Ex1 L2 Flashcards
Ion most responsible for resting membrane potential
Potassium
What does not occur in SA node?
Rapid depolarization
Largest perfusion to coronaries
During diastole
Increased demand of O2 from
Increased:
HR, afterload, contractility
Simple form - angina pectoris
Mismatch of O2 supply & demand
Hearts way of compensating a mismatch in supply/demand of O2
Decreased HR + contractility
Angina pectoris risk factors
Males Increasing age HTN HL Smoker DM Obesity
Stable angina
Chest pain not changing for 2+ months
Unstable angina
Pain at rest, new onset, or increase in severity/frequency
Angina - diagnosis
ECG
Non-invasive or invasive imaging
Best information of coronary arteries
Coronary angiography
Revascularization
CABG or PCI +/- stents for failed medical management
LMCA occlusion > 50%
Significant CAD + EF 40%
Tx STEMI
MONA Beta Blockers Reperfusion therapy PCI CABG
Beta blockers should be avoided in
HF
Low CO or cardiogenic shock
Heart block
Reperfusion therapy should occur
30-60 minutes from arrival
**w/in 12h of onset
PCI should occur within
90 minutes of arrival
After angioplasty (w/o stenting) - time to wait for elective surgery
2-4 weeks
After bare metal stent placement - time to wait for elective surgery
At least 30 days
12 weeks preferable
Reperfusion therapy
TPA alteplase etc.
Reperfusion therapy risk
History of bleeding or hemorrhagic stroke — careful
After CABG- time to wait for elective surgery
At least 6w
Prefer - 12 w
After DES placement - time to wait for elective surgery
At least 12 months
Periop monitoring - stent pts
Must have interventional cardiologist on staff/available
*STAT consult for angina
Anesthesia techniques for stent pt
Neuraxial techniques not prudent unless anticoagulants held for 5-10 days prior
DES < 12 months + dual antiplatelet therapy
**Consult cardiology
Emergency surgery is 3.5x risk adverse events
Major risk of adverse cardiac events if d/c antiplatelet therapy + non cardiac surgery
UA/NSTEMI diagnosis
3 principal presentations:
- Angina at rest ( > 20 min)
- chronic angina pectoris that is more easily provoked
- New-onset angina (severe)
* often presents with arrhythmias
UA/NSTEMI ECG
Significant ST-segment depression in 2+ leads
+/or
Deep symmetric t-wave inversion
UA/NSTEMI Tx
Decrease O2 demand
Bed rest, O2, analgesia, BB, CaBlockers, ASA/clopidogrel, heparin
NO THROMBOLYTIC THERAPY
Cardiac risk factors in pts undergoing elective major non cardiac surgery
- high risk surgery
- IHD
- CHF
- CVA
- IDDM
- Cr > 2 mg/dL
- more risk factors = greater risk of complications
Hold ACE inhibitors when?
24h prior to surgery
Intraop events that decrease O2 delivery
Tachycardia Decreased DBP Hypocapnia Anemia Arterial hypoxemia Shift of oxyhem —> L Coronary artery spasm
Intraop events that increase O2 requirements
Increased:
HR, BP, SNS, contractility, pre/afterload
Intraop MI - Tx
Nitroglycerine
If needed: sympathomimetics (restore coronary pressure) + fluids (restore bp)
Preferred volatile with intraop MI
Sevoflurane
Evaluation of cardiac reserve
Exercise tolerance
Cardiomegaly
Heart > 50% thoracic cage in chest radiograph
Valve replacement that requires long-term anticoagulation
Mechanical (prosthetic)
Pt cannot tolerate anticoagulation - which type of valve replacement do they most likely have?
Bioprosthetic
Pt on Coumadin - major surgery planned. When to hold?
3-5 days preoperatively
IV/SubQ heparin or LMWH until day prior or day of surgery
When is antbx prophylaxis recommended?
- Dental procedures (+ gingival/periapical/perf of oral mucosa)
- invasive procedures (incision/biopsy of resp/infected skin/skin structures/musculoskeletal)
**NOT GI/GU
*Exceptions: Congenital heart dx, cardiac transplant (cardiac valvulopathy), immunocompromised
Commonly associated with mitral stenosis
Afib, pulmonary edema
over time—> pHTN, RHF
Pts with mitral stenosis should be taking
Anticoagulation
Prevent embolic stroke: 7-15%
Mitral stenosis: diagnosis
Echo
Valve area < 1.5 cm^2
Opening snap - diastole (murmur)
Mitral stenosis
Pulmonary edema - common in mitral valve stenosis when?
Afib, sepsis, pregnancy
Mitral Stenosis - risks associated
High risk for systemic thromboembolism - should be on anticoagulation especially if Afib
Mitral Stenosis - ECG
p wave notch (LA hypertrophy)
Not always
Mitral Stenosis Tx
- Diuretics
- HR control (increased HR=increased LA pressure/decreased LV filling)
- Anticoagulation
- Surgery: symptomatic +/- pHTN
Anesthetic Rx - Mitral Stenosis
Preop: anxiolytics to reduce tachy
Induction: balanced or nitrous/narcotics
*avoid ketamine, atracurium
Resume anticoagulation asap
Wedge pressure in mitral regurgitation
Overestimate LV filling pressure
LAP > LVEDP
Size of___ wave in PAOP correlates with _____
V wave
Magnitude of mitral regurgitation
Mitral regurgitation - anesthetic goals
Afterload reduction
*CO - maintained (via increased HR, decreased SVR)
I.e. nitroprusside gtt to decrease SVR
Induction Rx - Mitral regurgitation
Etomidate/Ketamine are okay — do not want to decrease HR
Factors associated with aortic stenosis
- Degeneration/calcification of leaflets—> stenosis
2. Presence of bicuspid rather than tricuspid valve
Most common valvular dx
Aortic stenosis
Normal aortic valve area
2.5-3.5 cm^2
Critical AS
Valve < 0.8 cm^2
+
Transvalvular pressure gradient > 50mm
Aortic Regurgitation - maintenance mneumonic
Full, Fast, Forward
A-Line changes with aortic regurgitation
Bisferins pulse
ECG changes with aortic regurg
Widened QRS
Goal hr/bp aortic regurg
Do not increase SVR (forward)
HR > 80, do not decrease (fast)
Drug to avoid in aortic regurg
Phenylephrine (decrease HR)
ECG changes - tricuspid regurg
Peaked p wave (leads II, III, aVF)
Drugs to avoid in tricuspid regurg
Nitrous
Causes of pulmonic valve regurg
pHTN
