Cardiovascular System Flashcards
Conduction System
Electrical current stimulates each cardiac contraction can be seen on an ECG
Cardiac cycle
Defines events in each heartbeat: systole contraction, diastole relaxation
Normal heart sound: S1
“lub”
1st heart sound heard upon closure of the AV valves
signals the beginning of systole
heard best at the apex of the heart
Normal heart sound: S2
"dub" 2nd heart sound heard upon the closure of the SL valves signals the end of systole heard best at the base of the heart
Abnormal heart sound: S3
S1 S2 S3
- ken tuck y
- associated with rapid filling of the left ventricle after the mitral valve opens during diastole
- S3 gallop signifies volume overload in adults but is common in children and adolescents.
Abnormal heart sound: S4
S4 S1 S2
- Ten nes see
- associated with atrial contraction at the end of diastole
- common in children and young adults
- indicate resistance to filling due to non compliant ventricle or volume overload
- Diagnostic of: HTN, CAD, aortic stenosis, anemia, hyperthyroidism.
Murmurs
Gentle blowing and swooshing sound that can be heard on the chest wall for longer than abnormal heart sounds. associated with turbulence in blood flow.
can be diagnostics if valvular disease.
Stenotic valve
narrowed valvular opening that obstruct blood flow
Regurgitation
failure of valve to fully close allowing blood to flow backwards.
Cardiac output
- Volume of blood pumped out in one minute
- CO=SV x HR
Stroke volume
- Amount of blood pumped out by heart with each beat. determined by preload, afterload and contractility.
- Preload: venous returned to the heart
- Afterload: resistance in which heart has to work against
- Contractility: strength of the contraction
Heart Rate
How fast the heart beats per min
Average person has a resting HR of 70 beats per min and a resting SV 70ml per min
