COMPREHENSIVE REVIEW 2026
◉ Sinus Bradycardia. Answer: <60bpm
Present in healthy and diseased hearts
Associated with sleep, pain, MI, acute spinal cord injury, drugs
(digitalis, beta-blockers, verapamil, dilitiazem)
In hearts that can't compensate it will lead to low cardiac output.
Tx: none unless symptomatic. Tx can include: atropine or cardiac
pacing.
◉ Sinus tachycardia. Answer: >100bpm
Stress, exercise, stimulants (caffeine & nicotine), fever, anemia,
hyperthyroidism, hypoxemia, HF, shock, drugs-atropine,
epinephrine, dopamine.
Causes inc in O2 demand on myocardium and dec filling time of the
ventricles
Tx: treat underlying cause ie. Sedation, O2 admin, digitalis, diuretics,
beta-blockers
◉ Sinus dysrhythmias. Answer: Shortest RR interval to longest RR
interval varies by >0.12 secs.
Rate can inc with inspiration and dec with expiration
,Normal, especially in young ppl so not necessarily diseased heart
Tx: none, usually asymptomatic
◉ Premature Atrial Contraction (PAC). Answer: Can occur at any rate
The rhythm is irregular because of the early beat but is regular at
other times
There is a P for every QRS and a QRS for every P
The P waves all look the same except the P in front of the PAC will be
different—P wave is buried in the preceding T wave
Causes: emotions, tobacco, alcohol, caffeine, rheumatic heart
disease, ischemic heart disease, mitral stenosis, HF, hypokalemia,
hypomagnesemia, medications, hyperthyroidism, atrial irritability.
Symptoms: Usually asymptomatic, May feel pause or skipped beat,
May lead to atrial fibrillation or other atrial rhythms
Treatment: none
◉ Supraventricular Tachycardia. Answer: A general term used to
describe any narrow tachycardia
Includes:
PSVT
Atrial tachycardia
Multifocal atrial tachycardia
Atrial flutter with 2:1 conduction
, Junctional tachycardia
◉ Paroxysmal Supraventricular Tachycardia (PSVT). Answer: Rate is
between 150 and 250 beats/minute
The rhythm is regular
QRS intervals can be within normal limits
There can be a P wave, but more likely it will be hidden in the T wave
or the preceding QRS wave
Starts and stops abruptlySymptoms:
Palpitations and lightheadedness dependent on the rate and
duration.
Pts wth heart disease can experience: dyspnea, angina, HF d/t dec
ventricular filling and CO
Causes:
May be due to emotions, tobacco, alcohol, caffeine, rheumatic heart
disease, AMI, digitalis toxicity, atrial enlargement, COPD, post-op
heart surgery, anxiety, or stimulant drugs.
Treatment:
Valsalva's maneuver, adenosine IVP, cardioversion.Unstable: HR >
150/min, prepare for immediate synchronized cardioversion. May
give a brief trial of medications based on specific arrhythmias, vagal
maneuvers, adenosine IVP
Stable: adenosine IVP