You are quite right, and I forgot to mention blood pressure medication in my other posts.
Several years ago, my then-rheumatologist was aghast at the appearance of my blue-black fingers, nails, feet/toes. She absolutely wanted me taken off the Metoprolol that I was on, at the time was 100 mg daily. Said that Metoprolol is especially prone to exacerbate Raynaud's. Wanted me on some other type of blood pressure med, so I discussed it with cardiologist who had specifically prescribed that medication for the arrhythmia (most of them barely detectable with heart monitor), and the drug was actually working really well with that and with keeping BP in check. So instead the dosage was cut to 50 mg daily of the succinate extended release formula, in 2 doses of 25 mg (one in morning, one in evening). Helped enormously with the Raynaud's, and also worked with the cardiac symptoms for which it had originally been prescribed.. Now it's been about 15 yrs, and my arrhythmia and BP have been misbehaving. Another BP med has been added rather than raise Metoprolol dosage. I take one 25 mg losartan. And yes, the conditions that I describe elsewhere within this site re: my hands/feet had been INCREDIBLY WORSE when on 100mg of Metropolol....This was clearly a case in which the cardiologist had not been knowledgeable of that drug's affects on a patient with my other conditions (and yes, they were in my chart) AND not having done a little investigating....Taught me to be extra vigilant about being proactive with whatever meds/supplements go into my body and ask questions....