Cardiac Assessment Flashcards
What is the goal of the cardiac pre-op assessment?
To identify patients with heart disease who are at high risk for perioperative cardiac morbidity or mortality or those with modifiable conditions or risk.
What are the 5 steps of the cardiac assessment?
- Step 1: Urgency of surgery
- Step 2: determine if active cardiac condition
- Step 3: determine surgical risk
- Step 4: assess functional capacity
- Step 5: assess clinical predictors/ markers
What is step 1 of the cardiac assessment?
urgency of surgery
What is step 2 of the cardiac assessment?
determine if active cardiac condition
What is step 3 of the cardiac assessment?
determine surgical risk
What is step 4 of the cardiac assessment?
assess functional capacity
What is step 5 of the cardiac assessment?
assess clinical predictors/ markers
Name the 6 MINOR clincal predictors of increased cardiac risk
- Uncontrolled HTN
- Advanced age > 75 years old
- Abnormal EKG
- Low functional capacity
- Hx. CVA
- Rhythm other than SR
If a patient has any of the minor clinical predictors of cardiac risk, is there an increase in perioperative risk?
Sometimes no, or only minor risk increase. These are indicators that there might be some underlying cardiac disease.
Name the 6 INTERMEDIATE clinical indicators of increased cardiovascular risk.
- Known CAD
- Prior MI >1 month and Q waves on EKG
- Hx. of mild, stable angina
- Compensated or previous LV failure/ CHF
- Diabetes Type 1 and 2
- CRI (cr>2.0mg/dL)
Name the 6 MAJOR clinical predictors of increased cardiac risk.
THese are active cardiac conditions
- Unstable coronary syndromes (active ischemia by EKG)
- Acute or recent MI < 1 month
- Unstable or severe angina
- Decompensated CHF
- Significant arrhythmias
- Severe valvular disease
What is meant by decompensated CHF?
CHF with active, current symptoms
What is meant by significant arrhythmia?
Arrhythmia that is associated with symptoms
Which valvular disease is the most concerning for intraoperative management?
Aortic stenosis
What is the overall mortality risk of acute MI after general anesthesia?
0.3%
Which 3 types of surgical procedures will cause an increased incidence of perioperative MI?
- intra-thoracic surgery
- intra-abdominal surgery
- surgery lasting more than 3 hours
If a patient has had an MI, but it was > 6 months ago, what is the incidence of perioperative MI?
about 6% (this data is on patients that have not been revascularized or stented)
If a patient has had an MI within 3-6 months of surgery, what is the incidence of perioperative MI?
15%
If a patient has had an MI within the past 3 months, what is the perioperative risk of MI?
30%
If patients who have had an MI suffer a reinfarction during the surgical procedure, what is the mortality rate?
50%
The highest risk period for perioperative MI in patients who have had a previous MI is:
within 30 days after acute MI
What are the AHA/ACC guidelines for patients undergoing elective surgery that have had a recent MI?
They should wait 4-6 weeks post MI before having elective surgery
Which types of surgeries put patients at high risk for perioperative MI? (list 5)
- aortic surgery
- other major vascular surgeries
- peripheral vascular surgery
- emergent major operations (esp. in elderly)
- prolonged procedures with large fluid shifts/ blood loss.
Which types of surgeries put patients at an intermediate risk of perioperative MI? (list 8)
- intraperiotoneal
- intrathoracic
- transplant
- carotid endarterectomy
- head and neck
- major neurologic
- major orthopedic
- endovascular aneurysm repair
A high risk surgery adds ___% of additional risk of morbidity or mortality.
5
Which types of surgeries or procedures put patients at a low risk of perioperative MI? (list 4)
- Endoscopic procedures
- superficial procedures
- biopsies
- cataracts
With low risk surgeries, what is the percentage of increased morbidity and mortality?
<1%
What are the 3 basic components of the pre-op cardiac assessment?
- History taking (including medications)
- Physical exam
- Resting 12 lead EKG (if indicated) within 30 days of surgery
List 7 adjunct tests you could order as part of a pre-operative cardiac assessment.
