Cardiac Phys/Patho Flashcards
(89 cards)
What causes the first (S1) and second (S2) heart sounds?
The first heart sound is caused by closure of the mitral and tricuspid valves at the beginning of systole. The second heart sound is caused by closure of the aortic and pulmonic valves (semilunar) at the beginning of diastole.
An S3 heart sound is an indicator of what condition?
Gallop rhythm during mid-diastole is most often heard in systolic heart failure in adults.
What is the postulated mechanism that produces the S3 heart sound?
Oscillation of blood back and forth between the walls of the ventricles initiated by inrushing of blood from the atria
Describe the murmur heard and stethoscope location in mitral stenosis
Opening snap heart in diastole, rumbling diastolic murmur. Best heard over cardiac apex
Describe the murmur heard and stethoscope location in mitral regurgitation
Holosystolic murmur heard throughout systole. Best heard over cardiac apex
Describe the murmur heard and stethoscope location in atrial stenosis
Systolic murmur best heard in the second right intercostal space (over the aortic arch)
Describe the murmur heard and stethoscope location in aortic regurgitation
Diastolic murmur best heard along the right sternal border
How is aortic regurgitation graded?
Assessed qualitatively: less than 20% of SV is mild, 20-39% is moderate, 40-60% is moderately sever, greater than 60% is severe
What portion of ventricular filling is atrial contraction responsible for?
Atrial kick accounts for 20-25% of ventricular filling, passive ventricular filling is responsible for the initial 75%
What is the normal range of stroke volume in the 70 kg adult
Normal range is 60-90 mL
What is the EF and normal range?
EF = end-diastolic volume - end systolic volume. Normal range is 60-80%
What are the two determinants of cardiac output
Stroke volume x heart rate
What is the cardiac index?
CO/BSA. Normal range is 2.5-4 L/min/m^2
When the ventricle fills more during diastole, more blood is ejected during systole, what law is this?
Frank-Starling’s law. Ventricular filling during diastole is directly related to the amount of blood ejected during systole.
Describe the process that describes ventricular myocyte relaxation (lusitropy).
Myocyte contraction requires increased intracellular Ca2+, therefore relaxation requires Ca2+ levels to return to resting levels which is accomplished by the SERCA2 pump located in the sarcoplasmic reticulum (an energy dependent process)
List the organs in the vessel rich group and the amount of CO they receive
Brain (15%), lungs (100%), heart (4-5%), liver (25%), kidney (20%), digestive tract, and endocrine tissues
What percent of the LV’s CO traverses the bronchial circulation? Vessels arise from what arteris?
1-2%, bronchial circulation arises form thoracic aorta and the intercostal arteries
What is the range of the normal pressures in each chamber of the heart?
RA 1-8
RV 15-30/0-8
LA 2-12
LV 100-140/0-12
What is the normal value for mPAP
mPAP = 16, 25/8
What is the normal range for PAOP
5-15
What causes a change in blood pressure when changing the patient’s position?
Altered preload (venous return) is most responsible for a change in blood pressure when the patient is re-position
What are two determinants of arterial blood pressure?
SVR and CO - application of Ohm’s law
What most determines SVR?
Vascular tone, especially that of the arterioles
What is the normal range for SVR?
1200-1500 dynes.sec.cm^-5