The document discusses cardiac medications and their role in managing conditions like angina, hypertension, and cardiac failure, emphasizing cardiac output's dependence on heart rate and stroke volume. It details various medication groups, including beta blockers, calcium channel blockers, nitrates, ACE inhibitors, diuretics, and digoxin, explaining their mechanisms and effects on the heart and kidneys. Nursing actions are outlined, highlighting the importance of monitoring patient symptoms, educating caregivers, and ensuring proper medication management.

1. CARDIAC
MEDICATIONS

2. Cardiac Output (CO)
 CO is the product of heart rate (HR) & stroke
volume (SV)
 SV is the amount of blood ejected from the
ventricles with each beat – average is approx
70mls
 SV is affected by preload, contractility & after
load

3. Preload
- the stretch of the ventricle at the end of diastole
- the amount of stretch decides the amount of blood
ejected
- volume administration is used to increase preload
- ventricular myocardium responds by contracting
more forcefully
- care must be taken not to overstretch the
myocardium

4. Contractility
- the force of the myocardial contraction for a given
preload
- the ability of the ventricles to increase stroke volume
- affected by electrolytes Na+, K+, Mg, Ca2+, Ph, +ve
& -ve inotropes preload & after load
- affected by oxygenation, areas of damage & disease
& ischaemic

5. After load
- the resistance of the arteries against
ejection
- increasing after load reduces stroke
volume
- increases cardiac workload
- a reduction in after load will reduce
preload with dilated vessels

6. Reasons for using
cardiac medications
 Angina
 Hypertension
 Arrhythmias
 Cardiac failure
 Fluid retention leading to cardiac conditions

7. Medication Groups
BETA BLOCKERS
- action on the sinus node
- if conduction is blocked then HR is
decreased leading to a fall in BP
- more reserve to increase HR without
angina on exertion
- caution in asthma and COPD as affects
all smooth muscle
- used for relief from angina, HT,
arrhythmia

8. Medication Groups cont’d
CALCIUM CHANNEL BLOCKERS
- action on Ca2+ transfer in cell function
affecting muscle contraction
- if blocked, contraction slows & strengthens
- Nifedipine/Felodipine acts on blood vessels
- Verapamil/Diltiazem acts on the heart muscle
- used for relief from angina, HT, arrhythmia

9. Medication Groups cont’d
NITRATES
- action has direct effect on veins
- dilates veins so less blood is returning to the heart,
therefore, the heart does not have to pump so hard
and fast (systole)
- resting phase is longer hence allowing more blood
and O2 to the myocardium (diastole)
- used for relief from angina, HT & cardiac failure

10. Medication Groups cont’d
ACE INHIBITORS
[Angiotensin Converting Enzyme]
- action affects both the heart and kidneys
- kidneys detect changes in BP, releasing renin when BP is low
- renin stimulates angiotension I leading to the development of
angiotension II leading to vasoconstriction
- vasoconstriction affects kidney function, hence lowered diuresis,
conserving fluids
- ACE inhibitors block the cycle
- dilation lowers preload, lowers afterload & increases diuresis
- used for relief from HT & cardiac failure

11. Medication Groups cont’d
DIURETICS
- action is directly on the kidney
- Thiazides work by inhibiting the re-absorption of Na &
Cl in the distal convoluted tubule
- Loop diuretics inhibit Na & Cl absorption in the
ascending loop of Henley
- K+ sparing diuretics act on the collecting tubule
- used for relief from HT & cardiac failure

12. Medication Groups cont’d
DIGOXIN
-action is to inhibit Na/K exchange across the cell membrane
- this augments the Ca influx leading to delayed, stronger
contraction
- consider electrolytes as low K enhances digoxin action and
increased K decreases digoxin effects
- belongs to the Glycoside family
- promote nocte administration

13. Medication Groups cont’d
SUMMARY
- usually cardiac medications work in combination
- withholding 1 medication may interrupt the
‘combination action’
- symptomatic patients must be assessed by medical
staff to address the cause
- if apex < 60bpm or BP low & patient is asymptomatic,
continue medications, report to medical staff

14. Nursing actions
 Learn the cardiac medication groups
 Record apical beats & document in medication chart
 Consider ‘combination effects’ – avoid with-holding medications
 Evaluate patient symptoms – medical review if required
 Consider patient monitoring – P [apex beat], RR, BP, SaO2, fluid
intake/output, weight
 Consider modifying activity i.e. patient position change, escort

15. Nursing actionscont’d
 Teach other staff i.e. HCA - FBC, accurate weighing,
patient position change, escorting
 Consider medication options if NBM or pre-
operatively
 Communication with team
 Documentation – include updated nursing care plan
& risk assessments
 Accurate handover considering risks

16. Nursing actionscont’d
Educate
Patient/Family/Caregivers/Whanau
 Medication actions & benefits
 Diet (low Na, alcohol, weight reduction)
 Smoking cessation
 Cholesterol/BP/weight monitoring
 Reporting of oedema, SOB, dyspnoea
 Exercise program
 Cardiac rehab/educator/dietician/case
manager/support groups

17. References
 MIMS online
 Pirret, A. (2005). Acute care nursing. A physiological approach to
clinical assessment and patient care. Pirret: Auckland.