Beware of fainters!

The following is a general framework to approach such arrhythmias. This is also the recommended algorithmic approach by the ACC/AHA and ESC guidelines on the diagnosis and management of supraventricular tachyarrythmias.

The 12-lead ECG in our patient shows the following findings:

- An irregular (irregularly irregular) narrow complex tachycardia (the QRS duration is hardly 1-1.5 small boxes wide; that is 40-60 msec).

- The QRS axis is deviated to the right. This is likely due to LPHB in an elderly, hypertensive lady who likely has ‘early’ degenerative conduction system disease. This is obviously a diagnosis of exclusion (but there don’t appear to be any other features in the ECG to explain the RAD e.g. RVH … etc)

- Incomplete RBBB

- There are wide-spread ST segment abnormalities. One can argue that the ST depression in seen in V1-V3 are due to RBBB. However, remember we mentioned earlier that the delayed conduction down the RBB is incomplete, and therefore unlikely to result in significant ST-T wave abnormalities. There is ST elevation in aVR and V1 and ST depression in II, III, aVF and V2-V6. These findings are consistent with diffuse subendocardial ischemia. This could be due to severe coronary artery disease (e.g. severe LM disease, triple vessel disease … etc) or due to non-coronary causes of global myocardial ischemia e.g. severe hypotension, severe hypoxia … etc. In this case, the elderly, postmenopausal lady is also hypertensive and likely has underlying coronary artery disease. Alternatively, she likely has concentric LVH from long-standing hypertension and the rapid ventricular rate from the irregularly rhythm resulted in (1) loss of much needed atrial contribution to forward cardiac output (can be as significant as 30-40% of the forward SV) (2) rapid ventricular rate and shortened diastole compromises myocardial coronary blood flow, which happens mainly in diastole (LV coronary perfusion mechanics).

- It is imperative to correct the QT interval for HR variability. Various equations have been suggested but all have their inherent limitations. The Bazzett’s formula for example tends to overcorrect at faster rates and undercorrects at lower rates.

The ECG is not consistent with a pre-excited arrhythmia as no delta waves are seen (unlike what is stated in some of the responses). Pre-excited AF would look like the tracing below. The diagram also summarizes the features characterizing the life-threatening arrhythmia.

Therefore, to answer the questions in this post:

1. The ECG shows an irregular narrow complex tachycardia with incomplete right bundle branch block, right axis deviation (likely due to LPHB), and diffuse subendocardial ischemia. The differential diagnosis for the irregular narrow complex tachycardia is:

a. AF (most likely)

b. Atrial flutter with variable AV block

c. Atrial tachycardia with variable AV block

d. Multifocal atrial tachycardia which is unlikely given

i. No predisposing conditions (COPD, theophylline intake … etc)

ii. There is no P wave before every QRS complex

2. Management would include:

a. ABC – make sure the patient is under continuous ECG monitoring

b. Obtain a BP recording in both arms

c. Consider pharmacological rate control. Options would include:

i. IV metoprolol

ii. IV diltiazem or verapamil

iii. IV adenosine: the response to adenosine can sometimes break the arrhythmias and declare the exact type as shown in the diagram below. The response in AVNRT and AVRT will be discussed in subsequent ECG cases.

d. Continuous ECG monitoring while administering the medications to understand the behavior of the arrhythmia (response to pharmacological agents and pattern of termination).

e. Carefully evaluate the post conversion ECG (if conversion was successful)

f. Serial ECG(s) and c-Tn-T ( I suppose that is reasonable given the worrisome ECG findings in an elderly lady with risk factors for CAD).

Stay tuned for Part (2) of this case. It is where all the action took place !!

Very interesting ECG !

- I can see irregular narrow QRS complexes with Delta wave noted in few occasions , So WPW with Afib is top differential. But I don’t know if this the age of it !.

- some P waves with short PR and noted as well ! Might think of Flutter with variable block.

