Hypothermia at 18 Celsius in V Fib arrest: CPR, then ECMO rewarming, for 3 hours, then Defib with ROSC. Interpret the ECG.

A middle-aged man was found outside in the cold in full arrest in ventricular fibrillation.

Chest compressions and ventilation were begun.

On arrival, CPR was continued and core temperature was measured at 18° C (64.4° F).

The patient was put on Extracorporeal Life Support in the ED

3 hours after initial resuscitation, the core temp was 30° C and the patient was defibrillated with a single attempt.

A 12-lead ECG was recorded:

There is sinus rhythm with RBBB and right axis deviation.  In all leads, there is a 2nd wave after the initial QRS.  

This is an Osborn wave.  I have not found any previous report of Osborn waves in RBBB.

There is also profound ST depression maximal in V3.  

Although in the context of chest pain such ST depression would be all but diagnostic of posterior OMI, one should make no conclusions in such an unusual case.

This Transesophageal ED Echo was recorded:

Cardiac POCUS.mov from Stephen Smith on Vimeo.

Guide to this image:

30 minutes later, at 31 C, this ECG was recorded:

The RBBB has resolved.  Osborn waves persist

The next day, this ECG was recorded at a normal temperature: 

Peak hs troponin I was 650 ng/L

Day 1 echo

ECMO flow 2.9 L/min, arterial BP 106/81 mmHg, HR 92 bpm

1. Estimated LVEF 25-30%, inferolateral abnormality possible 

Day 2 echo

Baseline: ECMO flow 3.0 L/min, BP 107/65 mm Hg, HR 71 bpm

LVEF 45%, no wall motion abnormality

The patient had a complete neurologic recovery, proving once again that the patient is not dead until he/she is warm and dead.

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MY Comment by KEN GRAUER, MD (2/8/2022):

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I thought this to be an intriguing case for a number of reasons. These include:

• The patient's initial core temperature was exceedingly low (ie, 18°C = 64.4°F). He remained in VFib until core temperature reached 30°C — at which time the 1st tracing in today's case was recorded ( = ECG #1 in Figure-1).
• The Osborn waves on ECGs #1 and #2 are huge!
• As per Dr. Smith — We haven't previously seen Osborn waves with RBBB.
• The profound ST depression in the initial tracing.
• The profound initial QTc prolongation.

Figure-1: For clarity — I've put the 3 sequential tracings done in this case together.

OSBORN Waves: The Osborn wave has been described as a deflection with a dome or hump that occurs at the point where the end of the QRS complex joins with the beginning of the ST segment. This is the J-Point (ie, it Joins the end of the QRS with the beginning of the ST segment) — so Osborn waves are exaggerated “J waves” or J-point waves. They’ve also been called the “camel-hump” sign.

• First described in 1953 (by Dr. John Osborn) — these Osborn waves are most commonly associated with significant hypothermia (usually not seen until core temperature is below 90°F).
• It is important to appreciate that other conditions may also be associated with this prominent J-point deflection. Osborn waves have been reported with hypercalcemia, brain injury, subarachnoid hemorrhage, Brugada syndrome, cardiac arrest from VFib — and — severe, acute ischemia resulting in acute MI (See My Comment in the November 22, 2019 post on Dr. Smith’s Blog).
• Rituparna et al — as well as Chauhan and Brahma (Int. J. Crit. Illn. Inj. Sci 5[4] 268-270, 2015) both highlight a likely association between acute development of ischemic J waves — and high risk of developing malignant ventricular arrhythmias. It is of credit to the health care team that this patient with an initial core temperature of 18°C — was successfully resuscitated, with resultant full neurologic recovery despite those huge Osborn waves.
• Other commonly associated ECG features with Hypothermia include: i) Bradycardia (which may be marked); ii) Atrial fibrillation or other arrhythmias; iii) Artifact (from baseline undulations resulting from associated shivering); iv) QTc prolongation (which may be marked); and, v) ST elevation in multiple leads.

MY Thoughts: It may be that the reason bradycardia and artifact from shivering are missing from the initial ECG recorded ( = ECG #1 in Figure-1) — is that 3 hours of resuscitation had already passed, during which time core temperature had increased from 18°C — to 30°C ( = 86°F).

• That said — the QTc is markedly prolonged in ECG #1 (ie, to ~600 msec.). Note how the QTc progressively shortens over these sequential tracings — until it is completely normal with ECG #3.
• Osborn waves are huge! These huge Osborn waves simulate ST elevation in leads II, III, aVF and V1 of ECG #1. I found it insightful to see clear delineation between the end of the QRS and the attached Osborn waves just 30 minutes later in ECG #2. Equally impressive is complete resolution of the RBBB/LPHB that was seen in ECG #1 — and which was gone 30 minutes later in ECG #2.
• Instead of ST elevation that is commonly reported with hypothermia-induced Osborn waves — ECG #1 was remarkable for diffuse and profound ST depression. Note that in addition — there was ST elevation in lead aVR of ECG #1. Given that this hypothermic patient had been resuscitated from VFib Cardiac Arrest (which at noted above — is a potential cause of ischemic-related Osborn waves) — I suspect that the huge size of these Osborn waves and the profound ST depression we saw in ECG #1 was at least in part a reflection of diffuse subendocardial ischemia, as a result of this patient's cardiac arrest. 
• Perhaps the bifascicular block (RBBB/LPHB) present on ECG #1 — but which resolved by ECG #2 — was also ischemic-related from the cardiac arrest.
• 
  
• BOTTOM LINE: A tremendous SAVE for the health care team!