Ken Grauer, MD

MARCH 29, 2023

M Y T houghts on the ECG in Figure-1: I have presented similar ECGs to the one in today's tracing on several occasions ( most recently in ECG Blog #284 ). M y I MPRESSION : The rhythm in Figure -1 is almost certain to be very rapid AFib in a patient with WPW. The patient was hemodynamically stable in association with this rhythm. (

Blog 78

Blog AFIB Arrhythmia Download 78

Ken Grauer, MD

FEBRUARY 28, 2023

By the P s, Q s, 3 R Approach ( See ECG Blog #185 ): Regarding R egularity — the rhythm is irregularly irregular. As a result — IF the 1 lead you are monitoring happens to be one in which P waves are not well seen — then you might assume the irregular rhythm in front of you was AFib. ECG Blog #199 — for Review of M AT.

Blog 78

Blog COVID-19 AFIB Pulmonary 78

Ken Grauer, MD

FEBRUARY 18, 2023

These findings suggest that instead of VT — the rhythm in Figure-1 is AFib with a fairly rapid ventricular response. Since the rhythm is supraventricular (ie, AFib ) — we can accurately assess QRS morphology. Given a lack of prior history — I don’t know if the AFib on ECG #1 is ( or is not ) a new finding.

Blog 78

Blog AFIB Chest Pain STEMI 78

Ken Grauer, MD

JULY 22, 2023

I see the following: Although there is no long lead rhythm strip — we can see that the rhythm is AFib with a controlled ventricular response ( ie, irregularly irregular rhythm without P waves — and with a heart rate between ~70-110/minute ). Regarding Intervals: There is no PR interval ( since the rhythm is AFib ).

Blog 78

Blog Chest Pain STEMI AFIB 78

Ken Grauer, MD

MAY 26, 2023

ECG Blog #185 — Review of the P s, Q s, 3 R Approach for systematic rhythm interpretation. ECG Blog #271 — Reviews the concept of diffuse Subendocardial Ischemia. ECG Blog #316 — The patient died. ECG Blog #184 — That magical inverse relationship between leads III and aVL. ECG Blog #183 — deWinter-like T waves.

Blog 78

Blog Ischemia STEMI Cardiac Arrest 78

Ken Grauer, MD

JULY 9, 2023

By the P s , Q s , 3 R Approach ( See ECG Blog #185 ): The rhythm in Figure-1 is clearly not R egular. PEARL #2: As cited in ECG Blog #252 — my favorite truism in arrhythmia interpretation is, "The commonest cause of a pause is a blocked PAC". ECG Blog #185 — Review of the P s, Q s, 3 R Approach for systematic rhythm interpretation.

Blog 78

Blog Cardiac Arrest Pulmonary AFIB 78

Ken Grauer, MD

MARCH 12, 2023

NOTE: The ECG in Figure-1 has been recorded at the usual 25mm/second speed — but with the Cabrera format ( Please see my Editorial Note near the top of the page in ECG Blog #365 for review of the basics of this recording system ). Among the fast Supraventricular Rhythms: This is not AFib — because the rhythm is regular.

Blog 78

Blog Atrial Flutter Arrhythmia AFIB 78

ECG Cases

OCTOBER 17, 2023

In this ECG Cases blog Dr. Jesse McLaren guides us through 10 cases, driving home the points that sepsis is a common cause of rapid Afib and diffuse ST depression with reciprocal ST elevation in aVR, myo/pericarditis is a diagnosis of exclusion, endocarditis or lyme carditis can cause AV block, PE can cause low grade fever and ECG signs of acute RV (..)

Pericarditis 101

Pericarditis AFIB Blog Atrial Fibrillation 101

Dr. Smith's ECG Blog

DECEMBER 13, 2024

NOTE: The ECGs in today's case are recorded in the Cabrera Format ( See Dr. Grauer Comment in the October 26, 2020 post of Dr. Smith's ECG Blog for review on the Cabrera Format ). KEY Point: Nothing other than AFib with WPW results in a ventricular response this fast ( which is why Figure-2 is pathognomonic for AFib in a patient with WPW ).