- CXR
- labs
- stress test
- echo
- MRI
- CT scan
- Coronary angiography
Which test is the gold standard for coronary anatomy?
coronary angiography
The goal of the history portion of the cardiac pre-operative assessment is to elicit what 3 things about the patients cardiac disease status?
- severity
- progression
- functional limitations
What are 4 questions to ask regarding cardiac history?
- Shortness of breath
- CHF
- MI
- Angina
How would you assess patients shortness of breath status?
Ask about orthopnea. Are you short of breath on exertion?
What questions should you ask to further explore if a patients reports a history of angina? (list 7)
- with activity or at rest
- chest pain/ pressure/ tightenss in the heart
- what precipitates it
- associated symptoms
- how frequently
- what is the duration when it occurs
- methods of relief
Are people who suffer from angina at a greater perioperative cardiac risk than people who do not?
Yes, they are much more at risk
Are post-menopausal women at greater risk for perioperative MI than pre-menopausal women?
Yes, estrogen will give some cardioprotection
What is a good way to assess a patient’s functional capacity?
By assessing their exercise tolerance
What is the most striking evidence of decreased cardiac reserve?
in the absence of lung disease, exercise intolerance is the most striking evidence.
What is the Duke Activity Status Index?
It assigns a MET score to patients. MET is a describing amount of energy consumption by an activity and comparing it to a baseline or expected amount of enegy consumption.
If a patient can do strenous exercise and sports like swimming, tennis, football and running, what would their METS score be?
>10
If a patient cannot do strenous exercise but can climb stairs, walk in their neighborhood, do heavy housework, bowl, golf, and dance, what would their METS score be?
4-10
If a patient can only do the basic things in daily living, like eat, dress themselves, walk around the house, do dishes, what would their METS score be?
1-4
Patients with which MET demand score are considered to be at a higher cardiac risk during surgery?
patients with 1-4 MET
What does angina tell us?
It is a sign of imbalance between myocardial oxygen supply vs. demand
Which type of patients may experience angina but have clear coronary arteries?
Patients with aortic stenosis
What is one thing that feels like angina but is not?
esphageal spasm caused by heartburn can feel like angina and is often relieved by NTG
Do ischemic episodes happen without causing angina?
Yes, up to 80% of ischemic episodes can happen in CAD patients without any pain. (silent)
What percentage of acute MIs are silent?
10-15%
2 types of patients get angina that do not have CAD. They have:
- esophageal spams or
- aortic stenosis
What is Printzmetal’s angina?
Vasospastic angina that occurs at rest
Do patients suffering Printzmetal’s angina actually have a coronary lesion?
Yes, 85% of them have a fixed proximal lesion in a coronary artery, however 15% of them just have a spasm.
Patients with Printzmetal’s angina have basic vasoactive disease, so they also see a higher incidence of what 2 other disease states?
- migraine headaches
- Raynaud’s disease
If my patient has a pacemaker or an ICD, what 5 things do I need to know about it?
- the indication for insertion
- the underlying rhythm and rate
- the type of pacer (demand, fixed, radio frequency)
- the chamber paced, the chamber sensed
- has the pacemaker/ defibrillator been interrogated by a qualified member of CIED
Do we need to evaluate the pacer in any way ourselves?
Yes, we should evaluate the effect of a magnet over the pacer.
What does a magnet do to a pacer when it is placed over it?
It turns of the sensing and puts the pacer into an automatic asynchronous mode.
Why would we want the pacer to be in an asynchronous mode during surgery?
We don’t want any artifical movement or activity to be sensed by the pacer as a patient’s intrinsic beat. With all of the electrical equipment in the room, it would be easy for activity to be sensed that does not belong to the patient. In response to this false sensing, a beat would not be generated by the pacer as it should be.
Do I need to do anything special to an AICD during surgery?
