Clinical Cases And ECG MIs Flashcards
What could sinus tachycardia be due to?
What is it normal in?
Normal if pregnant, emotional
Could also be response to:
- drugs
- hyperthyroid
- fever
- anemia
- CHF
- hypovolemia
What could cause sinus Bradycardia?
‣ Vagal response sleep apnea ‣ Meds ‣ MI ‣ Increased ICP ‣ Hypothyroid
When does a premature beat occur?
When an irritable focus spontaneously fires a single stimulus
What is premature atrial contraction associated w/ ?
Stress Alcohol Tobacco Coffee Copd Cad
Wha will a Premature Ventricular contraction present w/ on an ECG?
Wide QRS
What do multiple PVCs indicate on an ECG?
Ventricular Tachycardia
What can cause VTACH?
CAd Heart failure Hypertrophic cardiomyopathy Congenital HD Electrolyte abnormalities
How is a Supraventricular Tachycardia represented on an ECG?
Narrow QRS complex, fast HR
What are the causes of Supraventricular Tachycardia?
Thyroid disease
Caffeine
Medications w/ stimulants
Stress
Why is Atrial Fibrillation particularly dangerous?
Can develop clots from this
What are the causes of atrial fibrillation?
‣ Hypertensive heart disease ‣ Valvular heart disease ‣ CHF ‣ CAD ‣ Obesity ‣ DM ‣ Metabolic syndrome ‣ Chronic Kidney disease
How is AFIB seen on an ECG?
Undulating baseline
No discernible P waves
Irregular QRS complex
Irregularly irregular ventricular rhythm
How does a First degree AV block present on an ECG?
Prolonged PR interval (over .2 sec - or bigger than 1 big block)
What are the limb leads of an ECG and what do they show?
Show depolarizatio of heart in frontal/coronal plane
AVR, aVL, aVF, I, II, III
What are the precordial leads of an ECG and what do they show?
V1-V6
Show depolarization of heart in horiz. Plane
What is a normal axis on an ECG? How do you determine this?
Normal= 0-+90
Determined by looking at leads 1 and aVF
How common is Coronary heart disease (CHD)?
1/6 adults in us
What is the common Hx and Sxs seen with CHD?
Chest discomfort
Sxs of nausea, vomiting, diaphoresis, dyspnea
What is the pathophys of CHD?
Narrowing of coronary arteries secondary to erosion, fissure or rupture of plaque, thrombus
If there is partial occlusion of the coronary arteries, what can occur?
Unstable angina or NSTEMI
If coronary flow is completely occluded, what can occur?
STEMI
What does STEMI stand for?
ST elevation MI
What are most MIs caused by?
Atherosclerosis
What is the progression of CAD?
Normal heart —> stable angina —> unstable angina —> NSTEMI —> STEMI
What will myocardial ischemia present with on an ECG?
Why?
Change in T wave
- inverted
- tall, upright
- depressed
Bc deficient blood supply; Impaired REpolarization (t-wave)
What will myocardial injury present with on an ECG?
Why?
ST elevation
bc inability to fully polarize back to baseline
How will a myocardial infarcton/necrosis present on an ECG?
Why?
Change in Q waves
Bc dead tissue cant DEpolarize
What are the cardiac bio markers of necrosis?
When will these show up? Peak?
-elevated Troponin I or T
- show up 1-4 hours after AMI onset
- peak at 10-24 hours
What can cause a false positive elevation in troponin T?
Renal failure
What does an NSTEMI present with?
Elevated troponin, CK, and CK/MB
- no st elevation
- usually st depression or t wave inversion
How does a STEMI present on an ECG?
W/ a fireman’s hat
-ST elevation that is 2 mm or more higher than baseline when measured at J point
What is an Acute MI?
Complete interruption of blood flow *usually bc coronary occlusion
What vessels are supplied by the Left Anterior descending a. (Ant. Interventricular a.) ?
What MI is assoc.w/ occlusion of LAD?
V1-V7
V3 and V4
Anterior wall infarction
What vessels are supplied by the Right Coronary a.?
What MI is assoc.w/ occlusion of RCA?
II, III, aVF
V3R-V6R
Inferior wall infarction (RV)
What vessels are supplied by the circumflex a.?
What MI is assoc.w/ occlusion of Circ. A.?
I, aVL
V5-V6
Lateral Wall infarction
What vessels are supplied by the Posterior Desc. A.?
What MI is assoc.w/ occlusion of Post. Desc. A.?
How can you see this on an ECG?
V1-V3
Look for sharp R wave- then, turn ECG upside down to see fireman’s hat
Posterior wall infarction
(Most missed one)