Post on 01-Apr-2018
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Identification of Myocardial Identification of Myocardial
Ischemia and Infarction in the Ischemia and Infarction in the
Perioperative PeriodPerioperative Period
Peggy Contrera CRNA, MSNPeggy Contrera CRNA, MSN22
Scary StatsScary Stats
� Ischemic heart disease is the number one cause of mortality in the United States
� Of the 230 million adults world wide have non-cardiac surgery – 30 day mortality is 2% overall and > 5% for high risk patients– 500,000 to 900,000 nonfatal perioperative MI, nonfatal cardiac arrest and cardiac death.
� Patients experiencing an MI after non-cardiac surgery have an in house mortality rate of 15%-25%
� Patients suffering a perioperative MI have an increased risk of cardiovascular death and nonfatal MI for 6 months following surgery.
� Perioperative cardiac complications extend the average hospital stay by 11 days and add at least $10,000 onto the hospitalization costs.
Circulation 2009, 119:2936-2944
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Perioperative Myocardial IschemiaPerioperative Myocardial Ischemia
�� Study of Perioperative Myocardial IschemiaStudy of Perioperative Myocardial Ischemia–– ST changes in 20% ST changes in 20% preoppreop and 41% post opand 41% post op
–– Post op ischemia Post op ischemia ↑↑ 9x risk of in hospital morbid event9x risk of in hospital morbid event
�� LandesbergLandesberg: ischemia that lasted > 2 hours = 32 x : ischemia that lasted > 2 hours = 32 x ↑↑ morbid cardiac events morbid cardiac events
�� Postop MI is preceded by long periods of ischemia Postop MI is preceded by long periods of ischemia
�� ↑↑ ## of Predictors = of Predictors = ↑↑ Risk (22% w/ 0 vs. 77% w/ 4)Risk (22% w/ 0 vs. 77% w/ 4)�� PeriopPeriop MI = MI =
–– 20 20 -- 30% 30% ↑↑ hospital mortality + poor prognosis even after hospital mortality + poor prognosis even after dischargedischarge
–– 9 fold 9 fold ↑↑ in hospital morbid eventsin hospital morbid events
–– $10 $10 -- 20 K additional hospital expenses 20 K additional hospital expenses
JACC 2001, 37:1839-184344
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�� The results show that fewer than half the The results show that fewer than half the
anesthesiology residents nationwide correctly anesthesiology residents nationwide correctly
demonstrate the approach considered standard of demonstrate the approach considered standard of care for preoperative cardiac evaluationcare for preoperative cardiac evaluation
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�� Multiple studies show that physicians and nurses are not Multiple studies show that physicians and nurses are not taught to properly interpret taught to properly interpret ECGECG’’ss
�� Even when they are taught, unless the skill is utilized on a Even when they are taught, unless the skill is utilized on a regular basis, most of the information is forgottenregular basis, most of the information is forgotten
�� Active practitioners tend to be able to identify signs of Active practitioners tend to be able to identify signs of ischemia even if not formally taught to do soischemia even if not formally taught to do so
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Objectives for TodayObjectives for Today
�� Understand the basis for and detail the Understand the basis for and detail the five steps in the 2007/2009 ACC/AHA five steps in the 2007/2009 ACC/AHA guidelines on perioperative cardiac guidelines on perioperative cardiac evaluation.evaluation.
�� Discuss current terminology and criteria Discuss current terminology and criteria that is used to describe various levels of that is used to describe various levels of heart function and myocardial ischemia.heart function and myocardial ischemia.
�� Detail the evidenced based strategies that Detail the evidenced based strategies that minimizes risk of perioperative ischemia minimizes risk of perioperative ischemia and infarction.and infarction.
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Determining: Determining:
Who is at risk and how highWho is at risk and how high
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Copyright ©2009 American College of Cardiology Foundation. Restrictions may apply.
