The Electrocardiogram
Dynamic changes have occurred. The ST-segment depressions in the lateral precordial leads have resolved. A Wellens’ Type A pattern (with biphasic T-waves) is now present in precordial leads V2 and V3, warning of severe occlusion or unstable plaques in the left anterior descending artery. In fact, a STEMI may already be present, given the ST-segment elevation that is present in V2.
Lateral limb leads I and aVL now demonstrate more prominent T-wave inversions.
Clinical Course
The catheterization team was notified, and plans were made for immediate angiography. The troponin continued to trend upward.
A bedside echocardiogram demonstrated severe anterolateral hypokinesis. Heparin, a IIb/IIIa agent and nitroglycerin were administered prior to catheterization. The principal error in this case was the failure to appreciate the flat ST-segment depressions suggestive of regional subendocardial ischemia (unstable angina or non-STEMI) on the first tracing (and the ST-segment elevations in aVR). The other critical error was the failure to repeat the ECG in 15–30 minutes (not two hours later). Perhaps not surprising, given the dynamic ECG changes and the initial ST-segment elevation in lead aVR, his catheterization revealed a 99 percent occlusion of the proximal LAD, 90 percent stenosis of the ostial first obtuse marginal and an 80 percent ulcerative distal RCA stenosis. The patient had successful coronary artery bypass surgery the next day.
References
Einthoven W. Le Telecardiogramme.
Archives Internationale de Physiologie.1906;
4:132–164. Translation by
Dr. Henry Blackburn.Am Heart J.1957; 53:
602–615. Quotation from Willem Einthoven.
Marriott H. J. L.Emergency
electrocardiography. Naples, FL: Trinity Press, 1997.
325
Chapter 8: Critical Cases at 3 A.M.
Index
abdominal pain, 13–35
coronary mimics with, 246–261 abnormal Q-waves, 7–8
accelerated junctional rhythms (junctional tachycardia), 4
ACS.Seeacute coronary syndrome
acute anterior wall myocardial infarction, 88 acute coronary syndrome (ACS), 99, 114–136
acute pericarditis and, 234
with posterior wall myocardial infarction, 146
risk stratification, 191
ST-segment depressions and, 190 T-wave inversions, 197
acute IMI, 40–46 clinical course of, 45
ECG identification of, 41–42, 44–45 infarct-related artery identification, 43–46 LCA occlusion, 43–44
RCA occlusion, 43 acute STEMI, 236
acute T-wave inversions, 197 alcohol abuse
ECG case study, 288–318
anterior wall myocardial infarction, xii, 127–140
with ACS, 99, 114–136 acute, 88
anteroseptal STEMI, 92–98 bundle branch blocks, 88, 100–101,
102–104 LBBB, 104
coronary anatomy with, 89–90 coronary mimics of, differentiation
from, 88
de Winter complex, 100 definitions of, 88
ECG case studies, 104–141 with high lateral wall, 91–92 LAD artery occlusion, 88, 89 early warnings of, 92–98
hyperacute T-waves, 92, 94–98, 100 Wellens’Syndrome, 93, 100 lead aVR and, 99
LMCA occlusion, 88, 99 after OHCA, 100 old, 104 Q-waves, 104 ROSC and, 100
Sgarbossa criteria, 100–101 ST-segment equivalents, 99–101
depressions, 100 elevations for, 100
with ventricular fibrillation, 118–137 anteroseptal STEMI, 92–98
LVH and, 196–197
apical ballooning syndrome.Seetakotsubo syndrome
arrhythmogenic right ventricular dysplasia (ARVD), 242
atrial fibrillation, 165
atrial rhythms.Seeectopic atrial rhythms A-V nodes, 3
conduction through, 3 functions of, 3 IMI and, 58–59