AFIB 104

AFIB Atrial Fibrillation Tachycardia Blog 104

Dr. Smith's ECG Blog

FEBRUARY 2, 2024

See our other blog posts of hypothermia and Osborn waves -- Massive Osborn Waves of Severe Hypothermia (23.6 The rhythm is irregularly irregular, and appears to be AFib with a fairly slow ventricular response ( overall rate <70/minute ) — although marked baseline artifact renders the search for atrial activity futile.

Blog 139

Blog Cardiac Arrest Atrial Fibrillation Bradycardia 139

MIBHS

JANUARY 31, 2025

This blog explores the ways wearable technology can help track heart health, the advantages it offers, and how it contributes to better outcomes for those requiring surgical intervention. These early warnings are critical, as AFib increases the risk of stroke and other heart-related complications.

Heart Rhythm 52

Heart Rhythm Technology AFIB Exercise 52

Dr. Smith's ECG Blog

MARCH 7, 2024

This does NOT seem irregularly irregular enough for AFib … Instead — there is almost “group beating” with “Wenckebach periodicity”. The QRS is VERY wide — and the very wide Q in lead I ( showing marked axis deviation ) certainly suggest a ventricular etiology.

Hemorrhage 127

Hemorrhage Chest Pain Article AFIB 127

Dr. Smith's ECG Blog

MAY 7, 2024

Since the ventricular response in ECG #2 is comparable to the rate range for any patient who develops new-onset AFib — definitive diagnosis of WPW was not made in today's case until the 3rd ECG was obtained. FINAL Points in Today's CASE: Even though the SPERRI value during AFib in today's case was not below 250 msec.

Atrial Fibrillation 132

Atrial Fibrillation AFIB Ablation Chest Pain 132

Dr. Smith's ECG Blog

JULY 14, 2024

The rhythm in both tracings in Case #2 shows AFib with a controlled ventricular response ( with a PVC in the 2nd tracing ). Presumably the AFib is not a new rhythm — since new-onset AFib is usually associated with a rapid ventricular response.

AFIB 106

AFIB Stents Stent Chest Pain 106

Dr. Smith's ECG Blog

SEPTEMBER 18, 2024

Is longterm endurance-training a risk factor for AFib and AFlutter? == Why is Today's Initial Rhythm AFlutter? The answer to this question is fascinating — albeit extending beyond the scope of this ECG Blog. Smith immediately say the rhythm was AFlutter with 1:1 AV conduction? Does Exercise Induce Non-Sinus Tachyarrhythmias?

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Atrial Flutter Exercise AFIB Tachycardia 65

ECG Cases

FEBRUARY 28, 2022

Jesse McLaren explains his AFIB mnemonic for approach to atrial fibrillation that involves 4 questions: 1. and runs through 10 cases to elucidate the nuances of atrial fibrillation management on this ECG Cases blog. Is it atrial fibrillation? Does the patient need an anticoagulant started in the ED?

Atrial Fibrillation 52

Atrial Fibrillation AFIB Blog Atrial Flutter 52

Dr. Smith's ECG Blog

FEBRUARY 18, 2024

As I discussed in detail in My Comment at the bottom of the page in the January 13, 2024 post in Dr. Smith's ECG Blog — pacemaker spikes tend to be a high frequency signal. The April 6, 2023 post — excessive baseline artifact misdiagnosed as AFib ( instead of sinus rhythm with AV Wenckebach — as in Figure-4 in this post ).

Pacemaker 110

Pacemaker Blog Atrial Fibrillation Electrophysiology 110

Dr. Smith's ECG Blog

MARCH 28, 2024

I don’t see evidence of retrograde atrial activity during the WCT — but usually with the “almost regular AFib rhythms” — you can when you measure pick up some slight differences — so my hunch is that the initial ECG is a REENTRY SVT rhythm, that then breaks down to AFib. Theoretically — this can occur with BOTH AVNRT and AVRT.

Tachycardia 130

Tachycardia Atrial Fibrillation AFIB Atrial Flutter 130

Dr. Smith's ECG Blog

MARCH 15, 2023

. = My Comment by K EN G RAUER, MD ( 3/15 /2023 ): = I found today’s case highly instructive in highlighting a number of important aspects regarding the presentation and initial treatment of a patient who presents to the ED with new AFib. I focus my comment on a few additional aspects regarding new AFib.

