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How Many ECG leadsHow Many ECG leads
Dr. Zohair Alaseri, MDFRCPc, Emergency MedicineFRCPc, Critical Care MedicineIntensivest and Emergency Medicine ConsultantChairman, Department of Emergency Medicine King Saud University Medical City, Riyadh, KSA
How Many ECG leadsHow Many ECG leads
A. 12B. 15C. 16D. 18E. 25
Introduction to 15 lead ECGIntroduction to 15 lead ECG Anatomical ConsiderationAnatomical Consideration Rt Ventricular MI, diagnosis and Rt Ventricular MI, diagnosis and
challengeschallenges Posterior w. MI, diagnosis and Posterior w. MI, diagnosis and
challengeschallenges ECG CasesECG Cases SummarySummary
How Many ECG leadsHow Many ECG leads
Interactive presentation to cover the following
12-lead ECG is a less-than perfect indicator of AMI
The use of the additional leads provide a more accurate reflection of the true extent of myocardial damage.
How Many ECG leadsHow Many ECG leads
Am J Emerg Med 2003;21:563-573
How Many ECG leadsHow Many ECG leads
Why we need 15 lead ECG?
PMI &/or RVMI are very difficult to diagnose by the regular 12 lead ECG
Why acute posterior (PMI) and right ventricular (RV) myocardial infarctions are likely to be under diagnosed??
Because the standard lead placement of the 12-lead ECG does not allow these areas to be assessed directly
How Many ECG leadsHow Many ECG leads
Prospective comparison of 12- and 15-lead ECGs
11.7% increase in sensitivity of AMI diagnosis by STE from 47.1% to 58.8% with the use of additional leads.
Zalenski RJ, Cooke D, Rydman R, et al: Assessing the diagnostic value of an ECG containing leads V4R V8 and V9 the 15-lead ECG. Ann Emerg Med 1993;22:786-793
How Many ECG leadsHow Many ECG leads
RVMIRVMI
STE is less pronounced than is usually seen in the standard 12-leads of the ECG.
The right ventricle is composed of considerably less muscle when compared with the left ventricle
How Many ECG leadsHow Many ECG leads
Why??
Posterior MIPosterior MI
ST- Elevation is less pronounced than is typically seen
Relative distance of the posterior leads from the posterior wall of the LV
How Many ECG leadsHow Many ECG leads
Why??
(RV) is directly imaged only by V4R and, to a lesser
extent, standard precordial lead V1.
posterior leads directly image the posterior wall of the LV
V1 to V6 indirectly view the posterior wall of the LV
lead RV4
lead V8
lead V9
V1R is same as standard V2,
V2R is the same as standard V1,
V3R is halfway between V2R
V4R, V4R is fifth intercostals space at right midclavicular line, V5R is same level as V4R in right anterior axillary line
V6R is same level in right midaxillary line
How Many ECG leadsHow Many ECG leads
leads V8 and V9V4R
reflects the status of the
right ventricle.
image the posterior wall of the left ventricle
Additional leads
Isolated RV infarction is a rare
Most RV infarctions result from occlusion of the Rt coronary artery proximal to the Rt ventricular branch .
The left circumflex artery supplies the RV in approximately 10% of patients. RV infarction will present in the setting of a lateral wall AMI.
RV AMIHow Many ECG leadsHow Many ECG leads
Electrocardiographic studies have consistently shown that RV infarction occurs in approximately one-third of IMIs
Zeymer U, Heuhaus KL, Wegscheider K, et al: Effects of fibrinolytic therapy in acute myocardial infarction with or without right ventricular involvement. J Am Coll Cardiol 1998;32:876-881
Braat SJ, Brugada P, DeZwaam C, et al: Value of the electrocardiogramin iagnosing right ventricular involvement in patientswith acute inferior wall myocardial infarction. Br Heart J 1983;49: 368-372
Klein HO, Tordjman T, Ninio R, et al: The early recognition ofright ventricular infarction: diagnostic accuracy of the electrocardiographic V4R lead. Circulation 1983;67:558-565
RV AMIIts relation with the inferior mi
•STE in lead V4R is represented by a rightward and anteriorly oriented vector.
So•leftward ST-segment deviation, as is seen in leads V5 and V6 during a lateral AMI, could cancel the right-lead STE and obscure the diagnosis.
•Additionally, if STE is not prominent in the inferior leads, then it will be less prominent in V4R.
ChallengesChallenges
RV AMI
ChallengesChallenges
Coexisting AMI of the left ventricle’s posterior wall can obscure the STE resulting from RV infarction in lead V1 as seen in patients with the acute inferoposterior MI with RV involvement
RV AMI
RV infarction can be diagnosed with 80% to100% sensitivity by STE greater than 1 mm
in lead V4R
Braat SJ Value of the electrocardiogramin iagnosing right ventricular involvement in patients with acute inferior wall myocardial infarction. Br Heart J 1983;49: 368-372
Klein HO The early recognition of right ventricular infarction: diagnostic accuracy of the electrocardiographic V4R lead. Circulation 1983;67:558-565
RV AMI
Robalino BD, Whitlow PL, Underwood DA, et al: Electrocardiographicmanifestations of right ventricular infarction. Am Heart J 1989;118:138-144
STE greater than 1 mm in V4R has
100% sensitivity87% specificity
92%predictive accuracy
in detecting acute RV MI.
RV AMI
RV AMI
ST-segment elevation inferior leads
ST- elevation in the rt precordial chest leads, particularly V1
STE is greatest in lead III compared with the other inferior leads
RBBB
second- and third-degree AV blocks
STE in lead V2 greater than 50% the magnitude of ST- depression (STD) in lead aVF
12-lead ECG are suggestive RV AMI
The term posterior myocardial infarction (PMI) refers to AMI of the posterior wall of the left ventricle.
