Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
27 Cards in this Set
- Front
- Back
|
What does "Lub" (the first heart sound) correspond with? |
The closure of AV valves when the ventricles contract |
|
|
Intensity of "lub" dependednt on |
Rate that pressure differentials are created across the valves
*Will be louder when the force of contraction is enhanced |
|
|
How can we enhance force of ventricle contraction? |
Inotrope drugs |
|
|
"Dub" (second heart sound) corresponds with? |
Closure of aortic and pulmonary (semilunar) valves when the ventricles relax |
|
|
Intensity of "Dub" determined by? |
Rate that ventricular pressure decreases at the end of systole |
|
|
When is "dub" louder? quieter? |
Louder when systemic or pulmonary blood pressure is high
Quieter when systemic blood pressure is low (ex. patients in shock, heart failure) |
|
|
3rd and 4th heart sounds |
"Gallops" - normal in horses, heart disease in cats Low intensity (quiet) |
|
|
3rd and 4th heart sounds result from? |
Flow of blood into ventricles during atrial contraction |
|
|
Murmurs |
Abnormal heart sounds that are detected on auscultation with a stethoscope (Lub and Dub no longer clear) |
|
|
Murmurs can be: |
Pathologic Physiologic Innocent |
|
|
Pathologic murmurs occur when.. |
Blood flow changes from laminar to turbulent as a result of: 1. Holes in the heart (ASD, VSD) 2. Abnormal arterial venous connection (PDA) 3. Stenotic heart valves 4. Insufficient heart valves |
|
|
Physiologic murmurs and examples |
Known cause, but not related to cardiac disease Ex. Exercise, anemia, fever, hyperthyroidism, pregnancy, hypertension, low protein |
|
|
Intensity of murmur scale. |
1 - quietest 6 - loudest |
|
|
Murmurs: Loudness does not indicate... |
The severity of the underlying problem |
|
|
Need to characterize murmurs in terms of... |
1. Location over heart (which valve?) 2. Timing in cycle (systolic vs diastolic) 3. Duration (holosystolic, early systolic, early diastolic or pansystolic) |
|
|
Heart valves open and close passively based on... |
Pressure gradients on either side of valve |
|
|
Systole |
Period of contraction Time interval between closure of the mitral and tricuspid valves and closure of the pulmonary and aortic valves |
|
|
Diastole |
Period of relaxation Time interval between closure of the pulmonary and aortic valves and closure of the mitral and tricuspid valves |
|
|
What happens during systole? |
High ventricular pressure forces AV valves closed and semilunar valves open Blood accumulates in atria, ready to enter through the AV valves once they open |
|
|
What happens during first 1/3 of diastole? |
Ventricles fill rapidly, accounting for 70% of blood that enters the ventricles |
|
|
What happens during the last part of diastole? |
Atria contract and deliver remaining 30% of end diastolic volume to ventricles |
|
|
If the last 30% of filling is lost.... |
SV and CO are compromised |
|
|
What happens during start of systole? |
Abrupt increase in intraventricular pressure, causing mitral and tricuspid valves to close |
|
|
Initially, aorta and pulmonary valves closed.... |
due to backpressure from blood in the aorta and pulmonary arteries, until intraventricular pressure is high enough to push the valves open |
|
|
When semilunar valves open |
Blood is rapidly ejected, with most of the stroke volume being delivered in the first 1/4 of systole |
|
|
Ejection fraction |
During systole, ventricles eject 40-60% of their end diastolic volume |
|
|
What happens at end of systole? |
Intraventricular pressure drops rapidly, allowing higher pressures in the aorta and pulmonary arteries to close the aortic and pulmonary valves |
