ECGs part 2

Question 1

ventricular tachycardia

Answer 1

● Run of 3 or more PVCs sequentially; very rapid (100–250 bpm)
● ECG: no P waves, wide and bizarre QRS complex
● Nonsustained ventricular tachycardia (NSVT): up to 30 seconds
➤ Occurs in groups of 3 to 5 PVCs (salvos) or runs of 6 or more PVCs lasting up to
30 seconds
➤ High risk indicator (lethal arrhythmias)
● VT (sustained): lasts at least 30 seconds in duration and is accompanied by a HR of at
least 100 bpm
● Emergency!
● VT is a serious issue → activate EMS!

Question 2

Ventricular fibrillation (V-fib)

Answer 2

● Chaotic activity of ventricle from multiple foci; run of different-looking PVCs
➤ Multifocal
● ECG: P waves and QRS complex cannot be discerned
➤ Multiple ectopic foci
● Emergency! → Call 911 (cardiopulmonary resuscitation [CPR], defibrillator)
➤ Clinical death in 4 to 6 minutes; no CO

Question 3

supraventricular tachycardia

Answer 3

● Supraventricular = above the ventricle
● Supraventricular ectopy: rapid firing of one or more ectopic foci that originates in any location above the ventricles (atrial or junctional area)

● Supraventricular tachycardia: Run of either premature atrial contractions or premature junctional contractions at a rate of 150 to 250 bpm

● ECG: no P waves; narrow QRS complex
● To reduce HR in patients with supraventricular tachycardia
➤ Carotid massage: produces parasympathetic response
➤ Techniques such as coughing or breath holding achieved through the Valsalva
maneuver

Question 4

premature atrial contraction

Answer 4

➤ Single sinus complex occurs earlier than next expected sinus complex
Ectopic beat that originates in atria
➤ P wave of the early beat is noticeably different from normal P waves
Early-beat P wave is buried under T wave
QRS complexes of the early beat and the normal beat should look similar
➤ Usually does not compromise CO
Not an emergency; can continue exercise

Question 5

atrial tachycardia

Answer 5

rapid increased rate (100–250 bpm)
➤ 3 or more PACs in a row
➤ ECG: shortened PR interval
➤ Keep exercising; just monitor

Question 6

atrial flutter

Answer 6

1 ectopic focus (250–350 bpm)
➤ “Sawtooth” appearance of P waves
➤ Stop exercise; refer patient to a physician (not 911)
➤ Relatively non-life-threatening if HR <100 bpm at rest, but can be life-threatening
at higher HRs
➤ Initiate medical treatment if HR is elevated above 100 bpm at rest

Question 7

atrial flutter

Answer 7

irregularly irregular and often very rapid rhythm (400–600 bpm)
➤ Multiple ectopic foci
➤ No true P waves
Rapid irregular atrial contractions (P waves)
Can be common in older individuals as a result of age-related weakness of
the heart
➤ Stop exercise; refer patient to a physician (not 911)
Can exercise in atrial fibrillation if HR <115 bpm (asymptomatic, managed by
MD)