text_1: Sudden death can occur in patients with orthostatic hypertension without cardiac conduction abnormalities.
text_2: The increase in HR after injection of atropine as well as of MQNB was lower in patients compared with control subjects despite a similar basal HR (DeltaHR after atropine, 11+/-21% versus 62+/-17%; P<0.001), consistent with parasympathetic denervation.