Cardio Flashcards
MAP must be ___ to maintain blood flow through coronary arteries
At least 60 mm Hg
MAP must be ___ to maintain perfusion of major body organs
Between 60 and 70 mm Hg
The left anterior descending branch supplies blood to what?
- Portions of LV
- Ventricular septum
- Chordae tendineae
- Papillary muscle
- RV
The left circumflex branch supplies blood to what?
- LA
- Lateral/posterior LV surfaces
- Portions of interventricular septum
- SA node in 1/2 people
- AV node for small # of people
The right coronary artery supplies blood to what?
- RA
- RV
- Inferior LV
- AV node
- SA node to 1/2 people
How to calculate CO
HR x Stroke Volume
Normal CO range
4-7 L/min
How to calculate CI
Body surface area/CO
Normal CI range
2.7-3.2 L/min/m squared
Stroke volume
Amount of blood ejected by the LV during each contraction
The degree of myocardial fiber stretch at the end of diastole and just before contraction
Preload
Determined by the amount of blood returning to the heart from both the venous system and the pulmonary system
Preload
Starling’s Law
The more the heart is filled during diastole, the more forcefully it contracts
The pressure/resistance the ventricles must overcome to eject blood through the semilunar valves and into peripheral blood vessels
Afterload
Afterload is directly related to what?
Arterial BP and the diameter of the blood vessels
Amount of pressure generated by the LV to distribute blood into the aorta with each contraction
Systolic BP
Amount of pressure against the arterial walls during the relaxation phase of the heart
Diastolic BP
Coronary arteries originate where?
Just above the cusp of the aortic valve
When does coronary blood flow to the heart muscle occur?
During diastole
Blockage in LAD is called what?
“Widow maker” bc the mortality rate is so high. It supplies a large portion of muscle mass
Function of papillary muscles
Keep valves where they’re suppose to be
Branches on the LAD
Diagonal
Branches on the LCX
Obtuse marginal
Problems in LCX
Conduction problems/arrhythmias bc it supplies blood to SA node where impulses are generated
CVP filling pressures
Preload
Resistance heart pumps against
Afterload
Take oxygen in
Arteries
Take waste products and unoxygenated blood out
Veins
Where does the transition take place from O2 and unO2 blood?
Where arterial capillaries merge with venous capillaries
Sympathetic nervous system
Increases HR and BP, vasoconstricts
Parasympathetic nervous system
Decreases HR and BP, vasodilates
Baroreceptors
Sense when there is a fall in MAP, present around carotid arteries and aortic notch. Strategically places where arteries carry blood to your head.
Chemoreceptors
Respond to a decrease in O2 levels, will increase constriction to increase perfusion
Stretch receptors
The more they’re stretched, the harder the heart will contract
How does the renal system regulate BP when it senses a decrease in renal flow?
Retains sodium and water, renin-angiotensin-aldosterone system vasoconstricts to increase perfusion pressure
How does endocrine system regulate BP?
When you get angry or scared, there is a release of catecholamines, kinins, and histamine which stimulates the SNS to increase BP
What helps propel venous system?
Skeletal muscles in extremities
Primary function of the venous system
To complete the circuit of unoxygenated blood back to the heart
Effects of gravity on venous system
Increased when standing up (orthostatic hypotension) and lessened when laying down. This is why “raising extremities” increases blood flow to heart
Age related changes to heart
- Valves thicken/stiffen
- SA node decreases in mass/function (low HR)
- Decreased contractility
- Coronary arteries dilate, more tortuous/calcified
Age related changes to blood vessels
- Thicken/stiffen (can’t constrict and dilate as fast, so less responsive to intrinsic changes)
- Slowed exchange of nutrients from blood and tissues (slow healing)
Age related changes to blood
- Decreased volume
- Decreased marrow and production of RBC
- Decreased H&H
- Increased risk for clots r/t increased plt aggregation and decreased fibrinolytic action
Deconditioning
Changes in blood and heart with aging are from decreased activity, not “age”
PQRST chest pain assessment
- Provocation
- Quality
- Region/radiation
- Severity (1-10)
- Timing/treatment
Paroxysmal nocturnal dyspnea
Abrupt onset of SOB after lying flat for several hours r/t redistribution of blood flow
Alternating strong and weak heart beats
Pulsus alterans
Epigastric area
Over the lower right sternal border
Tricuspid area
5th intercostal space at the lower left of the sternal border
Mitral area
5th intercostal space at the apex of the heart (mid-clavicular line)
Pulmonic area
2nd intercostal space just left of the sternum
Aortic area
2nd intercostal space just right of the sternum
Closure of AV valves
S1
Closure of PV/AV
S2
Heard during diastole
S2
Best heard at apex or LLSB
S1
Heard during ventricular systole
S1
Best heard at base of heart
S2
Ventricular gallop, early sign of heart failure
S3
Atrial gallop. Indicates HTN, MI, aortic or pulmonic stenosis
S4
Heart murmurs
Turbulent blood flow across valves, grades I-VI
Grade 1 heart murmur
You’re pretty sure it’s there but can’t get to it-usually only used by cardiologists
Grade 6 heart murmur
It’s so loud you can hear it at the bedside without a stethoscope
Total cholesterol normal levels
What should HDL be?
> 40 mg/dL
What should LDL be?
What should triglycerides be?
