ECGs (again!)
Mary L. Dohrmann, MD
Professor of Clinical Medicine
Division of Cardiovascular Medicine
ECG Interpretation
Practice!
Practice!
Practice!
http://ecg.bidmc.harvard.edu/maven/maven
main.asp
What is ECG Wave-Maven?
Proficiency in electrocardiogram (ECG) interpretation is
an essential skill for medical students, housestaff, and
clinicians. However, medical school and postgraduate
resources to develop and upgrade the necessary high
level of "ECG literacy" are severely limited. Further,
current textbook and classroom instructional materials
do not adequately integrate ECG interpretation into
specific contexts where waveform findings must be
correlated with other clinical data. We have begun to
address the limitations in traditional approaches to ECG
pedagogy by creating the infrastructure for a unique
web-based tutorial.
ECG Interpretation
Observation
Conclusion
Clinical context/significance
Rhythm
Sinus
Morphology
Not sinus
Supravent.
Ventricular
Morphology Hierarchy
WPW > LBBB > LVH > MI
The Normal ECG
The Normal ECG
Sinus rhythm (P before @ QRS)
Rate 50 – 100 bpm
Axis +90o to –30o
Intervals: PR .12-.21 sec
QRS <.10 sec
QTc <.46 sec (observed QT⁄ √ (RR) interval)
51 y/o male with chest pain
100% occlusion of a diagonal
(also had 3 vessel disease, normal LVEF)
29 y/o with chest pain
Diffuse ST elevation c/w pericarditis,
?PR segment depression
47 y/o male with chest pain
Acute inferior MI – culprit vessel RCA
41 y/o male with severe SOB
Extensive anterior/anterolateral MI
54 y/o male with exertional chest pain
AMI, indeterminate age; RBBB and left axis
60 y/o comatose s/p MVA
Low voltage
Simple cifferential of low voltage: air, fat, fluid, no muscle
60 y/o with chest pain
LVH with LAD, ST-T abn, & LAE
In patient with angina and LVH, always think of aortic stenosis and
hypertrophic cardiomyopathy in differential diagnosis
40 y/o with chest pain & palpitations
short PR/delta wave c/w preexcitation
(WPW) – note pseudo-Qs inferiorly
70 y/o with exertional chest pain
LBBB
If need stress test in this patient, use pharmacologic stress with adenosine combined
with imaging modality (sestamibi or cardiac MRI)