Posterior MIPosterior MI
V7, posterior axillary line;
V8, posterior scapular line;
V9, left border of spine.
Posterior Leads
All in the same horizontal plane of V4
to V6
Usually occur in conjunction with inferior or lateral AMIs and are estimated to occur in 15% to 21% of all infarctions
Posterior MIPosterior MI
)1 (horizontal STD ;)2 (a tall, upright T
wave ;)3 (a tall, wide R
wave)4 (an R/S wave ratio
greater than 1.0.)5 (Inferior or lateral
walls MI
Posterior MIPosterior MI
PMI can be suspected if 12 ecg showes on of the following changes primarily in leads V1 and V2, V3:
STE greater than 1 mm in leads V8 and V9 confirms the diagnosis of PMI
Posterior MIPosterior MI
Adjusting the ischemic threshold from 1 to 0.5 mm of STE in leads V7 to V9 improved sensitivity for diagnosing PMI from 49% with the 12-lead ECG to 94% with the 15-lead ECG
Wung S, Drew B: New electrocardiographic criteria for posteriorwall acute myocardial ischemia validated by a percutaneoustransluminal coronary angioplasty model of acute myocardial infarction. Am J Cardiol 2001;87:970-974
Posterior MIPosterior MI
Khaw K, Improved detection of posterior myocardial wallischemia with the 15-lead electrocardiogram. Am Heart J 1999;138(5 Pt 1):934–40.
There are reports of ST elevationin posterior leads in the absence of
changes in anterior leads
Posterior MIPosterior MI
A prospective ECG analysis during angioplasty for single-vessel disease involving LCX or RCA found that
ST segment elevation in leads II, aVF, and III is the most common ECG change during RCA occlusion
(95%.)
Posterior ST elevation in leads V7 to V9 (68%) is the most common change during LCX occlusion.
Kulkarni AU, Brown R, Ayoubi M, et al. Clinical use of posterior electrocardiographic leads: a prospective electrocardiographic analysis during coronary occlusion. Am Heart J 1996;131(4):736–41.
15 Leads ECG
ST-segment elevation in leads V8 and V9 minimal ST-segment depression with large R waves in V1 to V3 confirming (posterior wall AMI)
ST-segment elevation in leads II, III, and AVF, leads V8 and V9 and lead V4R consistent with an inferoposterior AMI with RV MI.
ST-elevation in the inferior leads & leads V1 and V4RMinimal ST- elevation in leads V8 and V9 suggestive of early posterior wall AMI. The lack of appropriate findings in leads V1 to V3 suggestive of a posterior wall AMI is explained by the presence of RVMI and related ST-elevation in the Rt precordial leads.
Posterior MI with reciprocal depression in V1-V3
a 15-lead ECG recorded before balloon occlusion in a 68-year-old male patient without a history of prior MI .
15-lead ECG during occlusion of a nondominant LC at the proximal site.
No significant DST deviation of >1 mm was observed in the standard ECG.
Isolated posterior DST elevation of 0.7 mm or 70 mV was present in V7 & V8.
70 y o woman presented to the ED by ambulance after being found to be unresponsive in the bathroom by her
family.
ST-segment depression in V1 through V4 and ST-segment elevation in isolated lead V6.
1-mm ST-segment elevation in leads V7 and V8, and 1.5-mm ST-segment elevation in lead V9
ST elevation is present in II, III, aVF, and V1; reciprocal ST depression in all other leads
Acute right ventricular MI.
Usefulness of Three Posterior Chest Leads for the Detection of Posterior Wall Acute Myocardial Infarction Aqel RA - Am J Cardiol - 15-JAN-2009; 103(2): 159-64
A 15-lead electrocardiogram in response to LC occlusion.
ST-segment elevation is evident in the posterior leads (V7 to V9) despite no significant ST elevation in the standard 12 leads.
(A)ECG at baseline and (B)(B)during fully occlusive balloon inflation in the proximal LC artery
A 68-year-old man presented with chest pain radiating to the left arm of 3 hours’ duration .
He was diaphoretic and pale.
ST-segment depression, prominent R wave, and upright T waves in leads V1 to V3 in addition, ST-segment depression was seen in the inferior and lateral leads
A 68-year-old man presented with chest pain radiating to the left arm of 3 hours’ duration .
He was diaphoretic and pale.
A 56-year-old man, history of HTN developed epigastric pain while working .
pale, diaphoretic with a BP of 70 mm/Hg.
ST-segment elevation
ST-segment depression, prominent R wave
RV and Posterior MI
A 56-year-old man, history of HTN developed epigastric pain while working .
pale, diaphoretic with a BP of 70 mm/Hg.
ST-segment elevation in leads II, III, and AVF, leads V8 and V9 and lead V4R consistent with an inferoposterior AMI with RV MI.
15 lead ECG showing Right Ventricular MI and Posterior )recip in V1-V4(
•Inferior STE & reciprocal STD •STE in lead V1 is typical for RV AMI • widespread STE
Inferior & RV MI
(1 )STD or suspicious isoelectric ST-segments inleads V1–V3
(2 )borderline STE in leads V5 and V6 or inleads II, III, and aVF
(3 )all STE inferior AMIs (STE in leads II, III, and aVF)
(4 )STE in leads V1 and V2 or isolated STE in lead V1 .
The established specific indications for using 15-lead ECGs include the following:
RV infarction
•RBBB
•second- and third-degree AV blocks,
•STE in lead V2 less than 50% the magnitude of STD in aVF.
•Inferior AMI presenting with hypotension
The established specific indications for using 15-lead ECGs include the following:
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