This PPT is on Cardiovascular System ,prepared By Dr.A.R.Joshi & uploaded by Prof.Dr.R.R.Deshpande on 25-8-13

1. CARDIOVASCULAR SYSTEM
BY
Dr. A.R. JOSHI
PROFESSOR OF PHYSIOLOGY

2. CARDIOVASCULAR SYSTEM
Properties of Cardiac Muscle
1. Autorhythmicity
2. Conductivity
3. Contractility
4. Excitability
5. All or none law
6. Long refractory period

5.  Electrodes (leads).
 Amplifier
 Recording unit

6.  Bipolar leads – I, II, III.
 Unipolar leads –
Limb leads – aVR , aVL , aVF
Chest leads – V1 to V6.

9.  P-Wave- Depolarization of atria
 QRS Complex- Depolarization of
ventricles
 T-Wave – Repolarization of ventricles

10.  PR interval – AV conduction time
• (0.12 – 0.16 Sec.)
 QT interval – Ventricular systole
• (0.26 – 0.30 Sec)
 TP interval – Ventricular diastole
• (0.46 – 0.50 Sec)
 ST- Segment should be iso-electric




11.  Diagnosis of arrhythmias & heart
blocks.
 Diagnosis of hypertrophy.
 Diagnosis of IHD.
 Diagnosis of other diseases like
electrolyte imbalance, pericarditis
etc.

12. NERVE SUPPLY OF HEART
Autonomic Nervous System
Sympathetic supply( T1 to T5 )
Effects of stimulation
(Due to Noradrenalin and Adrenalin )
1. Increase in Heart rate
2. Increase in Force of contraction
3. Increase in Excitability
4. Increase in Conductivity
(Effects blocked by alpha & beta blockers)

13. PARA SYMPATHETIC SUPPLY
(Lt. & Rt. Vagus)
Effects of Stimulation :
(Due to Acetyl Choline )
1. Decrease in Heart rate
2. Decrease in Force of contraction
3. Decrease in Excitability
4. Decrease in Conductivity
(All effects reverted by Atropine
which blocks muscarinic 2 receptors)

14. CARDIAC CYCLE
Total time – 0.8 sec when HR -75/min.
Events :
Atrial events :
1. Atrial systole 0.1 sec
2. Atrial diastole 0.7 sec
Ventricular events :
1. Ventricular systole 0.3 sec
2. Ventricular diastole 0.5 sec

15. VENTRICULAR SYSTOLE
(contraction)
Events :
1. Isovolumetric contraction phase
2. Maximum ejection phase
3. Reduced ejection phase
(First Heart sound occurs at beginning
of Iso-volumetric contraction phase)

16. VENTRICULAR DIASTOLE
(relaxation)
Events :
1. Protodiastole
2. Isovolumetric relaxation phase
3. First rapid filling phase
4. Diastasis
5. Last rapid filling phase
(Second heart sound occurs at beginning
of Isovolumetric relaxation phase )

17. FIRST HEART SOUND
Causes :
1. Closure of A-V valves
2. Contraction of Ventricles
3. Ejection of blood in big vessels
Peculiarities
1. Like LUBB
2. Intensity high & pitch low
3. More duration
4. Best heard at apex
5. Best heard with diaphragm
6. Coincides with carotid pulse

18. SECOND HEART SOUND
Causes :
1. Closure of S-L valves
2. Relaxation of Ventricles
3. Regurgitation of blood in big vessels
Peculiarities :
1. Like DUP
2. Intensity low & pitch high
3. Short duration
4. Best heard at base
5. Best heard with bell
6. Comes after carotid pulse

19. REGULATION OF HEART RATE
1. Nervous factors
2. Hormonal factors
3. Local factors
4. Reflexes : Cardio acceleratory reflex
Cardio inhibitory reflex
5. Miscellaneous factors like body temp.

20. CLINICAL EXAMINATION OF
ARTERIAL PULSE
1. Rate
2. Rhythm
3. Volume
4. Force
5. Tension
6. Equality
7. Condition of vessel wall
8. Peripheral pulsations
9. Apex–pulse co-relation

22. CARDIAC OUTPUT
1. Stroke Volume (70 ml)
2. Minute volume=S.V x H.R.(5 litres/min.)
3. End systolic volume (60 ml)
4. End diastolic volume (130 ml)
5. Ejection systolic fraction (0.55)
=Stroke volume/End diastolic volume
(Criterion of cardiac fitness )

