Ques. 1 What is heart block? What are its causes?
Ans. It means impairment of conduction in heart excitation ; often applied specifically to atrioventricular heart block.
Causes of heart block:
- Disordered, atrial rhythms, e.g. auricular fibrillation and flutter.
- Idiopathic focal fibrosis-is a common cause of chronic heart block.
- Rheumatic fever and Diphtheria.
- Drugs e.g. Digitalis, quinine.
- Congenital causes, e.g. ventricular septal defect or maldevelopment of the bundle, etc.
- Aortic stenosis.
- Depression of conductivity is most commonly due to ischaemia, fibrosis of inflammation of the A.V. bundle, or to vagal stimulation.
- Myocardial infarction is the commonest cause.
Ques. 2 What are the types of heart block?
Ans. Types of Heart Block :
- First Degree- All S.A. impulses are allowed to pass through A.V. node but the time is prolonged.
- Second Degree – Here S.A. impulses are not allowed to pass through A.V. node from time to time.
- Third Degree of complete heart block – Here no S.A. impulses are allowed to pass through A.V. node, therefore ventricles generate their own rhythm 30 to 40 per minute.
Important Clinical Features :
- First degree heart block can be diagnosed only by E.C.G.
- Second degree heart block-here, from time to time, some S.A. impulses are not allowed to pass through A.V. node. Thus auricles contract but not the ventricles resulting in absence of heart sounds and missing of pulse. This may occur at regular intervals giving rise to 2 : 1 or 3 : 1 heart blocks or may occur irregularly. E.C.G. help in diagnosis.
- Third degree or complete heart block : (i) