Cardiac diseases Flashcards
Cardiac tamponade is classified as either ____ or ____.
Traumatic or non-traumatic
How much serous fluid is contained in a normal pericardium?
35mL
True or false: the pericardium can readily stretch
False
What is the definition of cardiac tamponade?
Gradual or sudden accumulations of >100-200mLs of fluid that increases pressure and compresses the heart, preventing diastolic filling of atria and ventricles
What are the S&S of late stage cardiac tamponade?
Shock Narrowed pulse pressure Pulsus paradoxus (peripheral pulse becomes weak or disappears on inhalation - can be difficult to detect with hypotensive pts) Beck's triad (increased jugular venous pressure [JVP], hypotension, and muffled heart sounds) Usually clear lung fields Signs of fever (pericarditis) Pleural effusions Peripheral cyanosis (often upper body)
True or false: increased JVP may not be present in significant hypovolaemia
True
Does absence of hypotension rule out cardiac tamponade?
No
True or false: early cardiac tamponade is often asymptomatic
True
What are the ddx for cardiac tamponade?
Massive pulmonary embolism Tension pneumothorax Superior vena cava obstruction Chronic constrictive pericarditis Air embolism Right ventricular infarct Severe CCF/cardiogenic shock Extrapericardial compression (haematoma, tumour)
Describe the mx of cardiac tamponade
Secure airway
High flow O2
Consider fluids if hypotensive (no tx delay)
What is pericarditis?
Inflammation of the pericardium
What are the causes of pericarditis?
Idiopathic (probably viral) Viral (mumps, influenza, HIV) Rheumatoid arthritis Radiation injury Trauma AMI Hypersensitivity to drugs Renal failure, uraemia, myoxedema
What are the S&S of pericarditis?
Hx of recent viral illness
Retrosternal pain oninspiration, movement &
supine posture
Pain improves sitting and leaning forward
Not dyspnoaeic (may have shallow breathing
because of pain)
Sinus tachycardia is common
What are common ECG changes in pericarditis?
- ST elevation in inferior and anterior leads with a concave upwards (saddle shaped) appearance in first stage of acute pericarditis
- As this resolves widespread T wave inversion is often seen
- PR segment depression
What is constrictive pericarditis?
Thickening, fibrosis and calcification (especially with
tuberculous) of the pericardium, encasing the heart in a solid, non-compliant envelope that impairs diastolic
filling
What may appear the same as constrictive pericarditis?
Pleural effusion as a result of pericarditis that leads to cardiac tamponade
What are the causes of constrictive pericarditis?
Any pericardial injury or inflammation:
- Cardiac surgery (radiation therapy & idiopathic causes are most common)
- Tuberculous constriction (rare in developed countries, but remains significant in underdeveloped countries - consider this in relation to increasing numbers of refugees in Australia from underdeveloped countries and an increase in tuberculosis in developed countries)
True or false: years may elapse between the insult and the clinical manifestation of constrictive pericarditis
True
What is the definition of an aneurysm?
A sac formed by the localised dilation of the wall of an artery, vein, or the heart.
What is usually the cause of ventricular aneurysm?
Poor ventricular remodelling after a large transmural infarction
List the various types and locations of aneurysms
Berry aneurysm - Circle of Willis
Micro aneurysm - Intracerebral arteries
Ventricular aneurysm - Myocardial ventricle
Thoracic Aneurysm - Root of aorta (ascending/arch of
aorta)
Pseudoaneurysm - result of ventricular aneurysm (these have narrow necks and are not lined with endocardium)
Abdominal aneurysm (most common) - Usually lower abdomen
Visceral Aneurysm - Splenic, hepatic, superior
mesenteric, renal, popliteal, femoral, upper limb & carotid
What are the risk factors for abdominal aortic aneurysm?
Family history Male Age > 55 Hypertension Atherosclerosis Peripheral vascular disease Hyperlipidaemia Smoking Diabetes Connective tissue disorders
The risk factors for abdominal aortic aneurysm are almost identical to those for what two major disease groups?
Ichaemic heart disease and cerebrovascular disease
What is the pathophysiology behind aneurysms?
It is now thought that a defect in connective
tissue metabolism may be the primary cause of
aneurysms. Dilation occurs with loss of elasticity, especially in the setting of hypertension, and there is less ability to withstand additional wall pressure.
What principle is important to remember with regards to aneurysms and the Laplace law?
The larger the aneurysm becomes the more rapidly it expands and the weaker the vessel becomes
What is the Laplace law?
Note: slide note claims don’t need to know
Wall tension = (Pressure x radius) / tensile force
What are some S&S of a ruptured AAA?
