Download 09 Antianginal Agents. Antidysrythmic Agents

Antianginal Agents.
Antidysrythmic
Agents
Coronary Ischemia:
Supply and Demand
Economics
Coronary Ischemia:
Supply and Demand Economics
The Grip of Angina
Supply-Demand Mismatch
Oxygen Supply
-Blood Flow
-O2 Carrying
Capacity
Oxygen Demand
-Heart rate
-Contractility
-Wall stress
Myocardial
Oxygen Demand
Heart Rate
Wall Stress
Contractility
Adapted from Runge et al, Netter’s Cardiology
Determinants of Myocardial
Oxygen Supply
Oxygen Delivery
Hgb
O2 Carrying
Capacity
Coronary Blood
Flow
Determinants of Myocardial
Oxygen Supply
Extrinsic
Compression
Perfusion
Pressure
Intrinsic
Vascular
Resistance
Coronary Blood
Flow
O2 Carrying
Capacity
Coronary Flow
Reserve
Adapted from Maseri A, Ischemic Heart Disease, Churchill Livingstone, 1995
Angina Pectoris (Chest
Pain)


When the supply of oxygen and
nutrients in the blood is insufficient to
meet the demands of the heart, the
heart muscle aches.
The heart demands a large supply of
oxygen to meet the demands placed
on it.
Antianginal Agents



Nitrates
Beta blockers
Calcium channel blockers
Antianginal Agents:
Therapeutic Objectives



Minimize the frequency of attacks and
decrease the duration and intensity of
anginal pain
Improve the patient’s functional capacity
with as few side effects as possible
Prevent or delay the worst possible
outcome, MI
Nitric Oxide
Opie LH: Heart Physiology Lippincot Williams & Wilkins, 2004
Antianginal Agents:
Nitrates
Available forms:
Sublingual
Buccal
Chewable tablets
Capsules
Ointments
Transdermal patches
Inhalable sprays
Intravenous solutions
Antianginal Agents:
Nitrates
Side Effects



Headache
– Usually diminish in intensity and
frequency
with continued use
Tachycardia, postural hypotension
Tolerance may develop
Nitrate Tolerance
Occurs with chronic administration
of long acting nitrates.
 Efficacy of drug diminishes with
chronic exposure (tachyphylaxis).
 Tolerance readily reverses with
nitrate free interval.

Adrenergic Receptors
Beta1



Beta-1

SA node, AV node, His-Purkinje
system
Myocardium
Juxtaglomerular apparatus
Adipocytes
Beta2


Beta-2


Alpha
Adapted from Runge et al, Netter’s
Cardiology
Peripheral and coronary
vasculature
Bronchi
Peripheral Muscle
Uterine Muscle
Alpha

Peripheral circulation
Antianginal Agents: Beta
Blockers
Mechanism of Action


Decrease the HR, resulting in decreased
myocardial oxygen demand and increased
oxygen delivery to the heart
Decrease myocardial contractility, helping to
conserve energy or decrease demand
Antianginal Agents: Beta
Blockers
Therapeutic Uses



Antianginal
Antihypertensive
Cardioprotective effects, especially after MI
Antianginal Agents:
Calcium Channel Blockers



verapamil (Calan)
diltiazem (Cardizem)
nifedipine (Procardia)
Role of Calcium Channels in
Myocardial Contraction
Opie LH, Heart Physiology, Williams Lippincott and Williams 2004
Role of Calcium Channel in Vascular
Smooth Muscle Function
Opie LH, Heart Physiology, Williams Lippincott and Williams 2004
Antianginal Agents:
Calcium Channel Blockers
Mechanism of Action



Cause peripheral arterial vasodilation
Reduce myocardial contractility
(negative inotropic action)
Result: decreased myocardial oxygen
demand
Antianginal Agents:
Calcium Channel Blockers
Therapeutic Uses



First-line agents for treatment of angina,
hypertension, and supraventricular
tachycardia
Short-term management of atrial fibrillation
and flutter
Several other uses
Antianginal Agents:
Calcium Channel Blockers
Side Effects


Very acceptable side effect and safety
profile
May cause hypotension, palpitations,
tachycardia
or bradycardia, constipation, nausea,
dyspnea
Treatment of Ischemic
Heart Disease
Antianginal Agents:
Nursing Implications


Patients should not take any medications,
including OTC medications, without
checking with the physician.
Patients should report blurred vision,
persistent headache, dry mouth, dizziness,
edema, fainting episodes, weight gain of 2
pounds in 1 day or 5 or more pounds in 1
week, pulse rates under 60, and any
dyspnea.
Antianginal Agents:
Nursing Implications



