For more than a decade our research has focused on the mechanisms whereby behavioral factors predispose to sudden death, the leading cause of cardiac mortality in the United States. We have developed well-defined behavioral models which simulate stress states and have evolved state-of-the-art methodologies for assessing cardiac electrophysiologic and coronary hemodynamic function in conscious, chronically instrumented animals. The investigations have demonstrated that stress-induced vulnerability results both form direct effects of neurotransmitters on the heart and by indirect influences which result in impaired myocardial perfusion. The latter effect is due to inappropriate coronary vasoconstriction in response to certain stress states. Anger in particular has been shown to increase cardiac vulnerability and predispose to profound coronary vasoconstriction int he period following arousal. This raises the possibility that the physiologic responses associated with the post-stress state may be particularly hazardous. A.
SPECIFIC AIMS; 1. To elucidate further the factors involve in delayed myocardial ischemia. 2. To define the influence of contrasting behavioral states on coronary hemodynamic and cardiac electrophysiologic function. 3. To investigate the mechanisms responsible for cardiac vulnerability during the post-stress state. The techniques will include Doppler flow measurement, radiolabeled microspheres, coronary angiography, biochemical assessment of cardiac metabolism, electrochemical detection of catecholamine levels, and cardiac electrical testing. These studies will serve to define underlying mechanisms mediating the effects of diverse stresses on coronary hemodynamic function and the propensity to life-threatening arrhythmias. Ultimately, the insights derived could lead to improved therapeutic strategies relevant to both behavioral medicine and cardiology.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL033567-07
Application #
3345572
Study Section
Biopsychology Study Section (BPO)
Project Start
1988-12-01
Project End
1993-11-30
Budget Start
1989-12-01
Budget End
1990-11-30
Support Year
7
Fiscal Year
1990
Total Cost
Indirect Cost
Name
Georgetown University
Department
Type
Schools of Dentistry
DUNS #
049515844
City
Washington
State
DC
Country
United States
Zip Code
20057
Kovach, J A; Nearing, B D; Verrier, R L (2001) Angerlike behavioral state potentiates myocardial ischemia-induced T-wave alternans in canines. J Am Coll Cardiol 37:1719-25
Kovach, J A; Gottdiener, J S; Verrier, R L (1995) Vagal modulation of epicardial coronary artery size in dogs. A two-dimensional intravascular ultrasound study. Circulation 92:2291-8
Verrier, R L; Nearing, B D (1994) Electrophysiologic basis for T wave alternans as an index of vulnerability to ventricular fibrillation. J Cardiovasc Electrophysiol 5:445-61
Nearing, B D; Oesterle, S N; Verrier, R L (1994) Quantification of ischaemia induced vulnerability by precordial T wave alternans analysis in dog and human. Cardiovasc Res 28:1440-9
Nearing, B D; Verrier, R L (1993) Personal computer system for tracking cardiac vulnerability by complex demodulation of the T wave. J Appl Physiol 74:2606-12
Dickerson, L W; Huang, A H; Thurnher, M M et al. (1993) Relationship between coronary hemodynamic changes and the phasic events of rapid eye movement sleep. Sleep 16:550-7
Dickerson, L W; Huang, A H; Nearing, B D et al. (1993) Primary coronary vasodilation associated with pauses in heart rhythm during sleep. Am J Physiol 264:R186-96
Huang, A H; Nearing, B D; Verrier, R L (1993) Hypoperfusion of the myocardium relative to myocardial metabolism during delayed coronary constriction. Cardiovasc Res 27:435-41
Verrier, R L; Dickerson, L W; Nearing, B D (1992) Behavioral states and sudden cardiac death. Pacing Clin Electrophysiol 15:1387-93
Nearing, B D; Huang, A H; Verrier, R L (1991) Dynamic tracking of cardiac vulnerability by complex demodulation of the T wave. Science 252:437-40

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