Yes, put a magnet over it to turn of tachyarrhythmia detection. Instead of using the AICD, we will place pacer pads on the patient so we can control the shocks.
Does an AICD or pacemaker need to be evaluated by EP before surgery?
An AICD/pacer should be evaluated within 3-6 months of surgery
How do we turn of an AICD?
EP has to do it. Then they can come back and turn it on again after surgery.
Why would a pacer not fire during surgery?
Electromagnetic interference can occur with electrocautery which can inhibit pacemaker firing
Why should you have a magnet immediately available for all patients with pacemakers?
Most pacemakers can be converted to a fixed rate (asynchronous mode) by placing a magnet over the pacemaker box in the chest.
Are there any special requirements when placing grounding pads on a patient with a pacemaker?
Place grounding pads as far away from the pulse generator and leads as possible.
What is the difference between bipolar electrocautery and monopolar electrocautery?
In bipolar electrocautery, the electricity travels back and forth like down the legs of tweezers. In monopolar electrocautery, the electricty travels straight through a straight line like a pencil. When it comes out it needs to find the grounding pads
Which type of electrocautery should be used in patients with pacemakers?
bipolar
In patients with a pacemaker, we should always monitor:
some type of blood flow, either from an aline or a pulse ox.
What should you always have available in paced patients, in case of pacemaker failure?
You should have an external pacer available
In the overall appearance portion of the cardiac assessment of the physical examination, what are some physical things you could be looking at?
- obesity
- shortness of breath
- sternal incision
- pacemaker box
When auscultating the heart, what are you listening for?
Heart sounds, murmurs
What are some things in the patient’s neck that would indicate cardiac disease?
- the presence of JVD
- carotid bruits
Where would you listen to hear the best aortic valve sounds when auscultating the heart?
The 2nd intercostal space at the right sternal border.
Where would you listen to hear the best pulmonic valve sounds when auscultating the heart?
2nd intercostal space, left sternal border
Which ausculation spot is at the 3rd intercostal space at the left sternal border?
Erb’s point
Where would you listen to hear the best tricuspid valve sounds when ausculatating the heart?
4th or 5th intercostal space, left sternal border
Where would you hear the best mitral valve sounds when auscultating the heart?
5th intercostal space, left midclavicular line
When performing the cardiac assessment, what are some signs you see from the lungs?
- lung sounds (rales)
- shortness of breath
- effort of breathing
When performing the cardiac assessment, should you measure the patient’s BP?
Yes, in both arms, and maybe even do orthostatics.
When performing the cardiac assesment what are 4 things you may be looking for in the peripheral extremities?
- clubbing (mostly in children)
- skin color
- peripheral edema
- pulses
In the pre-op assessment, what number values are considered hypertension?
140/90
Does HTN put the patient at a greater risk for cardiac mortality in the OR?
Yes, it is a major risk factor for cardiac mortality
HTN increases the risk for : (list 5)
- stroke
- CHF
- MI
- progression to renal insufficiency
- malignant htn
At what BP would do you want to treat HTN?
SBP>160, DBP>90
What type of drug is a good choice for pre-op treatment of patients with HTN?
beta blockers, they have protective CV benefit.
What should you do if a patient has long-standing severe HTN or uncontrolled HTN?
you may need to delay surgery to control BP
What are 2 tests you should order on a patient with severe HTN?
- EKG
- serum BUN/Cr (they may be suffering from renal failure)
If the hypertensive patient is on diuretics, what additional test might you order. In addition to EKG and Bun/Cr?
Chem 7, check lytes
Should a hypertensive patient stop their meds before surgery?
No, they should continue their meds
What is one differential diagnosis you should consider if your patient is hypertensive preoperatively?
They may just have anxiety. Try an anxiolytic
What do the ACC/ AHA guidelines say about continuing your beta blocker before surgery?
They say to stay on it. Discontinuing it may increase perioperative CV morbidity
Which other group of patients (not those with HTN) does the ACC/AHA recommend get a dose of beta blocker during surgery?
high risk patients having vascular surgery
What does heart failure do to contractility of the heart?
