ABSOLUTELY CORRECT, the arm must be comfortably supported with the elbow at exactly heart level.
My cardiologist tried a technique where he caught my arm between his arm and body with my hand sticking out behind him, as he pumped the old sphig. That felt clumsy for me, sort of both supported and NOT really supported, so I patted his *** with the hanging hand and I'm sure HE felt equally clumsy. But I think he got my point.
I'm not making this up!
We both laughed, I more comfortably than HE.
At home I use the nice padded armrest on a Lazy Boy and I recline.