Valvular Heart disease therapy Flashcards
What is cardiac isachemia?
- lack of BF/O2 to the cardiac muscle
- artery can be blocked narrowed for short period of time
State the causes of cardiac isachemia
- atherosclerosis
- embolism
- coronary thrombosis
- aortic dissection ( injury to T.intima which allows BF to occur between the layers. T intima and T.adevenia seperate )
- arteritis
- congenital
What conditions can IHD lead to?
- angina
- MI
- arrythmia
- chronic HF
- sudden death
State patterns of CAD
- left main stem(CA) stenosis
- 3 vessel coronary artery disease (the left anterior descending, right coronary and circumflex arteries have blockages from atherosclerotic plaques.)
State indications for coronary artery bypass grafting (CABG)
- if symptomatic ( of any CAD pattern)
- prognostic (LMSS, 3VCAD)
Criterieas of patients for CABG
Adequate:
- LF
- MF
- HF
- ascending aorta OK
- distal coronary targets OK
State conduits for CABG
- reversed saphenous vein
- internal mammary arteries
- radial arteries
Sternotomy required to gain access to middle mediastinum
Reversed saphenous vein CABG
- reversed to ensure the BF of the blood is operating in the right direction.
- valves
- long saphenous vein
Explain the CABG procedure + the CPB
CABG
- graft vessel used to replace a narrowed artery ( coronary)
- Internal mammary artery is preferred as it doesn’t narrow over time unlike others.
- After graft vessels removed, sternoctomy performed to gain access to heart. Blood is rerouted to a heart-lung bypass machine(CPB), which pumps blood and O2 through body.
- Heart is temporarily stopped using medication as new graft attachments are made.
- After grafts made, controlled electrical shocks to start the heart
State sternocotomy related problems
- wire infection
- painful wires
- sternal dehiscence ( when wires press into RV > haemorrage)
- sternal malunion ( when sternum heals abnormally)
Post op problems in cardiac surgery
- cardiac tamponade ( when pericardial fluid builds resuting in comptrssion of heart)
- death
- stroke
Clinical symptoms of cardiac tamponade + Treatment
Primary features
-high CVP, HR, low BP
Secondary features
-oliguria, increased O2 requirements, metabolic acidosis
Treatment
-chest re opening
Surgery for valvular HD in adult and paediatrics
Adult Cardiac surgery
-aortic and mitral valve surgery
Paediatric cardiac surgery
-all 4 vales operated with equal frequency
State causes of valvular HD in ADULTS
- degenerative
- congenital
- infective
- inflammatory
- LV/RV dilation
- trauma
- neoplastic
- paraneoplastic
Most common valve problems requiring cardiac surgery in Abdn
- senile tricuspid AS
- Bicuspid AS
- degenerative MR
What is rheumatic fever and what is it caused by?
- relapsing illness caused by streptococcal infections
- hallmark pathology is pancarditis ( inflammation of whole heart including pericardium and heart walls)
- sydenham’s chorea
Treatment of rheumatic fever
- antibiotics after treatment to prevent steptococcal infections(penicillin sensitive)
- aspirin + bed rest
Test for rheumatic fever
ASO titre
- blood test to measure antibodies against streptolysin O ( produced by Grp A strept bacteria)
What is chronic rhemuatic HD
- progressive mitral valve disease and/or aortic valve disease
- major cause of death in pregnancy ; cardiac surgery
Endocarditis pathogens
- streptococcus viridans
- staphylococus aureus ( most aggressive)
- can be diseased/normal beforehand
State indications for surgery in endocarditis
- if severe valvular regurgitation
- large vegetations
- pyrexia(fever)
- progressive renal failure
Treatment of endocarditis
-IV for 6 weeks post operatively
Presentation of aortic stenosis
- HF, angina, syncopal episodes(faint), asymptomatic incidental finding
- murmur easily heard
- AVR recommended for severe AS
Describe heart sounds of aortic stenosis vs aortic sclerosis
-no aortic S2 ( differentiates it from aortic sclerosis)
Presentation of aortic regurgitation
-HF, angina, or asymptomatic incidental finding
-murmur difficult to hear
-the louder, more severe AR
-AVR recommended for severe especially with LV dilatiion
-
Presentation of mitral stenosis
- mumur difficult to hear. The louder, more severe
- patient excercise in order to hear
- surgery recommended if MVA on echo is <1.5cm2
Presentation of mitral regurgitation
- easily heard
- severe assoc with LV and LA dilation, onset AF and pulmonary hypertension
- MVR recommended if severe
- if severe, on ECHO systolic BF reversal in pulmonary veins
Explain cardiopulmonary bypass surgery
- blood drained from RA and returned to ascending aorta?
- heart and lung function taken over by CPG machine
- induced hypothermia
- non pulsatile flow during CPG
Types of valves and explain difference
Biological valve
-no warfarin required but wears out > 15 yrs
Mechanical valve
-warfarin required for life. Valve lasts for >40yrs
-Sometimes repair>replacement for mitral valve once complete valve competence is restored,
What is coronary angioplasty? Compare benefits/limitations of this and CABG
- alternative to CABG
- procedure that widens arteries
- a small catheter with balloon attached at end(deflated) and reaches narrowed artery (guided by Xray). Balloon is inflated to push artery open and a stent(metal tube) is inserted to help keep artery open.
- less invasive to CABPG but higher chance it needs to be repeated. Not used when multiple coronary arteries is blocked / abnormal vessel structure surrounding heart abnormal