- of note , ST elevation in aVR , ? RBBB , S1Q3T3 but since Trop negative and the previous history of palpitations ; will be down in the list to consider ischemia and PE.

in this stage if no hemodynamics instability as we see, will use medications for rate control and will avoid AV node blocking medications to avoid increase conduction via the accessory pathway and resulting in VT or VF. The optimal option will be procainamide or ibutilide.

Also we need to make sure correcting any electrolytes abnormalities so we need to check Mg as well and optimize it even without waiting results.

reviewing previous ECGs and patient medications will be of great benefit.

ECG showed irregular irregular rhythm , rapid heart rate of 178, STE aVR , Delta wave in lead 11, aVF ?

Shape of ST depression, digoxin effect? Scoop ST depression

Clinically seems stable

DD :

AF with RVR ,

AF with WPW ,

Digoxin toxicity ?

less likely atrial flutter with variable conduction

Keep her on chest lead monitors , monitor BP

Review her file , medication, previous ECG , ask about herbal medication for digoxin toxicity

ACS to be ruled out , negative trop not ruled out ACS, for serial  ECG and troponin

Echo to look for structural abnormality, possible of vegetation formation as she has syncope / LOC history , possible of TIA ?

Electrolyte abnormalities : normal potassium level

Digoxin level is there is strong suggestion from history or h/o digoxin

TFT

CT head after stabilizing her rate

Mx

Currently seems stable to me , no need for cardioversion and cardioversion decision will be difficult choice bcz her sx for months and possible of thromboembolism event is more

pre-excitation features in ECG >>> AV nodal block agents to be avoided

To be treated with procainamide

If digoxin toxicity for Fab therapy

also to send Ca and Mg level , not only potassium to be checked

ECG showed irregular irregular rhythm , rapid heart rate of 178, STE aVR , Delta wave in lead 11, aVF ?

Shape of ST depression, digoxin effect? Scoop ST depression

Clinically seems stable

DD :

AF with RVR ,

AF with WPW ,

Digoxin toxicity ?

less likely atrial flutter with variable conduction

Keep her on chest lead monitors , monitor BP

Review her file , medication, previous ECG , ask about herbal medication for digoxin toxicity

ACS to be ruled out , negative trop not ruled out ACS, for serial  ECG and troponin

Echo to look for structural abnormality, possible of vegetation formation as she has syncope / LOC history , possible of TIA ?

Electrolyte abnormalities : normal potassium level

Digoxin level is there is strong suggestion from history or h/o digoxin

TFT

CT head after stabilizing her rate

Mx

Currently seems stable to me , no need for cardioversion and cardioversion decision will be difficult choice bcz her sx for months and possible of thromboembolism event is more

pre-excitation features in ECG >>> AV nodal block agents to be avoided

To be treated with procainamide

If digoxin toxicity for Fab therapy

1- this ECG is showing irregularly irregulr rythum. with QT is prolonged, around 470 using Bezzet formula.

diagnosis: Long QT + MAT ( there is clear p waves in lead 2 varrying in its morphology with variable PR)

differential diagnosis for her Irregularly irregulr rythum: AF

( there is slight widening in the QRS, but it dosnt fit "AF with accessory pathway": the rate is too slow )

2- managment:

1-send the Mg, Ca, k levels.

2- elaborate in the hx if she is on any meds causing prolong QT.

3- elaborate in the hx for family history of sudden death or syncopal attacks.

4-start on IV Magnisium sulfate for prolong QT.

5- for MAT : look for the undrlying causes and treat it.

ECG showed irregularly irregular rate with no clear P waves with slightly wide QRD complex

ddx :

AF withWPW ( although with this combination we expect HR to be higher than this) and the age is not typical!

MAT is another ddx although I cant see a clear P wave , maybe if we slow her HR the ECG will be more clear

flutter is less likely as HR is not the typical and I can not see any flutter waves

my top ddx is AF with reentry pathway

mangment : all AV nodal blockage should be avoided

the best and safest drug is procinamide

If she was unstable ( which is not the current status) cardiovesrion will be the option