ICU: Where is the tip of this PA line?

ICU: What's wrong with this picture...

6-mo old. s/p Complete AVSD repair. Immediate postop. Just arrived from operating room.

Hint: The anomaly is the relationship between LA pressure and PA pressure.
Panel 1 - Has a problem/mistake. (Pardon the shaken image)
Panel 2 - The problem/mistake has been rectified.


ICU: Pulsus Alternans

What is the significance of Pulsus Alternans?
6 mo old baby girl, s/p VSD closure, Repair of Cleft mitral valve. Postop. ICU stay. Residual VSD with Pulmonary hypertension. Pulsus alternans is noted in the PA line pressure traces.
Panel 1 - DDD pacing

Panel 2 - Pacing Off

Panel 3 - AAI pacing

Panel 4 - VVI pacing

ICU: Arterial Pressure Trace Distortion

(From Cardiovascular Dynamics by Robert F. Rushmer. 3rd Ed. 1970. W.B. Saunders Company)


Quiz, EKG: What is the rhythm? Junctional vs. Low Atrial rhythm?

11 yr old boy. s/p Repair of Sinus venosus ASD. Started with AAI pacing at 80 bpm in the operating room. You set out to determine the underlying rhythm. The following strips are availabe for analysis. Second-from-the-last panel has atrial lead electrogram in V1. (Click on the images to enlarge).

Last panel image is from Principles of Clinical Electrocardiography by Mervin J. Goldman. Lange Medical Publications. 11th ed. 1982.


ICU: Pericardial Tamponade

Beware of the importance of looking "all-around" when you are doing a "quick" echo when a baby is unstable, in the immediate postoperative period. (Poor image quality is part of the deal!)

The first two panels show no significant effusion. However, in the lower-most panel - angled more posteriorly - there is a localized collection of clot compressing right atrium and part of right ventricle. This was not recognized due to poor images. Chest was opened to cannulate for ECMO! Clot was noted in the pericardial space, compressing right atrium (Lower-most panel). Hemodynamic status improved when the clot was removed. ECMO was not necessary.

Newborn, s/p Arterial switch operation. 3 hrs postop.


EKG: Nomogram / Table: Cycle Length to Heart Rate Table

L = Cycle length (seconds)
R = Heart rate

In pediatrics, it is useful remember the cycle length range of 200-300 ms (0.2 to 0.3 seconds) where most of pediatric arrhythmias occur.

EKG - Normal values, Basics

Kirschoff's Law: Algebraic sum of all the potential differences in a closed circuit equals zero. Based on this law, I + II + III = 0.

But, Einthoven reversed the polarity of II. Instead of connecting RA - LL, he connected it LL - RA. Therefore, the formula becomes I - II + III = 0.

When this equation is solved, it becomes Einthoven's equation: II = I + III.

(To verify, take the net amplitude of QRS complexes respective leads from any EKG and do the calculations)

Relationship between Augmented unipolar limb leads (aVR, aVL, aVF) & Standard bipolar leads (I, II, III):
aVR = (I + II)/2
aVL = (I - III)/2
aVF = (II + III)/2

From Principles of clincal electrocardiography by Mervin J. Goldman. 11th ed. 1982. Lange Medical Publications.


Cath Lab: Artifacts in Pressure Traces...Underdamped waveform

Both panels below have LV pressure trace recorded in the same patient.
Upper panel has artifact (Underdamping of the trace)
This artifact is corrected in the lower panel.

What is the mechanism of this artifact (Underdamping)?
What are the methods that can be used to correct such artifact?