It causes abnormal contractility and relaxation of the heart muscle.
Heart failure can be caused by what 2 other disease states?
- HTN
- IHD (ischemic heart disease)
If any of these 9 symptoms occur, you should suspect some element of heart failure.
- orthopnea
- nocturnal coughing
- fatigue
- peripheral edema
- 3rd/ 4th heart sound
- resting tachycardia
- rales
- JVD
- ascites
What EKG finding should make you suspicous of heart failure?
LVH
Does decompensated HF/LV function place a patient at high risk for surgery?
Yes. In these pateints elective surgery should be postponed.
In patients with HF, what tests should you consider ordering preoperatively?
- EKG
- Chem 7 with BUN/Cr
- BNP
- CXR (if suspected pulmonary edema)
- Echo (as an objective measure of LVEF)
Do you always need to get an echo on patients with HF?
No, most patients with HF are followed by their cardiologists regularly and know a recent EF.
What is BNP and what is the normal value?
Brain naturetic peptide and it should be < 100 pg/mL
Which of these drugs that the heart failure patient is taking should be d/c’d prior to surgery?
- beta blockers
- hydralazine
- nitrates
- digoxin
- ACEIs
- ARBS
- diuretics
- anticoagulants
None. the patient should stay on all of these meds, even the anticoagulant if possible.
If a patient says they have a heart valve problem what should your next action be?
to identify the type of valvular lesion
What 2 things should you evaluate in patients with valve disease?
- clinical symptoms
- testing data
Which valve disorder causes the greatest perioperative risk?
aortic stenosis
Severe aortic stenosis poses the greatest risk if the valve area is:
< 1cm2
If a patient with aortic stenosis is symptomatic what should you do?
Postpone surgery
What do we know about diastolic murmurs?
They are ALWAYS pathologic and require further evaluation
What two things do you need to consider if your patient has a prosthetic heart valve?
- If they have a pig valve, there is no anticoagulation, but if they have a metal prosthetic valve they will be on lifelong anticoagulation. We may need to bridge anticoagulation during surgery, i.e. switch to heparin gtt.
- They many need SBE antibiotic prophylaxis (Subacute bacterial endocarditis)
As far as arrhythmias are concerned, what 2 types of arrhythmias are associated with the highest periperative cardiac risk?
- Ventricular arrhythmias
- SVT
If your patient has a L. BBB on EKG, what is your next thought?
LBBB is highly associated with CAD. If it’s new LBBB, stress testing or consultation is needed.
Which 5 EKG rhythms would casue you to postpone surgery?
- uncontrolled a-fib
- VTach
- new onset a-fib
- symptomatic bradycardia
- high degree or 3rd degree HB
Name 7 medication types that cardiac patients are typically on.
- Beta blockers
- Statins
- ACE inhibitors/ ARBs
- Ca++ Channel blockers
- Nitro (for angina)
- Diuretics
- Antiarrhythmics
When should you D/C an antiplatelet aggregator like ASA or Plavix?
D/C 7-10 days before surgery
When should you D/C an anticoagulant like Coumadin?
D/C 3-5 days before surgery. INR should be <1.5 for surgery
When should you D/C LMWH?
12 hours before surgery
When should you D/C fibrinolytics like TPA, Urokinase, and Streptokinase?
If patients are on these, it is usually a critical situation, these drugs typically cannot be d/c’d
Chest X-rays are not specific for ischemic heart disease, but can tell you which 3 things:
- cardiomegaly
- pulmonary vascular congestion/ pulmonary edema (CHF)
- Pleural effusions
You should order a CXR in which 3 types of patients? (but really only indicated if the pt. is symptomatic)
- > 75 years old
- Hx of CHF
- symptomatic CV disease
What 5 general things can you gather from the 12 lead EKG?
- Acute MI
- Prior MI
- Rhythm or conduction disturbances
- Cardiomegaly or ventricular hypertrophy
- Other EKG abnormalities, electrolyte imbalances
What are the 5 principal indicators of acute ischemia on EKG?
