title: Radionuclide monitoring of left ventricular function after sublingual nifedipine administration at rest and during moderate physical activity.
abstract: BACKGROUND
  This study investigates the acute effects of nifedipine administration on left ventricular (LV) function in patients with different degrees of heart failure at a fixed heart rate under resting conditions and during moderate physical activity.
  
  
  RESULTS
  Eleven patients with non-rate-responsive DDD pacemakers were studied. According to baseline LV ejection fraction, patients were divided into 2 groups: 6 patients with an ejection fraction of less than 50% (group 1) and 5 patients with an ejection fraction of 50% or more (group 2). LV function was monitored by a radionuclide system (Vest) at rest and during moderate physical activity (10-minute walk test) before and after sublingual nifedipine administration (10 mg). In all patients, both the systolic blood pressure and diastolic blood pressure were significantly reduced (P <.05) 6 minutes after nifedipine administration. In group 1, end-diastolic volume and ejection fraction decreased after 3 minutes and remained significantly lower (P <.05) than resting values until 10 minutes after drug administration, whereas end-systolic volume was unchanged. In group 2, nifedipine induced a minor decrease in end-diastolic volume and a slight but not significant decrease in ejection fraction and end-systolic volume. During the walk test, nifedipine induced similar changes in all parameters of cardiac performance in both groups.
  
  
  CONCLUSIONS
  In patients with impaired LV function, acute nifedipine administration has a negative effect on cardiac performance, which occurs before blood pressure reduction. On the other hand, during moderate physical activity, nifedipine does not affect the improvement in LV function.
authors.affiliation: Department of Biomorphological and Functional Sciences, Nuclear Medicine Center of the National Council of Research (CNR), University Federico II, Napoli, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Ferro
authors.forename: M
authors.initials: M
authors.lastname: Salvatore
authors.forename: A
authors.initials: A
authors.lastname: Cuocolo
mesh_terms: D000286:Administration, Sublingual; D000368:Aged; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D002306:Cardiac Volume / Q000187:drug effects / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000187:drug effects; D005260:Female; D015637:Gated Blood-Pool Imaging; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000008:administration & dosage* / Q000494:pharmacology*; D012146:Rest / Q000502:physiology*; D013318:Stroke Volume / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000008:administration & dosage* / Q000494:pharmacology*; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D016277:Ventricular Function, Left / Q000187:drug effects* / Q000502:physiology*
chemical_list: D014665:Vasodilator Agents; D009543:Nifedipine