Intro to EKG Interpretation - Practicing Tachyarrhythmia Identification

Summary

In this video, Eric provides practical examples to help diagnose various types of tachyarrhythmias using a simple six-question framework. By analyzing EKG strips, viewers learn to determine key characteristics such as rhythm rate, regularity, QRS width, atrial activity, p-wave relationship, and rhythm onset. With a series of real-life examples, including atrial fibrillation, sinus tachycardia, ventricular tachycardia, and others, Eric walks through the process of making accurate diagnoses. The goal is to make diagnosing tachyarrhythmias more intuitive and efficient, enhancing both knowledge and clinical decision-making.

Takeaways

• 😀 Use the six easy questions to diagnose tachyarrhythmias: rate, regularity, QRS width, atrial activity, relationship of P waves to QRS, and onset/variability.
• 😀 The 10-second rule and 300-rule are useful for estimating the heart rate, especially in irregular rhythms.
• 😀 Atrial fibrillation is identified by an irregularly irregular rhythm with fibrillation waves and no identifiable P waves.
• 😀 Sinus tachycardia is characterized by a regular rhythm, normal P waves, and a consistent PR interval.
• 😀 Wide complex tachycardias with dissociated P waves, such as in ventricular tachycardia, are key to recognizing the rhythm.
• 😀 Atrial flutter is irregularly irregular with flutter waves, and can be accompanied by variable AV block.
• 😀 Polymorphic VT with a long-short pattern is highly indicative of torsades de pointes, which is associated with a prolonged QT interval.
• 😀 Superventricular tachycardia (SVT) has a narrow QRS complex and abrupt onset, often following a premature atrial contraction.
• 😀 To diagnose multifocal atrial tachycardia, look for at least three different P wave morphologies in an irregular rhythm.
• 😀 In cases with unclear diagnosis, additional tests like vagal maneuvers or adenosine administration can help differentiate between SVT and atrial flutter.

Q & A

What are the six easy questions for diagnosing tachyarrhythmias?

The six easy questions for diagnosing tachyarrhythmias are: 1) What is the rhythm's rate? 2) What is the regularity? 3) Are the QRS complexes narrow or wide? 4) What is the atrial activity? 5) What is the relationship of P waves to QRS complexes? 6) Is the onset of the rhythm abrupt or gradual, and does the rate vary?

How do you estimate the rate of a rhythm strip using the 10-second rule?

To estimate the rate using the 10-second rule, count the number of QRS complexes across a 10-second strip and multiply that number by 6. This gives an estimate of the beats per minute.

What does it mean when a rhythm is described as 'irregularly irregular'?

'Irregularly irregular' means that there is no consistent pattern to the spacing between successive QRS complexes. This is often seen in conditions like atrial fibrillation.

What is atrial fibrillation and how can you identify it on an EKG?

Atrial fibrillation is a rhythm where the atrial activity is chaotic with no distinct P waves or flutter waves. On an EKG, you will see small amplitude undulations in the baseline, known as fibrillation waves (f-waves). The rhythm is also irregularly irregular with narrow QRS complexes.

What is the main difference between sinus tachycardia and supraventricular tachycardia (SVT)?

Sinus tachycardia has a regular rhythm, normal P waves, and a gradual onset. SVT, on the other hand, typically has an abrupt onset, no visible P waves, and may have a more erratic or irregular rhythm.

How can you differentiate between wide and narrow QRS complexes?

Narrow QRS complexes (less than 120 milliseconds) typically originate from above the ventricles, while wide QRS complexes (greater than 120 milliseconds) suggest a ventricular origin or bundle branch block.

What is ventricular tachycardia, and how is it identified on an EKG?

Ventricular tachycardia (VT) is characterized by a rapid, regular rhythm with wide QRS complexes. It may present with dissociated P waves, meaning P waves are not related to the QRS complexes, often seen with a monomorphic pattern.

What is atrial flutter and how can it be identified on an EKG?

Atrial flutter is a rhythm where there are flutter waves (sawtooth pattern) at a rate of about 300 beats per minute. It is often seen in the inferior leads and V1, with a characteristic variable AV block, causing a 2:1, 3:1, or other ratios.

What is torsades de pointes and how is it related to prolonged QT intervals?

Torsades de pointes is a form of polymorphic ventricular tachycardia associated with a prolonged QT interval. It often presents with a 'long-short' pattern of RR intervals, with one unusually long RR interval followed by one unusually short one.

How can you identify multifocal atrial tachycardia on an EKG?

Multifocal atrial tachycardia is characterized by an irregularly irregular rhythm, narrow QRS complexes, and at least three different morphologies of P waves. No one P wave morphology is predominant, and the P waves vary in size and shape across leads.