This statement is particularly interesting as it goes against the common sense, and the common suggestion that some (most?) cardiologists and doctors give to cardiac patients (lower / no caffeine).

However, some arrhythmologists and electrophysiologists sing a different tune. When I was diagnosed with something complex and novel that results in ventricular arrhythmia (PVCs and VT), my EP was, to put it mildly, uninterested in my consumption of caffeine. He said that, at worst, it made no significant difference. That was a few years ago. I was pleasantly surprised.