Atrial Fibrillation 52

Atrial Fibrillation AFIB Arrhythmia Exercise 52

Dr. Smith's ECG Blog

AUGUST 18, 2024

As per Dr. Meyers — the underlying rhythm is either slow AFib or a junctional escape rhythm ( There is a fairly-but- not -completely regular underlying bradycardic rhythm — with narrow QRS — and no P waves ).

Pacemaker 111

Pacemaker AFIB Atrial Fibrillation 111

Dr. Smith's ECG Blog

JULY 5, 2018

My Comment , by K EN G RAUER, MD ( 7/5/2018 ): This blog post provides an excellent example of how a patient with SSS ( = S ick S inus S yndrome ) may present. Many patients have a T achy- B rady syndrome in which tachyarrhythmias ( most commonly rapid AFib ) alternate with periods of bradycardia. second in duration.

Atrial Fibrillation 52

Atrial Fibrillation AFIB Bradycardia Pacemaker 52

Dr. Smith's ECG Blog

DECEMBER 26, 2023

For more on Giant T waves — See My Comment at the bottom of the page in the June 22, 2020 and September 19, 2022 posts in Dr. Smith's ECG Blog ). WPW Cardiac arrhythmias ( including AFib ). Depth of the inverted T waves in leads V4 and V5 in Figure-1 attains this range. ( PEARL #1: Truly “giant” T waves are not overly common.

Chest Pain 95

Chest Pain Cardiomyopathy Blog AFIB 95

Dr. Smith's ECG Blog

JUNE 14, 2024

. == Links to Examples of ARTIFACT: What follows below is an expanding list of technical "misadventures" — most from Dr. Smith's ECG Blog — some from other sources ( NOTE: As I did not previously keep track of these — there are additional examples of artifact sprinkled through Dr. Smith's ECG Blog that I have not yet included here. ).

Atrial Fibrillation 82

Atrial Fibrillation Tachycardia Blog Chest Pain 82

Dr. Smith's ECG Blog

JULY 5, 2024

As we often emphasize ( See My Comment in the May 5, 2020 post of Dr. Smith's ECG Blog ) — Statistically (ie, even before we look at the ECG itself ) — at least 80% of all regular WCT rhythms without clear sign of P waves will turn out to be VT ( V entricular T achycardia ). I'd add the following thoughts to Dr. Smith's discussion.

Atrial Flutter 114

Atrial Flutter Tachycardia Atrial Fibrillation AFIB 114

Dr. Smith's ECG Blog

OCTOBER 24, 2024

For "My Take" regarding optimal use of computerized ECG Reports — Check out my ECG Podcast #3 in the July 24, 2024 post in Dr. Smith's ECG Blog ). Learning Points: Today's patient was an older woman with a complex medical history ( including recent ablation of AFib ) — who was on multiple medications including Amiodarone.

Dysrhythmia 111

Dysrhythmia Atrial Fibrillation Bradycardia Ablation 111

Dr. Smith's ECG Blog

JANUARY 9, 2024

The patient also has a history of AFib and HFmrEF ( = H eart F ailure with M inimally- R educed E jection F raction ). I have emphasized on many occasions in Dr. Smith's ECG Blog how AFlutter is by far (!) This patient presented to the ED “after a couple of days of chest discomfort”. Why was it Wrong to Think the Rhythm was AFlutter?

Tachycardia 120

Tachycardia Electrophysiology Atrial Flutter Ischemia 120

Dr. Smith's ECG Blog

SEPTEMBER 24, 2023

This is written by Magnus Nossen, with some edits by Smith This ECG diagnosis will be obvious to the majority of the readers of this blog. Thoughts about Today's CASE: On occasion — a patient may present for acute care because of CP ( C hest P ain ) due solely to a tachyarrhythmia ( including new AFib, a reentry SVT or VT ).

Chest Pain 87

Chest Pain Atrial Fibrillation AFIB Myocardial Infarction 87

Dr. Smith's ECG Blog

MARCH 11, 2020

Therefore — the rhythm in ECG #1 is almost certain to be AFib ( A trial F ibrillation ) , seen here with a “rapid” ventricular response. Under normal conditions with AFib — the refractory period of the AV node does not allow more than 150-to-200 impulses/minute to be conducted to the ventricles.

