EXAM #1: CARDIAC CYCLE Flashcards
What is the first event in the cardiac cycle?
Atrial contraction
When does the second phase of the cardiac cycle start?
AV valves close
What is the second phase of the cardiac cycle?
Isovolumetric contraction
What is the third phase of the cardiac cycle?
Ventricular ejection
What marks the beginning of ventricular ejection?
Semilunar valve opening
What is the 4th phase of the cardiac cycle?
Isovolumetric relaxation
What marks the beginning of isovolumetric relaxation?
Aortic valve closes
What is the fifth phase of the cardiac cycle?
Rapid ventricular filling
What marks the beginning of rapid ventricular filling?
AV valve opening
What is the sixth phase of the cardiac cycle?
Diastasis
What does CVP stand for?
Central Venous Pressure
What are three common causes of increased CVP?
1) Heart Failure
2) Tricuspid valve disorder
3) Pulmonary arterial HTN
What is a common cause if tricuspid valve disorders?
CHF–dilation of the RV
What causes pulmonary arterial HTN?
1) Pulmonary vein HTN
2) Abnormalities in the pulmonary tree
Draw the normal jugular venous pressure waveform and label the distinct parts of the wave.
N/A
What does the “a” wave of the jugular venous pressure waveform represent?
Atrial systole
What does the “c” wave of the jugular venous pressure waveform represent?
Ventricular contraction and ballooning of the tricuspid valve into the RA
What does the “x” wave of the jugular venous pressure waveform represent?
Atrial relaXation and a fall in RA pressure
What does the “v” wave of the jugular venous pressure waveform represent?
Venous filling of the RA
What does the “y” wave of the jugular venous pressure waveform represent?
RA emptYing i.e. rapid ventricular filling
What is the “h” wave of the jugular venous pressure waveform represent?
Continued filling of the RA during diastole
What vessel should be cannulated for measurement of the jugular venous pressure/ CVP?
Right Internal Jugular
What does a large “a” wave on the jugular venous pressure waveform represent?
Reduced RV compliance or elevated RV EDV i.e.
1) Tricuspid stenosis
2) Complete heart block
What will cause the absence of the normal “x” wave on CVP monitoring?
Tricuspid regurgitation i.e. blood flowing back into the RA during ventricular systole
This can be caused by severe CHF
What causes S1?
Closure of the AV valves (Lub)
What causes S2?
Closure of the semilunar valves (Dub)
What causes physiologic splitting of S2?
Respiration
*Inspiration causes pulmonary valve to say open longer b/c bigger EDV from decreases intrathoracic pressure
How do you identify a widened splitting of S2?
Splitting is audible during expiration and widens during inspriation
What causes a widened splitting of S2?
1) RBBB
- Delay in RV contraction
- Delay in pulmonic closure
2) COPD leading to straining of the RV
3) Pulmonic stenosis
What is Fixed Splitting of S2?
Widened split of S2 that is CONSTANT with respiration
What causes fixed fixed splitting of S2?
Atrial Septal Defect
*More blood is brought in but it is shunted to the LA via the septal defect
What is Paradoxical Splitting of S2?
1) P2 component occurs before A2
2) Gets BETTER in inspiration
What causes Paradoxical Splitting of S2?
1) LBBB
2) Aortic stenosis
What is an “opening snap” associated with?
Mitral Valve Stenosis
- Opening should be silent
- Calcified/ stiffened–>a sharp-high pitched sound occurs
When does the opening snap of mitral valve stenosis occur?
After the end of S2
What is an S3?
- Heart sound heard during rapid ventricular filling
- Caused by rapid flow of blood from the atria into the ventricles
What causes an S3?
- Normal in kids
- Adults= volume overload e.g. CHF
What is S4?
Late diastolic sound, corresponds with atrial contraction
Occurs prior to S1**
What causes S4?
Atrial contraction against a stiff (poorly compliant) LV e.g.
1) LVH
2) MI
What is the mnemonic to remember the locations of the cardiac valves on auscultation of the chest?
“All Physicians Take Money”
A= Aortic P= Pulmonary T= Tricuspid M= Mitral
What are the three types of systolic murmurs?
1) Ejection
2) Pansystolic
3) Late systolic
What are the ejection type mumurs?
1) Aortic stenosis
2) Pulmonic stenosis
What are the pansystolic murmurs?
1) Mitral regurgitation
2) Tricuspid regurgitation
3) Ventricular Septal Defect
What is the late systolic murmur?
Mitral valve prolapse
What feature of aortic stenosis signifies severity?
Location of the peak
- Early= mild
- Late= severe
What commonly causes mitral regurgitation?
Heart Failure
Describe the intensity of mitral regurgitation.
Constant
How is the murmur associated with aortic reguritation described?
Early decrescendo
Where is aortic regurgitation best heard?
3rd or 4th left ICS
Think that the blood is going from the aorta back into the LV