Abdominal, flank, back or leg pain
Syncope
Hypovolaemic shock
PEA
Occasional neurological defect (due to spinal cord ischaemia)
Classical presentation: pulsatile mass, hypotension, and flank pain (though this is found in <50% pts)
Other presentations: Pain Absent or unequal distal pulses Periumbilical ecchymosis (Cullen's sign) or flank ecchymosis (Grey Turner's sign) Scrotal haematoma Abdominal tenderness
In what way are AAA are likely to dissect, and how does this complicate dx?
Likely to dissect across vessel sinuses feeding other organs, producing signs of ischaemia in these organs and confounding the clinical picture
What is the most common site for aortic aneurysm?
Between the renal and iliac arteries
True or false: deep palpation is useful and recommended when suspecting AAA
False
What are the mx goals for all types of anerysms?
- Maintain cerebral perfusion at all times
- Contain the propagating haematoma by limiting arterial pressure
- Arrange for potential rapid surgical repair (feasible in many patients)
Is a ruptured aneurysm controlled or uncontrolled haemorrhage?
Uncontrolled
Does the minimal fluid resuscitation principle apply to ruptured aneurysms?
Yes
What would indicate fluid therapy for a pt with a ruptured aneurysm?
Inadequate cerebral perfusion
What are the goals of fluid therapy (if initiated) in AAA?
Systolic BP ~80mmHg
HR ~60-80bpm
Describe the mx points for AAA
Bilateral large bore IV access
12 lead monitoring
High flow O2
Rapid tx
Should pain relief be withheld in AAA?
No
Mortality for AAA is over ____.
90%
For which pts is high suspicion of AAA warranted?
Patients over 65 who present with abdominal or back
pain and/or unexplained hypotension
What is the range of high but normal hypertension?
120-139/80-89
What is the range for grade 1 hypertension?
140-159/90-99
What is the range for grade 2 hypertension?
160-179/100-109
What is the range for grade 3 hypertension?
> 180/>110
Hypertension is also listed as what values?
SBP >140-150mmHg
DBP >90mmHg
What are the predisposing factors for hypertension?
Age >60 Sex (men and postmenopausal women) Family history of cardiovascular disease Smoking High cholesterol diet Co-existing disorders such as diabetes, obesity and hyperlipidaemia High intake of alcohol Sedentary lifestyle
What is hypertensive encephalopathy?
Cerebral dysfunction with diffuse/transient disease or damage of the brain
What is characteristic of hypertensive encephalopathy?
Disorientatiation, excitability, and abnormal behaviour reversible if BP can be reduced
What is the definition of a hypertensive emergency?
Severe increase in BP that is complicated by evidence of end-organ dysfunction and requiring immediate BP reduction
What are some examples of hypertensive emergencies?
Hypertensive encephalopathy Intracranial hemorrhage Unstable angina pectoris AMI Acute LVF Dissecting aneurysm Eclampsia Autonomic dysreflexia
What is autonomic dysreflexia?
A hypertensive emergency - triggering sensory stimulus (bladder/bowel/skin/#) causes excessive reflex activity in the ANS (increased sympathetic activity)
What are the S&S of autonomic dysreflexia?
Hypertension Headache Bradycardia Flushing Blotching Sweating of the skin above level of injury Goose bumps Chills without fever SOB Anxiety
Describe the mx of autonomic dysreflexia
Remove the cause
GTN
Morphine (if unresponsive to GTN)
What is a hypertensive crisis?
Severe increase in BP without evidence of progressive target organ dysfunction
What are some S&S
of hypertensive crisis?
Upper levels of stage 3 hypertension Papilloedema (inflammation of the optic disk) Headache SOB Pedal oedema
What are some S&S of hypertensive emergencies?
BP usually >220/140mmHg Headache Confusion Somnolence Stupor Visual loss Seizures Focal deficits Coma CHF Oliguria N + V
Describe the mx points for hypertensive crisis
Rx target organ dysfunction
Progressive BP reduction (cannot be done in prehospital setting)
What is the exception for progressive BP reduction rx for hypertensive crisis?
Ischaemic stroke
What is the definition of pre-eclampsia?
Note: not the QAS definition
Hypertension in pregnancy beyond 20 weeks gestation and proteinuria
What are the risk factors for pre-eclampsia?
Gestational hypertension Family hx of pre-eclampsia Increased BMI Renal disease Diabetes mellitus No prenatal care Hypercoaguable states
What is the mx for pre-eclampsia?
IV fluid therapy Magnesium sulphate (CCP - works as a muscle relaxant without affecting the baby - if magnesium sulphate is unavailable use midazolam as second line treatment) Maintain quiet environment Minimise body movement Position comfortably
What is the QAS definition of pre-eclampsia?
Systolic equal to or above 140 and/or diastolic equal to or above 90 PLUS one or more of: Neurological problems Proteinuria Renal insufficiency Haematological disturbances Foetal growth restriction
What two things are encompassed by venous thromboembolism (VTE)?
