EKG artifact

(Click on the image to enlarge)

This would have been reported as tachycardia if Channel III was not available! (Not sure what the reason for this artifact is. Recording was auto-triggered by the event monitor. Patient does not know; was probably sleeping).

ICU: Arterial Line Artifact - "Standing Wave"

Pardon the poor quality images.

Newborn, s/p Norwood procedure.

Upper panel shows arterial pressure traces from 2 different lines - Right radial arterial (Red) and Umbilical arterial lines (White). There is a "standing wave" or "fling" in the red trace. This is secondary to being a small/distal vessel, smaller catheter, and state of peripheral vascular tone (vasoconstricted state).

Lower panel shows the same patient, approx. 30 min after the loading dose of Milrinone. Presumably, there is adequate vasodilation of the peripheral artery that the "standing wave" or "fling" is no longer evident or not as prominent as before!

(Click on the images to enlarge)

Echo artifacts

Five types of artifacts:
1) Mirror image artifact (Created by residual waves continuing to travel beyond the object of interest. Then, gets reflected back from interfaces beyond. These waves are once again reflected by the object giving rise to the second image.

 2) Reverberation artifact

 3) Side lobe artifact  (Produced by radial vibration of piezo electric crystals, instead of the longitudinal vibrations of the main beam)

4) Grating lobes artifact (no image) occurs in array transducers (?)

5) Acoustic shadowing (occurs due to highly reflective interface such as calcification).

(All images are from  TEE for congenital heart disease by Wong PC, Miller-Hance WC. Springer Verlog London. 2014.)

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.

(Click on the image to enlarge)

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.

ICU: Arterial Pressure Trace Distortion

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

ICU, EP: DDD pacemaker

8 month old girl s/p Repair of AVSD. Permanent pacemaker (DDD) has been placed for postoperative A-V block. Currently, admited for respiratoy distress. Interpret this ICU monitor trace.

Radial A line trace...why is it like that?!

This is a newborn baby with PA-VSD, MAPCAs.
Postop day#2 after RVOT patch (transannular).
Generally, doing well.

And, one day later...the same arterial line trace looks like this!!!

Possible explanations: (i) Papaverine was started or (ii) Tubing for the transducer was changed to a rigid, "pressure-tubing" (from a more compliant, "non-pressure" tubing).

This improvement in waveform may also occur when the arterial catheter is changed to a larger caliber.

Description & study of the above distortion in arterial line is illustrated below:

(From Cardiovascular Dynamics by Robert F. Rushmer MD. 3rd ed.1970. W.B.Saunders. page 162)