Released with any myocardial damage
Troponin 1
Point of Care Troponin 1 test
Results should be available within 15 minutes
CK-mb
Heart damage
CK-mm
Skeletal muscle damage (bruise on leg)
CK-bb
Brain damage
Creatine Kinase peak and rise
Peaks within 24 hrs
Rise begins within 3 hrs
Myoglobin
Earliest marker available, never used
Risk for CAD is 3x greater with serum cholesterol greater than what?
260
Positively correlated with CAD
LDL
Decreased K and Mg levels means what?
Increased risk for DVTs
Heart Cath
NPO, must lie flat on table, bedrest 4-6 hrs after, check distal pulse
What do you ask a pt who just had a heart cath and reports chest pain?
If it’s the same kind of pain that brought them to the hospital
Transesophageal echo
Swallow the tube, must be NPO
Transthoracic echo
Don’t have to be NPO
NICS
Looks at carotid arteries
NIAS
Looks at arteries in legs
NIVS
Looks at veins in legs to rule out DVT or at veins in arms for placement of a dialysis shunt
12 lead ECG
Circumferential around whole heart. Doesn’t predict anything. If pt is having chest pain, get another ECG.
Thickening or hardening of arterial wall associated w/ aging
Arteriosclerosis
Formation of plaque within the arterial wall itself
Atherosclerosis
Stable plaque
Fibrous covered cholesterol core
Unstable plaque
Usually liquid lipid center
What eventually happens to plaque in arteries?
They become ulcerated or thrombosed and impacts the entire vessel wall
Stable angina pectoris
- Temporary ischemic state, usually associated with activity
- Freq, duration remains stable/predictable
How to manage stable angina
Nitrates, beta blockers, rest
Stable angina is associated with what kind of plaque?
Stable
Increase in the incidence and intensity of chest pain
Unstable angina pectoris
Prinzmetal’s angina (variant)
Chest pain occurs at the same time every day, caused by spasms not blockage
Goal of angina treatment
Increase O2 supply and decrease O2 demand
What medication dilate coronary arteries?
Calcium channel blockers
Nitrates vasodilate which causes what?
Increasing supply of O2
Nitrates
Nitroglycerine (fast acting, short acting), indur (slower and longer acting), isordil
Common complication of nitrates
Headache
Effect of beta blockers
Decreases contractility and slows HR, decrease demand of O2
Usually treat prinzmetal’s angina with what?
Ca channel blockers to decrease spasms
Smoking causes what
Coronary artery vasoconstriction
Diet for atherosclerosis
Low fat, low triglycerides
How to use Nitroglycerine
IV, sublingual (can take q 5 minutes up to 3 doses), and a spray which goes under their tongue. 1-2 sprays at onset of chest pain, 3rd spray after 5 minutes. The medication is good for 30 days. Protect the meds from light
Most important thing to do when giving nitroglycerine
Tell them to keep it with them at all times
Most common anti platelet med prescribed
Aspirin, then plavix, elequis
Percutaneous transluminal coronary angioplasty
Thread a wire into obstruction, thread cath over it, inflate balloon, remove, obstruction is moved back onto wall, NOT GONE. Artery is widened
Problem with stent insertion
Body reacts to foreign body, lots of people developed clots and heart attacks were caused. 30% of stents occlude within 6 months
PTCA candidate selection
- Blockage in one or two arteries (If all 3…bypass sx)
- Not left main disease bc if something messes up the pt dies
PTCA is treatment of choice for what?
Non-calcified lesions and straight lesions
Significant artery blockage
> 60%
Complications of PTCA
Patency of vessel, distal circulation (take plavix every day for a long time), chest pain (artery reoccluded)
Priority after PTCA
Chest pain, patency of vessel. Not distal circulation, you can live without a leg but not without heart.
Selection for CABG
Leg vein last 7-15 yrs, mammory artery last 15-20
What co-morbidities affect CABGs?
Pulmonary, renal, DM
Cardioplegia
Temporary stopping of heart muscle during CABG. Ice cold, potassium rich
Cardiopulmonary bypass
Temporarily takes over the function of the heart and lungs during surgery, maintaining the circulation of blood and the oxygen content of the body
How long can you stay on cardiopulmonary bypass?
Depends on the skill of the surgeon, the less time on bypass the better outcome
Normal post op CABG
-Ventilated
Complications of CABG
- Prolonged vent
- Renal failure-came with it or kidneys didn’t like being on bypass
- “Pump head”-out of it for a while
- A fib from sticking cannula in right atrium
- Pneumonia/atelectesis
- Infection (more likely with decreased immune system or COPD cause they’re on prednisone which decreases wound healing and decreases immune system)
Mediastinal chest tube
Strictly for drainage. Only thing in mediastinum is heart.
Pleaural chest tube
In pleural space, drains pleural fluid and expands lungs
Chest tubes after CABG
Usually 2 mediastinal and 1 pleural
Pacing wires after CABG
Right side-atrial
Left side-ventricular
Incision care after CABG
Plain soap and water, incision open to air
Activity order after CABG d/c
Tell them to walk up and down their driveway a few times, not down the street cause they’ll walk until they’re tired and then they have to walk back still.
Follow up appointments after CABG
CV surgeon in 2 weeks
Cardiologist in 4 weeks
CV surgeon in 6 weeks