clinical course of, 59 etiology of, 59
biphasic T-wave inversions, 197 Brugada syndrome, 242–243
ECG case study, 289–318
bundle branch blocks, 88, 100–101, 102–104 LBBB, 104
RBBB, 239
cardiac arrest.Seeout-of-hospital cardiac arrest
cardiac tamponade, shortness of breath and, 160, 163
cardiomyopathies, 189, 198–199
case studies, with ECGs, 13–38, 268–325.See also specific illnesses
acute pericarditis, 235, 285–317 anterior wall myocardial infarction,
104–141
Brugada syndrome, 289–318 coronary artery disease, 282–316 coronary mimics, 245–262 IMI, 64
posterior wall myocardial infarction, 157–158
shortness of breath, 15–34, 160, 183–187, 275–321
ST-segment depressions, 200–228 ST-segment elevations, 245–262 T-wave inversions, 200–228 chronic obstructive pulmonary disease
(COPD), 24, 165–167 ECG case study, 281–315 low QRS voltage, 165
poor R-wave progression, 165–167 posterior axis, 166
right atrial enlargement, 165 right ventricular enlargement, 165 tachycardias, 165
concave upward ST-segment, 231–232 congestive heart failure
ECG case study, 301–322 shortness of breath and, 181–187 ST-segment depressions and, 217–227 T-wave inversions with, 217–227 COPD.Seechronic obstructive pulmonary
disease coronary anatomy
anterior wall myocardial infarction, 89–90
posterior wall myocardial infarction, 144 coronary artery disease
ECG case study, 282–316
ST-segment depressions with, 216–228 T-wave inversions with, 216–228 coronary mimics, 88, 230–232, 246–259
ECG case studies, 245–262 tall T-waves, 243–244
BER, 244
common causes of, 244 hyperacute, 244 hyperkalemia, 244 LVH, 244
de Winter complex, 100 depolarization current, 1–2 depression in lead aVL, 47–50, 51 depressions.SeeST-segment depressions diffuse myocarditis, 163
digitalis effect, 189, 191–192
downward concavity, ST-segments and, 50 dyspnea
exertional, 155–158 PE as cause of, 160
early repolarization pattern (ERP), 230, 232–234, 244
acute pericarditis and, 236 benign, 232–233
BER, 244
ECG features of, 232
with healthy heart patterns, 233 prevalence of, 232
subtle STEMI and, 237–238 early STEMI, xii
ECGs.Seeelectrocardiograms ectopic atrial rhythms, 35 electrocardiograms (ECGs)
A-V nodes, 3
conduction through, 3 functions of, 3
computer-assisted interpretation of, xii with COPD, 24
depolarization current in, direction of, 1–2 junctional rhythms, 3–5
accelerated, 4
ectopic atrial rhythms as distinct from, 35
escape, 4 for P-waves, 3–5 LAE, 9–10
left arm lead reversal, 10–12 limb leads, 2
as bipolar, 2
regional monitoring by, 2 with myocardial infarction, 28–37 normal sinus rhythm, 2–3 principles of, 1
326
QRS complexes, 6–8 abnormal Q-waves, 7–8 precordial chest leads, 6 precordial transition zones, 6–7 R-waves, 6–7
septal Q-waves, 7 RAD, 38
RAE, 9–10, 22–35
right arm lead reversal, 10–12 for self-study, 12–38
emphysema, 160
ERP.Seeearly repolarization pattern focal myocarditis, 160
high lateral infarction, 40 high lateral infarction IMI, 40
high lateral wall myocardial infarction, 91–92 hyperacute T-waves, 92, 94–98, 100, 244 hyperkalemia
ST-segment elevations and, 242 tall T-waves, 244
hypotension, from RVMI, 52 hypothermia, 239–241
Osborn wave correlates, 240 hypothyroidism, IMI with, 84–85
inferior wall myocardial infarction (IMI), xi, 84–85
acute, 40–46
clinical course of, 45
ECG identification of, 41–42, 44–45 infarct-related artery identification,
43–46
