A 55 yo woman lost consciousness at home. When the ambulance arrived she was pale, BP 70/40 with an irregular heart rhythm and ventricular frequency varying between 20 and 40 BPM. The ECG was sent through the “cloud” and the cardiologist on call ordered fluids and atropine. Upon arrival in the ED the patient was very ill, giving the impression of imminent cardiac failure. Diaphoretic, somnolent, BP 100/60 with an unchanged heart rate and frequency. The past medical history was significant for chronic kidney disease, pre-dialysis. Priority number one was to attach the defibrillator plates. Number two – an ECG.
Regular rhythm? P-waves present? QRS width? QTc? ST-segments and T-waves?
It seems to be some kind of a nodal escape rhythm. What about the ultrasound? UnFortunately you’ll have to use your fantasy on this one. I’ll be faster with the trigger finger next time. Imagine a gorgeous ejection fraction, the best one you’ve seen. The problem was that the ventricular rhythm was irregular, frequency low and successively getting lower by the minute. The impressions was that there was a failure of the SA-node, AV-node and other escape foci. Last swan dance.
Any electrolyte disorder that springs to mind?
The blodgas rightfully showed a potassium of 8, pH 7, creatinine 640 (6.8mg/dL), lactate 5.5, Base excess -20, pCO2 10.4, sodium 132. Not completely unexpected. Full measures were taken. Membrane-stabilizing calcium IV without any ECG improvements. Sodium bicarbonate, insulin/glucose and salbutamol nebulization followed. An isoprenalin-drip was started. The result?
Rising potassium and lactate. Dropping heart rate.
Lactic acidosis leads to rising extracellular potassium and vice versa. Like a dead fish turns its belly up, drifting away in loneliness, the mitral valve made a grand final agonal motion whereupon the gracious magic vanished. Seconds felt like minutes. A swirl of spontaneous contrast began making its presence. True ultrasound-witnessed asystole. What do the guidelines say? Compressions/ventilations/Adrenalin?
Based on the ultrasound and the appreciation of the hearts capabilities, the decision was made to try an alternative treatment modality. With continuous ultrasound observation, the external pacing function was started on the defibrillator. Note that part of the pacing-electricity was transmitted to the operator (Don’t try this at home kids)
Eureka! Time to pacing was of utmost importance. Any further delays and the race would have been lost. Followup blodgas showed improvement on all values. But why now? Most probably the cardiac output, previously deranged, now managed to deliver the drugs to the systemic circulation. The patient was dialyzed and had a temporary transvenous pacemaker implanted. She was discharged from the ICU after three days without any further complications. Neurological sequela? Nada.