Cardio Questions Flashcards
Define mediastinum
Central compartment in thoracic cavity between pulmonary cavities
What covers the mediastinum?
Mediastinal pleura - covers all thoracic viscear bar lungs
How is volume and pressure change permitted in the mediastinum?
CT is loose and parietal pleura of lungs flexible
CT stiffens with age - structures less mobile
Parts of the mediastinum
Superior
Inferior - Anterior, Middle, Inferior
Limits of the superior mediastinum
Superior aperture to the transverse thoracic plane - T4/5
Limits of inferior mediastinum
Transverse thoracic plane to the diaphragm
Anterior inferior mediastinum
Body of sternum, transverse thoracic plane and pericardium. Continues with superior mediastinum superiorly
Contents of anterior inferior mediastinum
Sternopericardial ligaments
What is found in the anterior inferior mediastinum in children?
Thymus
Middle inferior mediastinum
Pericardium, Heart, ASC aorta, pulmonary trunk, SVC, arch of azygos, main bronchi
Borders of the heart
Right, Left, Superior, Inferior
Anterior/sternocostal surface is formed by which part of the heart?
Right ventricle
Posterior or base is formed by which part of the heart?
Left Atrium
Inferior surface of the heart
Left ventricle, partly right
To what structure is the inferior border of the heart related?
Central tendon of the diaphragm
What spinal level is the heart anterior to?
T5-T8
As the heart is related to the diaphragm, what happens to its position when standing upright?
Vertical position
What type of blood is carried by the aorta?
Oxygenated
Parts of the aorta
Ascending
Arch
Descending - thoracic and abdominal
Wheter does the abdominal aorta bifurcate and into which vessels?
L4- right and left common iliac
At what level do the common iliac vessels bifurcate?
L5
Name the branches of the ascending aorta
Left coronary artery
Right coronary artery
Branches of the left coronary artery
Anterior interventricular
Circumflex
Branches of the right coronary artery
Posterior interventricular
Right marginal
Position of the right marginal artery
Sinks into right ventricle
Where do both coronary arteries originate>
Aortic sinus
Describe the anastamosis of the coronary arteries
Anterior interventricular and posterior interventricular
Circumflex and right coronary artery as it continues
Branches of the aortic arch
Braciocephalic
Left subclavian
Left common carotid
Describe the veins of the heart
Great - within anterior ventricular groove
Middle - posterior ventricular groove
Small - next to right marginal
Where do the veins of the heart drain?
Into the coronary sinus to the right atrium
Branches of the descending thoracic aorta
Oesophageal arteries
Bronchial arteries
Pericardial arteries
Posterior intercostal arteries
Terminal branches of abdominal aorta
Common iliac L4
External iliac - L5
Internal iliac
Where do the common iliac arteries lie?
Iliac fossa
What artery does the external iliac become?
Femoral
What does the internal iliac artery supply>
Pelvic viscera
Which organs are supplied by branches of the abdominal aorta?
Diaphragm Adrenals Kidneys Gut tube Gonads
What electrolyte abnormality is consitent with prolonged QT interval>
Hypokalaemia
What does a long QT interval indicate?
Delayed repolarization of ventricles
What are the possbile consequences of long QT syndrome>
Ventricular tachycardia
/ Torsades de pointes
Collapse/Sudden death
What is a normal corrected QT interval?
less than 430 ms in males and 450 ms in females.
What is the physiological cause of a long QT interval>
defects in the alpha subunit of the slow delayed rectifier potassium channel
Name some causes of LQTS
Congenital - Jervell-Lange-Nielsen syndrome, Romano Ward Syndrome
Drugs - amiodarone, sotalol class 1a antiarrhythmic drugs tricyclic antidepressants selective serotonin reuptake inhibitors (especially citalopram) methadonechloroquine terfenadine** erythromycin haloperidol ondanestron
Electrolyte - hypocalcaemia, hypokalaemia, hypomagnesaemia acute myocardial infarction myocarditis hypothermia subarachnoid haemorrhage
What is the difference between Jervell Lange Nielsen Syndrome and Romano Ward syndrome?
Both congenital and associated with LQTS
Jervell has deafness included due to abnormal postassium channel
No deafness in Romano Ward
Features of LQTS
may be picked up on routine ECG or following family screening
Long QT1 - usually associated with exertional syncope, often swimming
Long QT2 - often associated with syncope occurring following emotional stress, exercise or auditory stimuli
Long QT3 - events often occur at night or at rest
sudden cardiac death
Management of LQTS
Avoid drugs exacerbating long QT interval
Reduce strenuous exercise
Beta blockers - * sotalol may exacerbate
Implantable cardioverter defib in high risk case
What is the gold standard investigation for Pulmonary embolism?
CTPA
What must be arranged if CTPA unavailable and patient has suspected PE?
Administer interim therapeutic anticoagulation - DOAC - apixabon, rivaroxaban
What ECG changes are seen in patient with PE?
S1Q3T3
Right bundle branck block and right axis deviation
Sinusd tachycardia
CXR findings in PE
Typically normal
May find wedge shaped opacification
Which drugs can cause torsades de pointes?
Macrolides eg clarithromycin
Characteristics of torsades de pointes on ECG
rapid, irregular QRS complexes, which appear to be ‘twisting’ around the baseline
What is torsades de pointes?
a form of polymorphic ventricular tachycardia associated with a long QT interval. It may deteriorate into ventricular fibrillation and hence lead to sudden death.
Management of torsades de pointes
IV Magnesium sulfate
Features of acute pericarditis
Chest pain - may be pleuritic
Pericardial rub
Tachypnoea
Tachycardia
Cause of acute pericarditis
Uraemia viral infections (Coxsackie) tuberculosis uraemia (causes 'fibrinous' pericarditis) trauma post-myocardial infarction, Dressler's syndrome connective tissue disease hypothyroidism malignancy
Changes on ECG in acute pericarditis
Saddle shape ST elevation
PR depression
What additional investigation should patient with acute pericarditis have with ECG?
Transthoracic echocardiogram
Management of acute pericarditis
Treat underlying cause
NSAIDs and colchicine
ECG signs of hyperkalaemia
Small or absent P waves, tall tented T waves and broad bizarre QRS complexes
Long PR interval
Sine wave
Symptoms of hypokalaemia
fatigue, muscle weakness, myalgia, muscle cramps, constipation, hyporeflexia and rarely paralysis.
ECG signs of hypokalaemia
U waves small or absent T waves (occasionally inversion) prolong PR interval ST depression long QT
