EKG of the Week 2019 3-17

This EKG comes courtesy of Dr. Podlog, Dr. Zhi, and Dr. S. Hassan.

 

An 83 year old female presented to the emergency department complaining of dizziness and sob on exertion for two days. Her first EKG is below (EKG A):

2019 3-17a.jpg

She later had a second EKG (EKG B):

2019 3-17b.jpg

 

1.    What does EKG A demonstrate?

2.    What does EKGB demonstrate?

3.    How would you manage this patient?

ANSWER:

EKG A shows a 2:1 AV block with a ventricular rate of 40.

EKG B shows a 3rd degree AV block.

The patient should have a pacemaker placed.

 

The patient presented with dizziness and SOB and was found to be bradycardic. The EKG helps elucidate the type of bradycardia.

EKG a shows bradycardia with the presence of P waves but some dropped P waves. This can occur in 2nd degree or 3rd degree AV block. On EKG A, it appears that some P waves are followed by QRS complexes and others are not. This is consistent with 2nd degree AV block. Every 2nd P wave is dropped, so we can not tell if it is 2nd degree type I or 2nd degree type II.

However, on the repeat EKG, there appears to be no relationship between the P waves and the QRS complexes. The R-R intervals are regular and the PR intervals are irregular. This is consistent with 3rd degree AV block.

Patients with 2nd degree AV block can progress to 3rd degree AV block. Close monitoring is essential. Also, running a loner rhythm strip or frequently repeating the EKG can be helpful to allow you to identify higher grade AV block.

Patients with symptomatic 3rd degree AV block require pacing. Prehospital, these patients should be treated with transcutaneous pacing. In the hospital, a transvenous pacemaker should be placed.

Our patient had a transvenous pacemaker placed. EKG C is the repeat EKG after the pacemaker:

2019 3-17c.jpg

The following algorithm is helpful in diagnosing bradycardias on EKG:

Bradycardia algorithm.jpg

EKG of the Week 2018 9-9

This EKG comes courtesy of Dr. Yousseff.

A 25 year old male presented to participate in an elective research study. He had no complaints. A screening EKG was performed.

Vital Signs: Pulse – 50, R -16, BP 120.70.

His EKG is below.

2018 9-9.jpg

1.       What is the rhythm?

2.       How would you manage this patient?

ANSWER:

The rhythm is 3rd degree AV block. In this patient it turned out to be congenital.

This patient is asymptomatic. In asymptomatic congenital complete AV block, no specific treatment is needed.

 

The EKG demonstrates a bradycardia with dropped P waves, regular R-R intervals and irregular P-R intervals. This is consistent with 3rd degree AV block.

In congenital 3rd degree AV block, treatment depends on whether or not the patient has structural cardiac abnormalities. If the echocardiogram demonstrates structural abnormalities of the heart, treatment includes placement of a permanent pacemaker. If there are no structural abnormalities and the patient is asymptomatic, pacemaker placement can be delayed.

In this patient, he remembered being told as a child that he had “some kind of block in his heart”. He in fact had congenital 3rd degree AV block. His echo was normal. So, placement of a pacemaker was delayed. Ultimately most of these patients become symptomatic at some point in their life and they then require pacemaker placement.

The algorithm below is helpful for diagnosing bradyarrhythmias.

Bradycardia algorithm.jpg

EKG of the Week 2018 7-29

An 82 year old female presents for light-headedness. She states she feels weak and feels like she will pass out. No chest pain, no SOB.

Vital signs: Pulse – 45, BP 100/70, Respirations – 16.

Her EKG is below.

2018 7-29.jpg

1.       What does the EKG demonstrate?

2.       How would you manage this patient?

 

ANSWER:

The EKG shows 3rd degree AV block.

Pacing pads should be placed on the patient’s chest. Causes of the AV block should be sought and corrected.

 

The EKG shows a bradycardia, with the presence of P waves and some dropped P waves (i.e. P waves without a QRS following it).

2018 7-29 dropped P waves.jpg

This can be caused by 2nd degree or 3rd degree AV block. Differentiating these can sometimes be difficult. First, measure the R-R intervals. If they are irregular, you are likely dealing with a 2nd degree AV block (likely type I). If the R-R intervals are regular, you should then measure the P-R intervals. If the R-R intervals are regular and the P-R intervals are also regular, you are again dealing with a 2nd degree AV block (likely type II). If the R-R intervals are regular and the P-R intervals are irregular, that is consistent with 3rd degree AV block.

On this EKG, the R-R intervals are regular…

2018 7-29 R-R intervals are regular.jpg

…and the P-R intervals are irregular:

2018 7-29 P-R interals are different.jpg

This is consistent with 3rd degree AV block.

