Cardiac Flashcards
What is Inotropy?
Force of cardiac contraction (Regulated by the autonomic nervous system)
What is Chronotropy?
Heart rate (Regulated by the autonomic nervous system)
What is Dromotropy?
Speed of conduction specifically dealing with the AV node.
What does the “T” wave represent?
The ventricles repolarizing
What does the “QRS” represent? What other process is occuring in the middle of the “QRS”?
-Ventricles contracting.
-Atrial polarization
What does the “P” wave represent?
Atria depolarizing and the atria contracting
What is the S1 “Lub” sound and when does it occur?
-Bi/Tricuspid Closing
-Systole
What is the S2 “Dub” sound and when does it occur?
-Aortic and Pulmonary valves closing
-Diastole
What is the S3 “da” sound and when does it occur?
-Extra fluid sloshing
-Ventricular diastole
What is the S4 “bla” sound and when does it occur?
-Ventricle too thick
-Atrial systole
What is Preload affected by?
-Venous blood pressure
-Venous return
What systems affect Preload?
-The thoracoabdominal pump (ability to pump blood back to heart through pressure)
-The skeletal muscles in the legs (muscles contract to “milk” blood back to heart)
What is Afterload?
-Systemic pressure that the ventricles have to push against. –Also known as the amount of pressure the heart needs to exert to eject the blood during ventricular contraction
What is preload?
-Force that stretches the cardiac muscle before contraction.
-Composed of the volume that fills the heart form venous return. The more it fills the more it will contract (Starling’s Law)
What does the Sodium (Na+)/Potassium (K+) do for a cell?
Exchanges Na+ and K+ at the cost of energy, bringing the cell back to resting potential