Alcohol consumption and hot baths or
spending time in jacuzzis, hot tubs, or
saunas will result in vasodilation,
hypotension, and the possibility of fainting.
Teach patients to change positions slowly to
avoid postural BP changes.
Encourage patients to keep a record of their
anginal attacks, including precipitating
factors, number of pills taken, and
therapeutic effects.
Antianginal Agents:
Nitroglycerin
Nursing Implications
 Instruct patients in proper technique and
guidelines for taking sublingual NTG for anginal
pain.
 Instruct patients never to chew or swallow the
SL form.
 Instruct patients that a burning sensation felt
with SL forms indicates that the drug is still
potent.
Antianginal Agents: Nitroglycerin
Nursing Implications


Patients are taught to take up to three tablets every 5
minutes. If no relief from chest pain is obtained after
three tablets, they should seek medical assistance.
Absorption nitroglycerin ointments best over a
nonfatty and nonhairy portion of skin. The upper torso
is the preferred site of application. The nurse should
wear gloves when applying to prevent transdermal
absorption by the applier. The ointment is measured
as one straight line on the nitroglycerin patch and is
gently spread over paper and applied, but not rubbed,
into the skin.
Antianginal Agents:
Nitroglycerin
Nursing Implications


Instruct patients to keep a fresh supply of
NTG on hand; potency is lost in about 3
months after the bottle has been opened.
Medications should be stored in an airtight,
dark glass bottle with a metal cap and no
cotton filler to preserve potency.
Antianginal Agents:
Nitroglycerin
Nursing Implications


Instruct patients in the proper application of
nitrate topical ointments and transdermal
forms, including site rotation and removal of
old medication.
To reduce tolerance, the patient may be
instructed to remove topical forms at
bedtime, and apply new doses in the
morning, allowing for a nitrate-free period.
Antianginal Agents:
Nitroglycerin
Nursing Implications



Instruct patients to take prn nitrates at the
first hint of anginal pain.
If experiencing chest pain, the patient taking
SL NTG should be lying down to prevent or
decrease dizziness and fainting that may occur
due to hypotension.
Monitor VS frequently during acute
exacerbations of angina and during IV
administration.
Antianginal Agents:
Nitroglycerin
Nursing Implications



IV forms of NTG must be contained in glass IV
bottles and must be given with infusion pumps.
Discard parenteral solution that is blue, green,
or dark red.
Follow specific manufacturer’s instructions for IV
administration. Use special IV tubing provided or
non-PVC tubing.
Antianginal Agents:
Calcium
Channel
Blockers
Nursing Implications



Blood levels should be monitored to ensure
they
are therapeutic.
Oral CCBs should be taken before meals and
as ordered.
Patients should be encouraged to limit
caffeine intake.
Antianginal Agents: Beta
Blockers
Nursing Implications



Patients taking beta blockers should monitor
pulse rate daily and report any rate lower
than 60 beats per minute.
Dizziness or fainting should also be
reported.
Constipation is a common problem. Instruct
patients to take in adequate fluids and eat
high-fiber foods.
Antianginal Agents: Beta
Blockers
Nursing Implications


These medications should never be abruptly
discontinued due to risk of rebound
hypertensive crisis.
Inform patients that these medications are
for
long-term prevention of angina, not for
immediate relief.
Antidysrhythmics
Dysrhythmia

Any deviation from the normal rhythm of
the heart
Antidysrhythmics

Drugs used for the treatment and
prevention of disturbances in cardiac rhythm
Heart and Conduction System
Resting Membrane Potential
of a Cardiac Cell
Abnormal Heart Rhythms
Arrhythmia
tachycardia
BPM
150-250
bradycardia
<60
atrial flutter
200-350
atrial fibrilation
>350
prem. atrial cont.
variable
prem. vent. cont.
variable
vent. fibrilation
variable
Premature
Ventricular
Contraction
Action Potential



A change in the distribution of ions
causes cardiac cells to become excited.
The movement of ions across the
cardiac cell’s membrane results in the
propagation
of an electrical impulse.
This electrical impulse leads to
contraction
of the myocardial muscle.
Action Potentials: Phases
(SA Node)
Action Potentials: Purkinje
Fiber
Action Potentials: Intervals
Abnormal Heart Rhythms


Caused by:
– ischemia, infarction, alteration of body
chemicals
Symptoms:
– palpitations, syncope, lightheadedness,
visual disturbances, pallor, cyanosis,
weakness, sweating, chest pain,
hypotension