Cardiovascular Devices Flashcards
Complications
thromboembolic complications
infection
dysfunction due to materials degeneration
abnormal healing
Mechanical heart valves
mobile occluder (carbon disc, high strength, fatigue, wear resistance) metallic cage - cobalt-chrom or Ti alloy purely passive life long anticoags
Tissue heart valves
porcine aortic valve or bovine pericardium mounted on a metal or plastic stent
preserve tissue, kill cells, decrease immunological activity
AD: pseudoanatomic central flow, relative nonthromb (no anticoags)
Heart valve complications
thromboembolism - less in tissue but rates the same due to mech anticoags - chronic oral anticoags increases risk of hemorrage infection (early is staphylococcal) - at prosthesis tissue junction material degradation - require reoperation - most in tissue valve - hemolysis
Atherosclerotic plaque composition
central lipid core
cholesterol crystals
cells (mac, SM cells)
PTCA problems
restenosis (due to fibrous tissue formation owing to SM prolif from angioplasty injury)
acute thrombosis
Types of stents
balloon expandable 316L stainless steel
bioresorbable (PLA)
Stent complications
subacute stent thrombosis
restenosis
damage to endothelial lining -> adherence and accumulation of platelets and leukocytes
stent wires embedded in SM cells in collagen matrix
Vascular graft
Synthetic conduit made from Darcon or PTFE (large small respectively)
can be porous to enhance healing
can be impregnated with proteins to aid clotting (bad)
research to prevent coag, inhibit SM ad/prolif, promote endothelial cell ad/prolif
Pacemaker wishlist
ideal pacing stable fixation maintain minimal stimulation threshold maximise sensing function reliably
Pacemaker complications
non excitable fibrous tissue between electrode and depolarisable myocardial tissue infection dislodgement thromboembolism interference
VAD situations of use
potentially reversible heart failure end stage (as a bridge)
Cardiac assist and replacement device complications
haemorrhage
thrombosis
infections
