42
PSYCHOLOGICAL STRESS

PSYCHOLOGICAL STRESS. ACUTE PSYCHOLOGICAL STRESS Confront a Bear arouses Fear elicits Adaptive Responses Cardiovascular Responses heart rate, contractile

Embed Size (px)

Citation preview

PSYCHOLOGICAL STRESS

ACUTE PSYCHOLOGICAL STRESS

Confront a Bear arouses Fear elicits Adaptive Responses

Cardiovascular Responses heart rate, contractile force Preparatory and serve to increase cardiac output to

supply additional blood to skeletal muscles

BEAR

Sudden Cardiac Death

EMOTION AND SUDDEN CARDIAC DEATH

BIBLE - BOOK of ACTS When Ananias was charged by Peter “you have not lied to man but to God,” he fell dead;as did Sapphira, his wife, when told that “thefeet of them which have buried thy husbandare at the door and shall carry thee out”

George Engel (1971). Life Settings in which Sudden Death Occurred

• On impact of the collapse and death of a loved one (21%)

• During acute grief (20%)• Threat of loss of a loved one (9%)• During mourning or anniversary of death of

loved one (3%)• Loss of status or self-esteem (6%)• Personal danger or threat of injury (27%)• After the danger is over (7%)

Engel - (cont)

• Reunion, triumph or happy ending (6%)

Common Thread - Events were impossible for the victims to ignore.

Trichopoulus et al. 1983. Psychological stress and the

fatal heart attack: the Athens (1981) earthquake

natural experiment.

Trichopoulus et al. - 1983

• February 24-11:00 p.m. Earthquake

• February 25

• February 26

• February 27 Aftershocks

• February 28

• March 1

Trichopoulus et al. - (cont.)

• Death Certificates at time of earthquake

• Death Certificates from Control Periods - 1980, 1981,1982

• Immediate cause of death due to sudden cardiac event

Trichopoulus et al. - Results

• Daily Number of Deaths due to Cardiac Event

• Control Period Mean = 7.1

• Quake Period:

Feb. 25 = 9

Feb. 26 = 11

Feb. 27 = 14 Mean = 10.4

Feb. 28 = 9

Mar. 1 = 9

Meisel et al. (1991). Effect of Iraqi missile war on incidence of acute myocardial infarction

and sudden death in Israeli Civilians.

Meisel et al.(1991)

• Gulf War SCUD Missile attacks on Tel Aviv.

• Sapir Medical Center

• First week of the war – Jan. 17-25, 1991

- Number of patients who were seen/died from acute myocardial infarction (heart attack)

- Compared to number of patients during control periods

Meisel et al.,(1991)- Results

Sapir Medical Center Patients Seen*

Out of hospital Sudden Deaths n = 41 First week of the war n = 22 Jan. 17-25, 1990

Loer et al. (1996). Sudden death triggered by an

Earthquake

The Northridge, California earthquake

Kawachi et al. (1994). Prospective study of phobic anxiety and risk of coronary

heart disease in men.

Kawachi et al.(1994)

• Studied 2000 men from 1961 to 1993

• 1961 – Physical exam

Questionaire – Five Questions

1. Do strange people or places make you afraid?

2. Are you considered to be a nervous person?

3. Are you constantly keyed-up or jittery?

4. Do you often become scared for no good reason?

5. Do you often break out in a cold sweat?

QUESTIONAIRE RESULTS - 89% scored a 0, 8.9% scored a 1, 1.9% scored a 2 or more.

Kawachi et al. (1994) – cont.• From 1961- 1993

1. Every three years

- Medical history

- Physical exams

- Lab tests

2. Cause of death monitored in deceased men

• RESULTS – Those men who scored a 2 or higher on the questionaire were 4 times more likely to die of sudden cardiac death than those who scored a 0. That is, phobic anxiety is a risk factor for sudden cardiac death.

