Week 119 Coronary artery disease Flashcards
What are the 2 layers to the pericardial sac?
- fibrous
- serous
What layers form the serous pericardium?
- Parietal (fused and inseparable from the fibrous pericardium)
- Visceral pericardium (part of the epicardium- layer immediately outside of the heart muscle proper)
Where are the arteries of the pericardium derived from?
Internal mammary and its musculophrenic branch, and from the descending thoracic aorta
Where are the nerves of the pericardium derived from?
Vagus and phrenic nerves and the sympathetic trunks
What is in between the parietal and visceral layers of the pericardium?
Potential space- pericardial cavity; normally lubricated by a film of pericardial fluid
too much fluid in the cavity (e.g. pericardial effusion) = pericardial tamponade (compression of heart within pericardial sac)- to treat this, perform pericardectomy
Name 3 pericardium pathologies
Pericarditis resulting in pericardial friction rub
Pericardial effusion which may lead to cardiac tamponade
Cardiac tamponade as a primary pathology following trauma
How is pericarditis classified?
according to the composition of the inflammatory exudate/transudate
e.g. serous purulent fibrinous caseous hemorrhagic post infarction
symptoms; chest pain dry cough fever fatigue anxiety (can be misdiagnosed for MI)
Describe pericardial effusion
Fluid around the heart- abnormal accumulation of fluid in the pericardial cavity
limited space in the pericardial cavity means fluid accumulation here will lead to an increased intrapericardial pressure- can negatively affect heart function
Transudative: congestive heart failure, myxoedema, nephrotic syndrome
Exudative: TB, spread from emyema
Malignant
Haemorrhagic
What is cardiac tamponade?
Cardiac tamponade also known as pericardial tamponade, is an emergency condition in which fluid accumulates in the pericardium(the sac in which the heart is enclosed). If the fluid significantly elevates the pressure on the heart it will prevent the heart’s ventricles from filling properly. This in turn leads to a low stroke volume. The end result is ineffective pumping of blood, shock, and often death
Describe invasive angiography
Insertion of catheter via groin or wrist Find coronary ostia Inject contrast Advantages Good spatial resolution Gold standard Treatment Disadvantages Complications Radiation dose Cost
What does systolic myocardial contraction do?
Reduces myocardial perfusion
When is coronary flow best?
During systole
Where do coronary arteries arise from?
Aorta (L and R coronary arteries)
Where do coronary veins drain?
Into Right atrium (some directly into chambers)
What arises from the left coronary artery?
Circumflex branch
Left anterior descending
What vein runs parallel to the circumflex branch of LCA?
Great cardiac vein
Where does the left circumflex branch run?
Between the left atrium and ventricle
Where does the LAD run?
Between the two ventricles
What arises from the LAD?
Marginal branches
Diagonals
Septals
(D and S supply lateral wall of LV, anterolateral papillary muscle; 37% have median ramus)
What arises from the right coronary artery?
Posterior descending artery (PDA)
Acute marginal
What are branches of the left circumflex artery?
Obtuse marginal
Posterolaterals
(supply posteriolateral LV, anterolateral papillary muscle)
Where is the right coronary artery origin?
Right aortic sinus (lower origin than LCA)
What are branches of the posterior descending artery?
Septals
What is amlodipin?
Ca2+ channel blocker - antihypertensive
What is aspirin?
Antiplatelet agent- secondary prevention of vascular events
What is atorvastatin?
Statin- secondary prevention
What is ramipril?
ACE inhibitor- antihypertensive
What is the management for crescendo/unstable angina?
Admit to wards (cardiac monitor)
–Dual antiplatelet therapy (aspirin & clopidogrel)
–Anticoagulant (clexane 65 mg bd. s.c.)
–Beta-blocker (bisoprolol 2.5 mg bd)
–Refer to Cardiac centre for coronary angiogram
further pain- GTN infusion (IV)
What is hypoxia?
condition in which the body or a region of the body is deprived of adequate oxygen supply resulting in cell injury
What is ischaemia?
is a condition of lack of blood supply from a stenotic / occluded artery or reduced venous drainage causing ischaemia
Ischaemia causes cell injury more rapidly than hypoxia.
What is infarction?
Irreversible cell damage due to ischaemia –and hypoxia
What are causes of cell injury?
Hypoxia and Ischaemia •Infections •Metabolic / Nutritional •Trauma •Drugs/ Chemicals •Autoimmune •Genetic diseases
What is the most common type of cardiac disease and commonest cause of death in the western world?
Ischaemic heart disease