American College of Cardiology Foundation, et al. J Am Coll Cardiol 2009;54:e13-e118
Cardiac Evaluation and Care Algorithm for Noncardiac Surgery Based on Active Clinical Conditions, Known Cardiovascular Disease, or Cardiac Risk for Patients 50 Years of Age
or Greater
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11�������� Emergency?Emergency?
J Am Coll Cardiol, 2009; 54:2102-2128
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22�������� Active Cardiac Condition?Active Cardiac Condition?
J Am Coll Cardiol, 2009; 54:2102-2128
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Evaluate and Treat Active Evaluate and Treat Active
Cardiac Conditions Cardiac Conditions �� Major predictors Major predictors �������� require intensive management and may lead to require intensive management and may lead to
delay in or cancellation of the operative procedure unless emergdelay in or cancellation of the operative procedure unless emergentent
�� Unstable Coronary SyndromesUnstable Coronary Syndromes–– Unstable anginaUnstable angina
–– Severe anginaSevere angina
–– Recent MIRecent MI
�� Decompensated Heart Failure (NYHA class IV)Decompensated Heart Failure (NYHA class IV)
�� Significant arrhythmiaSignificant arrhythmia–– MobitzMobitz IIII
–– 33rdrd degree or CHBdegree or CHB
–– SVT or ASVT or A--fib with rate > 100fib with rate > 100
–– Symptomatic ventricular arrhythmias or Symptomatic ventricular arrhythmias or bradycardiabradycardia
–– New onset VTNew onset VT
�� Severe valvular diseaseSevere valvular disease–– ASAS
–– MSMS J Am Coll Cardiol, 2009; 54:2102-2128
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33�������� Determine Risk of SurgeryDetermine Risk of Surgery
J Am Coll Cardiol, 2009; 54:2102-2128
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ACC/AHA guideline summary: ACC/AHA guideline summary:
Cardiac risk stratification for noncardiac surgical Cardiac risk stratification for noncardiac surgical
proceduresprocedures
�� High risk >5%High risk >5%–– Aortic and other major vascular surgeryAortic and other major vascular surgery–– Peripheral artery surgeryPeripheral artery surgery
�� Intermediate risk (1Intermediate risk (1--5%)5%)–– Carotid Carotid endarterectomyendarterectomy
–– Head and neck surgeryHead and neck surgery–– IntraperitonealIntraperitoneal
–– intrathoracicintrathoracic surgerysurgery
–– Orthopedic surgeryOrthopedic surgery–– Prostate surgeryProstate surgery
�� Low risk <1% Low risk <1% �������� straight to ORstraight to OR–– Ambulatory surgeryAmbulatory surgery
–– EndoscopicEndoscopic proceduresprocedures–– Superficial procedureSuperficial procedure
–– Cataract surgeryCataract surgery–– Breast surgeryBreast surgery
J Am Coll Cardiol, 2009; 54:2102-2128
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44�������� Level of ActivityLevel of Activity
� “in highly functional asymptomatic patients management will rarely be changed on the basis of results of any further cardiovascular testing...it is therefore appropriate to proceed with the planned surgery.”
