Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CCN > CV surgery > Flashcards

CV surgery Flashcards

1
Q

How big must a block be for intervention to be needed?

A

When block reaches 70% of coronary diameter or 50% of left main artery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are indications for CABG?

A
  • Chronic disabling angina or unstable angina unresponsive to medical therapy
  • Triple vessel disease esp with Left main coronary artery
  • Continuing chest pain after MI
  • Failed angiopalsty
  • Symptoms after prior CABG
  • Coronary artery aneurysm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the types of conduits for CABG and pros/cons?

A

Venous: Saphenous vein graft (SVG)
Pros: Long vein, easy to access, straight.
Cons: Long term patency rate / graft occlusion not as good (risk decreased with early ASA)

Arterial: LIMA / RIMA, radial, gastroepiploic arteries
Pros: Tougher, muscular layer more durable and patency better. Rarely affected by atherosclerosis
Cons: Slower to harvest, may cause bleeding, arterial spasm (treated with ca ch blockers)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How is LIMA / RIMA CABG done?

A

Left / Right Internal Mammary Artery originates from the subclavian artery and is dissected from the chest wall but origin left intact. Other end attached post blockage, so only one anastomosis is necessary.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Principles of cardiac surgery

A
  • Medial sternotomy
  • Heart is stopped and cooled by administration of cardioplegia (mix of blood and electrolyte solution high in potassium)
  • Blood diverted from right heart to heart/lung machine and then returned to arterial circulation
  • Temporary epicardial pacing wires on right ventricle and may be placed on right atrium
  • Mediastinal and possibly pleural chest tubes placed to prevent blood accumulation post-op
  • Sternal bone closed with stainless steel wires
  • Insulin shift may be required if serum K remains high
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are negative effects of using Cardio Pulmonary Bypass?

A

1) Induction of SIRS with possible multi organ failure
2) Risk of stroke and embolism
3) Risk of bleeding (high dose heparin administered to prevent circuit clot)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How does the heart get restarted after cardio-pulmonary bypass?

A

Oxygenated blood infused via cardioplegia circuit to wash high potassium solution out. Heart usually beats spontaneously but may fibrillate requiring defib and use of anti-arrythmic meds. Pt may be bradycardic requiring temporary pacing.

Pts that have difficulty weaning due to hemodynamic instability may require inotropic support and IABP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the post-op care for CABG?

A
  • Continuous ECG monitoring 48-72 hrs with ST segment analysis
  • ASA 100-325mg daily starting 6hrs post op (Improve SVG patency rate, decrease mortality)
  • Afib prophylaxis (MgSo4, amio)
  • Statins (aggressive LDL cholesterol lowering reduces rate of graft atherosclerosis)
  • ACE inhibitors (stated when pt is stable and if taken pre-op and EF < 40%, HTN, DM, CKD)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are 2 categories of valvular heart disease?

A

1) Stenosis –> Narrowing of valve orifice, valve unable to open normally causing blood accumulation (and higher pressures) in the proximal chamber. Chamber has to work harder to generate higher pressures to eject blood
2) Insufficiency –> Regurgitation results in leakage of blood backward through a valve which does not close properly.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are causes of valvular heart disease?

A
  • Congenital defects
  • Degenerative
  • Infection and inflammation, endocarditis
  • Ischemic damage –> Papillary muscle rupture
  • Abnormal heart wall movement secondary to infarction can impair valve function
  • Cardiac tumors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Valve repair vs valve replacement?

A

Valve repair preferred because it maintains normal geometry and function of ventricle and avoids risk associated with chronic anticoagulation and prosthetic valve failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the main procedures for valve repair?

A

VALVULOPLASTY performed to open a stenotic valve.

  • COMMISSUROTOMY –> Split/incision is made through the commissures (fused valve leaflets). Can be done in cath lab percutaneously by balloon valvuloplasty or in OR. Leaflets must be pliable with no calcification or insufficiency
  • ANNULOPLASTY –> Done for valvular regurg, provides support for annulus which allows the leaflets to close properly. Esp for mitral or tricuspid insufficiency associated with a dilated valve annulus leading to failure of leaflets to close
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are other procedures for valve repair?

