Mid 2: Drugs for heart failure

Question 1

cardiac output

Answer 1

litres of blood pumped per minute

Question 2

Determinants of stroke volume

Answer 2

-contractility (ionotropy)
intrinsic strength of muscle contraction

-Preload
stretching of muscle fibers before contraction
Determined by end diastolic volume or pressure

-Afterload
Load that the heart fights to eect blood
Primarily aortic pressure

Question 3

Two types of heart failure

Answer 3

systolic and diastolic

Question 4

Positive ionotropic drugs

Answer 4

increase heart contractility

Question 5

Digoxin

Answer 5

Positive ionotropic drug for heart failure

increases contractility, cardiac output, and parasymp activity

Inhibits Na/K atpase which eventually results in increases intracell Ca and higher contractility

Question 6

Digoxin adverse effects

Answer 6

cardiac arrythmia cause by spontanous Ca release from SR

Low therapeutic index

drug interactions: diuretics increase tox by reducing K

Question 7

Dobutamine

Answer 7

positive ionotropic drug for heart failure

dobutamine agonizes Beta receptors, increases cardiac contractility

Question 8

Milrinone

Answer 8

Positive ionotropic drug for heart failure

increases Camp level by inhibiting phosphodiesterase 3