Heart rate physiology

1. Heart rate

2. HEART RATE
• 60-100 beats/min

3. bradycardia
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Athletes
Sick sinus syndrome
Drugs
Obstructive jaundice
Raised intra cranial pressure
Myxedema
Junctional rhythm
Complete heart block

4. tachycardia
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Anxiety
Fever
Hypoxemia
Thyrotoxicosis
Cardiac failure
Cardiac failure
Acute carditis
Ectopic tachycardia

5. tachycardia
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Atrial premature beats:
Anxiety
Tea
Viral infection
Rhemautic heart disease
Coronary artery disease
Cardiomyopathies
thyrotoxicosis

6. tachycardia
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Rheumatic heart disease
Coronary artery disease
Cardiomyopathies
Thyrotoxicosis
Atria flutter:
Rhemautic heart disease
Coronary artey disease
Ventricular premature beat
Ventricular tachycardia

7. Effect of parasympathetic
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Decreases heart rate by decreasing sinus rhythm
Decreasing the rate of transmission of impulse to ventricles
Strong PNS stimulation can completely block transmission into
ventricles
Right vagus SAN
Left vagus AVN

8. Effect of sympathetic stimulation
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Release of NE
Opening of L type calcium channels
Force of contraction increases
Increases heart rate.