title: Effect of quinapril on blood pressure and heart rate in congestive heart failure.
abstract: The effect of quinapril on blood pressure (BP), heart rate (HR) and their variabilities in 12 patients with severe congestive heart failure (New York Heart Association class III and IV) was assessed using ambulatory electrocardiographic and intraarterial monitoring. Mean +/- standard deviation daytime BP was 122/75 +/- 20/15 mm Hg at baseline and 113/70 +/- 13/16 mm Hg after 16 weeks of therapy with quinapril (p greater than 0.05 for systolic and diastolic BP); mean nighttime BP was 114/69 +/- 19/14 mm Hg at baseline and 107/69 +/- 15/14 mm Hg with quinapril (p greater than 0.05 for systolic and diastolic BP). Mean daytime HR was unchanged but nighttime HR was reduced from 77 +/- 11 to 71 +/- 10 beats/min, p = 0.02. HR variability (difference between the 75th and 25th percentiles of the frequency distribution of RR intervals) increased from 91 +/- 34 to 134 +/- 47 ms, p = 0.008. The variability of successive differences between RR intervals also increased significantly (75th to 25th percentile = 17 +/- 4 ms at baseline and 31 +/- 26 ms with quinapril, p = 0.02). Long-term quinapril caused clinically unimportant decreases in BP in patients with severe congestive heart failure. An increase in vagal activity caused by the reduction in circulating angiotensin II may account for the effect of converting enzyme inhibition on HR and its variability.
authors.affiliation: Department of Cardiovascular Medicine, University of Birmingham, Queen Elizabeth Hospital, Edgbaston, United Kingdom.
authors.forename: J N
authors.initials: JN
authors.lastname: Townend
authors.forename: J N
authors.initials: JN
authors.lastname: West
authors.forename: M K
authors.initials: MK
authors.lastname: Davies
authors.forename: W A
authors.initials: WA
authors.lastname: Littler
mesh_terms: D000328:Adult; D000368:Aged; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects*; D004562:Electrocardiography / Q000187:drug effects; D015716:Electrocardiography, Ambulatory; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007546:Isoquinolines / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D000077583:Quinapril; D012083:Renin / Q000097:blood; D012815:Signal Processing, Computer-Assisted; D044005:Tetrahydroisoquinolines
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D007546:Isoquinolines; D044005:Tetrahydroisoquinolines; D012083:Renin; D000077583:Quinapril; D009638:Norepinephrine