First Aid Flashcards
Pulse pressure is inversely proportional to; what is it proportional to
Compliance; SV
What causes increases in pulse pressure
Hyperthyroidism, aortic regurgitation, aortic stiffening, obstructive sleep apnea, exercise
What causes decreased pulse pressure
Aortic stenosis, cardiogenic shock, cardiac tamponade, heart failure
What causes increased CO for early exercise? Late?
Increases in HR and SV; as SV plateaus only HR can increase
Which phase is shortened with increased heart rate
Diastole -> decreased filling -> decreased CO -> v-tac
What increases SV
Increased contractility, increased preload, decreased afterload
Contractility increases with
- Catecholamine stimulation via β1 (causes more Ca to enter cell because of phosph. Ca channels and phosph. phospholambin means more Ca stored in SR)
- Increased intracellular Ca
- Decreased extracellular Na
- Digitalis
Contractility decreases with
- β1 blockade (decreased cAMP)
- HF with systolic dysfunction
- acidosis
- hypoxia/hypercapnia
- Non-dihydropyridine Ca channel blockers
What causes increases in myocardial O2 demand
Increased contractility
Increased afterload
Increased heart rate
Increased diameter of ventricle (more stress)
What does nitroglycerin dilate
Veins
What do venous vasodilators do
Decrease preload
What approximates preload
EDV (general measure of blood in circulation)
What do arterial vasodilators do
Decrease afterload
What do ACE inibitors and ARBs do
Decrease preload and afterload
What does a narcotics overdose do for the heart
Decrease inotropy
The first side of the pressure volume loop represents what phase
Isovolumetric contraction (both valves are closed)
Where is the first heart sound heart in pressure volume loop
Bottom right corner
What is the top curve in the pressure volume loop
Systolic ejection after aortic valve opens
What is the left side of the pressure volume loop
Isovolumetric relaxation
Where is the second heart sound on pressure volume loops
Top left corner
Where is the this heart sound on the pressure volume loop
Bottom left corner to the left of midline
Where is the 4th heart sound on the pressure volume loop
Bottom right corner on the bottom line
What does the bottom line of the pressure volume loop represent
Rapid and reduced filling
What events make up systole
Atrial systole, isovolumetric contraction, rapid ejection, and reduced ejection
What events make up diastole
Isovolumetric relaxation, rapid ventricular filling, and reduced ventricular filling
What happens during atrial systole
Starts mid p wave, there is the first hump in jugular venous pressure (a wave), ventricular volume raises slightly, we hear S4, and it ends with the mitral valve closing
What happens during isovolumetric contraction
Mitral valve closes, we hear S1, it begins mid R wave and ends after S wave
What happens during rapid ejection
Begins with aortic valve opening, encompasses the end of S1, the C wave of venous jugular pressure, and we are in the ST interval
What happens during reduced ejection
This encompasses the T wave, it ends with the dicrotic notch (aortic valve closes)
What happens with isovolumetric relaxation
It begins with the aortic valve closing, ends with mitral valve opening, contains S2, and the V wave of jugular venous pressure
What happens during rapid ventricular filling
Starts with the mitral valve opening, contains S3, contains the Y wave of venous presssure
What happens with reduced ventricular filling
Nothing really on the graphs, but the ventricles continue to fill
What is associated with a strong S3
Increased filling pressures (mitral valve regurg. and HF) and is more common in those with dilated ventricles (young adults/kids)
What is S4 also called
Atrial kick
What is loud S4 related to
High atrial pressure and ventricular non-compliance (hypertrophy)
Always abnormal
What is normal splitting of heart sounds
There should be a delay in pulmonic valve closing on inspiration but normal on expiration
What is wide splitting
This is the same as the normal delay but the time is increased (extra delay on inspiration)
Caused by pulmonic stenosis or RBBB
What is fixed splitting
The aortic and pulmonic valve are at the same time regardless of inspiration or expiration
This is seen in ASD
What is paradoxical splitting
Pulmonary valve closes before aortic valve and there is a larger gap on expiration, not inspiration
Thisis caused by aortic stenosis and LBBB
What ion predominates in myocyte phase 0
Na
What ion(s) are moving in phase 1
Inactivation of v-gated Na and activation of v-gated K
What ions are moving in phase 2
This is the plateau phase where we have K leaving and Ca coming in so there is no net change in Vm
What ion(s) are moving in phase 3 of myocytes
V-gated slow K channels are allowing K out and v-gated Ca channels have closed
What ion(s) are moving in phase 4 of myocytes
K through leak channels
What causes a prominent U wave
Hypokalemia and bradycardia
What causes torsades de pointes
Drugs, decreased K, decrease Mg, congenital abnormalities
What can lead to torsades
Long QT syndromes
What is the delta wave and what does it mean
It is a gradual slope up to the R wave in which the AV node is bypassed
What can a prominent delta wave be linked to
Supraventricular tachycardia
What is a first degree AV block
A prolonged PR interval that is benign and asymptomatic
What is a type 1 second degree AV block
The PR interval is progressively lengthened until there a QRS is dropped
What is a type 2 second degree AV block
Dropped beats that are not proceeded by a PR lengthening
What is a third degree AV block called? What is it
Complete block; the A and V beat independently of eachother
What is the difference between a STEMI and NSTEMI
STEMI affects full thickness of the heart; NSTEMI affects inner portions and has ST depression