23. FACTORS AFFECTING
STROKE VOLUME
Venous return (Input factors) :
1. Muscle pump
2. Respiratory pump
3. Blood volume
4. Pressure gradient
5. Venous tone

24. FORCE OF CONTRACTRION
(Output factors)
1. Nervous factors
2. Hormonal factors
3. Frank-Starling’s law
4. Coronary perfusion
5. Diastolic period

25. CAUSES OF CARDIAC FAILURE
1. Ischaemic
2. Hypertensive
3. Valvular
4. Cardiomyopathies

26. RIGHT HEART FAILURE
Causes : COPD
Ischaemia
Pulmonary valve diseases
Secondary to chronic LVF
Effects: Pitting oedema over feet
Prominent neck veins
Liver enlargement & ascitis
Hepato-jugular reflex present

27. LEFT HEART FAILURE
Causes : Hypertension
Ischaemia
Aortic valve diseases
Effects : Pulmonary oedema
Basal crepitations
Pulsus alternans

28. (Preferably with hospitalization)
1. Treat the basic cause
2. Oxygenation
3. Salt restricted diet
4. Cardiotonic drugs like digitalis
5. Drugs to reduce load on heart like
diuretics
TREATMENT OF CARDIAC FAILURE

31. PHYSIOLOGICAL VARIATION
1. Age
2. Sex
3. Exercise
4. Posture
5. Diurnal
6. Mental stress
7. High altitude

32. FACTORS AFFECTING B.P.
Systolic B.P. depends upon Cardiac output
Diastolic B.P. depends upon Peripheral
Resistance, which depends upon-
● Diameter of blood vessel
● Elasticity of blood vessel
● Viscosity of blood
● Velocity of blood
● Length of blood vessel

33. REGULATION OF B.P.
Short term regulation :
Nervous regulation
1. Baroreceptors
2. Chemoreceptors
3. CNS ischemic response
Hormonal regulation
1. Renin angiotensin
2. Catecholamines
3. ADH

36. REGULATION OF B.P.(cont.. )
Intermediate :
1. Vascular stress relaxation
2. Capillary fluid shift mechanism
Long term :
1. Role of aldosterone
2. Role of kidney

37. HYPERTENSION
Definition :
Types : 1. Primary
2. Secondary
Predisposing factors for primary hypertension :
1. Age
2. Sex
3. Heredity
4. Life style(Diet,sedentary work,stress,habits)
5. D.M. and obesity

38. HYPERTENSION (cont.. )
Symptomatology :
● Asymptomatic
● Classical symptoms
● Complications
LVF
Encephalopathy and stroke
Nephropathy
Retinopathy

39. TREATMENT OF PRIMARY
HYPERTENSION
● Mild hypertension :
Life style modification
Salt, fat and sugar restriction
Tranquillizers if required
● Moderate hypertension :
All above
Diuretics
● Severe hypertension:
All above
Anti hypertensives

40. ANTIHYPERTENSIVE DRUGS
1. Beta blockers e.g.atenolol
2. Calcium channel blockers e.g.amlodipine
3. ACE inhibitors e.g.captopril
4. Angiotensin receptor blockers e.g.losartan
5. Alpha receptor blockers e.g.doxazocin

41. SHOCK
Persistent hypotension leading to
inadequate tissue perfusion.
Types :
1. Hypovolemic
2. Cardiogenic
3. Anaphylactic
4. Neurogenic
5. Septic

42. STAGES OF HYPOVOLEMIC
SHOCK
1. Compensatory : Blood loss upto 500ml
(All B.P.regulating mechanisms working to maximum)
2. Progressive : Blood loss upto 1 litre
(External help in form of fluid or blood transfusion )
3. Irreversible : Blood loss more than 1 litre
(Harmful positive feedback sets in )

43. PRINCIPLES OF TREATMENT
1. Hospitalization
2. Replacement therapy
3. Drugs e.g dopamine
4. Treatment of complications
e.g renal failure

44. PECULARITIES OF CORONARY
CIRCULATION
(Normal flow –250 ml per min )
1. End arteries
2. Filled in diastole
3. High capillary density
4. A-V difference of oxygen is high
5. Local factors regulate blood flow
6. Presence of beta receptors
7. Energy derived from fatty acids

45. PECULARITIES OF PULMONARY
CIRCULATION
( Normal flow –5lits per min )
1. Low pressure system
2. No tissue fluid formation
3. Distensible
4. Nerves and hormones have no effect
5. Hypoxia causes vasoconstriction
6. Less blood flow to apex and more to base
7. Rich lymphatic supply