- ST segment elevation >1mm
- T wave inversion
- Development of Q waves
- ST segment depression; flat or downslope of >1mm
- Peaked T waves
Where are Leads I, II, and III located?
Where are leadsd aVL, aVF and aVR located?
Which leads are the inferior leads?
II, III, and aVF
Changes in the inferior leads indicate problems with which coronary artery?
RCA
Which leads are the posterior leads?
V1, V2, and V3
Changes in the posterior leads indicate problems in which coronary artery?
RCA
Which leads are the anteroseptal leads?
V1, V2, V3, and V4
Changes in the anteroseptal leads indicate problems with which coronary artery?
LAD
Which leads are the lateral leads?
I, aVL, V5 and V6
Changes in the lateral leads indicate problems in which artery?
Circumflex branch of LCA
If your patient has 1 or more clinical risk factor and is having vascular surgery should you order an EKG?
Yes
If your patient has known CAD, PVD, or CVD (cardiovascular disease) and is having intermediate or high risk surgery, should you order an EKG?
Yes
If a patient has no clinical risk factors, but is having vascular surgery, should you order an EKG?
Maybe
If your patient has at least 1 clinical risk factor and is having intermediate or high risk surgery, should you order an EKG?
Maybe
If your patient is asymptomatic and having a low risk surgery do you need to order an EKG?
No, but ACC/AHA recommends an EKG within 30 days of surgery
Name 5 labs you might order to ascertain general medical condition related to comorbidities?
- K+
- Bun/Cr
- ABG
- Hgb/ Hct
- PT/Inr
What does a treadmill stress test do?
Stimulates SNS activity by increasing BP and HR and therefore increasing myocardial O2 demand and consumption with exercise.
What are you looking for in the cardiac stress test?
Ischemic changes on EKG
Treadmill stress testing is interpreted based on which 5 criteria?
- duration of exercise the pt. can perform
- max HR achieved
- time of onset of ST depression
- degree of ST depression
- time until resolution of the ST segment
What are the EKG changes that would yield a positive treadmill stress test, predictive of CAD? (list 4)
- ST segment depression >2.5mm
- ST depression occurs early in the test (first 3 minutes)
- Serious ventricular arrhythmias
- Prolonged duration of ST depression in the post recovery period
What are some non-EKG responses to a treadmill stress test that would be predictive of CAD? (list 2)
- if increase in BP and HR occurs at time of ST depression
- if hypotension occurs
How serious is hypotension during a treadmill stress test?
Hypotension is an ominous sign
Why would you use pharmacological stress testing?
in patients who are unable to exercise
What substance in injected during pharmacological stress testing that permits imaging of the blood within the heart and lungs?
Thallium ( a gamma emitting radiopharmaceutical)
What 3 drugs are given as vasodilators during pharmacologic stress testing to vasodilate and increase coronary blood flow?
- Dobutamine
- Adenosine
- Dipyridamole
In pharmacological stress testing, an area of decreased perfusion (cold spot) only during stress (reperfuse at rest) would indicate what?
ischemia
In pharmacological stress testing, an area of constant perfusion defect is indicative of what?
old MI
Areas of redistribution defects are at highest risk of:
ischemia and infarction
In pharmacologic stress testing we are looking for signs of ischemia by__________ and not by __________.
perfusion imaging and not by EKG changes
In what 2 conditons would you want to order cardiac stress testing?
- Active cardiac condition
- 3 or more clinical risk factors and poor functional capacity, having vascular surgery
Which active cardiac conditions need to be stress tested before surgery?
- unstable coronary syndromes
- unstable or severe angina
- recent MI
- decompensated HF
- significant arrhythmias
- severe valvular disease
In which 2 groups of patients should you maybe consider stress testing before surgery?
- if they have at least 1-2 clincial risk factors and poor functional capacity, having intermediate risk surgery, if the results will change how you manage them in the OR
- at least 1-2 clinical risk factors and good functional capacity but having vascular surgery.
