Cardiovascular conditions:

Question 1

Cardiac dysrhythmias:

Answer 1

• dysrhythmias are disorders of impulse formation, conduction of impulses or both
• common dysrhythmias include bradycardia, tachycardia, atrial fibrillation, premature atrial contractions and heart block

Question 2

Causes of dysrhythmias:

Answer 2

• irritable foci - areas other than the SA node firing off impulses
• Ischaemia and myocardial damage
• anxiety, stress, caffeine or nicotine, medications and fatigue
• secondary to disease in another body system e.g. hyperthyroidism
• secondary to fluid and electrolyte imbalance

Question 3

Signs and symptoms of dysrhythmias:

Answer 3

• pulse rate, volume or rhythm may be abnormal
• patient may complain of palpitations
• faintness, lightheaded, fatigue
• syncope (transient loss of consciousness) due to inadequate blood flow to the brai

Question 4

Sinus bradycardia:

Answer 4

• S&S:
• hypotension
• pale, cool skin, weakness, angina
• dizziness, syncope
• confusion, disorientation, shortness of breath
• Treatment:
• atropine, pacemaker, stop any medication causing bradycardia

Question 5

Sinus tachycardia:

Answer 5

• S&S:
• dizziness, dyspnea, hypotension, angina
• Treatment:
• guided by cause (e.g. treat pain)
• vagal maneuver
• beta blockers

Question 6

Premature atrial contraction:

Answer 6

• palpitations, heart “skips a beat”
• Treatment:
• monitor for more serious dysrhythmias
• withhold sources of stimulation
• B-adrenergic blockers

Question 7

Paroxysmal supraventricular tachycardia (PSVT):

Answer 7

• HR is 150-220 beats per minute
• Clinical significance:
• cardiac output, stroke volume
• hypotension, dyspneoa, angina
• Treatment:
• vagal stimulation, IV medications
• calcium channel blockers
• anti-dysrythemic drugs

Question 8

Atrial flutter:

Answer 8

• 200-350 beats per minute
• ‘sawtooth’ shaped flutter waves
• Treatment:
• medications
• electronical cardioversion
• ablation of irritable foci

Question 8

Atrial fibrillation:

Answer 8

• Clinical significance:
• causes a decrease in cardiac output and an increased risk of a stroke
• Treatment:
• drugs to control ventricular rate and/or convert sinus rhythm (e.g. digoxin)
• electrical cardioversion
• anticoagulants
• ablation

Question 9

Ventricular tachycardia:

Answer 9

• ventricular rate is 150-250 beats per minute
• ectopic foci take over as pacemaker
• precipitating causes must be identified and treated (e.g. hypoxia)
• VT with pulse (stable) treated with antidysrhythmic drugs of cardioversion
• pulseless VT treated with CPR and rapid defibrillation

Question 9

Third-degree AV heart block:

Answer 9

• AKA complete heart block
• AV dissociation in which no impulses from the atria are conducted to the ventricles

Question 10

Ventricular fibrillation:

Answer 10

• multiply ectopic foci in the ventricle
• no effective contraction and consequently no cardiac output occurs

Question 11

Asystole (flatline):

Answer 11

• represents total absence of ventricular electrical activity
• no ventricular contraction
• patient unresponsive, pulseless, apnoeic
• must assess in more than one lead

Question 12

Pacemakers:

Answer 12

• used to pace the heart (atria and/or ventricles) when the normal conduction pathway is damaged
• most pace on demand, firing only when the heart rate drops below present rate