A

Repair of structural supports (chordal reimplantation, addition of new chords)
Resection / reconstruction of leaflets (removal of access tissues from leaflets, covering holes or tears with a tissue patch)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Compare tissue vs mechanical valve replacements

A

TISSUE VALVE:

  • Porcine or bovine
  • Anticoagulants not required after 3 months
  • Indicated for children, young females, pts with bleeding disorders, peptic ulcer

MECHANICAL VALVE:

  • Metal and synthetic
  • Indicated for adults < 50yrs
  • Life long anticoagulant required
  • Good durability, more common
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the biggest risk during aortic valve replacement?

A

Risk of dislodging calcification deposits from around the valve causing a systemic emboli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a transcatheter aortic valve replacement (TAVR)? How is it done?

A

When open aortic valve surgery is too risky, TAVR involves placement of new tissue valve within the native valve using catheters that deliver the valve through the aorta (femoral approach) or apex of LV via an incision in the chest wall (if pt has inadequate vascular access).

Catheter passes through the diseased aorta then balloon is inflated crushing the native valve to the side in order to position the new valve at the site.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is a mitral valve replacement done? What is the biggest risk during mitral valve replacement?

A

Incision made in left atria to access valve site (OPEN HEART). Risk of entrapping air within the heart, careful “de-airing” required or pt will have a large embolus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are potential complications of all prosthetic valve replacements?

A
  • Valve thrombosis / emboli (mechanical valves require anticoag for life, tissue valves for 3 months)
  • Structural failure
  • Hemolysis
  • Endocarditis (prophylactic antibiotics)
19
Q

What is aortic stenosis patho and S&S?

A

Is the narrowing of the opening of the aortic valve. Heart compensates by hypertrophy, left atria enlargement due to pressure overload. Diastolic dysfunction occurs due to hypertrophy, eventually leads to ventricular dilation and decreased contractility

S&S: Syncope, angina, dyspnea, harsh medium pitched murmur during systolic radiating into carotid arteries

20
Q

What is aortic stenosis intervention and post op issue?

A

Therapies if symptomatic: Replacement or TAVR

Post op issues:
-HTN (LVH = strong myocardium) ** Vasodilators can greatly reduce preload and if pts are preload dependent then BP becomes very labile

21
Q

What is the most likely cause of low CO for hypertrophied heart?

A

-In Hypertrophied heart, low CO most likely related to hypovolemia despite high filling pressures (high PAD or wedge is the norm for the pt)

22
Q

What is aortic regurg / insufficiency patho and S&S?

A

Inability of aortic valve to close completely, blood flows backward during diastole from aorta back to LV.

Initially heart compensates for increased volume by hypertrophy but eventually LV thins and dilates. VOLUME OVERLOAD leads to high filling pressures, dilated LA, potential pulm HTN

S&S: Diastolic murmur, may have S3. Increased pulse pressure (high systolic d/t high stroke volume, low diastolic d/t lower pressure in aorta from regurgitant blood flow), signs of heart failure (pulm. edema, peripheral edema, ascites) or may be asymptomatic

23
Q

What is aortic insufficiency therapies?

A
  • Good BP control to prevent increases in systemic pressure (would increase regurg)
  • HF meds as needed
  • Aortic valve replacement
24
Q

What is mitral stenosis patho and S&S?

A

Narrowing of the opening of mitral valve leading to reduced filling of the LV

Valves and sometimes chordae tendinae become thickened, LA enlargement, pulm HTN, RV hypertrophy

S&S: Develops over time, insidious, general malaise, fatigue, SOB. Diastolic murmur over apex with opening snap (accentuated S1), left parasternal heave (RV hypertrophy)

25
Q

What are mitral stenosis therapies and interventions?

