Medline ® Abstracts for References 2-5

of 'Silent myocardial ischemia: Epidemiology and pathogenesis'

2
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Silent ischemia as a marker for early unfavorable outcomes in patients with unstable angina.
AU
Gottlieb SO, Weisfeldt ML, Ouyang P, Mellits ED, Gerstenblith G
SO
N Engl J Med. 1986;314(19):1214.
 
We examined the prevalence and prognostic importance of silent myocardial ischemia detected by continuous electrocardiographic monitoring in 70 patients with unstable angina. All the patients received intensive medical treatment with nitrates, beta-blockers, and calcium-channel blockers. Continuous electrocardiographic recordings were made during the first two days in the coronary care unit to quantify the frequency and duration of asymptomatic ischemic episodes, defined as a transient ST-segment shift of 1 mm or more. Thirty-seven patients (Group 1) had at least one episode of silent ischemia, and the other 33 patients had no silent ischemia (Group 2). Over the subsequent month, myocardial infarction occurred in 6 patients in Group 1 and in only 1 in Group 2 (P less than 0.01); bypass surgery or angioplasty was required for recurrent symptomatic angina in 10 patients in Group 1 and only 3 in Group 2 (P = 0.02). Survival-curve analysis demonstrated that silent ischemia was associated with these outcomes (P less than 0.002), and multivariate analysis showed that silent ischemia was the best predictor of these outcomes among the 15 variables tested (P less than 0.002). Patients in Group 1 with 60 minutes or more of silent ischemia per 24 hours had a worse prognosis than those with under 60 minutes per 24 hours (P = 0.04). Silent ischemia occurred in more than 50 percent of our patients with unstable angina, despite intensive medical therapy, and it identified a subset who were at high risk for early unfavorable outcomes.
AD
PMID
3
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Silent ischemia on Holter monitoring predicts mortality in high-risk postinfarction patients.
AU
Gottlieb SO, Gottlieb SH, Achuff SC, Baumgardner R, Mellits ED, Weisfeldt ML, Gerstenblith G
SO
JAMA. 1988;259(7):1030.
 
The relative prognostic significance of ischemic ST changes on two-lead continuous electrocardiographic (Holter) monitoring in 103 high-risk postinfarction patients was examined. Ischemic ST changes were detected in 30 patients, with a median number of five episodes per day and median total daily duration of 157 minutes. Only one third of these patients reported any angina in the hospital, and 28 of the 30 patients had silent ST changes on Holter monitoring. The remaining 73 patients had no ischemic ST changes on Holter monitoring. At one year, nine (30%) of 30 patients with ischemic ST changes were dead vs only eight (11%) of 73 patients without such changes. Multivariate Cox's hazard function analysis on 18 variables, including age, type of infarction, Lown and Killip class, ejection fraction, and medications, showed that the presence of ST changes on Holter monitoring was a significant predictive variable for one-year mortality in the overall study population and particularly in the subgroup of 59 patients who could not undergo early exercise treadmill testing. Thus, ischemic ST changes on Holter monitoring, the majority of which are silent, occur in nearly one third of high-risk postinfarction patients and are significantly associated with one-year mortality.
AD
Department of Medicine, Francis Scott Key Medical Center, Baltimore, MD 21224.
PMID
4
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Prognostic significance of ischemic episodes in patients with previous myocardial infarction.
AU
Tzivoni D, Gavish A, Zin D, Gottlieb S, Moriel M, Keren A, Banai S, Stern S
SO
Am J Cardiol. 1988;62(10 Pt 1):661.
 
This study assessed the prognostic significance of ischemic changes during daily activity as recorded by ambulatory electrocardiographic monitoring in a group of 224 low-risk postinfarction patients. Of the 224 patients studied, 74 (33%) had transient ischemic episodes on Holter monitoring. During the 28 months of follow-up the frequency of cardiac events (cardiac death, reinfarction, hospitalization for unstable angina, balloon angioplasty or coronary bypass surgery) was 51% among those with ischemic episodes on Holter monitoring, compared with 12% in those without such changes (p less than 0.0001). The 74 patients with positive results in their exercise tests and Holter monitoring had a 51% event rate, compared with 20% among the 44 patients with a positive exercise test result but negative Holter results (p less than 0.001). The event rate in those without ischemic changes either on the exercise test or on Holter was only 8.5%. Among patients with good (greater than 40%) or reduced (less than 40%) left ventricular ejection fraction, those with transient ST depression on Holter had a significantly higher cardiac event rate compared with those without it. A similar event rate was found in patients with only silent, only symptomatic and with silent and symptomatic ischemic episodes.
AD
Heiden Department of Cardiology, Bikur Cholim Hospital, Jerusalem, Israel.
PMID
5
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Prevalence and patterns of silent myocardial ischemia during daily life in stable angina patients receiving conventional antianginal drug therapy.
AU
Deedwania PC, Carbajal EV
SO
Am J Cardiol. 1990;65(16):1090.
 
The prevalence and patterns of silent myocardial ischemia were evaluated in 105 stable angina patients receiving conventional antianginal drug therapy. During 2,520 hours of electrocardiographic monitoring, silent ischemia was detected in 45 (43%) patients. A total of 188 ischemic episodes was observed; 163 (87%) were silent and accounted for a total ischemic duration of 5,771 minutes. There was no difference in the baseline clinical characteristics between the patients with and without ambulatory silent ischemia. However, patients with silent ischemia on ambulatory electrocardiographic monitoring had earlier onset of ischemia during exercise testing. The highest density of silent ischemic events occurred between 6 A.M. and 6 P.M. Comparison of the class or combination of antianginal agents used by the 2 groups revealed no difference. However, in patients with silent ischemia the mean duration per event was shorter for those receiving 2 (p less than 0.05) or more (p = 0.001) antianginal agents compared to those receiving monotherapy. The average duration of silent ischemia per event was significantly less (p less than 0.001) in patients receiving beta blockers. These results demonstrate that silent ischemia during ordinary daily activities occurs frequently despite conventional antianginal drugs prescribed for control of symptoms.
AD
Department of Medicine, Veterans Affairs Medical Center, Fresno, California 93703.
PMID