title: Baroreflex sensitivity and heart rate variability in coronary disease compared to dilated cardiomyopathy.
abstract: This study was designed to compare baroreceptor sensitivity and heart rate variability as measures of cardiac autonomic tone in patients with coronary disease (CAD, n = 49) and idiopathic dilated cardiomyopathy (IDC, n = 130). Time domain heart rate variability, including SDNN, SDANN, and pNN50, was determined during 24-hour Holter ECG. Baroreflex sensitivity was analyzed nonivasively using the phenylephrine method. Baroreflex sensitivity and heart rate variability were comparable between patients with CAD versus IDC (baroreflex sensitivity: 6.1 +/- 3 vs 6.9 +/- 5 ms/mmHg; SDNN: 97 +/- 40 vs 114 +/- 41 ms; SDANN: 83 +/- 33 vs 99 +/- 41 ms; pNN50: 3.9 +/- 4 vs 9.6 +/- 13 ms, P = NS for all comparisons). Likewise, a subgroup analysis of patients with a left ventricular ejection fraction (LVEF) < or = 30% showed no significant difference in baroreceptor sensitivity and heart rate variability between IDC and CAD patients. Patients with CAD and an LVEF > 30% had a decreased heart rate variability but not a decreased baroreflex sensitivity compared to patients with IDC and LVEF > 30% (baroreflex sensitivity: 6.4 +/- 4 vs 8.3 +/- 6 ms/mmHg, P = NS; SDNN: 98 +/- 19 vs 128 +/- 42 ms, P < 0.05; SDANN: 86 +/- 21 vs 112 +/- 43 ms, P < 0.05; pNN50: 4.2 +/- 3 vs 12.3 +/- 8 ms, P < 0.05). Patients with a markedly depressed LVEF show comparable alterations in cardiac autonomic tone whether they have CAD or IDC. Patients with CAD and preserved LV function, however, have a decreased heart rate variability compared to patients with IDC and preserved LV function. The prognostic significance of these findings will be determined prospectively in a large patient cohort at our institution.
authors.affiliation: Department of Cardiology, Philipps-University of Marburg, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Menz
authors.forename: W
authors.initials: W
authors.lastname: Grimm
authors.forename: J
authors.initials: J
authors.lastname: Hoffmann
authors.forename: S
authors.initials: S
authors.lastname: Born
authors.forename: C
authors.initials: C
authors.lastname: Schmidt
authors.forename: B
authors.initials: B
authors.lastname: Maisch
mesh_terms: D017704:Baroreflex / Q000502:physiology*; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology*; D003327:Coronary Disease / Q000503:physiopathology*; D015716:Electrocardiography, Ambulatory; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011311:Pressoreceptors / Q000503:physiopathology*; D012815:Signal Processing, Computer-Assisted; D013318:Stroke Volume / Q000502:physiology; D013997:Time Factors; D016277:Ventricular Function, Left / Q000502:physiology