LCA occlusion, 43–44 RCA occlusion, 43 A-V nodal block and, 58–59
clinical course of, 59 etiology of, 59 classic features of, 40 complications of, 51–57
anatomic correlations, 51–52 ECG case studies, 64
high lateral infarction, 40 old, 60–61
Q-waves, 60–61 over-diagnosis of, 61–63
false positives, 61 PDA and, 51
into posterior wall, 57–59 ECG readings for, 58 presentations of, 47–51 with pulmonary edema, 84 RVMI and, 52–57
complications from, 52 ECG signs of, 52–53, 54–56 hypotension from, 52
ST-segment elevation in, 52–53 ST-segments
with depression in lead aVL, 47–50
without depression in lead aVL, 51 downward concavity, 50
ECG readings, 48–50 elevations of, 50–51 regionality of, 50 with RVMI, 52–53 straightening of, 47–51
upward concavity, 50 under-diagnosis of, 61–63
through false negatives, 61–62 with ventricular fibrillation, 85–86 intra-cerebral hemorrhage, 189, 198 ischemia
ST-segment depressions with, 189, 190–191
subendocardial, 190
ST-segment depressions, 190–191 T-wave inversions, 190–191 T-waves, 190–191
inversions, 189
isolated posterior wall myocardial infarction, 143, 144, 146
J-point ST-segment, 231–232 junctional rhythms, 3–5
accelerated, 4
ectopic atrial rhythms as distinct from, 35
escape, 4 for P-waves, 3–5
junctional tachycardia.Seeaccelerated junctional rhythm
LAD artery.Seeleft anterior descending artery
LAE.Seeleft atrial enlargement lateral STEMI, xii
LBBB.Seeleft bundle branch blocks LCA.Seeleft circumflex artery lead aVR, 99
left anterior descending (LAD) artery anterior wall myocardial infarction, 88,
early warnings of, 92–9889
hyperacute T-waves, 92, 94–98, 100 Wellens’Syndrome, 93, 100 left arm lead reversal, 10–12 left atrial enlargement (LAE), 9–10 left bundle branch blocks (LBBB), 104
ST-segment elevations and, 230, 239 Sgarbossa criteria, 239
left circumflex artery (LCA), 43–44
left main coronary artery (LMCA) occlusion, 88, 99
left ventricular aneurysm, 230, 241 left ventricular hypertrophy (LVH) anteroseptal STEMI and, 196–197 clinical signs of, 193
diagnostic criteria, 193
ST-segment depressions, 189, 193–197 with repolarization abnormalities, 193, with strain pattern, 193–195195
ST-segment elevations and, 230, 238–239
tall T-waves and, 244 T-wave inversions with, 189 Wellens’Syndrome and, 196–197 limb leads, 2
as bipolar, 2
regional monitoring by, 2
LMCA occlusion.Seeleft main coronary artery occlusion
low voltage complexes pericardial effusion, 163
QRS, in COPD, 165
LVH.Seeleft ventricular hypertrophy LVH with repolarization abnormalities,
193, 195
LVH with strain pattern, 193–195 MAT.Seemulti-focal atrial tachycardia multi-focal atrial tachycardia
(MAT), 165
myocardial infarction.See alsoanterior wall myocardial infarction; inferior wall myocardial infarction; posterior wall myocardial infarction
abnormal Q-waves, 7–8 ECGs with, 28–37 myocarditis, 163, 183
focal, 160
shortness of breath and, 160, 163 acute, 163, 183
diffuse, 163
T-wave inversions, 189, 198–199 myopericarditis.Seepericarditis narrow T-wave inversions, 197 negative QRS complexes, 197
non-coronary ST-segment elevations, 230, shape of segment as factor, 231–232231 non-STEMI indications, 190–191 non-STEMI T-wave inversions, 190–191 normal sinus rhythm, 2–3
normal T-wave inversions, 197
OHCA.Seeout-of-hospital cardiac arrest old anterior wall myocardial infarction, 104 old inferior wall myocardial infarction,
60–61 Q-waves, 60–61
