Cardiovascular Pathology Pt. 1 Flashcards
Factors Affecting Preload (Left Ventricle Diastolic Volume)
- Total volume
- Venous tone (sympathetic)
- Body position
- Intrathoracic and intrapericardial pressure
- Atrial contraction
- Pump action of the skeletal muscle
Factors Affecting Afterload (amount of pressure that the heart needs to exert to eject the blood during ventricular contraction)
- Peripheral vascular resistance
- Left ventricular stroke volume
- Elasticity of the arterial tree or presence of obstructions.
Factors Affecting Contractility (independent of preload and afterload)
Increasing contractility: • Sympathetic nerve impulses • Circulating catecholamines • Digital, calcium other inotropic agents • Heart rate increase or, post-extrasystolic increase Decreasing contractility: • Anoxia, acidosis • Pharmacologic depression • Myocardial loss • Intrinsic depression.
Factors Affecting Heart Rate
- Autonomous nervous system
* Temperature, metabolic rate
Stages of Hypertension
Systolic Diastolic
Normal <120 and <80
Elevated 120-129 and <80
Stage I 130-139 or 80-89
Stage II >140 or >90
Hypertension crisis >180 and/or >120
Hypertension - Definition, Symptoms and Diagnosis
Blood pressure in arteries persistently increased - Damage.
Often symptom-free for decades.
Symptoms: headache, dizziness, nosebleed, dyspnea, chest pain.
Monitored for 24h with a holster.
Hypertension - Risk Factors
50% of population over 50 has hypertension. 95% of cases have no identifiable cause (primary/essential hypertension) Medication Other diseases Genetic Overuse of sodium chloride Renal diseases Abuse of cigarettes Stress Overweight Abuse of alcohol, caffeine
Hypertension - Consequences
↑ morbidity and mortality in cardiovascular diseases Damage on heart, vessels, brain, kidneys Hypertrophy of the left ventricle Ischemic heart diseases Stroke
Hypertension - Therapy
Medication (Beta-blockers, diuretics..., useful for acute phase, useless if no life style changes are made) Endurance sports Nutrition (+weight) Stress reduction Quit smoking
Hypotension - Definition
Systolic pressure < 90 mmHg OR diastolic < 60mmHg
Without symptoms: not unhealthy
Pathologic: (if symptomatic)
Dizziness, unconsciousness, fainting, orthostatic hypotension
Hypotension - Causes
Blood loss, dehydration.
Female, pregnancy.
Physical inactivity, immobilization.
Cardiovascular: Heart Failure, Aortic Stenosis, cardiac arrythmia.
Infections.
Medication (anti-hypertensive medication).
Idiopathic (chronic asymptomatic hypotension).
Hypotension - Diagnosis and Therapy
Find underlying cause.
Blood tests (haemogram), Electrocardiogram, Echocardiogram, Stress test.
Therapy will depend on underlying cause.
Exercise training. Medication: fludrocortisone.
Orthostatic Hypotension
Disturbance in regulation of heart rate and peripheral resistance in change of positions i.e. lying to standing.
Drop of blood pressure >20mmHg systolic or diastolic >10mmHg.
Hypovolemic Shock - Definition and Symptoms
Not enough blood flow to the tissues of the body, extreme hypotension, life-threatening.
- Confusion (especially in older subjects)
- Cold, clammy and pale skin
- Rapid, shallow breathing
- Weak and rapid pulse
Hypovolemic Shock - Cause and Compensation
Anaphylactic, septic, cardiogenic, hypovolemic, neurogenic.
Compensation:
- Increase heart rate, vasoconstriction, ischemia of non-vital organs.