J Am Coll Cardiol, 2009; 54:2102-2128
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Based on Functional Based on Functional
CapacityCapacity
J Am Coll Cardiol, 2009; 54:2102-21281818
Running rapidly for moderate to long distances12
Skiing cross country, playing full-court basketball11
Swimming quickly, running or jogging briskly10
Jumping rope slowly, moderate cycling9
Rapidly climbing stairs, jogging slowly8
Playing singles tennis7
Playing golf, carrying clubs6
Climbing 1 flight of stairs, dancing, bicycling5
Raking leaves, gardening4
Walking 1-2 blocks3
Walking down stairs or in your house, cooking2
Eating, working at a computer, dressing1
Functional Levels of ExerciseMET
4
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55�������� Consider Clinical Risk Consider Clinical Risk
Factors Together with Risk Factors Together with Risk
of Surgeryof Surgery
�� 5a) No risk factors5a) No risk factors�� Proceed with surgeryProceed with surgery
2020
�� These were considered intermediate risk These were considered intermediate risk
factors in the original Goldman cardiac risk factors in the original Goldman cardiac risk
IndexIndex
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Goldman Revised Cardiac Risk Index
�� History of ischemic heart diseaseHistory of ischemic heart disease–– Prior MI (>30 days)Prior MI (>30 days)
–– Positive treadmill testPositive treadmill test
–– Use of nitratesUse of nitrates
–– Current complaint of chest pain (cardiac in origin)Current complaint of chest pain (cardiac in origin)
–– ECG with abnormal Q wavesECG with abnormal Q waves
–– Do not count prior CABG unless one of the other criteria Do not count prior CABG unless one of the other criteria are metare met
�� Compensated or prior CHFCompensated or prior CHF�� History of cerebrovascular diseaseHistory of cerebrovascular disease
–– TIATIA
–– CVACVA
�� Diabetes mellitus requiring insulinDiabetes mellitus requiring insulin�� CreatinineCreatinine >2.0>2.0 mg/mg/dLdL 2222
5b5b��������Consider Noninvasive Testing Consider Noninvasive Testing
(if it will change management) or (if it will change management) or
Surgery with HR ControlSurgery with HR Control�� 11--2 clinical risk factors2 clinical risk factors
–– Intermediate risk surgeryIntermediate risk surgery
–– Vascular surgeryVascular surgery
�� 3 or more risk factors3 or more risk factors–– Intermediate risk surgeryIntermediate risk surgery
–– Vascular surgeryVascular surgery
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PreopPreop ECG?ECG?
�� Class IClass I–– 1 or more clinical risk factor who are undergoing vascular surgi1 or more clinical risk factor who are undergoing vascular surgical cal proceduresprocedures
–– Known CHF, PVD, or cerebrovascular disease who are undergoing Known CHF, PVD, or cerebrovascular disease who are undergoing intermediateintermediate--risk surgical proceduresrisk surgical procedures
�� Class Class IIaIIa–– Reasonable for vascular surgery even with mo clinical risk factoReasonable for vascular surgery even with mo clinical risk factorsrs
�� Class Class IIbIIb–– Reasonable with 1 or more clinical risk factor who are undergoinReasonable with 1 or more clinical risk factor who are undergoing g intermediateintermediate--risk operative proceduresrisk operative procedures
�� Class IIIClass III–– Preoperative and postoperative resting 12Preoperative and postoperative resting 12--lead lead ECGsECGs are not indicated for are not indicated for asymptomatic persons undergoing lowasymptomatic persons undergoing low--risk surgical proceduresrisk surgical procedures
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Eagle StudyEagle Study
Clinical Variables:Clinical Variables:
�� Q waves on EKGQ waves on EKG
�� Age greater than 70Age greater than 70
�� History of anginaHistory of angina
�� History of History of ventricular ventricular ectopyectopyrequiring treatmentrequiring treatment
�� Diabetes mellitus Diabetes mellitus requiring treatmentrequiring treatment
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2007 Guidelines2007 Guidelines
�� GreenGreen�� No testingNo testing�� OrangeOrange�� Consider testingConsider testing�� RedRed�� Testing recommendedTesting recommended
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�� CABG:CABG:–– L MainL Main
–– 3 vessel3 vessel
–– 2 vessel + LAD or 2 vessel + LAD or ↓↓EFEF–– Pt with DES that needs Pt with DES that needs surgery and must stop surgery and must stop APTAPT
�� PCIPCI–– Unstable anginaUnstable angina
–– STEMI/NSTEMI STEMI/NSTEMI
–– Angina that need Angina that need surgery surgery w/iw/i 12 months12 months