The algorithm below may be helpful:

Algorithm 2nd degree vs 3rd degree AV block.jpg

The management of 3rd degree AV block depends on the patient’s stability and symptoms.

First look for correctable causes such as medication toxicity (beta blockers, calcium channel blockers, digoxin), or electrolyte abnormalities (hyperkalemia). If none of these exist and the patient is unstable they should have an emergent pacemaker placed. If the patient is stable, pacing pads should be placed on the chest in case the patient deteriorates and you need to start pacing them quickly. Otherwise they can then be observed until a permanent pacemaker can be placed.

EKG of the Week 2017 4-2

This EKG comes courtesy of Dr. Adamakos.

An 88 y/o male presented to the ED after syncopal episode. Vital signs: Pulse 40, Respirations 14, BP 130/80. The EKG is below.

1.       What rhythm is demonstrated on this EKG?

2.       How would you manage this patient?

 

ANSWER:

The rhythm is 3rd degree AV block (AKA complete AV block).

The patient is stable. Atropine can be attempted but is unlikely to be successful. Pacing pads should be placed on the chest. A cause of the heart block should be sought.

 

The EKG demonstrates a bradycardic rhythm at a rate of approximately 30. P waves are present but there are dropped P waves. The RR intervals are regular and the PR intervals are irregular. This is consistent with 3rd degree AV block.

Differentiating 2nd degree from 3rd degree AV block can sometimes be difficult. The following algorithm is useful.

If the patient is unstable, they should be treated with a transcutaneous pacer followed by a transvenous pacer. If the patient is stable, reversible causes should be sought. These include hyperkalemia, and toxicity from digoxin, beta blockers or calcium channel blockers. If no reversible cause is identified, the patient will need a permanent pacemaker.

 

This EKG comes courtesy of Paramedic Guttman!

67 y/o male with a history of MS c/o chest pain and weakness.
The following rhythm strips are obtained.

1. How would you describe this rhythm?
2. How would you manage this patient?

 

ANSWER:

The rhythm strip begins with an escape rhythm (likely junctional) followed by a very long pause with complete AV block and no escape rhythm. It then converts back to a junctional escape rhythm.

The patient should be treated with pacing if they are symptomatic or if the escape rhythm does not return.

 

The rhythm begins with a wide complex rhythm at a rate of 60 with absent P waves.

Escape rhythms can be junctional or ventricular. Junctional rhythms are usually at a rate of 45-60. They usually have a narrow QRS complex unless the patient has an underlying bundle branch block. Ventricular escape rhythms are usually at a rate of 30-45 with a wide QRS complex. Our patient has an underlying bundle branch block. The initial rhythm likely represents a junctional escape rhythm.

After the first four beats there is a long pause. Pauses on EKG can be caused by: 1) non-conducted PAC’s (most common cause); 2) sinus node disease (Sinus arrest or SA block); 3) AV block.

In a non-conducted PAC, you will see a P wave that comes earlier than expected with no QRS complex following it. This happens because the PAC occurs so early that when it hits the AV node, it is still refractory. The P wave may come so early that it is buried in the preceding T wave just before the pause. Look back at the last T wave before the pause and see if it looks different than the other T waves on the strip. If it looks different, it might be because there is a P wave buried in that T wave. An example is below.

In sinus node disease, you will see a pause with no P waves. In sinus arrest, the SA node takes a little vacation and doesn’t fire. So there will be a pause with no P waves and the length of the pause will be random. In SA block, the SA node continues to fire but can’t depolarize the atrium. So, again there are absent P waves, however the length of the pause will be a multiple of the normal P-P length. Meaning, if you make believe a P wave happened during the pause at it’s expected location, the next P wave will come on time. An example is attached.

Finally, if the pause is due to AV block (2nd or 3rd degree), there will be P waves coming on time with no QRS complex following. Differentiate 2nd degree from 3rd degree and 2nd degree type I from type II the same way you would in any other AV block.

The following algorithm is useful in diagnosing pauses:

In our patient, there is a long pause. There are P waves present and they do not come earlier than expected. So, they are not PAC’s. Since there are P waves present during the pause, it is not sinus arrest or SA block. So, we are dealing with an AV block. In this case there are P waves only with no QRS complexes at all. So, there is no conduction to the ventricles at all so we are dealing with a 3rd degree AV block. Usually a 3rd degree AV block is accompanied by an escape rhythm. During this long pause, there is no escape rhythm that kicks in. Later on the strip (b), the junctional escape rhythm returns.

Patients with long pauses that are symptomatic or unstable should be treated with transcutaneous (pre-hospital) or transvenous (in-hospital) pacing.

Our patient had a cardiac cath which showed clean coronaries. He then had a permanent pacemaker placed.