Heart Basics
Three layers of heart
endocardium, myocardium, and pericardium
3 main ions in cardiac muscle action potential
calcium, sodium, and potassium
Most common arrythmia in clinical setting and what can it cause
A fib. blood clot formation.
Main Causes of Myocardial ischemia
coronary artery thrombosis, atherosclerotic plaque, coronary artery vasospasm
Diagnostic Tests for MI:
What you would see in STEMI v NSTEMI
EKG + cardiac triponin
STEMI: ST elevation; NSTEMI: ST depression
Heart muscle contracts and pressure is at its highest; Heart muscle relaxes and pressure is at lowest
systolic; diastolic
this occurs when action potential is interrupted by a second impulse
dysthymias
Flattened T wave indicates
hypokalemia
Three types of angina and what characterizes them
Stable angina: consistent, chronic chest pain with physical/emotional stress. relieved by rest
Unstable angina: medical emergency.. is not relieved by stress, new pain
Prinzmetals angina: variant angina occurs during rest from vasospasms
Worsening of pericardial effusion:
what indicates this and what does it include:
cardiac tamponade. becks triad (low BP, JVD, muffled heart sounds)
pulmonary circuit is low pressure system where blood move to where for what?
Systemic circuit is high pressure system where blood moves towards the?
lungs for gas exchange; body
If SA impulse fails to be conducted, the ____ takes over.
AV
Waveform evaluated in MI
ST segment/T wave
Classic signs of angina vs. equivalents and who experiences
Classic: chest pain down left side, diaphoresis, N/V, dyspnea, pallor
Equivalents: faintness, dyspnea, epigastric pain, extreme fatigue, dizziness
- women/older women feel them
Endocarditis (causes, signs/symptoms, whats affected)
endocardium affected. caused by IV drug use, prosetic valves, staph. symptoms: new/worsening heart murmur, sepsis
coronary artery that supplies LV and most commonly involved in MI? Nickname?
left anterior descending artery! Widowmaker!
Main conduction spots in the heart and average heart rate if impulse originates in each
Sinoatrial node: 60-100
Atrioventricular node: 40-60
Bundle of his/perkunjie fibers: 30-40
Symptoms decreased cardiac output can be observed with dysrhythmias
tissues are not getting enough oxygen
amount of damage on an MI depends on
collateral circulation, time (less than 30 min), location
Myocarditis (causes, signs/symptoms, whats affected)
myocardium. caused by virus. symptoms: myalgias
Blood flow through heart
Deoxygenated blood from Sup/inf vena cava -> RA -> tricuspid valve -> RV -> pulmonic valve -> pulmonary arteries -> lungs -> pulmonary veins -> LA -> mitral valve -> LV -> aortic valve -> aorta -> body
What happens during depolarization and repolarization of a cell
depolarization: Na inters cell (pushes K out) and Ca inters to prolong this, contracting the muscle
Repolarization: K reenters the cell to push Na/Ca out, relaxing the muscle
5 waveforms of EKG/what is occurring during waveform
P: atrial depolarization
QRS complex: atrial repolarization and ventricular depolarization
T: ventricular depolarization
Partial coronary artery occlusion =
complete coronary artery occlusion =
NSTEMI MI
STEMI MI
Pericarditis (causes, signs/symptoms, whats affected)
pericardium. caused by: MI, infection, radiation, surgery. Symptoms: pericardial friction rub and chest pain worsening with deep breathing