Triggers of Ventricular Arrhythmias (TOVA) Study

This study is currently recruiting patients.

Sponsored by

National Heart, Lung, and Blood Institute (NHLBI)

Purpose

To investigate factors which trigger the discharge of implantable cardioverter-defibrillators (ICDs).

Study Type: Epidemiology

Location and Contact Information

Muller, James E.      Lexington,   Kentucky,   United States      

Kentucky

University of Kentucky, Lexington,    Kentucky,   United States; Recruiting

Study chairs or principal investigators

Muller, James E.,  Study Chair

University of Kentucky   Lexington,   Kentucky,   United States

More Information

Results

The Determinants Study accomplished its four Specific Aims. It demonstrated that awakening/activity, rather than the absolute time of day, is responsible for morning triggering, that heavy exertion, anger, and sexual activity are triggers of Ml with relative risks of 6, 3, and 2 respectively, that beta-blockade prevents triggering by awakening/activity, and that a sedentary lifestyle markedly increases the relative risk of triggering of Ml by heavy exertion. Educational attainment, anger, and the risk of triggering myocardial infarction onset were reported on in the April 14, 1997 issue of the Archives of Internal Medicine. While it has recently been shown that anger may trigger the onset of acute myocardial infarction, there has been no study of the role of socioeconomic factors in such triggering. Socioeconomic factors, such as educational attainment, may modulate the risk of triggering because of their influence on individual reactivity to external stressors and on the prevalence of traditional cardiac risk factors. The authors evaluated the influence of educational attainment on the relative risk of myocardial infarction onset following episodes of anger. They interviewed 1,623 patients (501 women) an average of 4 days following a myocardial infarction. Data were collected on standard demographic variables as well as risk factors for coronary artery disease. Educational attainment was categorized into 3 levels: less than high school, completed high school, and at least some college. Anger was assessed by the Onset Anger Scale, a single-item, seven level, self-report scale. Occurrence of anger in the two hours preceding the onset of myocardial infarction was compared with its expected frequency using self-matched control data based on the case-crossover study design. The risk of having a myocardial infarction triggered by isolated episodes of anger declined consistently and significantly with increasing levels of educational attainment (P = .03). The relative risk was twice as high among those with less than high school education (relative risk, 3.3; 95 percent confidence interval, 2.0-5.4) compared with patients with at least some college education (relative risk, 1.6; 95 percent confidence interval, 0.9-2.9). The authors concluded that these findings indicate that socioeconomic factors are potent modulators of the risk of triggering acute cardiovascular disease onset. The triggering of acute myocardial infarction by episodes of anger was reported in the October 1, 1995 issue of Circulation. Many anecdotes and several uncontrolled case series have suggested that emotionally stressful events, and more specifically, anger, immediately precede and appear to trigger the onset of acute myocardial infarction. However, controlled studies to determine the relative risk of myocardial infarction after episodes of anger have not been reported. The authors interviewed 1623 patients (501 women) an average of four days after myocardial infarction. The interview identified the time, place, and quality of myocardial infarction pain and other symptoms, the estimated usual frequency of anger during the previous year, and the intensity and timing of anger and other potentially triggering factors during the 26 hours before the onset of myocardial infarction. Anger was assessed by the onset anger scale, a single-item, seven-level, self-report scale, and the state anger subscale of the State-Trait Personality Inventory. Occurrence of anger in the two hours preceding the onset of myocardial infarction was compared with its expected frequency using two types of self-matched control data based on the case-crossover study design. The onset anger scale identified 39 patients with episodes of anger in the two hours before the onset of myocardial infarction. The relative risk of myocardial infarction in the two hours after an episode of anger was 2.3 (95% confidence interval, 1.7 to 3.2). The state anger subscale corroborated these findings with a relative risk of 1.9 (95% confidence interval, 1.3 to 2.7). Regular users of aspirin had a significantly lower relative risk (1.4; 95% confidence interval, 0.8 to 2.6) than nonusers (2.9; 95% confidence interval, 2.0 to 4.1) (P < .05). The authors concluded that episodes of anger are capable of triggering the onset of acute myocardial infarction, but aspirin may reduce this risk. A better understanding of the manner in which external events trigger the onset of acute cardiovascular events may lead to innovative preventive strategies aimed at severing the link between these external stressors and their pathological consequences.

Study ID Numbers  1124

NLM Identifier  NCT00005243

Date study started April 1, 1989;   Date Study Completed  August 31, 2003

Last Updated  May 18, 2000

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