–– High risk ischemia with High risk ischemia with 4 or 5 abnormal 4 or 5 abnormal segments on segments on dobutamine stressdobutamine stress
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Rate of cardiac death and nonfatal myocardial infarction, Rate of cardiac death and nonfatal myocardial infarction,
cardiac arrest or ventricular fibrillation, pulmonary cardiac arrest or ventricular fibrillation, pulmonary
edema, and complete heart block according to the edema, and complete heart block according to the
number of predictors and the nonuse or use of beta number of predictors and the nonuse or use of beta
blockersblockers
�� No risk factors No risk factors -- 0.4 to 1.0 % 0.4 to 1.0 % vsvs <1 % <1 %
with beta blockerswith beta blockers
�� One to two risk factors One to two risk factors -- 2.2 to 6.6 % 2.2 to 6.6 %
vsvs 0.8 to 1.6 % with beta blockers0.8 to 1.6 % with beta blockers
�� Three or more risk factors Three or more risk factors -- >9 % >9 % vsvs
>3 % with beta blockers>3 % with beta blockers
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BetaBeta--BlockersBlockers
�� Beta blockers should be continued in patients Beta blockers should be continued in patients undergoing surgery who are receiving beta blockers undergoing surgery who are receiving beta blockers for treatmentfor treatment
�� Beta blockers titrated to heart rate and blood Beta blockers titrated to heart rate and blood pressure pressure –– Recommended for high risk patients undergoing vascular Recommended for high risk patients undergoing vascular surgerysurgery
–– Reasonable for intermediate (> 1 clinical risk factor) Reasonable for intermediate (> 1 clinical risk factor) patients undergoing vascular surgerypatients undergoing vascular surgery
– Reasonable for high or intermediate risk patients undergoing intermediate-risk surgery
J Am Coll Cardiol, 2009; 54:2102-2812
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Impact of Heart RateImpact of Heart Rate
Mean heart rate in relation to myocardial ischemia assessed by continuouselectrocardiography and troponin T release. Data from Feringa et al. (61). ECG electrocardiogram 3232
BetaBeta--Blockers Blockers
Not RecommendedNot Recommended
�� Routine administration of highRoutine administration of high--dose beta dose beta blockers in the absence of dose titration is blockers in the absence of dose titration is not useful and may be harmful to patients not useful and may be harmful to patients not currently taking beta blockers who are not currently taking beta blockers who are undergoing noncardiac surgeryundergoing noncardiac surgery–– POISE study showedPOISE study showed
�� ↓↓ Rate of MIRate of MI�� ↑↑ rate of CVArate of CVA
�� ↑↑ rate of death rate of death
�� Insufficient evidence in all other situationsInsufficient evidence in all other situations
J Am Coll Cardiol, 2009; 54:2102-2128
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Final RecommendationsFinal Recommendations
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Consensus definition of MIConsensus definition of MI
1. 1. �� Clot (ACS)Clot (ACS)
2. 2. �� Supply/demandSupply/demand
3. 3. �� DysrhythmiaDysrhythmia
4. 4. �� PCIPCI
5. 5. �� CABGCABG
Circulation 2007, 116:2634-2653:
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Perioperative MI (PMI)Perioperative MI (PMI)
�� 2 mechanisms2 mechanisms
–– Type 1 PMI Type 1 PMI
�� AKA ACS (acute coronary syndrome)AKA ACS (acute coronary syndrome)
�� Rupture of plaqueRupture of plaque
�� Coronary thrombosisCoronary thrombosis�� ischemiaischemia�� MIMI
–– Type 2 PMIType 2 PMI
�� CAD and prolonged myocardial oxygen CAD and prolonged myocardial oxygen
supplysupply--demand imbalancedemand imbalance�� ischemiaischemia�� MIMI
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PMIPMI
�� Fatal PMIFatal PMI
–– Majority of patients have 3 vessel or LMT Majority of patients have 3 vessel or LMT
CADCAD�� type 1 PMI may be responsibletype 1 PMI may be responsible
�� NonNon--fatal PMIfatal PMI
–– Majority of patients do not have high Majority of patients do not have high
grade CADgrade CAD�� type 2 PMI may be type 2 PMI may be
responsibleresponsible
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PeriopPeriop Cardiac Events in Cardiac Events in
Major Noncardiac SurgeryMajor Noncardiac Surgery
J Am Coll Cardiol, 2008; 51:1913-24 3838
PMIPMI
�� Peaks in the postoperative periodPeaks in the postoperative period--
Usually within 48 hoursUsually within 48 hours
�� Almost always preceded by ST Almost always preceded by ST