A
  • Na restriction and intermittent diuretics of pulmonary edema.
  • Anti-arrythmic agents due to risk of atrial arrythmias
  • Anticoags if afib, prior embolitic events, LA thrombus
  • Percutaneous repair in cath lab (valvuloplasty)
  • Valve replacement
26
Q

What are post-op issues for valve interventions?

A
  • Heart blocks (mitral, aortic valve near AV node)
  • May require higher filling pressures, inotropes
  • Higher risk of post op RV dysfunction d/t pre-existing pulm HTN
  • Anticoags and afib prophylaxis
27
Q

What is mitral regurgitation and S&S?

A

Inability of mitral valve to close completely, blood flows backward during systole from LV back to LA

Left atrial enlargement, pulm. HTN, increased volume in LA returns the LV increasing LV volume which initially hypertrophies then thins and dilates.

S&S: Systolic murmur at the apex, pulm edema, signs of heart failure, may be asymptomatic if chronic

28
Q

What are mitral regurgitation therapies and interventions?

A

Meds reducing afterload (ACE inhibitors, ARBs)

MV repair or replacement
Percutaneous repair in cath lab (mitraclip)

29
Q

How is replacement of the ascending aorta / hemiarch done?

A

Surgery performed through a median sternostomy, aorta is unable to be cannulated for connection to the bypass machine in the normal manner so aorta is cross-clamped and circulatory arrest is stablished. Surgeon may or may not choose to perfuse the brain during arrest period. Aneurysm is over-sewed or removed and a graft inserted.

If dissection extends down into sinus of valsalva, then aortic valve needs to be replaced and coronary arteries re-inserted into an aortic graft. Procedure called BENTALL procedure.

Post op important to control systolic BP to limit stress on aorta

30
Q

What is general post op care for all SV surgery pts?

A

Obtain baseline info: Hemodynamics, chest tube levels, blood works, 12 leads, CXR

Obtain parameters for inotropes / pressors
Warm the pt (decreases coagulopathies, improves FOC, decreases afterload, risk of shivering)

Once stable: Decrease NMBA, sedation, extubate, mobilize, treat pain

31
Q

What are specific post op care principles for CABG?

A
  • Early ASA administration
  • ST monitoring (risk for thrombolytic event, spasm, decreased coronary perfusion)
  • May require nitrates, Ca channel blockers, IABP, emergent heart catheterization
  • Monitor circulation distal to harvested graft site
  • Glucose control (BS < 10)
  • Afib prophylaxis (beta blocker, amio), statin, VTE prophylaxis, restart cardiac meds as needed
  • Smoking cessation
32
Q

What are specific post op care principles for valve surgery?

A
  • Check coags, more susceptible to bleeds than CABG
  • Monitor closely for arrythmias
  • Anticoags (3 months for tissue, lifetime for mechanical), afib prophylaxis, VTE prophylaxis, restart cardiac meds as needed
  • ACE inhibitors for heart failure pts (MR, AI)
33
Q

What are cardiac complications associated with post-op CV surgery?

A

1) Hypotension (BP/PAC)
- –> cardiogenic vs hypovolemic, possible SIRS or anaphylaxis if warm strong pulses and high CO. Cautious use of vasodilators

2) Ischemia (ST/PAC)
- –> Inadequate myocardial protection during CPB, embolism, graft failure, incomplete revascularization, spasm

3) Bleeding (Chest tube drainage, CBC, coags)
- –> Hemodilution, hypothermia, anticoags (heparin, ASA, plavix), decreased circulating clotting factors, multiple transfusions (citrate)

4) Tamponade (Chest tube output, CVP/PAWP/PAP), BP, CO)
- –> Accumulation of fluid in pericardial space resulting in compression and impaired diastolic filling

5) Arrythmias (ECG, pacemaker settings)
- –> Ischemia, pericarditis, electrolyte imbalance, edema near conduction system, reperfusion, AV blocks, afib

34
Q

What is S&S of tamponade?

A

Initially BP may be unchanged d/t compensatory mechanisms.