Pulmonary embolism (PE) and deep venous thrombosis (DVT)
Explain the pathophysiology behind VTE encompassing two concepts
A DVT is a thrombus that forms (usually) in the leg -> a piece breaks off and becomes an embolus -> if it lodges in the lung it is a PE
PE survivors are susceptible to the development of what two conditions?
Chronic pulmonary hypertension and chronic venous insufficiency
What may cause PE to reoccur?
Anticoagulation therapy
Describe the aetiology (risk factors) of PE
Underlying hypercoaguable state (specific condition may not be identifiable; these patients have a clinically silent tendency towards thrombosis)
Prolonged immobilisation
Oral contraceptives
Pregnancy
Hormone replacement therapy (HRT)
Medicial illnesses (cancer, CHF, COPD)
Pts undergoing hip/knee/gynaecological cancer/major trauma/craniotomy surgery are at high risk of secondary PE
True or false: PE cannot occur in absence of trauma or surgery
False
True or false: PE may occur up to a month post surgery
True
True or false: risk of PE in pregnancy is highest in the third trimester
True
Why is pregnancy a significant risk factor for PE?
Pregnancy causes hypercoagulability
What are the S&S for PE?
Non specific dysponea, tachypnoea, chest pain
or tachycardia
May present as pain free with dysponea, syncope or cyanosis
PE should be expected in pts presenting with…
Hypotension with evidence of predisposing factors and
clinical findings of acute RVF
What is the mx goal for PE?
Prevent thrombus propagation and embolisation
Describe the mx for PE
High flow O2 Pain relief Haemodynamic support Emotional support Positioning IV access Monitor 12 lead ECG and SPO2 Rapid tx
Sudden obstruction in the pulmonary circulation puts
an extra load what part of the heart?
RV
True or false: a small emboli may not produce any ECG changes
True
What are some typical ECG changes in PE?
Note: “this is a guide, don’t memorise it
Peaked P waves leads II, III, aVF
S wave in lead I
Q wave & T wave inversion in lead III
T wave inversion/flattened in R chest leads
S wave in L chest leads
What is the definition of stenosis?
Heart valve does not open properly, obstructing the flow of blood
What is the definition of valve regurgitation?
The valve does not close properly, allowing blood to leak backwards
What are some S&S of mild heart disease?
Exercise causes palpitations/breathlessness/tiredness/SOB/lower limb oedema
What are some generalised findings consistent with heart valve disease?
Respiratory distress/CHF/APO Tachycardia & palpitations Peripheral vasoconstriction Peripheral and facial cyanosis Murmur JVD Signs of RHF
True or false: aortic stenosis can be congenital
True
What is the aetiology of aortic stenosis?
Congenital
Calcification of valve
Rheumatic disease when pt is 30-70
Degenerative calcification in pts >70
What pt hx findings are consistent with aortic stenosis?
Palpitations Fatigue Visual disturbances Decreased physical activity with increased dyspnoea Angina GTN-induced syncope is higher than normal Syncope during exertion LVF symptoms
What are the causes of acute aortic regurgitation?
Rheumatic disease Infective carditis Trauma Valve surgery Aortic dissection/laceration
What are the causes of chronic aortic regurgitation?
Rheumatic disease Syphilis Aortitis Marfan syndrome Interventricular defect Arthritis Hypertension Infective endocarditis
What are the causes of mitral stenosis?
Rheumatic fever Congenital mitral stenosis Systemic lupus erythematosus (SLE) Rheumatiod arthritis Bacterial endocarditis Congenital causes (rare)
What are the causes of mitral regurgitation?
Acute rheumatic heart disease Chordae tendinae rupture and papillary muscle degeneration Myocardial ischemia Mitral calcification Left ventricular dilatation Systemic lupus erythematosus (SLE) Marfan syndrome
What are the differential dx for mitral regurgitation?
Aortic stenosis CHF APO Mitral valve prolapse MI Myocarditis
What generally causes infective endocarditis?
Non-bacterial thrombotic endocarditis resulting from turbulence or trauma to the endothelial surface of the heart. Transient bacteremia leads to seeding of lesions with adherant bacteria, and infective endocarditis develops
What hx is consistent with infective endocarditis?
Infective endocarditis is an often missed diagnosis - hx is often vague, highly variable, and may focus on primary cardiac effects or secondary embolic phenomena. Fever & chills (most common) Anorexia Weight loss Malaise Headache Myalgias Night sweats SOB Cough Joint pain Focal neurologic complaints and stroke syndromes (20%)
Which valve is commonly involved in IV drug use-related endocarditis?
Tricuspid, followed by aortic
What is the most common infective organism in IV drug-use related endocarditis?
Staphylococcus aureus
True or false: prosthetic valve endocarditis usually presents shortly after surgery
True
True or false: endocarditis does not occur in associated with intravascular devices
False
Fungal endocarditis is commonly found in what two types of pts?
IV drug users and ICU pts who receive broad spectrum antibiotics