segment depression and tachycardiasegment depression and tachycardia
�� Usually silent and nonUsually silent and non--Q waveQ wave
–– Only 15% have chest painOnly 15% have chest pain
–– Only 53% have any clinical symptomOnly 53% have any clinical symptom
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TriggersTriggers
�� SurgerySurgery�� Stress responseStress response
–– CatecholaminesCatecholamines and cortisol increaseand cortisol increase
–– VasospasmVasospasm
–– Hypertension Hypertension
–– TachycardiaTachycardia
–– Increases sheer stressIncreases sheer stress
–– InflammationInflammation
–– Hypercoagulable stateHypercoagulable state
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The Ultimate Stress TestThe Ultimate Stress Test
�� SurgerySurgery–– Hemodynamic changes associated with the induction of Hemodynamic changes associated with the induction of anesthesia, intubation, surgical stress, pain, volume changes, anesthesia, intubation, surgical stress, pain, volume changes, and blood lossand blood loss
–– The stress response includes increased levels of catecholamine'sThe stress response includes increased levels of catecholamine'sand cortisol. This leads to hypertension and tachycardia. These and cortisol. This leads to hypertension and tachycardia. These not only increase myocardial oxygen demand, they also cause not only increase myocardial oxygen demand, they also cause sheer stress which leads to plaque rupturesheer stress which leads to plaque rupture
–– Inflammatory and hypercoagulable states are also part of the Inflammatory and hypercoagulable states are also part of the perioperative physiologic response. Inflammatory substances perioperative physiologic response. Inflammatory substances play a role in plaque fissuring and the hypercoagulable state play a role in plaque fissuring and the hypercoagulable state could then lead to acute coronary thrombosiscould then lead to acute coronary thrombosis
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Type I MI (ACS)Type I MI (ACS)
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Type II MI (stable CAD)Type II MI (stable CAD)
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Probability of Type 1 and Type Probability of Type 1 and Type
2 MI Based on % of Coronary 2 MI Based on % of Coronary
StenosisStenosis
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Newer TerminologyNewer Terminology
STEMI/NSTEMISTEMI/NSTEMI
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ST DepressionST Depression
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Naming Naming MIMI’’ss
�� QQ--wave MIwave MI–– Previously thought to be Previously thought to be caused by transmural MI caused by transmural MI
–– Actually depends on extent Actually depends on extent and location of damageand location of damage
–– QQ--waves can resolve over waves can resolve over time. Correlates w/ time. Correlates w/ improved survivalimproved survival
–– ““SignificantSignificant”” when .04 sec when .04 sec and/or 1/3 the height of and/or 1/3 the height of the total complexthe total complex
�� Non QNon Q--wave MIwave MI–– Previously thought to be Previously thought to be subendocardial or subendocardial or subepicardialsubepicardial damagedamage
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Newer TerminologyNewer Terminology
�� Stunned MyocardiumStunned Myocardium–– ACSACS
–– Acute vessel occlusion Acute vessel occlusion that subsequently reopens that subsequently reopens and and reperfusesreperfuses
–– Wall motion abnormalitiesWall motion abnormalities
–– Completely reversibleCompletely reversible
�� Hibernating MyocardiumHibernating Myocardium–– Occurs with chronic, Occurs with chronic, stable plaquestable plaque
–– Chronic reduction in flow Chronic reduction in flow –– Function is Function is ↓↓ to match to match flowflow
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Systolic DysfunctionSystolic Dysfunction
�� ↓↓ Inotropy (contraction)Inotropy (contraction)
�� Results in Results in ↑↑ compliance as compliance as the heart dilates to try to the heart dilates to try to maintain COmaintain CO
�� Supply ischemiaSupply ischemia
�� Often expressed as EFOften expressed as EF
–– >50% >50% -- normalnormal
–– 3535--50% 50% -- mild mild (dysfunction)(dysfunction)
–– 2525--35% 35% -- moderatemoderate
–– <25%<25%-- severesevere5050
Diastolic DysfunctionDiastolic Dysfunction
�� ↓↓ Lusitropy Lusitropy (relaxation)(relaxation)
�� Results in Results in ↓↓compliancecompliance
�� Demand ischemiaDemand ischemia
�� EF can be normal, EF can be normal, increased or increased or decreased!decreased!
