Recurrent asystolia in right middle cerebral artery infarct with predominant insular involvement

A 42-year-old woman who smoked had a right middle cerebral artery (MCA) stroke of undetermined origin (initial NIHSS 19). CT and perfusion-CT after 7 h (fig 1B) showed no mass effect. Between 7 and 20 h, she suffered five episodes of asystolia of 10 s duration (fig 1C ), each accompanied by brief loss of consciousness, resolving spontaneously. The plain CT at that time showed no mass effect, cardiac enzymes and echocardiography were normal, and she had no prior cardiac history. At 20 h after stroke onset, she developed decreased consciousness, seen on the CT scan, and underwent decompressive craniectomy at 36 h. No further asystolic events occurred during the 14 days in the stroke unit. At 3 months, she had recovered partially from her left hemisyndrome and was able to transfer herself, but not to walk without assistance (modified Rankin scale 4).

Figure 1. (A) Acute perfusion CT before asystolia: red, middle cerebral artery infarct; green, penumbra; line, right insular anatomical topography. Note the extensive involvement of the right insula.³ (B) Plain CT after the first episode of asystolia, showing no mass effect. (C) Acute phase ECG showing the third of five episodes of asystolia, lasting about 10 s (paper velocity 25 mm/s).

Cardiac arrhythmias are quite common in acute stroke, but asystolia has only rarely been documented.¹ Although the Cushing reflex due to intracranial hypertension may result in extreme bradycardia, this is an unlikely mechanism in this patient, as asystolia occurred well before the mass effect developed (after 36 h). We suspect a transient interruption of sympathetic cardiac tone due to right insular ischaemia as the likely mechanism.² As this region has been implicated in the central control of cardiac function, it has also been called the “cardunculus”.