What 7 things will an echocardiogram tell you?
- measure the dimensions of the cardiac chambers and vessels and thickness of the myocardium
- global ventricular systolic function (EF)
- regional wall motion abnormalities
- valve structure and motion
- can detect blood flow and measure gradients
- chamber enlargement
- detection of pericardial fluid
How does a stress echo work?
We give dobutamine or dopamine to make the heart work harder. looking at how the heart works under stress will let you know how the heart will respond to the stress of surgery.
What is the stress echo looking for specifically?
regional wall motion abnormalities under stress
An abnormal stress echo, during infusion of dobutamine, consists of:
- new regional wall motion abnormalities
- worsening of existing regional wall motion abnormalities
Are stress echos a worthwhile test?
Yes, they are highly predictive of adverse cardiac events
A patient with what 3 conditons would trigger us to order a pre-op echo?
- current or prior heart failure (with worsening dyspnea or other change in clinical status)
- dyspnea of unknown origin
- questionable aortic stenosis
Which test provides the best method for defining coronary anatomy?
coronary angiography
What 9 things can be gathered from coronary angiography?
- diffuseness of obstructive disease
- adequacy of any previous angioplasties or bypass grafts
- coronary artery spasms
- LV pressures, volumes and EF
- LV dysfunction (akinesis, dyskinesis, low EF, high LVEDP,
- Valvular lumen area and pressure gradients across valves
- Pressure gradients across valves and shunts as well as degree of regurgitation
- PA pressures
- CO and SVR
What is the gold standard test for patients undergoing cardiac surgery?
coronary angiography
Patients with which 5 conditions should have a pre-op cath?
- Stable angina with L. main CAD
- Stable angina with 3 vessel disease
- Stable angina in 2 vessel disease with signficant proximal LAD lesion and EF <50% or demonstratable ischemia on non-invasive stress testing
- high risk unstable angina or NSTEMI
- acute STEMI
If a patient has had a PCI or sugery, is it important for them to stay on the prescribed antiocoagulant therapy?
Yes, in fact elective surgery should be postponed so patients can stay on their anticoagulants for the prescribed high risk window of reocclusion
If a patient has had a balloon angioplasty, how long do they need to wait before having surgery?
>14 days
If a patient has had a bare metal stent placed, how long do they have to wait before having surgery?
>30-45 days
If a patient has had a drug eluding stent placed, how long do they have to wait before having surgery?
> 365 days
Is MRI useful in cardiac assessment?
yes, it used to assess function and viability of the myocardium
An MRI with gadolinium is highly sensitive in detecting:
infarctions
What sorts of intracardiac things are MRIs good at detecting?
- clots
- masses
- intracardiac tissue characterization
What is subacute bacterial endocarditis?
Infection in the muscle of the heart
When were the guidelines for SBE prophylaxis last updated?
2006
Name 6 high risk cardiac conditions that should receive SBE prophylaxis.
- prosthetic heart valves
- Hx of infective endocarditis
- Unrepaired cyanotic congental heart disease
- Repaired congenital heart defect with prosthetic material or device, during 1st 6 months after the procedure
- Reparied congental heart disease with residual defects
- Cardiac transplant recipients with cardiac valvular disease
For patients with high cardiac risk, antibiotic prophylaxis is recommended for which 2 procedures?
- All dental procedures that involve manipulation of gingival tissue, perforation of oral mucosa, or the periapical region of teeth
- Invasive respiratory tract procedures with incision or biopsy of respiratory mucosa
Name 2 types of procedures that SBE prophlyaxis is no longer recommended for.
- genitourinary
- Gi tract surgery
When is SBE antimicrobial prophylaxis given?
30-60 minutes before the procedure
Name the 4 standard drugs and doses you could give for SBE prophylaxis.
- Ampicillin 2gm IV
- Cefazolin 1gm IV
- Ceftriaxone 1gm IV
- Clindamycin 600mg IV (if PCN allergic)