AFIB 52

AFIB Tachycardia Atrial Fibrillation Arrhythmia 52

Dr. Smith's ECG Blog

MAY 3, 2024

Despite the irregularity of QRS complexes — this rhythm is not AFib — because at least some definite P waves are present ( RED arrows that I added at the bottom of ECG #1 ). Smith has noted — recognition of Shark Fin morphology told us that the seemingly wide and irregular rhythm in Figure-1 was almost certain to be supraventricular!

Cardiogenic Shock 128

Cardiogenic Shock Cardiac Arrest Hospital Ischemia 128

Dr. Smith's ECG Blog

APRIL 24, 2022

Patient was referred to electrophysiologic testing due to suspicion of afib and WPW. During electrophysiologic testing AVRT was induced, which degenerated to afib with ortho and antidromic conduction. Despite the near regularity in places — the reasons I immediately thought of WPW with very rapid AFib were i ) As per per Drs.

AFIB 52

AFIB Tachycardia Atrial Fibrillation Blog 52

Dr. Smith's ECG Blog

SEPTEMBER 12, 2023

Figure-2: A rapid method for estimating the QTc ( Figure from My Comment in the March 19, 2019 post in Dr. Smith's ECG Blog ). == Clinical Implications of a Short QTc: The differential diagnosis for today's tracing, with its short QTc ~360 msec. ) — but as can be seen, my estimate of ~360 msec. mg/dL — vs normal values = 4.4-5.2

Cardiac Arrest 70

Cardiac Arrest Blog Atrial Fibrillation AFIB 70

Dr. Smith's ECG Blog

JANUARY 22, 2020

C linical P oints R egarding E CG # 1 : We are told that the patient is a middle-aged woman and that she previously had been in AFib with LBBB. While I agree that AFib + complete AV block is the most likely rhythm diagnosis I'd like to see additional monitoring strips to be sure. Clinically What has happened in the interim?

Pulmonary 52

Pulmonary AFIB Atrial Fibrillation Pacemaker 52

Dr. Smith's ECG Blog

FEBRUARY 6, 2024

I've copied KEY points from My Comment in the August 6, 2022 post in Dr. Smith's ECG Blog — regarding the answer to this question. Other Arrhythmias ( PACs, PVCs, AFib, Bradycardia and AV conduction disorders — potentially lethal VT/VFib ). Figure-1: The initial ECG in today's case. What are the ECG Findings of Cardiac Contusion?

Tachycardia 116

Tachycardia Dysrhythmia Atrial Fibrillation Bradycardia 116

Dr. Smith's ECG Blog

AUGUST 17, 2022

The rhythm is rapid AFib. These are the "Take-Home" Lessons from today's tracing: As per Dr. Smith — Rapid AFib may sometimes simulate acute posterior OMI. This anterior ST depression often resolves ( or at least greatly decreases ) when AFib is controlled and the heart rate slows. The QRS complex in lead I looks "funny".

Atrial Fibrillation 52

Atrial Fibrillation Ischemia AFIB Tachycardia 52

Dr. Smith's ECG Blog

JUNE 1, 2020

MY THOUGHTS on ECG #1: My initial impression on looking at the ECG in Figure-1 — was that the rhythm was either rapid AFib in a patient with WPW — or — PMVT ( P oly M orphic VT ). The reason I initially thought the underlying rhythm was AFib — is that no atrial activity is seen in any lead and the rhythm “looks” irregular. See text ).

Tachycardia 52

Tachycardia AFIB Blog Heart Disease 52

Dr. Smith's ECG Blog

MAY 26, 2023

This was a very complex case and the details are too much for an ECG Blog, but suffice it to say that, s hortly thereafter, the patient had an asystolic arrest and was resuscitated. He was placed on ECMO. Peak troponin I at 24 hours was 480 ng/L.

Cardiogenic Shock 98

Cardiogenic Shock Arrhythmia Blog Education 98

Dr. Smith's ECG Blog

JANUARY 15, 2024

ECG 2 Especially in the context of the first ECG, readers of this blog will readily appreciate the ST elevations and hyperacute T waves in II, III, aVF, V6, and to a lesser extent V5. As discussed on this blog many times before, proportionality is key to the diagnosis of OMI by ECG. [link] I also texted the ECG to Dr. Smith.

Chest Pain 65

Chest Pain Blog Arrhythmia Critical Care 65