Osborn wave correlates, 240 out-of-hospital cardiac arrest
(OHCA), 100
PDA.Seeposterior descending artery PE.Seepulmonary embolism
pericardial effusion.See alsopericarditis shortness of breath and, 163
low voltage complexes, 163 signs of, 163
ST-segment elevations and, 235 pericarditis
ACS and, 234
acute STEMI differentiated from, 236 complications of, 236
ECG case study, 235, 285–317 ERP and, 236
PR-segment depression, 235 risk stratification for, 236 ST-segment elevations and, 230,
234–238 T-waves, 235 pneumonia
anterior wall myocardial infarction with, 128–139
ECG case study, 270–312 Pope, Zachary, xi
post-coronary bypass surgery, 148–157 posterior descending artery (PDA), 51 posterior leads, 146–147, 153–158
Index
327
posterior wall myocardial infarction, xii, 143, 146
with ACS, 146 acute, 143, 146
clinical approach to, 145 coronary anatomy, 144 ECG case studies, 157–158 isolated, 143, 144, 146
posterior leads, 143, 144, 146–147, 153–158 with pulmonary edema, 154–158
reciprocal signs, 144–145 right precordial leads, 143 R-waves, 145, 146
ST-segment depressions, 145–146 true, 144
T-waves, 144–145 precordial chest leads, 6
posterior wall myocardial infarction, 143 precordial transition zones, 6–7
PR-segment depression, 235 pulmonary edema
IMI with, 84
with posterior wall myocardial infarction, 154–158
pulmonary embolism (PE) dyspnea and, 160 ECG in, 160–162
prognostic value of, 161 right axis deviation, 161 S1-Q3-T3 pattern, 161 shortness of breath and, 160 sinus tachycardia and, 161, 162 ST-segment depressions with, 215–226 T-wave inversions with, 161–162, 197–198,
215–226 T-waves, 160, 161
inversions, 161–162, 189, 197–198
P-waves, 3–5
QRS complexes.Seeventricular depolarization
Q-waves abnormal, 7–8
with anterior wall myocardial infarction, 104
old inferior wall myocardial infarction, 60–61
septal, 7
RAD.Seeright axis deviation RAE.Seeright atrial enlargement RBBB.Seeright bundle branch blocks RCA.Seeright circumflex artery
return of spontaneous circulation (ROSC), right arm lead reversal, 10–12100
right atrial enlargement (RAE), 9–10, 22–35 in COPD, 165
right axis deviation (RAD), 38
right bundle branch blocks (RBBB), 239 ST-segment elevations and, 239 right circumflex artery (RCA), 43 right precordial chest leads, 143
right ventricular enlargement, in COPD, 165 right ventricular myocardial infarction
(RVMI), 52–57 complications from, 52
ECG signs of, 52–53, 54–56 hypotension complications from, 52 hypotension from, 52
ST-segment elevation in, 52–53 risk stratification
ACS, 191
acute pericarditis, 236 ST-segment depressions, 191 T-wave inversions, 191
ROSC.Seereturn of spontaneous circulation R-waves, 6–7
COPD, 165–167
posterior wall myocardial infarction, 145, 146
S1-Q3-T3 pattern in PE, 161
T-wave inversions with, 198 septal Q-waves, 7
Sgarbossa criteria, 100–101 LBBB, 239
shortness of breath.See alsochronic obstructive pulmonary disease;
pulmonary embolism causes of
cardiac, 163 extra-cardiac, 163
ECG case studies, 15–34, 160, 183–187, 275–322
emphysema, 160 myocarditis and, 160, 163
acute, 163, 183 diffuse, 163 PE and, 160
pericardial effusion and, 163 low voltage complexes, 163 signs of, 163
ST-segment depressions with, 203–225
T-wave inversions with, 203–225 after vaccine administration, 170–183 sinus tachycardia
PE and, 161, 162 T-wave inversions, 189
“smiley face”ST-segment, 231–232
ST-elevation myocardial infarction (STEMI).
