Circulation, Vol 78, 60-67, Copyright © 1988 by American Heart Association
EG Nabel, J Barry, MB Rocco, S Campbell, K Mead, T Fenton, EJ Orav and AP Selwyn
Ambulatory electrocardiographic (ECG) monitoring of patients with chronic
stable angina has demonstrated frequent and prolonged episodes of ischemic
ST segment depression, but its clinical use requires an understanding of
the components and extent of variability. Therefore, variations in the
frequency and duration of episodes of ST segment depression were evaluated
with ambulatory ECG recording at daily, weekly, and monthly intervals in 42
patients with chronic stable angina and known coronary artery disease. Data
were analyzed with a nested analysis of variance design that yields
estimates of variance components. From the estimates of variance
components, power calculations and minimum significant percent reductions
in frequency and duration of ischemia were derived. During 4,656 hours of
ambulatory ECG monitoring, 1,262 episodes of ischemic ST segment depression
were detected. The frequency of episodes was 6.3 +/- 0.45/24 hr (mean +/-
SEM), and the duration of episodes was 18.3 +/- 2.8/24 hr. Because of
variability over time, the ability to detect significant changes was
dependent upon the number of subjects, length of monitoring period, and
intervals between monitoring periods. In a clinical trial, for example, a
sample size of 25 patients monitored for 48 hours with 1 week between
control and test conditions would require a 65% reduction in frequency,
whereas a sample size of 50 patients monitored under similar conditions
would require a 46% reduction in frequency, to attribute the change with
90% power to a therapeutic intervention rather than to a spontaneous
variation. When monitoring a single patient for 48 hours with 1 week or 1
month between control and repeat monitoring sessions, episodes of ischemic
ST depression must be eliminated to detect significant therapeutic changes
in ischemic activity at the 95% confidence level.(ABSTRACT TRUNCATED AT 250
WORDS)
ARTICLES
Variability of transient myocardial ischemia in ambulatory patients with coronary artery disease
Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115.
This article has been cited by other articles:
 |
|
 |
|
  P. Deedwania, P. H. Stone, C. N. Bairey Merz, J. Cosin-Aguilar, N. Koylan, D. Luo, P. Ouyang, R. Piotrowicz, K. Schenck-Gustafsson, P. Sellier, et al. Effects of Intensive Versus Moderate Lipid-Lowering Therapy on Myocardial Ischemia in Older Patients With Coronary Heart Disease: Results of the Study Assessing Goals in the Elderly (SAGE) Circulation, February 13, 2007; 115(6): 700 - 707. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Enseleit and F. Duru Long-term continuous external electrocardiographic recording: a review. Europace, April 1, 2006; 8(4): 255 - 266. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. H. Stone, D. M. Lloyd-Jones, S. Kinlay, B. Frei, W. Carlson, J. Rubenstein, T. C. Andrews, M. Johnstone, G. Sopko, H. Cole, et al. Effect of Intensive Lipid Lowering, With or Without Antioxidant Vitamins, Compared With Moderate Lipid Lowering on Myocardial Ischemia in Patients With Stable Coronary Artery Disease: The Vascular Basis for the Treatment of Myocardial Ischemia Study Circulation, April 12, 2005; 111(14): 1747 - 1755. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Borghetti, M. Campana, C. Scotti, D. Domenighini, P. Totaro, G. Coletti, M. Pagani, and R. Lorusso Biological versus prosthetic ring in mitral-valve repair: enhancement of mitral annulus dynamics and left-ventricular function with pericardial annuloplasty at long term Eur. J. Cardiothorac. Surg., April 1, 2000; 17(4): 431 - 439. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. H. Crawford, S. J. Bernstein, P. C. Deedwania, J. P. DiMarco, K. J. Ferrick, A. Garson Jr, L. A. Green, H. L. Greene, M. J. Silka, P. H. Stone, et al. ACC/AHA guidelines for ambulatory electrocardiography: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Revise the Guidelines for Ambulatory Electrocardiography) developed in collaboration with the North American Society for Pacing and Electrophysiology J. Am. Coll. Cardiol., September 1, 1999; 34(3): 912 - 948. [Full Text] [PDF]
|
|
|
|
 |
|
 K. E. Raby, S. J. Brull, F. Timimi, S. Akhtar, S. Rosenbaum, C. Naimi, and A. D. Whittemore The Effect of Heart Rate Control on Myocardial Ischemia Among High-Risk Patients After Vascular Surgery Anesth. Analg., March 1, 1999; 88(3): 477 - 477. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Tavilla and D. Pacini Damage to the circumflex coronary artery during mitral valve repair with sliding leaflet technique Ann. Thorac. Surg., December 1, 1998; 66(6): 2091 - 2093. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. C. D. Gullette, J. A. Blumenthal, M. Babyak, W. Jiang, R. A. Waugh, D. J. Frid, C. M. O'Connor, J. J. Morris, and D. S. Krantz Effects of Mental Stress on Myocardial Ischemia During Daily Life JAMA, May 21, 1997; 277(19): 1521 - 1526. [Abstract] [PDF]
|
|
|
|
|
|
T. C. Andrews, K. Raby, J. Barry, C. L. Naimi, E. Allred, P. Ganz, and A. P. Selwyn Effect of Cholesterol Reduction on Myocardial Ischemia in Patients With Coronary Disease Circulation, January 21, 1997; 95(2): 324 - 328. [Abstract] [Full Text]
|
|
|
|
|
|
R. Scrofani, S. Moriggia, M. Salati, P. Fundaro, P. Danna, and C. Santoli Mitral Valve Remodeling: Long-Term Results With Posterior Pericardial Annuloplasty Ann. Thorac. Surg., March 1, 1996; 61(3): 895 - 899. [Abstract] [Full Text]
|
|
|
|
|
|
T. E. David Update on Mitral Valve Repair Ann. Thorac. Surg., May 1, 1995; 59(5): 1257 - 1258. [Full Text]
|
|
|
|
|
|
T. J. Vander Salm, L. A. Pape, and J. F. Mauser Mitral Valve Replacement With Complete Retention of Native Leaflets Ann. Thorac. Surg., January 1, 1995; 59(1): 52 - 55. [Abstract] [Full Text]
|
|
|
|
 |
|
 J. P. DiMarco and J. T. Philbrick Use of Ambulatory Electrocardiographic (Holter) Monitoring Ann Intern Med, July 1, 1990; 113(1): 53 - 68. [Abstract] [PDF]
|
|