technical difficulties

Mick Jagger's mitral valve no longer seats;
what should surge one-way sloshes to-and-fro.
'though myocardium's not missing beats,
Jack Flash can't jump with diastole so low.
Replacement parts, of plastic, or of pork,
are on the shelf and at the surgeons' choice.
Just as sir Mick gets healthcare in New York,
vast resources attend a rich man's voice.
Keith Richards stops to wish his brother well;
a lifetime they've been yoked, through thick, and thin.
Not ready to slough off this mortal shell,
the tour's on pause without his glimmer twin.
To miss one concert's date's a trifling loss;
this Stone's too busy to be gath'ring moss.