cardiac 2

Question 1

Diuretics

Answer 1

• Lower BP by decreasing blood volume. They
do this by reducing the reabsorption of NaCl
(Sodium Chloride) and water by the renal
tubule in the nephron of the kidney.

Question 2

types of diuretics

Answer 2

– 1. Thiazide Diuretics
– 2. Loop Diuretics
– 3. Potassium sparing diuretics

Question 3

Thiazide (diuretic)

Answer 3

– Act on the
early distal tubule to
block reabsorption of
Na, Cl and H2O.
Excretion of K is
increased.

Often first medication of choice in pt’s with normal renal function
• Also known as non-potassium sparing diuretic
• They are low cost and work well with beta blockers (discussed later)
• They act by inhibiting the reabsorption of sodium, chloride and water
in the distal renal tubule
• Used to treat hypertension and oedema resulting from cardiac failure,
liver disease and nephrotic syndrome
• Compared with loop diuretics, potency is lower with a slower onset
and longer duration of action (12 hours)
• Examples include:
– Bendrofluazide (Aprinox)
– Chlorothiazide (Chlotride)
– Hydrochlorothiazide (Dichlotride)
– Indapamide (Natrilix, Natrix SR)

Question 4

Loop (diuretic)

Answer 4

– Act on ascending
loop of Henle to block
reabsorption of Na, Cl
and H2O. Excretion of K
is increased

Most potent diuretics available
• Also known as non-potassium sparing diuretics.
• They are generally used on patients with renal impairment.
• They act by limiting the amount of sodium reabsorbed in the
peritubular capillaries surrounding the loop of Henle. The Loop
diuretics also block the reabsorption of calcium and magnesium.
• Often used in pt’s with CCF no longer responding to thiazide diuretics
• Frusemide (Lasix)
• Bumetamide (Burinex)
• Ethacrynic Acid (Edecril)
• Often given in conjunction with a potassium supplement e.g. Slow K,
Span K, Chlorvescent.
• ADVERSE EFFECTS are similar to Thiazide diuretics

Question 5

Potassium sparing (diuretic)

Answer 5

– Act
on late distal tubule and
reduce secretion of
potassium

Act on the distal end of the renal tubule so potassium is
retained and not excreted.
• Have a weaker action than the thiazide and loop diuretics
• Tend to be used in combination with thiazide diuretic. Eg.
Moduretic is a combination of hydrochlorothiazide and
amiloride.
• If used on own can lead to hyperkalaemia.
– Spironolactone (Aldactone)
– Amiloride (Midamor)

Question 6

ANGINA PECTORIS and drugs used

Answer 6

• Medical term for ‘chest pain’ caused by myocardial ischaemia
• The lumen size of the coronary arteries is reduced due to:
– 1. Atherosclerotic plaque
– 2. Coronary vasospasm
• Drugs used for treatment 
– Peripheral vasodilators
– Selective coronary vasodilators
– Beta adrenergic antagonists 
– Calcium channel blockers

Question 7

ANGINA PECTORIS:

1.Peripheral Vasodilators

Answer 7

• Method of Action
– These drugs act directly on vascular smooth muscle,
primarily veins, to cause relaxation and therefore dilation.
– Dilation of veins results in peripheral pooling of blood.
This in turn results in decreased venous return and a
decreased workload of the heart.
– Dilation of arteries leads to decreased peripheral
resistance. The heart doesn’t have to pump so hard to get
blood into the arteries as their diameter is wider

Question 8

ANGINA PECTORIS:

2. Selective Coronary Vasodilators

Answer 8

• Used prophylactically, not for an acute attack.
• E.g. Dipyridamole (Persantin) – causes
coronary artery vasodilation. Also used as an
anti-platelet drug. Not as commonly
prescribed these days.

Question 9

2 functions for heart to effectively pump

Answer 9

electrical: needs electrical current to stimulate an effective cardiac output
Mechanical: muscle need to contract and relax to pump blood around body.

Question 10

how to find issue with electrical heart

Answer 10

ecg - electrocardiogram

Question 11

how to find mechanical heart problems

Answer 11

decreased cardiac output, bradycardia, tachycardia, irregular or no pulse

Question 12

types of cardiac disorders

Answer 12

• congestive cardiac failure (CCF)
• hypertension
• angina / acute myocardial infarction (AMI)
• cardiac dysrhythmias
• coagulopathies
• high cholesterol

Question 13

• Inotrope (effect)

Answer 13

– Effect on the force of contraction of the heart
• Positive – increase e.g. Digoxin
• Negative – decrease e.g. Propanolol

Question 14

• Dromotrope (effect)

Answer 14

– Effect on the speed of conduction through the AV node
• Positive – increase conduction e.g. Dilantin
• Negative – decrease conduction e.g. Verapamil

Question 15

Chronotrope (effect)

Answer 15

– Effect on the rate of impulse formation in SA node
• Positive – increase heart rate e.g. Adrenaline
• Negative – decrease heart rate e.g. Digoxin

Question 16

major antihypertensive medication

Answer 16

– A: ACE Inhibitors
– B: Beta blockers
– C: Calcium channel blockers
– D: Diuretics

Question 17

Dysrhythmia

Answer 17

refers to an abnormality in the rhythm of the
heart associated with an impairment of the conduction
system