Hypotension, elevated filling pressures, equalization of diastolic pressures, low CO, high SVR, Beck’s triad (hypotension, elevated JVP/distended neck veins, muffled heart sounds), pulsus parodoxus, electrical alternans / low voltage ECG

35
Q

What is Beck’s triad?

A

INDICATIVE OF TAMPONADE!

1) Hypotension
2) Elevated JVP/distended neck veins
3) Muffled heart sounds

36
Q

What are non-cardiac complications associated with post-op CV surgery?

A

1) Neurological
- –> Cerebral ischemia, infarction (bleed, embolism), cognitive dysfunction, difficulty with memory, post op delirium, psychotic behaviour, seizures

2) Pulmonary hypoxemia
- –> Atelectasis (deflated lungs during bypass, may need higher PEEP or recruitment), non-cardiac pulmonary edema (SIRS, TRALI- transfusion related acute lung injury), emboli, pneumothorax/hemothorax, prolonged wean from ventilator (lung disease, phrenic nerve dmg)

3) AKI / failure
- –> Pro-inflammatory response, toxins during CPB, reduced renal perfusion pressure, micro-emboli, hematuria post-op d/t CPB

4) GI jaundice d/t transfusions, GI bleed (heparinization, ASA, potential NSAIDs, stress ulcers)

5) Infection
- –> Surgical wound, sternal dehiscence, deep wound infection

37
Q

What are the 2 main types of aortic pathologies?

A

1) Aneurysm
- –> Dilatation of aorta >50%, managed medically until they reach a certain diameter, enlarge too quickly, or have persistent pain.

2) Dissection
- -> Tear in the intima wall of the aorta, exposing medial layer to driving force of intraluminal blood. Longitudinal separation of intima and adventia (outer) leading to a channel or “false lumen” where blood exerts pressure on weakened aortic wall at risk of rupture. Additional tears to the intima may allow blood to return to “true lumen”.

38
Q

What are the 2 types of aortic aneurysm?

A

1) Thoracic Aortic Aneurysm (TAA) (Above diaphragm)

2) Abdonimal Aortic Aneurysm (AAA) (Below diaphragm)

39
Q

What are the 2 types of aortic dissection?

A

1) Type A dissection –> Tear involves ascending aorta or arch, surgical emergency
2) Type B dissection –> Tear in descending aorta, treated medically with BP controlled emergently with beta blockers and vasodilators

40
Q

How is replacement of the descending thoracic aorta done?

A

Surgery performed through a left lateral thoracotomy, one lung ventilation performed to allow access of the aorta (left lung deflated). Major arteries re-implanted in the new graft if possible. Partial bypass often done to divert blood proximal to cross clamp and deliver it distal to the surgical site

41
Q

What are complications of descending thoracic aorta replacement?

A

-Disruption of blood supply to spinal cord results in paraplegia (d/t embolization, thrombus, reperfusion injury, spinal cord hypoperfusion during cross aortic clamping)

**Risk minimized by < 30mins clamp time and keeping MAP 80-100, lumbar drains at L2-L3 to prevent buildup

***MUST MONITOR LOWER MOTOR FUNCTION and LUMBAR DRAINS OUTPUT

42
Q

How is repair of abdominal aortic aneurysm done?

A

Midline abdominal incision, aorta clamped above and below level of the aneurysm during repair, pts may require ICU d/t complications

43
Q

How is endovascular aortic repair (EVAR) done?

A

Repair done through a catheter inserted into one of the femoral arteries in IR or OR. Stent advanced over a guidewire and deployed sealing each end to normal aorta. Placement confirmed with fluroscopy. Pts unlikely to require ICU

***If procedure done in thoracic aorta, is a TEVAR and pts still at risk of paraplegia though reduced in comparison to open repair. Must carefully monitor lower motor function

44
Q

How can risk of paraplegia be reduced in context of thoracic aortic surgeries?

A
  • < 30mins clamp time
  • MAP 80-100
  • Lumbar drains at L2-L3 to prevent buildup

***MUST MONITOR LOWER MOTOR FUNCTION and LUMBAR DRAINS OUTPUT

CCN (27 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions