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Cardiovascular reactivity, Type A behavior, and coronary heart disease: comparisons between myocardial infarction
Insights
Middle-aged men with myocardial infarction exhibited distinct cardiovascular responses to stress compared to healthy controls. Type A men, regardless of heart condition, showed greater blood pressure reactivity to both mental and physical stressors.
Area of Science:
- Cardiology
- Psychophysiology
- Behavioral Medicine
Background:
- Cardiovascular reactivity to stress is a key factor in myocardial infarction (MI) development.
- Understanding the influence of behavioral patterns like Type A/B on cardiovascular response is crucial for risk assessment.
Purpose of the Study:
- To investigate cardiovascular responses to laboratory stressors in middle-aged men with diagnosed MI compared to healthy controls.
- To examine the impact of Type A and Type B behavior patterns on hemodynamic responses to mental and physical stress.
Main Methods:
- Participants included 30 male patients with NYHA Class 1 MI and 26 age-matched healthy controls.
- Cardiovascular variables (blood pressure, heart rate, forearm blood flow/resistance, impedance cardiography) were measured during mental and physical stress tasks and recovery.
- Subjects were nonsmokers, normotensive, and not on medication.
Main Results:
- MI patients displayed elevated systolic blood pressure and cardiac output reactivity, with prolonged systolic time ratio during mental stress.
- During physical tasks, MI patients showed increased total peripheral resistance and reduced cardiac output/stroke volume compared to controls.
- Type A men exhibited significantly higher systolic and diastolic blood pressure responses to both stress types than Type B men, irrespective of coronary status.
Conclusions:
- Cardiovascular differences between MI patients and controls during stress are partly vascular (physical tasks) and partly related to beta-adrenergic activation (mental tasks).
- Type A behavior is associated with heightened blood pressure reactivity, suggesting a potential mechanism for increased cardiovascular risk.
Abstract:
Cardiovascular responses to a series of laboratory stressors were examined in middle-aged Type A and Type B men. The subjects were 30 patients with diagnosed myocardial infarction (NYHA Class 1) and 26 age-matched healthy controls. All subjects were nonsmokers in the normotensive range, and none were on medication. Blood pressure, heart rate, forearm blood flow and resistance, and impedance cardiography-determined response variables were obtained during performance and recovery periods of both mental and physical tasks. The patients showed elevated reactivity in systolic blood pressure and cardiac output and prolonged systolic time ratio during mental stress tasks and elevated total peripheral resistance and lower cardiac output and stroke volume during physical tasks, as compared with control subjects. Thus, the difference in blood pressure reactivity between patients and controls appeared to be primarily dependent on the vascular component during physical tasks, whereas the mental tasks promoted a hemodynamic response pattern more consistent with beta adrenergic activation. Type A men, irrespective of coronary status, showed larger systolic and diastolic blood pressure response to both mental and physical stress than did Type B men.