Download Arrhythmia Monitoring Arrhythmia Monitoring

Dynamics of Critical Care 2008
CACCN, Montreal, Canada
Pulling it all Together
Case Studies in
ECG Monitoring, Part 1
Barbara J. Drew, PhD, RN, FAAN
Professor of Medicine & Nursing
University of California, San Francisco
UCSF
UCSF
When attaching a cardiac monitor, assess
patient's need for 3 potential goals of monitoring
Arrhythmia
Ischemia?
(ST-segment monitoring)
QT interval?
AHA Practice Standards for ECG Monitoring in Hospital Settings Circulation 2004
Practice Standards for ECG Monitoring
Recommendations:
1. Monitor at least 2 leads
2. Leads V1 & II
Arrhythmia
Monitoring
V1
1. Select the best ECG leads
for arrhythmia diagnosis
II
UCSF
Advantages of Lead II
Advantage of Lead V1
Provides a tall R wave in most people
(accurate heart rate detection, less noisy signal)
Diagnosis of rhythms with a
wide QRS complex (e.g., BBB)
Shows clear-cut saw-tooth atrial waves
in atrial flutter
Distinguish VT from SVT with
aberrant conduction
UCSF
Advantages of V1 for arrhythmia monitoring
V1 is the best Lead to diagnose
Right Bundle Branch Block (RBBB)
Occlusion of the LAD with acute anterior MI
may cause bundle branch & fascicular block
Left Main Artery
A-V Node
Bundle of His
Right Coronary
Artery (RCA)
Left Anterior
Descending (LAD)
LBB
Left Posterior
Fascicle
R′
Posterior
Descending
r
Left Anterior
Fascicle
RBB
s
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UCSF
Advantages of V1 for arrhythmia monitoring
Advantages of V1 for arrhythmia monitoring
Patient in CCU with acute anterior MI
Lead V1 10:00 am
Patient A has VT (dx from EP study)
V1
Lead V1 1:00 pm
II
Lead V1 4:00 pm (Temporary transvenous pacer was being inserted)
If lead II had been monitored instead of V1, there would have
been no warning prior to CHB and ventricular standstill
Taller Left Peak Pattern = VT
Drew & Scheinman, PACE 1995;18:2194
UCSF
Advantages of V1 for arrhythmia monitoring
Patient B has SVT with aberrant
conduction (dx from EP study)
Advantages of V1 for arrhythmia monitoring
Patient C has VT (dx from EP study)
notch on S
downstroke
V1
V1
rsR′ or rR′ pattern = SVT
= VT
II
II
QRS onset to
S nadir interval
>.06 sec
Drew & Scheinman, PACE 1995;18:2194
UCSF
UCSF
Drew & Scheinman, PACE 1995;18:2194
Advantages of V1 for arrhythmia monitoring
LA
V1 requires
5 electrodes
Patient D has SVT with aberrant
conduction (dx from EP study)
V1
RA
C
II
ALL of these criteria in both
V1 & V2 plus no Q in V6= SVT
no R ≥ .04 sec
no notch on S downstroke
QRS onset to S nadir < .06 sec
RL
Drew & Scheinman, PACE 1995;18:2194
UCSF
LL
UCSF
Practice Standards for ECG Monitoring
V1
Arrhythmia
Monitoring
II
V1
2. Place electrodes in their
correct anatomic site
II
UCSF
From Anita Christiansen, RN, MS, CCRN, Good Samaritan Hospital, San Jose
How accurate is Lead placement?
Random survey of RN’s in USA
What were
the errors?
300
250
200
# RNs
150
electrodes
77%
100
50
23%
0
Correct
Incorrect
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Practice Standards for ECG Monitoring
Recording an AEG from epicardial pacemaker wires
Drew BJ, et al. Heart & Lung 1991;20:597-609.
Arrhythmia
Monitoring
3. Print out an AEG whenever a
post-op. cardiac surgery
patient develops a tachycardia
of unknown mechanism
UCSF
Ventricular
Wires
Atrial Wires
Kern LS, et al. AACN Adv Crit Care 2007;18:294-304
Wear rubber gloves to protect
patient from microshocks
Wrap atrial wire
in chest lead-wire
Use chest (V)
lead-wire
(brown)
Either atrial
wire may be
used
Printing an AEG
Sample AEG
1. Set up printer to print
simultaneous limb & “V”
lead
AEG has larger
P waves than
monitor leads
2. Print a long strip of the
rhythm. Re-label the “V”
lead as “AEG”
From Marion McRae, Acute Care Nurse Practitioner, Cardiac Surgery, Toronto General Hospital
UCSF
What is the rhythm?
Lead II
UCSF
What is the rhythm?
