Short-Coupled PVC

 

Premature Ventricular Contractions - Site of Origin

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 RVOT origin - 70-80 %

    Pulmonary valve sinus origin - ~4 %

LVOT origin - 15-25 %

    Aortic valve sinus origin - ? %

Ref: Anderson RD, et al. Circulation: Arrhythmia and Electrophysiology. 2019;12:e007392. DOI: 10.1161/CIRCEP.119.007392.

ICU: Postoperative AV block - Recovery

Study period: 1991-4. Boston Children's Hospital. n=2698 surgeries (73% on bypass).

Overall incidence of AV block was 3% (n=54).

Common diagnoses associated with development of AV block were VSD, Tetralogy, LVOTO repair, L-TGA and others. 

32 recovered conduction in 30 days after surgery (Graph below shows the postop. day at which conduction recovered in these 32 patients). 

9 did not recover conduction in 30 days after surgery. 

Weindling SN., et al. Duration of complete atrioventricular block after congenital heart surgery. Am J Cardiol 1998;82:525-527.

EKG: Apparent Atrial Flutter (Artifact due to muscle tremor)

13 yr old girl, transferred to ICU for Atrial Flutter noted in the trace below. She also had muscle tremors and neurologically obtunded. EKG & Pulse oximeter trace on in the upper panel.

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The following Doppler trace was obtained by placing the sampling cursor midway between Mitral inflow and Aortic outflow (2D image is upside down as is the standard in adult cardiology). There is one-to-one correspondence of mitral inflow to aortic outflow indicating lack of Atrial flutter with 2:1 or 3:1 conduction. Conclusion: Sinus tachycardia. When muscle tremors subsided, the baseline was normal with small P waves (& QRS complexes) were noted due to a concomittant pericardial effusion.

Quiz: EKG, Postop. Repair of AVSD

5 mo old, Postop. day 3 after AVSD repair.
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1) What is different between first half and second half of the EKG trace?

2) What type of pacing is being done?

3) What is the pacing rate?

4) What is the atrial rate?

5) What is the native ventricular rate?

6) What is the diagnosis for the underlying rhythm?

WPW syndrome - Natural History

From James Perry & Arthur Garson Jr. JACC 1990;16:1215-20.

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LQTS - Type Recognition by T wave Morphology

Zhang et al. Circulation 2000;102:2849-55

LQTS1 - Broadbased T wave

LQTS2 - Bifid T wave

LQTS3 - Late-onset T with Peaked/Biphasic T wave

Link to Criteria for diagnosis of Long QT syndrome

EKG: Intermittent WPW

Intermittently manifest accessory pathway

Note: Two beats in this rhythm strip have normal PR interval without Delta wave.

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Narrow Complex Tachycardia - Atrial Flutter

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Pacemaker - Non-capture

Attempt to detect the underlying rhythm. (Postop. patient)
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DC Cardioversion: Apparent VT. But,...

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Apparent wide-complex tachycardia. Generally, it is safe (and recommended) to provide treatment as "wide-complex tachycardia". However, in this patient, his baseline EKG was well known and has wide-complex QRS from acute myocarditis. And, based on 12-lead EKG it was decided that this is SVT with wide-complex QRS. Therefore, synchronized cardioversion was attempted and delivered (1 J/kg dose was used for this patient).


Probably due to wide QRS complexes, the defibrillator had hard time to "sync" the shock and automatically, switched off the sync and delivered the shock. Note: the QRS complexes after the DC cardioversion are paced beats (Epicardial, temporary pacing wire at VVI 100 bpm).

ICU: DDD pacemaker

This is 2 year old postop. patient with DDD pacemaker. What a sinking feeling one gets upon seeing this! (Absolutely no capture of either the atrium or the ventricle).
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Narrow complex tachycardia - Re-entry type

2 yr old, 10 kg. Unbalanced AV septal defect. s/p Takedown of Glenn Operation. Postop. day 5.
Sequence of events during management of tachyarrhythmia:

On Epinephrine, Dobutamine and Milrinone infusions, Digoxin maintenance dose.
Abrupt increase in heart rate from 111/min to 165/min.
Initial diagnosis of SVT. Adenosine (1 mg) administration reveals multipe P waves.
Atrial Flutter is treated with synchronized DC cardioversion (5 Joules).

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EP - What is the diagnosis

7-day old, s/p Norwood Operation. This was observed on the night of surgery.

This is AV block. Is it 2nd degree-type 2 AV block or 3rd degree?

Atrial ectopy

Plain and simple, atrial ectopy!

ICU: Permanent Pacemaker

3 yr old, Heterotaxy, s/p Fontan procedure. s/p Permanent pacemaker for sick sinus syndrome. Develops sepsis, returns from percutaneous drainage of pyonephrosis. Dexmedetomidine and ketamine were used for this short interventional radiology procedure. After return to ICU, the child has the following trace on the monitor. Interpret.

1) What is the underlying rhythm?
2) What is the pacemaker set at? Guess the mode and rate.
3) Is there native AV conduction? If yes, what is the native AV interval?
4) What is the AV interval for paced beats?
5) What is the pacemaker doing? What is the final assessment of this patient?
6) Why do the pacing spikes appear irregular?
7) How would you manage this patient? (Further studies tests and evaluations are necessary to make an assessment and management).

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CVP trace: Junctional rhythm vs. Sinus Rhythm

6 week old, s/p Repair of TAPVR.
Upper panel - A-paced at 130 bpm.
Lower panel - No pacing.
Diagnosis is clear from EKG trace itself.
Notice the difference in waveform in CVP trace between the two panels. Name the waves in CVP trace. Which is the prominent wave in CVP in the lower panel (in junctional rhythm).
Also, notice the change in BP between the two panels. (Time display at the right lower corner indicates that the two panels were recorded 1 minute apart from each other). Explain the 2 reasons for the lower BP while in junctional rhythm.

Interpret this - EKG...Monitor printout

1 week old, s/p Arterial Switch Operation. 6 hrs postop.
Clue: Arterial trace gives it away.

Narrow Complex Tachycardia/SVT - 3 types of responses to Adenosine

Response 1 - Adenosine terminates SVT to sinus rhythm
Response 2 - Adenosine terminates SVT to sinus rhythm; but, SVT returns
Response 3 - Adenosine decreases ventricular response, enabling the correct diagnosis of Atrial Flutter (This narrow complex tachycardia was not SVT)

Thus, if Adenosine does not treat it. It helps to uncover the correct diagnosis! It is important to record EKG strip during Adenosine administration so that the type of response can be carefully analyzed and documented.

SVT - Onset & Termination from Holter recording

Is it SVT or AET?
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