See alsoanterior wall myocardial infarction; inferior wall myocardial infarction; posterior wall myocardial infarction; ST-segment depressions;
ST-segment elevations acute, 236
anteroseptal, 92–98 early, xii
lateral, xii
ST-segment depressions, 190 subtle, xii
ERP and, 237–238
stress cardiomyopathy, 198–199.See also takotsubo syndrome
ST-segment depressions, 190–197 ACS and, 190
with altered mental status, 208–223 anterior wall myocardial infarction, 100 with coronary artery disease, 216–228 differential diagnosis, 189
digitalis effect, 189, 191–192 ECG case studies, 200–228
IMIwith lead aVL, 47–50 without lead aVL, 51 ischemia and, 189, 190–191 with lung cancer, 218–227 LVH and, 189, 193–197
with repolarization abnormalities, 193, with strain pattern, 193–195195
non-STEMI, 190–191 with PE, 215–226 risk stratification, 191
shortness of breath and, 203–225 STEMI, 190
subendocardial ischemia, 190–191 ST-segment elevations.See alsocoronary
mimics; early repolarization pattern;
pericarditis
Brugada syndrome and, 242–243 concave upward, 231–232 ECG case studies, 245–262 hyperkalemia and, 242 hypothermia and, 239–241
Osborn wave correlates, 240 J-point, 231–232
LBBB and, 230, 239 Sgarbossa criteria, 239
left ventricular aneurysm and, 230, 241 LVH and, 230, 238–239
non-coronary causes, 230, 231–232 shape of segment as factor, 231–232 pericardial effusion and, 235
RBBB and, 239
“smiley face,”231–232
takotsubo syndrome and, 241–242 ST-segments
anterior wall myocardial infarction, 99–101
depressions, 100 elevations for, 100 downward concavity and, 50 IMI
with depression in lead aVL, 47–50
without depression in lead aVL, 51 downward concavity, 50
ECG readings, 48–50 elevations of, 50–51 regionality of, 50 with RVMI, 52–53 straightening of, 47–51 upward concavity, 50
posterior wall myocardial infarction, 145–146
subendocardial ischemia, 190
ST-segment depressions with, 190–191 T-wave inversions, 190–191
subtle STEMI, xii ERP and, 237–238
symmetric T-wave inversions, 197 tachycardia.See alsoaccelerated junctional
rhythm atrial fibrillation, 165 COPD, 165
MAT, 165 sinus, 161, 162
T-wave inversions, 189 Index
328
takotsubo syndrome, 198–199 ST-segment elevations and, 241–242 tall T-waves, 243–244
BER, 244
common causes of, 244 hyperacute, 244 hyperkalemia, 244 LVH, 244
true posterior wall myocardial infarction, 144 T-wave inversions, 189, 197–199
ACS, 197 acute, 197 biphasic, 197
with coronary artery disease, 216–228
ECG case studies, 200–228
intra-cerebral hemorrhage, 189, 198 ischemic, 189
with LVH, 189
myocarditis and, 198–199 narrow, 197
negative QRS complexes, 197
non-STEMI, 190–191 normal, 197
with PE, 161–162, 189, 197–198, 215–226
risk stratification, 191 S1-Q3-T3 pattern, 198
shortness of breath and, 203–225 sinus tachycardia, 189
stress cardiomyopathy and, 198–199
subendocardial ischemia, 190–191 symmetric, 197
T-waves.See alsotall T-waves acute pericarditis, 235 asymmetric limbs, 194 hyperacute, 92, 94–98, 100 ischemia and, 190–191 non-STEMI and, 190–191 PE, 160, 161
inversions, 161–162
posterior wall myocardial infarction, 144–145
upward concavity, ST-segments and, 50 ventricular depolarization (QRS complexes),
abnormal Q-waves, 7–86–8 in COPD, 165
hyperkalemia and, 242 negative, 197
precordial chest leads, 6 precordial transition zones, 6–7 R-waves, 6–7
septal Q-waves, 7 T-wave inversions, 197 ventricular fibrillation
anterior wall myocardial infarction, 118–137
with anterior wall myocardial infarction, 118–137
IMI, 85–86
Wellens’Syndrome, 93, 100 LVH and, 196–197
Index
329