“Pumphead,” or postperfusion syndrome, is the name given to a set of neurocognitive impairments attributed to the use of a heart-lung machine during cardiac surgery.

These include deficits associated with attention, concentration, short-term memory, fine motor function, and speed of mental and motor responses.

Whether such a syndrome exists, and to what extent, is the subject of controversy.

A study published in the journal Circulation showed persistent cognitive decline following coronary bypass.

Other studies have also found a decline, but a temporary one — a contention that some patients, who have published accounts, take issue over.

This complication was one reason why “off-pump” heart surgery was initially assumed to be preferable to the use of the heart-lung machine. But research has demonstrated there to be little or no difference.