70 y/o post-cardiac surgery patient
P
Heart rate 146 bpm
(220 - 70 = 150)
Atrial fibrillation
AEG
Sinus tachycardia
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From Marion McRae, Acute Care Nurse Practitioner, Cardiac Surgery, Toronto General Hospital
Practice Standards for ECG Monitoring
Top priority for ST
segment monitoring
Ischemia
(ST- segment)
Monitoring
1. Present to the ED with chest pain
2. Admitted to the hospital with acute
coronary syndrome (unstable angina
or acute MI)
3. Post PCI with complications in the
cath lab (vessel dissection) or a
suboptimal angiographic result
1. Identify patients who need
ST-segment monitoring
UCSF
AHA Practice Standards for ECG Monitoring in Hospital Settings Circulation 2004
ST alarm is an earlier sign of abrupt
reocclusion following PCI than chest pain
Post PTCA of
RCA & dig Rx
10:00 am
ST monitor alarm
10:30 am
Best ECG leads to
detect occlusion
of the 3 main
coronary arteries
Chest pain
10:45 am
I
LCX
V3
II
III
RCA
III, aVF, II
aVR
aVL
LAD
V2, V3
aVF
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Drew BJ et al. J Electrocardiol 1998;30:157-165
Recommended leads for ST-segment
monitoring: II or III + V3
Aldrich HR et al. Am J Cardiol 1987;59:20
Bush HS et al Am Heart J 1991;121:1591
Drew BJ & Tisdale LA. Am J Crit Care 1993;2:280
UCSF
IMMEDIATE AIM Study
Initial ECG in 40 y/o male presenting to the ED with
increasing chest pain episodes; Troponins negative
5:00 pm
LA
RA
LA
LL
C
V3
C
RL
C
RA
RL
LL
IMMEDIATE AIM Study
6 days following hospital discharge, patient was
brought to ED after witnessed collapse on golf course
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IMMEDIATE AIM Study
Rapidly developed profound shock, could
not be resuscitated, and died
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Practice Standards for ECG Monitoring
R
QT Interval
Monitoring
Certain drugs prolong QT interval &
put patient at risk for developing TdP
T
P
1. Measure QT intervals to prevent
cardiac arrest due to druginduced Torsades de Pointes
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S
How long it takes the ventricles to repolarize
Generic Name
QT prolonging
drugs
Torsades de Pointes
www.torsades.org
Risk Factors:
Rapid administration (IV route)
Renal / hepatic dysfunction
Hypokalemia, hypomagnesemia
QT=0.64 sec
(640 ms)
Bradyarrhythmias with long
pauses (sinus arrest, CHB)
Female gender (70% of druginduced TdP cases are women)
Advanced age
Upper limits of normal = 460 ms, males
470 ms, females
Heart disease (LVH, HF)
UCSF
Things to know about QT
measurement
QT interval gets shorter with increasing
HR and longer with decreasing HR
QT must be corrected for heart rate
(QTC)
QT
interval
Q
Poly-pharmacy
Brand Name(s)
Clinical Use
Amiodarone
Cordarone, Pacerone
Anti-arrhythmic
Arsenic trioxide
Trisenox
Cancer/Leukemia
Bepridil
Vascor
Anti-anginal
Chlorpromazine
Thorazine
Anti-psychotic
Cisapride
Propulsid
GI stimulant
Clarithromycin
Biaxin
Antibiotic
Disopyramide
Norpace
Anti-arrhythmic
Dofetilide
Tikosyn
Anti-arrhythmic
Domperidone
Motilium
Anti-emetic
Droperidol
Inapsine
Sedative; Anti-emetic
Erythromycin
E.E.S., Erythrocin
Antibiotic
Halofantrine
Halfan
Anti-malarial
Haloperidol
Haldol
Anti-psychotic
Ibutilide
Corvert
Anti-arrhythmic
Levomethadyl
Orlaam
Opiate agonist
Mesoridazine
Serentil
Anti-psychotic
Methadone
Dolophine, Methadose
Opiate agonist
Pentamidine
NebuPent, Pentam
Anti-infective, Pneumocystitis
Pimozide
Orap
Anti-psychotic
Procainamide
Pronestyl, Procan
Anti-arrhythmic
Quinidine
Quinaglute, Cardioquin
Anti-arrhythmic
Sotalol
Betapace
Anti-arrhythmic
Sparfloxacin
Zagam
Antibiotic
Thioridazine
Mellaril
Anti-psychotic
Case Example
78 y/o woman started on IV erythromycin
Baseline QT interval prior to start of drug = 0.44 sec
(440 ms)
HR = 60, QTC = 440 ms
QTC tells you what the QT interval would
be if the HR were 60 bpm
QTC >500 ms is dangerous; consider
stopping the drug to prevent TdP
UCSF
On the next shift, her QT interval on the drug = 440 ms
HR = 80, QTC > 500 ms
What else do we need to know?
Incidence of drug-induced events
TdP
QTc > 500 ms
Distinguishing TdP from
ventricular fibrillation
Rare
Uncommon
64 y/o male on no medications presents to the emergency dept.
with symptoms of acute MI
60 bpm
QT Prolongation
Common
Heist & Ruskin, Heart Rhythm 2005;S1-S8.
QT=440 ms
UCSF
Methods to monitor QTC in
hospital units
UCSF
Sequence of ECG events in TdP
1. Standard "diagnostic" 12-lead ECG
Typically, only one/day
↑ QTC >500 ms after start of drug
2. Manually with calipers; apply correction formula
Polymorphic PVC’s & couplets
Time-consuming; inter-rater differences
T wave alternans may/may not occur
3. E-calipers from the Central Monitoring Station
Still time-consuming; inter-rater differences
Non-sustained TdP after pause
4. Continuous QT monitoring
Measures QTc every 5 mins; no inter-rater
differences; alarm alerts for ↑QTc from baseline
>60 ms or QTc >500 ms
Sustained TdP and cardiac arrest
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UCSF
One hour earlier…
Elderly woman in the ICU being treated with IV erythromycin
PVC’s & couplets
Lead V1
Lead V1
Lead II
Lead II
T wave alternans
UCSF
Drug should have been stopped
here to prevent TdP !!!