12 lead EKG Flashcards
lead 2, 3, aVF
-view inferior wall of heart
lead V1 and V2
-view septal wall of heart
lead V3 and V4
-view anterior wall of heart
lead 1, aVL, V5, V6
-view lateral wall of heart
myocardial insult: ischemia
- lack of oxygenation
- ST depression or T wave inversion*
- permanent damage avoidable
myocardial insult: injury
- prolonged ischemia
- ST elevation*
- permanent damage avoidable
myocardial insult: infarct
- death of myocardial tissue
- damage permanent
- may have Q wave*
evaluating for ST segment elevation
- locate the J point
- identify/estimate where the isoelectric line is noted to be to
- compare the level of the ST segment to the isoelectric line
- elevation (or depression) is significant if more than 1 mm (one small box) is seen in 2 or more leads facing the same anatomical area of the heart
j point
-where the QRS complex and ST segment meet
ST segment elevation
-evaluated .04 seconds (one small box) after J point
contiguous leads
- lateral wall- 1, aVL, V5, V6
- inferior wall- 2, 3, avF
- septum- V1 and V2
- anterior wall- V3 and V4
- posterior wall- V7-V9 (leads placed on the patients back 5th intercostal space creating a 15 lead EKG)
inferior wall
-positive MI makes us worried about posterior wall
evolution of AMI
- pre-infarct (normal)
- Tall T wave (first few minutes of infarct)
- tall T wave AND ST elevation (injury)
- elevated ST (injury) inverted T wave (ischemia), Q wave (tissue death)
- inverted T wave (ischemia), Q wave (tissue death)
- Q wave (permanent marking)
- LOOK AT SLIDES PICTURE -> 11
take ur reading
-about a box after J point (.04s)
EKG monitoring
- evaluates electrical activity of the heart
- can indicate myocardial insult and location
- ischemia- initial insult -> ST depression seen
- injury- prolonged myocardial hypoxia or ischemia -> ST elevation seen
- infarction- tissue death
infarction: tissue death
- dead tissue no longer contracts
- amount of dead tissue directly related to degree of muscle impairment
- may show Q waves
contiguous ECG leads
- EKG changes are significant when they are seen in at least two contiguous leads
- two leads are contiguous if they look at the same area of the heart or they are numerically consecutive chest leads
aVR
- control lead
- global MI - ST elevation everywhere
- pericarditis if there is a elevation in the aVR
heart arteries
- right coronary artery
- right ventricular marginal branch
- posterior descending artery
- left main coronary artery
- circumflex artery
- obtuse marginal
- diagonal artery
- left anterior descending artery (LAD)
- arteries arnt on quiz but maybe final
- cross over
complications of lateral wall MI
- lead 1, aVL, V5, V6
- complication arise due to the conduction components that are in the septum
- conduction dysrhythmias most common:
- second degree type 2- classical
- 3rd degree- complete heart block
- bundle branch blocks- partial
- monitor patient closely for these blocks:
- 2nd degree type 2 and 3rd degree are serious dysrhythmias that need to be treated aggressively with TCP -> pacemaker
complications of inferior wall MI
- lead 2, 3, aVF
- 40% of patients with inferior MIs have right ventricular infarcts
- in the presence of a right ventricular infarct, there is a high likeliness of both ventricles being damaged
- contraction capabilities will be negatively affected
- patients may present hypotensive
- nitrates and morphine alone will dilate blood vessels worsening hypotension
- under medical control direction patients are often treated with a fluid challenge with the nitrates
- 1st degree heart block and secondary degree type 1 wenckebach most common heart blocks
- fluids! to support preload
complications of septal wall MI
- lead V1 and V2
- Significant amount of conduction components are in the septal area
- Patient predisposed to dysrhythmia
- Second degree Type II – classical
- 3rd degree heart block
- Bundle branch block
- Lethal heart blocks treated aggressively - TCP
- Rare to have a septal MI alone
- Common to have anterior or lateral involvement along with septal area
complications of anterior wall MI
-leads V3, V4
-Known as the “widowmaker” due to the potential for a massive area of infarction from blockage of the large amount of myocardium supplied by the LAD (left anterior descending artery)
-Often the septal or lateral walls are also involved
-Watch for lethal ventricular dysrhythmias and cardiogenic shock
-Second degree Type II and 3rd degree heart block are more common than other blocks
-Early death within a few days often from CHF
-Massive area of ventricular tissue infarcted if LAD totally occluded
-important to obtain history of recent MI
diagnosis and hospital discharge
-Increased incidence of ventricular tachycardia (VT) and ventricular fibrillation (VF) up to 1 -2 weeks post acute anterior M
acute pulmonary edema
- nitroglycerin given to dilate blood vessels and reduce preload
- lasix given to dilate blood vessels and reduce preload -> as a diuretic
- morphine given to dilate blood vessels and reduce preload -> reduce anxiety
all medications and interventions (ex. CPAP) can drop the BP
-monitor carefully!
cardiogenic shock
- ineffective pumping from the damaged heart
- IV fluid challenge if lung sounds are clear
- dopamine drip titrated to maintain a systolic blood pressure of less than or equal to 100 mmHg
- start at low dose (5mcg/kg/min)
- estimate the patients pounds (ex. 100#)
- take the 1st two numbers dropping the last number (ex. 10)
- minus 2 from the 1st two numbers
- this is the starting point for minidrips/minute (ex. 10-2 = 8)
common terms to describe chest pain
- heaviness
- pressing
- suffocating
- squeezing
- strangling
- burning
- constricting band
- a weight in the center of my chest
- a vise tightening around my chest
patient complaints or presentations
- Difficulty breathing
- Excessive sweating
- Unexplained nausea or vomiting
- Generalized weakness
- Dizziness
- Syncope or near syncope
- Palpitations
- Isolated arm or jaw pain
- Fatigue
- Dysrhythmias
atypical presentation in the elderly
- most frequent symptoms of acute MI
- shortness of breath
- fatigue and weakness (i just dont feel well)
- abdominal or epigastric discomfort
- often have preexisting conditions making this an already vulnerable population:
- hypertension
- CHF
- previous AMI
- likely to delay seeking treatment
atypical presentation in women
- described as:
- aching
- tightness
- pressure
- sharpness
- burning
- fullness
- tingling
- frequent acute symptoms:
- shortness of breath
- weakness
- unusual fatigue
- cold sweats
- dizziness
- nausea/vomiting
- often have no actual chest pain to offer as a complaint
- often the pain is in the back, shoulders, or neck
atypical presentation in patient with diabetes
- atypical presentation due to autonomic dysfunction
- common signs/symptoms:
- generalized weakness
- generalized feeling of not being well
- syncope
- lightheadedness
- change in mental status
region X SOP- acute coronary syndrome
-a 12 lead EKG is obtained on all patients presenting with signs and symptoms of acute MI
OR
-for patients where suspicions are raised that the patient may be experiencing an acute MI (ex. heart block)
case 2
-inferior MI
case 3
- elevation in V1, V2, V3, V4
- septal and anterior
- anterioral septal wall MI
case 4
-2, 3, aVF, V3, V4
case 5
- 2, 3, avF, V4
- inferior wall MI
case 6
- anterior septal wall MI
- V1, V2, V3, V4
case 7
-no ST elevation
case 8
-V2, V3, V1
case 9
- V3 is not positive
- V4 might be positive
- no MI
case 10
- 2, 3, aVF
- inferior wall MI
