- A patient's EKG shows QRS complexes that gradually change in size and shape over several beats, appearing to 'twist' around the baseline, before stopping and returning to normal rhythm. The episodes last 15-20 seconds and the patient reports brief dizziness. What rhythm is this?
Answer: Torsades de pointes (polymorphic ventricular tachycardia)
When you encounter rhythm strips showing QRS complexes that change in morphology and appear to "twist" around the baseline, you're looking at a distinctive ventricular arrhythmia pattern that requires careful analysis.
The key features described—QRS complexes that gradually change size and shape, creating a "twisting" appearance around the baseline, lasting 15-20 seconds with spontaneous termination—are pathognomonic for torsades de pointes. This polymorphic ventricular tachycardia gets its name from the French phrase meaning "twisting of the points," perfectly describing the characteristic EKG appearance. The brief dizziness reflects hemodynamic compromise during the episode, which is typical since ventricular rates are often 200-250 bpm.
Choice A correctly identifies this classic presentation. Choice B, ventricular tachycardia with variable morphology, is tempting but lacks the specific "twisting" pattern—regular VT typically maintains more consistent QRS morphology even when variable. Choice C, atrial fibrillation with rapid ventricular response, would show irregularly irregular rhythms with normal QRS width (unless aberrantly conducted), not the wide, polymorphic complexes described. Choice D, ventricular flutter, presents as a sinusoidal pattern without discrete QRS complexes and rarely converts spontaneously.
For EKG technician exams, remember that torsades de pointes has three hallmark features: polymorphic wide QRS complexes, the characteristic "twisting" appearance, and often self-termination. When you see descriptors like "twisting around the baseline" or "changing morphology," torsades should immediately come to mind. This rhythm is also associated with prolonged QT intervals, though that wasn't mentioned in this scenario.
- A patient's rhythm strip shows normal sinus rhythm with occasional wide QRS complexes that occur earlier than expected. These ectopic beats are followed by a pause. When you measure the interval from the beat before the ectopic to the beat after the pause, it equals exactly two normal R-R intervals. What type of rhythm abnormality is this?
Answer: Premature ventricular contractions with compensatory pauses
When analyzing rhythm strips with ectopic beats, you need to examine three key features: the morphology of the abnormal beat, its timing, and the type of pause that follows.
The description reveals classic characteristics of premature ventricular contractions (PVCs). The wide QRS complexes indicate the ectopic beats originate from the ventricles rather than above the AV node, since ventricular depolarization spreads abnormally through cardiac muscle instead of the efficient conduction system. The "earlier than expected" timing confirms these are premature beats.
Most importantly, the pause measurement is diagnostic. When the interval from the beat before the PVC to the beat after the pause equals exactly two normal R-R intervals, this defines a compensatory pause. This occurs because the PVC doesn't reset the sinoatrial node's timing - the SA node continues its regular rhythm uninterrupted, making the next normal beat arrive precisely when it would have if you counted two normal cycles from the pre-PVC beat.
Option A is incorrect because PACs typically have narrow QRS complexes and usually cause non-compensatory pauses that reset the SA node. Option B fails because junctional beats also produce narrow QRS complexes, and their pauses are typically non-compensatory. Option C describes escape beats, which are late rescue beats that occur when the normal pacemaker fails - the opposite of premature beats.
Study tip: Remember the compensatory pause formula: if (pre-ectopic beat to post-pause beat) = 2 × (normal R-R interval), you're looking at PVCs with compensatory pauses. This measurement alone can distinguish PVCs from other ectopic rhythms.
- A patient with a history of heart attack develops premature ventricular contractions showing three different shapes, occurring 8 times per minute. Occasionally two PVCs occur back-to-back. The patient has no symptoms. What should the EKG technician do?
Answer: Notify the nurse or physician about the PVC frequency and patterns
When you encounter PVC patterns on an EKG, you need to assess both frequency and morphology to determine the urgency of intervention. This question tests your understanding of when PVC characteristics warrant immediate notification versus routine documentation.
The correct action is C) Notify the nurse or physician about the PVC frequency and patterns. This patient presents multiple concerning features: multifocal PVCs (three different shapes indicating multiple ectopic foci), a frequency of 8 per minute, occasional couplets (back-to-back PVCs), and a history of myocardial infarction. Even though the patient is asymptomatic, these patterns suggest electrical instability that could progress to more dangerous arrhythmias like ventricular tachycardia or ventricular fibrillation.
Option A is incorrect because asymptomatic status doesn't eliminate the need for intervention when PVC patterns are this concerning. The combination of multifocal morphology and couplets requires immediate attention regardless of symptoms.
Option B misses the point entirely - changing paper speed won't address the clinical significance of these dangerous PVC patterns.
Option D represents dangerous delay. Waiting an hour with these high-risk PVC characteristics could allow progression to life-threatening arrhythmias, especially in a post-MI patient with compromised cardiac tissue.
Remember this key principle: As an EKG technician, when you see multifocal PVCs, couplets, or high PVC frequency (especially >6 per minute), always notify clinical staff immediately. The patient's symptom status doesn't override the electrical instability these patterns represent.
- An EKG technician observes a rhythm where every third beat is a wide, early QRS complex with a compensatory pause. These ectopic beats have consistent morphology. When the patient moves or coughs, additional similar wide complexes occur rapidly in succession. What should the technician do?
Answer: Immediately notify the nurse or physician about the concerning rhythm changes
The baseline rhythm shows ventricular trigeminy (every third beat is a PVC). The concerning feature is that physical stress provokes additional rapid ventricular ectopy, which could indicate electrical instability. This change in pattern requires immediate notification of clinical staff. This is not normal variation (A), and while checking connections (D) is good practice, the clinical correlation with movement suggests real ectopy rather than artifact.
- While monitoring a patient, you notice the rhythm changes from normal sinus rhythm to an irregular, chaotic pattern with no identifiable QRS complexes and a wavy baseline. The patient becomes unresponsive. What is your most critical immediate action as an EKG technician?
Answer: Immediately call for emergency assistance and prepare for CPR
This describes ventricular fibrillation - a chaotic rhythm with no identifiable QRS complexes and immediate loss of consciousness. VF is a life-threatening emergency requiring immediate activation of emergency response and CPR. While checking connections (A) is normally good practice, the clinical correlation of unresponsiveness confirms this is a real emergency, not artifact.
