Autonomic neural control during acute myocardial ischemia after phenylephrine infusion and subsequent nitroglycerin-induced hypotension and bradycardia.
ST-elevation acute myocardial ischemia occurred after phenylephrine infusion in a patient with severe coronary artery disease and recent myocardial infarction. The subsequent administration of nitroglycerin led to a vasovagal response with symptomatic hypotension and bradycardia. During myocardial ischemia, heart-rate variability and baroreflex sensitivity analysis described a marked activation of sympathetic drive and severe impairment of baroreflex control. The nitroglycerin-induced hypotension-bradycardia was associated with complex changes in the autonomic pattern characterized by subsequent phases of abrupt activation/deactivation of the two limbs of autonomic nervous system developing into a loss of neural control mechanisms.
Del Greco
M
M
Divisione di Cardiologia, Ospedale di Trento, Instituto Ricerca Scientifica e Tecnologica, ITC.
Nollo
G
G
Disertori
M
M
D000787:Angina Pectoris / Q000188:drug therapy / Q000209:etiology; D001341:Autonomic Nervous System / Q000502:physiology*; D017704:Baroreflex / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000503:physiopathology*; D005996:Nitroglycerin / Q000494:pharmacology / Q000627:therapeutic use*; D010656:Phenylephrine / Q000008:administration & dosage; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents / Q000494:pharmacology / Q000627:therapeutic use*