Basic Arhythmias

Question 1

Characteristics of normal sinus rhythm

Answer 1

60-100 bpm
P-P interval regular, R-R interval regular
Positive P wave in lead II, one precedes each QRS, P waves look alike
PR interval .12-.2 seconds, constat from beat to beat
QRS less than .1 sec

Question 2

Sinus bradycardia

Answer 2

rate less than 60 bpm

everything else is the same as normal

Question 3

sinus tachycardia

Answer 3

rate more than 100 bpm, otherwise the same as normal sinus rhythm

Question 4

atrial flutter

Answer 4

atrial rate 250-400 bpm, ventricular rate variable
Rhythm: atrial regula, ventricular regular OR irregular if AV blockade exists
No identifiabl P waves, saw-toothed “flutter” waves present
PR interval not measurable
QRS less than .1 sec

Question 5

atrial fibrillation

Answer 5

rate: atrial rate 400-600 bpm; ventricular rate variable
ventricular rhythm usually irregularly irregular
No identifiable P waves, fibrillatory waves present; erratic, wavy baseline
PR interval not measurable
QRS duration less than .1 sec

Question 6

AV block general characteristics

Answer 6

3 different degrees. Conduction issue between atria and ventricles.

Question 7

First Degree AV block

Answer 7

the hallmark is .2 sec PR interval.
Example of what could do this is hyperkalemia (reduced starting point of the amplitude of AP)
positive P wave in leads, 2,3, aVF

Question 8

Second Degree AV block type I (Mobitz I, Wenckebach)

Answer 8

PR interval progressively lengthens until a P wave occurs without a QRS; PR interval after non-conducted beat is shorter vs one before

Question 9

Second-Degree AV Block type 2 (Mobitz type 2)

Answer 9

rate: atrial rate is greater than venricular rate, ventricular rate is often slow.
rhythm: atrial regular, ventricular irregular
P waves- normal, but some not followed by QRS
PR interval- within normal limits or slightly prolonged, constant for conducted beats
QRS duration: less than .1 sec if conduction block is in bundle of his, greater if conduction block is in the bundle branches.

Can be caused by a right coronary stenosis, ischemia in the nodal area, etc.

Question 10

Third-degree AV block

Answer 10

atrial rate is greater than and independent of ventricular rate; ventricular rate determined by origin of escape rhythm
rhythm: regular, but no relationship between atria and ventricles
P waes normal in size and shape
no true PR interval; A-V are independent
QRS .1 if ventricular pacemaker

Question 11

Premature ventricular complexes/ conduction (PVCs)

Answer 11

can be in either ventricle
can be an ectopic focus or reentrant circuit
Sometimes bigeminy (every other), trigeminy (every 3rd), quadreigeminy
Everything regular except with some premature beats

then the upside-down stroke happens

Question 12

ventricular tachycardia

Answer 12

rapid rate: 250-300 bpm
monomorphic or polymorphic
P waves can be absent in the monomorphic, and are always absent in polymorphic
QRS > .12 sec, difficult to differentiate T wave.

Question 13

ventricular fibrillation

Answer 13

no deefinable rate, waves or complexes