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CMAJ 2005,173(7):779-788
5252CMAJ 2005,173(7):779-788
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The Ischemia The Ischemia
CascadeCascade
�� Conversion from Conversion from aerobic to anaerobic aerobic to anaerobic metabolismmetabolism
�� Diastolic dysfunctionDiastolic dysfunction
�� Systolic dysfunction Systolic dysfunction (Wall Motion (Wall Motion Abnormalities)Abnormalities)
�� Hemodynamic Hemodynamic abnormalitiesabnormalities
�� ECG changesECG changes
�� AnginaAngina
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Monitoring Modalities Monitoring Modalities
Effectiveness Effectiveness
�� Angina: 70Angina: 70--90% is silent 90% is silent
�� ECG ECG –– 2525--50% of pt w/ CAD will have normal ECG at rest50% of pt w/ CAD will have normal ECG at rest
–– Additional 25% non interpretable d/t baseline defectAdditional 25% non interpretable d/t baseline defect
�� AECGAECG–– Silent ischemia preop is predictive postopSilent ischemia preop is predictive postop–– 3030--120 min. ischemia before MI120 min. ischemia before MI
–– 80% ischemia occurs postop80% ischemia occurs postop
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Monitoring Modalities Monitoring Modalities
EffectivenessEffectiveness�� PACPAC
–– ↑↑ demand demand →→ ↓↓ compliancecompliance–– ↑↑ in V or AC waves on the PAW tracein V or AC waves on the PAW trace–– ↑↑ LVEDP LVEDP →→ ↓↓ CO CO →→ pulmonary edemapulmonary edema–– Not specificNot specific
�� EchoEcho–– Sensitive and specificSensitive and specific
–– Expensive and requires extensive trainingExpensive and requires extensive training
–– 50% of pt with wall motion abnormalities have normal ECG50% of pt with wall motion abnormalities have normal ECG
�� Coronary sinus catheterCoronary sinus catheter
�� Nuclear imaging techniquesNuclear imaging techniques–– NMR/Pet scan (myocardial metabolism)NMR/Pet scan (myocardial metabolism)
–– Thallium scan (blood flow)Thallium scan (blood flow)
–– TcTc scanscan
�� CardiokymographyCardiokymography
�� Numerical indicesNumerical indices5656
Pragmatics of MonitoringPragmatics of Monitoring
Brown Chest Lead (V) should be placed 5th ICS, anterior axillary line!!
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Pragmatics of MonitoringPragmatics of Monitoring
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Pragmatics of MonitoringPragmatics of Monitoring
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Impact of Heart RateImpact of Heart Rate
�� 80% of LV coronary perfusion occurs during 80% of LV coronary perfusion occurs during
diastolediastole
�� CPP = DBP CPP = DBP –– LVEDPLVEDP
�� As HR As HR �������� �������� Diastolic Time Diastolic Time ��������
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�������� HR = HR = �������� Coronary PerfusionCoronary Perfusion
�������� HR = HR = �������� MVOMVO22
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Impact of Heart RateImpact of Heart Rate
Mean heart rate in relation to myocardial ischemia assessed by continuouselectrocardiography and troponin T release. Data from Feringa et al. (61). ECG electrocardiogram
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HR > 70 is HR > 70 is
Predictive of Bad ThingsPredictive of Bad Things
J Am Coll Cardiol 2007;50:823-830
Mean heart rate in relation to myocardial ischemia assessed by
continuouselectrocardiography and troponin T release. Data from Feringa et al. (61). ECG electrocardiogram
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Treatment AlgorithmTreatment Algorithm
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