Acute Psychological Stress

Ventricular Arrhythmias (abnormal heart beats)

Ventricular Fibrillation

Sudden Death

Predisposition to Electrical Instability

Digitalis

• Used to increase contractile force of the heart

• Can cause arrhythmias at high doses

Amygdala

Cardioregulatory Nuclei (Medulla)

Heart

Chronic Stress ? Cardiovascular Disease

• Cardiovascular Stress Response 1. Cardiac Output - heart rate contractile force 2. Changes in Blood Vessels - constriction produces blood pressure 3. Changes in blood flow - constriction of vessels to skin, kidney, viscera - dilation of vessels in skeletal muscles

PSYCHOSOCIAL STRESS AND ATHEROSCHLEROSIS

• Jay Kaplan – 1980’s ff

- cynomolgus monkeys

- in the wild

- mixed gender groups

- all male groups

- intrusions during the mating season

Kaplan et al. – Experiment 122 months duration

1. Unstable Social Condition

- Three groups of males

- n=5 per group

- Every 1-3 months Redistribution

Each male is placed with 3-4 new males

2. Stable Social Condition

- Three groups of males

- No redistribution

UNSTABLE SOCIAL CONDITION

N=5 N=5 N=5

Redistribution every 1-3 monthsEach male with 3 to 4 new males

N=5 N=5 N=5

No Redistribution

STABLE SOCIAL CONDITION

Kaplan et al. - Experiment 1(cont.)• Fed a “North American Diet” - moderately atherogenic (high fat, high cholesterol)• Routine evaluations - Pathological Observations - blood lipids, blood pressure, heart rate - Behavioral Observations - fighting behavior - patterns of dominance• Measured coronary artery atheroschlerosis - at 22 months

Kaplan et al.- Expt.1 RESULTS

• When compared to subordinates, dominant monkeys in unstable condition show

a. Increased heart rates

b. Increased atheroschlerotic lesions*

• No difference in atheroschlerosis and heart rates between subordinate and dominant monkeys in stable condition

Is the increased atheroschlerosis due to increased sympathetic nervous

system activation?

Kaplan et al. - Experiment 2

• Male monkeys

• 22 months

• Unstable social condition

- Two Drug Conditions

a. Norepinephrine Beta receptor antagonist group

propranolol = antagonist

b. Placebo control group

Kaplan et al.- Experiment 2 Results

• Propranolol inhibited the development of

atheroschlerosis in dominant monkeys.

• Propranolol had no effect on subordinate

monkeys.

Kaplan et al. - Conclusions

Psychosocial Stress activate

Sympathetic Nervous System produces

Atheroschlerosis

How does sympathetic nervous system innervation of the vascular system produce

atheroschlerosis?

Blood Vessels

Bifurcations Bends

Increased Force Increased Turbulence

Increased Wear and Tear

Mechanics of Wear

1. Smooth inner lining of vessel tears and scars2. Fatty acids and glucose work their way under the layer and stick there thickening plaques

Green = Atheroschler. plaque

Adrenal Glands

Norepinephrine Epinephrine released with stress Glucose, Fatty acids

Gender Differences in Development of

Atheroschlerosis in Humans• Expression of atheroschlerosis is delayed

in females by 10-15 years

• What contributes to this delayed onset?

Kaplan et al. - Experiment 3

• Female monkeys• Male monkeys - n=5-6 in stable social groups for 24 months• Evaluation of ovarian function in females - measurements of progesterone levels• RESULTS: Subordinate females - enlarged adrenal glands* - impaired ovarian function* - greater incidence of atheroschlerosis*

Dominant Subordinate

Progesterone levels Luteal phase of ovulatory cycle

8.89 ng/ml 3.79 ng/ml

Adrenal weights 168 mg/kg 201 mg/kg

Percentage cycles with luteal phase deficiencies

8.9 24.3

Does Impaired Ovarian Function Contribute to

Atheroschlerosis?

Kaplan et al. - Experiment 4• 24 months

• Ovarectomized females

• RESULTS :

- Ovarectomy increased atheroschlerosis in

dominant but not subordinate females

• CONCLUDE:

- Ovarian hormones are anti-atheroschlerotic

Kaplan et al. Expt 4. – cont.

Stress of Social Subordination

Impairment of Ovarian Function

Increased Risk of Atheroschlerosis

Kaplan et al. Experiment 5

• Exogenous estrogen treatment to female monkeys

• Triphasil=exogenous estrogen

• Measured iliac artery atheroschlerosis

• RESULTS:

- triphasil protected subordinate females*

- in control group, the more dominant the monkey,

the less the atheroschlerosis*

Sparing of coronary heart disease in pre-menopausal women compared to men

• Delay of disease onset in women

CHD Death Rate – 40 year olds

Men 40 per 100,000/yr

Women 8 per 100,000/yr

CHD Death Rate – 60 yr olds

Men 400 per 100,000/yr

Women 175 per 100,000/yr

5:1

2:1