superficial veins
- Calf swelling
- Localised pain along deep venous system
- Phlegmasia curulea dolens
How is proximal DVT of the leg in non-pregnant patients managed?
- Anticoagulation
- Physical activity
- Gradient stockings
How is distal DVT of the leg in non pregnant patients managed?
- Serial imaging of the deep veins and/or anticoagulation
- Physical activity
- Gradient stockings
How are DVTs in pregnant patients managed?
- Low molecular weight heparin or subcutaneous unfractionated heparin
- Physical activity
- Gradient stocks
What are the possible complications of deep vein thrombosis?
- Pulmonary embolism
- Acute bleeding during treatment
- Heparin induced thrombocytopenia
- Heparin resistance
- Post-phlebitic syndrome
- Delayed bleeding during treatment
- Osteoporosis due to heparin treatment
What is the prognosis of deep vein thrombosis?
- Whether a DVT is provoked or idiopathic is a significant determinant of recurrence
- Extent and location of the initial clot influence the risk of post-phlebitic syndrome
- When a patient dies from DVT, usually it is due to a pulmonary embolus or from a major haemorrhage as a complication of the anticoagulation therapy
What is Gangrene?
A complication of necrosis characterised by the decay of body tissues.
2 major categories:
- Infectious gangrene (wet gangrene)
- Ischaemic gangrene (dry gangrene)
What is the aetiology of gangrene?
May result from ischaemia, infection or trauma or a combination of these processed. Ischaemia may result from either arterial or venous comprosis, and may be an acute or chronic process.
Critically insufficient blood supply is the most common cause of gangrene and is often associated with diabetes and long term smoking
What are the risk factors of gangrene?
- Diabetes mellitus
- Atherosclerosis (ischaemic)
- Smoking (ischaemic)
- Renal disease
- Drug and alcohol abuse
- Malignancy
- Trauma or abdominal surgery (infectious)
- Contaminated wounds (infectious)
Weak factors: - Malnutrition (infectious)
- Hypercoagulable states (ischaemic)
- Prolonged application of tourniquets (ischaemic)
What is the epidemiology of gangrene?
- Occurs equally in men and women
- Type I necrotising fasciitis occurs most commonly in patients with diabetes and patients with peripheral vascular disease
What are the presenting symptoms of gangrene?
- Pain: history of chronic claudication-type pain in patients with ischaemic gangrene. A sudden onset of pain is usually the first symptoms of infectious gangrene
- Oedema (ischaemic)
- Skin discolouration: ecchymosis, purpura, skin blebs and haemorrhagic bullae