Figure 16.

Brain optical intensity (OI) and the optical intensity ratio (OIR) 660 nm / 940 nm changes following cardioversion (CV). Patient on venous arterial extra-corporeal membrane oxygenation (VA ECMO) following cardiac arrest. The patient underwent cardiopulmonary resuscitation (CPR) followed by cardioversion to revert long standing ventricular tachycardia to sinus rhythm. Following successful cardioversion acute changes in the OI the ΔOIR occurred particularly in the left brain. The recording covers a 2.6 minute period. The patient subsequently developed fixed dilated pupils 11 hours after sinus rhythm was restored. The falls in the OIR immediately following cardioversion raises the possibility of clot embolization from the heart. BP: blood pressure, AU: arbitrary units. Red brain pulse is 940 nm and blue brain pulse 660 nm.