Cardiology

Front 1

Outline the mechanism by which arrythmias arise in heart failure

Back 1

rapid ventricular response & loss of effective atrial contraction → systolic failure

• All arrythmias are more frequent in HF
• The more severe the underlying heart disease, the more severe & frequent the arrythmias
• Tx of HF must include Tx of arrythmia

^TG

Front 2

Give an example of an arrythmias that causes heart failure. (rare)

Back 2

SVT
(control of the arrythmia can completely reverse HF)

^TG

Front 3

Bradyarrythmias, examples?

Back 3

heart block

^TG

Front 4

Tachyarrythmias, examples?

Back 4

AF
atrial flutter with rapid ventricular response

^TG

Front 5

Types of atrial tachyarrythmias in HF?

Back 5

AF > atrial flutter

^TG

Front 6

Pathophysiology of atrial tachyarrythmias in HF?

Back 6

atrial enlargement → proarrhythmic effect of atrial stretch

^TG

Front 7

Management of substantial atrial enlargement

Back 7

Maintenance of sinus rhythm following reversion is unlikely long term

Therapeutic Options:
* ventricular rate control & antithrombotics

^TG

Front 8

Most sudden deaths in HF is due to

Back 8

ventricular fibrillation ± preceding ventricular tachycardia

^TG

Front 9

All antiarrythmic drugs are

Back 9

proarrythmic

^TG

Front 10

Antiarrythmic drugs can exacerbate which type of arrythmias?

Back 10

Bradyarrythmias

^TG

Front 11

What is the drug of choice to suppress symptomatic ventricular arrythmias in heart failure?

Back 11

amiodarone

^TG

Front 12

Patients with life-threatening ventricular arrythmias should be considered for?

Back 12

Implantable cardioverter-defibrillator (ICD)

^TG

Front 13

Tx Approach to arrythmias in HF?

Back 13

• avoid K+ depletion from diuretics (K+ > 4mM, optimally at 5mM)
• avoid Mg2+ depletion from diuretics
• ACEI / ARB
• Beta blocker
• Avoid cardiac stimulants (milrinone, beta agonists) because of proarrythmic risk
• Avoid class 1 antiarrythmics (flecainide)

^TG

Front 14

Pacemaker vs. ICD

Back 14

Pacemaker - regulate HR such as in bradyarrythmias
ICD - monitors HR & rhythm → sends electric shocks when there are abnormalities

Front 15

Define 1st degree heart block

Back 15

PR interval is fixed but > 0.2s

^djr im

Front 16

Define 2nd degree heart block (Mobitz type 1 or Wenckebach)

Back 16

PR intervals progressively ↑ until a beat is dropped (P wave is not followed by QRS)

^djr im

Front 17

Define 2nd degree heart block (Mobitz type 2)

Back 17

Fixed PR intervals with intermittent dropped QRS complexes

^djr im

Front 18

Define 3rd degree heart block (complete heart block)

Back 18

* Dissociation between atrial & ventricular activity (no relationship between P waves & QRS intervals)
* Uniform P-P and R-R intervals

^djr im

Front 19

Tx for 1st degree heart block

Back 19

no tx

Front 20

Tx for 2nd degree heart block (Mobitz type 1 or Wenckebach)

Back 20

cease offending drug
pacemaker if bradycardic

Front 21

Tx for 3rd degree heart block (complete heart block)

Back 21

pacemaker

Front 22

Tx for 2nd degree heart block (Mobitz type 2)

Back 22

pacemaker to prevent progression to 3rd degree / complete heart block

Front 23

Which drugs cause 2nd degree heart block?

Back 23

digoxin
beta blockers
CCB

Front 24

What is the most common chronic arrythmia?

Back 24

AF

Front 25

Types of Heart Block

Back 25

Front 26

ECG Finding: normal sinus rhythm

Back 26

Front 27

ECG Finding: sinus bradycardia

Back 27

Front 28

ECG Finding: sinus arrythmia

Back 28

Front 29

ECG Finding: AF

Back 29

Front 30

ECG Finding: Pacemaker Rhythm

Back 30

Front 31

ECG Finding: First Degree AV Block

Back 31

Front 32

ECG Finding: 2nd degree AV Block

Back 32

Front 33

ECG Finding: RBBB

Back 33

Front 34

ECG Finding: Sinus Tachycardia

Back 34

Front 35

ECG Finding: atrial flutter

Back 35

Front 36

ECG Finding: junctional rhythm

Back 36

Front 37

ECG Finding: premature ventricular contraction

Back 37

Front 38

ECG Finding: ventricular tachycardia

Back 38

Front 39

ECG Finding: ventricular fibrillation

Back 39

Front 40

ECG Finding: 3rd degree AV block

Back 40

Front 41

ECG Finding: LBBB

Back 41

Front 42

ECG Finding: LVH

Back 42

Front 43

ECG Finding: R/L atrial hypertrophy

Back 43

Front 44

ECG Finding: RVH

Back 44

Front 45

What are the 4 ECG changes with hyperkalemia & what is the order of progression?

Back 45

absent p-wave
nodal rhythm
Widened QRS complex
Peaked T-waves V3-V4

Mild levels of hyperkalaemia are associated with acceleration of terminal repolarisation, resulting in T-wave changes. The most common changes seen in the T-waves are “tenting” or “peaking”, they are considered to be the earliest abnormalities seen in the ECG. Mild to moderate hyperkalaemia causes depression of conduction between adjacent cardiac myocytes, this results in prolongation of the PR and QRS intervals as potassium levels rise. P-wave amplitude disappears early because of the sensitivity of atrial myocytes to hyperkalaemia. As the severity of hyperkalaemia increases, there is further suppression of sinoatrial and atrioventricular conduction, resulting in the appearance of escape beats and escape rhythms. The QRS complex will continue to widen and may blend with the T-wave, creating a sine-wave appearance to the ECG. If the potassium level is allowed to rise without treatment, ventricular fibrillation will result.