Coronary Heart Disease Clinical Manifestations
- chest discomfort (heavy, pressure, crushing)
- associated symptoms:
- nausea, vomiting, diaphoresis, dyspnea
- narrowing of coronary arteries secondary to Erosion, fissuring, or rupture of plaque
NSTEMI vs STEMI
NSTEMI = partial occlusion (Unstable Angina)
STEMI = occluded coronary flow
most MIs caused by atherosclerosis
ST-T Waves (Ischemia and Injury)
Ischemia = inverted T waves, tall peaked T waves, depressed
Injury = ST elevation
QRS Waves (Myocardial Infaction - death)
- big Q waves
- could mean that patient has had a heart attack in the past
Cardiac Biomarkers of Necrosis
TROPONIN I or T
- 1-4 hrs detectable after onset, 10-24 hours peak
- renal failure can cause false positive cTnT
Diagnosing STEMI in men vs women
Men: ST elevation of 2mm or more at J Point
- in V2-V3
Women: ST elevation of 1.5mm or more (no LVH)
- also 1mm or more in 2+ continguous chest leads
Acute Myocardial Infaction
aka “ST Segment Elevation MI”
- complete interruption of blood flow (coronary occlusion usually due to thrombus)
What leads are associated with Left Anterior Descending Artery? What infarction do they detect?
- V1-V7
Anterior Wall Infaction
What leads are associated with Right Coronary Artery? What infarction do they detect?
- II, III, aVF, V3R-V6R
Inferior Wall Infaction (RV Infaction)
What leads are associated with Circumflex Artery? What infarction do they detect?
- I, aVL, V5-V6
Lateral Wall Infaction
What leads are associated with Posterior Descending Artery? What infarction do they detect?
- V1-V3
Posterior Wall Infarction
Ventricular Tachycardia vs Supraventricular Tachycardia
VTACH: wide QRS complex
SVT: narrow QRS complex, fast HR
- atrial rate greater than 160-180, narrow, regular
- P-wave merges with QRS complex
Atrial Fibrillation
- atrial rate > 350-600 bpm
- no discernible P-waves
- “irregularly irregular” ventricular rhythm
First Degree AV Block
- measure PR by observation (one large square)
- block w/> 1 block difference