ECG Blog #518 — A WCT with Low Urine Output ...

The ECG in Figure-1 was obtained from a previously healthy middle-aged man — who presented to the ED (Emergency Department) with acute shortness of breath. The patient complained of malaise — but no chest pain or other bodily pain. He has had difficulty urinating.

QUESTIONS:

• How would you interpret the ECG in Figure-1?
• What are your first clinical considerations?

Figure-1: The initial ECG in today's case. (To improve visualization — I've digitized the original ECG using PMcardio).

MY Thoughts on the Rhythm in Figure-1:

Our 1st clinical consideration given the ECG shown in Figure-1 — is to ensure that this patient is hemodynamically stable.

• Determination of hemodynamic stability is not readily apparent from the brief history we are given (ie, Today’s patient is short of breath — but not in pain; The heart rate is ~130/minute, but we do not know the patient’s blood pressure).
• Sometimes, “Ya just gotta be there” — in order to determine if the patient is sufficiently stable to allow a moment to more closely assess the rhythm.

Let’s assume that this patient is hemodynamically stable! 

By the P's, Q's, 3R Approach (See ECG Blog #185) — the rhythm in Figure-1 is a regular WCT (Wide-Complex Tachycardia):

• The rhythm itself is Regular.
• The QRS is obviously wide (at least 4 large boxes in duration ==> ≥0.16 second — which is very wide).
• The Rate of the ventricular rhythm is ~130/minute.
• P waves are absent (which means that the 5th Parameter = Are P waves Related to neighboring QRS complexes? — is to be answered with a “No” —). 

As is often emphasized in this ECG Blog — We need to assume VT until proven otherwise whenever we see a regular WCT rhythm without clear sign of P waves.

• This leads us to our next STEPs in assessing a regular WCT without P waves: i) LOOK at QRS morphology. We want to determine if QRS morphology during the WCT rhythm provides further clue to the etiology of the rhythm (ie, A QRS morphology not consistent with any known form of conduction defect would strengthen our assumption of VT).
• At the same time: ii) We want to look at ST-T waves during the WCT rhythm to see if this suggests acute ischemia or other abnormality.

Take another LOOK at QRS and ST-T wave morphology in Figure-1.

• Consider that this patient has recently felt ill (malaise) — and has had trouble urinating ...

Figure-1: Take another LOOK at the ECG in Figure-1 ...

Taking Another LOOK: 

As noted above — the rhythm in Figure-1 is a regular WCT at ~130/minute, without clear sign of P waves.

• QRS morphology for the ECG in Figure-1 is consistent with LBBB conduction (ie, Monophasic R wave in leads I and V6 — with predominantly negative QRS in the anterior leads).
• BUT — Aren't T waves in many of the leads tall and peaked (if not pointed)?
• Not only are positive T waves peaked (and quite pointed in leads II,III,aVF; and V3,V4,V5) — but the negative T waves in leads I and aVL are also pointed at their deepest part! (See this Eiffel Tower effect for pointed positive and negative T waves below in Figure-2).
• 
  
• And — WHY is the QRS so wide? (can be seen to be at least 4 small boxes in duration in leads like V3,V4 ==> 0.16 second).

Figure-2: Note the Eiffel Tower effect of both positive and negative T waves in many of the leads in today's ECG.

=============================

CASE Follow-Up:

The above observations were appreciated by emergency providers:

• Based on this acutely ill patient's description of "difficulty urinating" — a foley catheter was inserted, and resulted in an output of 1,500 cc of urine within minutes.
• Based on a presumptive diagnosis of acute renal insufficiency — several empiric IV Calcium doses were given (before serum K+ levels returned). Within minutes — the QRS complex narrowed as the rhythm slowed and the patient stabilized (Unfortunately — I was unable to obtain those follow-up tracings).
• Lab results returned: Serum K+ = 8.7 mEq/L.
• The patient went for emergency dialysis and did well.

COMMENT:

• I'll refer the reader to my ECG Blog #516 — in which I detail empiric use of IV Calcium (formulations and dosing — with emphasis on the minimal downside from giving empiric IV Ca++ when the clinical situation is suggestive and the ECG shows a worrisome "too fast or too slow" arrhythmia).
• Also in ECG Blog #516 — I reviewed the challenges of assessing the rhythm when serum K+ is markedly elevated.
• More on hyperkalemia in ECG Blog #275 (including the textbook sequence of ECG changes with hyperK+ — with emphasis on why not all patients "read" the textbook).
• With yet one more hyperK case of another regular WCT in ECG Blog #244 — in which the cath lab was activated (reviewing how common Brugada-1 patterns may be seen with hyperK).
• And — More on "decreased urine output and acute kidney injury" in this review article by Chenitz and Lane-Fall (Anesthesiol Clin 30(3):513-526, 2012).
• 
  
• "Take-Home" Message: Among the many potential ECG presentations of hyperkalemia is a regular WCT rhythm that looks like VT. Sometimes one or more empiric doses of IV Calcium is indicated (even before the serum K+ level returns from the laboratory). In such situations — empiric IV Calcium may be lifesaving!

==================================

Acknowledgment: My appreciation to Hamid Himat (from Bratislava, Slovakia) — for allowing me to use this case and these tracings.

==================================