The 12 Leads of Christmas: V1

This article is the seventh in our latest series, The 12 Leads of Christmas, where each day we examine a new finding particular to an individual electrocardiographic lead.

Lead V1

Happy New Year everyone! Today’s post is going to be a bit of a hodge-podge as I recover from yesterday’s post on ST-elevation in aVR. Let’s talk about V1!

Brugada Syndrome

Like yesterday’s topic, we’ve reached the point where it seems like almost too many people are now aware of Brugada syndrome. It’s not a problem to have more people aware of a deadly disease, but it does become an issue when the general understanding of the topic becomes muddled. At present there is a lot of confusion over:

  • What is required to diagnose a patient with Brugada syndrome?
  • What is the significance of the three right-precordial ST-patterns originally described?
  • What role do 2nd and 3rd ICS electrode placement have in the diagnosis?
  • Do patients need a history of syncope, sudden death, or documented ventricular arrhythmias to qualify for the diagnosis?
  • What do I do with the patient who is asymptomatic but shows a spontaneous Brugada-type pattern?
  • What do I do with the patient who is febrile or on a sodium channel blocker and shows a type I pattern without documented syncope or ventricular arrhythmias?

I also see a lot of people who think every RBBB or incomplete-RBBB they come across is diagnostic of Brugada syndrome and that’s just silly.

There are several different consensus guidelines floating around but here are a few of the best resources I’ve found.

  1. Current electrocardiographic criteria for diagnosis of Brugada pattern: a consensus report. With Dr. Bayés de Luna as the lead and Josep, Pedro, and Ramon Brugada included as authors, this paper is obviously a must-read. It mostly covers the details of what sort of morphologies looking for on the ECG.
  2. HRS/EHRA/APHRS Expert Consensus Statement on the Diagnosis and Management of Patients with Inherited Primary Arrhythmia Syndromes. Section 3 covers Brugada syndrome, and while these guidelines are somewhat over-simplified and cast a wide net with the criteria for diagnosis, they’re a great starting point.
  3. Management of patients with a Brugada ECG pattern (from the European Society of Cardiology). Not overly detailed but this provides another jumping-off point.

There’s still a lot we have to learn about Brugada syndrome. I’m not comfortable trying to summarize the current general consensus so review the links above and talk to your local electrophysiologist (if you have one) to learn more.

01 - 0389 - 83yo M - 01

It might not been the formal definition requiring > 2 mm of elevation, but this pattern of coved ST-elevation in V1 and V2 certainly matches what we expect to see with a Brugada pattern.

The above EKG was captured by one of our technicians on a patient presenting with fever and malaise. I got pulled in because the team caring for the patient was worried about a STEMI but the Brugada pattern in V1 and V2 is what really caught my eye. That EKG was actually performed with improper precordial lead placement (V1 and V2 were way too high) so I repeated the tracing with correct electrode placement.

02 - 0389 - 83yo M - 02

With proper placement of the right-precordial leads the Brugada pattern mostly disappears.

This patient had no history of syncope, cardiac arrest, ventricular arrhytmias, or family history of the same. Does he patient automatically requite telemetry monitoring until his fever subsides and his fever-induced Brugada pattern disappears? Does he need further workup in the electrophysiologist’s office? He’s 83 years old so that seems unlikely, but what if this was a 45 year old?

I don’t have any good answers, I just want you to be aware that these diagnostic dilemmas exist.


V1 is still great for rhythm identification.

Nothing groundbreaking here. It should be common knowledge at this point that V1 is great for seeing P-waves, but here’s some interesting tracings anyway.

03 - 0060 - 84yo F - 01

Atrial tachycardia with type I AV-block and 4:3 conduction. P-waves are only visible in V1.

04 - 0077 - 87yo M

Sinus rhythm with first-degree AV-block and a PR-interval of approximately 440 ms. P-waves are best visible in V1, buried in the preceding T-wave. This tracing shows that sometimes it’s not the amplitude of the P-waves in V1 that makes them stand out but rather the sharp down-stroke that is sometimes visible.

05 - 0168 - 80yo M -02

Sinus tach with first-degree AV-block and a PR-interval of 400 ms, similar to the last case. What look like P-waves following the T-waves in V2-V5 are really just U-waves.

07 - 1178 - 79yo F - 08

Slow atrial flutter (atrial rate approx 200 /min) with variable conduction. F-waves are really only visible in V1.

08 - 1212 - 83yo F - 01a

Atrial flutter (atrial rate approx 300 /min) with 4:1 conduction. F-waves are really only visible in V1.

09 - 1220 - 01a

Isorhythmic AV-dissociation with an uncertain atrial bradycardia and junctional escape; both at approx 48 bpm. P-waves are only clearly visible in V1.

10 - 1347 - 84yo M - 02

Sinus rhythm with first-degree AV-block and a PR-interval of approximately 320 ms. The presence of P-waves can only be confirmed in V1.

11 - 1415 - 21yo M - 02

Uncertain (?low) atrial bradycardia with P-waves that are best visible in V1.


Make sure you’re putting V1 (and V2) in the right spot!

This is a big problem most everywhere I’ve seen EKG’s performed. No matter how much folks are trained to place V1 and V2 parasternally in the 4th intercostal spaces, there are still people who insist on placing them too high and wide on the chest. It really does affect how the EKG comes out and can even result in patients receiving inappropriate or unnecessary testing. For more on the topic see this awesome posts on how to cure incomplete RBBB and the most difficult step in obtaining an ECG from EMS 12-Lead associate-editor Dr. Brooks Walsh.

12 - 0251 36yo F - 01

V1/V2 were placed too high, resulting in a false incomplete-RBBB pattern in V1.

13 - 0251 36yo F - 02

Correction of the right-precordial leads led to resolution of the “abnormality.”



14 - 1180 - 62yo F - 01

While this patient does have an intraventricular conduction delay at baseline, improper lead placement led to the presence of an rSr’ pattern in V1.

15 - 1180 - 62yo F - 02

The rSr’ pattern resolved with correction of the lead positioning. This pattern of IVCD now matches the patient’s baseline.



16 - 1439 - 15yo M - 03

EKG of a 15yo with syncope shows a prominent rSr’ pattern in V1 due to V1 and V2 being placed too high.

17 - 1439 - 15yo M - 02

His EKG normalized (for age) with correction of the right-precordial lead placement. This is a huge change from the prior EKG.



18 - 1390 - 26yo M - 01

There is a very prominent RSr’ pattern in V1 in this patient presenting with intermittent palpitations. V1 and V2 were placed way too high on the initial ECG.

19 - 1390 - 26yo M - 02

Correction of the right-precordial lead placement resulted in normalization of the complexes in V1 and V2 (though this EKG is still a bit abnormal). This is a huge change from the prior tracing.


I hope you’re enjoying our 12 Leads of Christmas series. You can check out the rest of the posts below (updated as new posts come out):

12 Leads of Christmas: Lead I
12 Leads of Christmas: Lead II
12 Leads of Christmas: Lead III
12 Leads of Christmas: aVL
12 Leads of Christmas: aVF
12 Leads of Christmas: aVR
12 Leads of Christmas: V2
12 Leads of Christmas: V3
12 Leads of Christmas: V4
12 Leads of Christmas: V5
12 Leads of Christmas: V6


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