For years, cardiac amyloidosis was a diagnosis with almost nothing attached to it. Doctors understood the mechanism. They just could not do much about it.
That has changed completely.
Amyloidosis happens when abnormal proteins misfold and build up in the heart wall, causing it to thicken and stiffen. The heart can still squeeze normally. What it cannot do is relax and fill properly between beats. That is why the pumping function on a scan can look reassuringly normal in someone who feels profoundly unwell.
It is far more common than we once believed, particularly in men over 65 with unexplained heart failure. And it is frequently missed, because the symptoms look like so many other things: breathlessness on the stairs, fatigue out of proportion to activity, swollen ankles, numbness in the hands, dizziness on standing.