Cardiovascular Flashcards
What % of CO do the atrial contractions contribute?
25-30%
Atrial “kick”:
Atrial kick is the phenomenon of increased force generated by the atria during contraction. This event occurs late in atrial systole when blood flows from the left atrium into the left ventricle. The purpose of the atrial kick is to increase flow across the mitral valve by increasing the pressure gradient. In a healthy patient, the atrial kick can be responsible for 20 to 30% of the blood transferred to the left ventricle and may be heard as the fourth heart sound.
Name the AV valves:
When are they open?
Name the Semilunar valves:
Tricuspid and Mitral.
Open during DIASTOLE
Pulmonic and Aortic.
Open during SYSTOLE
How many main coronary arteries are there?
- The left and the right.
RCA: Right Coronary Artery
What does the RCA perfuse?
Right atrium
Right ventricle
SA node
VA node (nodes = heart rhythm)
Posterior wall in 90% of population.
When you hear “RCA occlusion” what main wall should you be thinking of?
Inferior wall. (distally=of the LEFT ventricle)
Inferior wall includes:
Rt atrium
Rt ventricle
SA
VA
Back of the septum
90% of population will have posterior wall affects as well.
Why is an occlusion of the Left Main (LM) called the widow-maker?
The LM supplies the LCA (left coronary artery), LAD (left anterior descending), and Circumflex artery.
What wall should you think of with a left anterior descending LAD occlusion?
What are the affects of this injury?
Anterior and Septal Wall.
Affects:
Front and bottom of left ventricle.
Front of septum.
What wall should you think of with a circumflex artery occlusion?
Lateral wall.
Affects:
Left atrium.
Back of left ventricle.
10% of population = posterior wall
Regarding perfusion, why is tachycardia an issue?
The coronary arteries are filled during DIASTOLE. If the heart is beating too fast, this decreased coronary filling and perfusion.
What do we call the concept/event of when the myocardium is stretched prior to contraction?
Preload.
Therefore, it’s r/t the sarcomere length at the end of diastole.
So, high preload would be associated with volume overload. (not always clinically true)
How to measure preload on RT side of heart?
Left?
Right sided measurement is done with CVP, central venous pressure. (have fallen away w/a lot of CVPs r/t not being able to tell if they’ll be fluid responsive or not)
Left sided by PAOP, pulmonary artery occlusive pressure, aka the “wedge” pressure.
What is the RESISTANCE your heart has to overcome in order to eject/contract called?
Afterload.
Vasoconstriction, chronic HTN has chronic high resistance (what leads to LV hypertrophy).
How to measure afterload on RT side of heart?
On Left?
PVR
Pulmonary vascular resistance
Left side of heart is measured by SVR, Systemic vascular resistance.
Where would you listen for the aortic valve?
Right sternal, 2nd intercostal space
Where would you auscultate the pulmonic valve?
Left sternal, 2nd intercostal space
Where would you auscultate the tricuspid valve?
Left sternal, 4th intercostal space
Where would you auscultate the mitral valve?
Left mid-clavicular, 5th intercostal
What is the “lub” of S1?
Closure of mitral and tricuspid valves.
Systole.
Loudest over the mitral auscultation point 5th ICS.
What is the “dub” of S2?
Closure of the pulmonic and aortic valves.
Diastole.
Loudest over the aortic auscultation point, 2nd ICS.
What is an S3 heart sound indicative of?
Fluid overload. Abnormal finding in adults.
Best heard over apex/ mitral valve site.
AKA ventricular “gallop.” (pre-systolic)
Ken-tuck-y or I Be-lieve
Normal finding in some kids.
Possibly during 3rd trimester.
What does a S4 indicate?
Sound of vibration from Atria ejecting blood against non-compliant ventricles…
AKA atrial gallop.
Best heard at apex. May have pt lie on left side.
* Cannot have S4 in Afib; would be a S3.
Typical pt = Left ventricular hypertrophy, Ischemia, HTN, pulmonary stenosis, CAD, aortic stenosis,
You hear the S4 right before the S1.
Ten-ne-ssee or Be-lieve me
When are splits best heard?
During INSPIRATION.
Split S1 - mitral closes before tricuspid
Ex: RBBB, V-paced rhythms, PVCs
Split S2 - aortic closes before pulmonary
Ex: Overfilled R ventricle, atrial septal defect (ASD)
What are our “heart strings?”
Chordae Tendinae (Kor-day Tendi-nay)
Thin strands of connective tissue that anchor the leaflets of each AV valve (to papillary muscles) so that they cannot open into the atrium (thus allowing backflow of blood into the atrium).
Sten-OH-sis mumur is heard when the valve is open or closed?
OH-pen.
Forward flow of blood through NARROW stenotic OH-pen valves.
Most common valve dysfunction.