Cardiovascular Meds Flashcards
List drug strategies to improve cardiac function
- Directly increase cardiac contractility
- Reduce workload of the heart by:
- reducing contractility → direct effect
- reducing afterload → indirect effect
- reducing preload → indiriect
- Increase myocardial blood flow
- Manage hemostasis
- Other
- antiarrhythmic drugs
- statins
what are ionotropic agents?
used to increase force of contraction
T/F: intravenous positive iontrophic agents can be used anywhere
FALSE
should only be used in inpatient settings
and then only in pts manifesting S/S of low CO-syndrome
T/F: pt services are probably on hold with pts recieving IV ionotropic therapy
TRUE
List several ionotrophic agents
- Dopamine
- Dobutamine
- Milrinone
what is the effect of low-dose dopamine?
associated with dilation within renal and splanchnic vasculature resulting in enhanced diuresis
what is the effect of moderate-dose dopamine?
enhances cardiac contractility and HR
what is the effect of high-dose dopamine?
increased afterload through peripheral vasoconstriction
describe dobutamine
- +ionotrophic and chronotrophic agent
- (increased contracility and HR)
- decreases afterlod
- beta-receptor agonist
- improved end organ perfusion
- improves MAP
describe Milrinone
- type 3 phosphodiesterase inhibitor
- increases iontrophy, chronotrophy, and lusitrophy
- contractility, HR, rate of myocardial relaxation
- increases intramyocardial ATP
- potent vasodilator
- used in management of pulmonary HTN
what is Digitalis used to treat and how does it work?
- Used to treat impaired cardiac contractility typically caused by HF
- works by directly increasing cardiac contracility
- direct ionotrophic effects
what else is digitalis referred to as?
- Foxglove
- cardiac glycoside
- digoxin
- digitoxin
how does Digitalis increase cardiac contracility?
- increases Ca2+ influx into myocytes
what are the electrophysiological effects of digitalis?
- increases the AV node’s refractory period, decreasing the ventricular response (anti-arrhythmic)
- used to treat A-Fib, Atrial tachycardia and HF
- can cause reflex stimulation of the vagus nerve
- decrease HR and contractility
List drug classes that work to directly reduce contractility and thus reduce workload of the heart
- Beta-blockers
- Ca2+ channel blockers
what is the effect on the heart when a beta-1 agonist is given?
increased HR
increased contractility
what is the clinical use of beta-1 agonists? What is the impact on cardiac work?
- Clinical use
- treat conditions of severe cardiac decompensation
- cardiovascular shock
- in conjunction with cardiac surgery
- HF
- treat conditions of severe cardiac decompensation
- Impact on cardiac work
- increases work load of the heart
what is the effect on the heart when a beta-1 antagonist is given?
decreased HR
decreased contractility
limit impact on sympathetic NS on the heart
what is the clinical use of a beta-1 antagonist and what is the effect on cardiac work?
- Clinical use
- used to treat compromised or diseased hearts
- Impact on cardiac work
- reduces workload of the heart
- reduces functional capacity
T/F: Beta-1 antagonists affect primarily the heart
TRUE
(called beta-blockers)
what is the effect of beta-blockers on the heart?
negative chronotropic and ionotrophic effect
(reduces workload of the heart)
differentiate between the 2 subtypes of beta-blockers
- non-specific beta-blocker
- positive effect on the heart
- negative effect (smooth muscle contraction) on bronchial smooth muscle
- cardioselective beta-blocker
- specific for B-1 receptors which are found most frequently on cardiac tissue
Beta-blockers suffic
-olol
Adverse effects of beta-blockers
- receptor overreach
- can cause bronchoconstriction which is not a problem in most ppl but becomes a problem in those with pulmonary disease (cor pulmonale)
- can cause excessive depression of cardiac function
- OH
- depression, lethargy and sleep disorders (long term use)
- reduced peak HR
- reduced exercise capacity
7.
how to calculate HRmax for someone on a beta-blocker
HRmax = 164 - 0.7*age
what is the effect of Ca channel blockers on the heart?
- reduce calcium entrance into myoctyes causing:
- reduced contractility
- reduced energy demands on heart
- reduced CO
AE of Ca channel blockers
- decreased BP
- flushing
- bradycardia
- HA
- dizziness
- peripheral edema
- May increase risk of MI
*result in peripheral vasodilation which explains many AE
List drugs that reduce afterload
- Alpha blockers
- direct vasodilators
- beta-blockers
- centrally acting agents
what is the effect of alpha blockers?
smooth muscle relaxation, vasodilation and decreased TPR
what is TPR?
Total Peripheral Resistance (aka systemic vascular resistance or SVA)
- the resistance to blood flow offered by all of the systemic vasculature beds to blood flow
- largely determined by changes in blood vessel diameter
*
AE of alpha blockers
- these are systemic drugs with systemic effects
- reflex tachycardia secondary to hypotension
- OH
- edema of LE
- syncope
- SOB
- Weakness
- N/V
how do direct vasodilators work?
work directly on smooth muscle cells to cause relaxation and thus reduce afterload and the workload on the heart
how can beta-blockers reduce afterload?
reduce vascular smooth muscle contraction and SVR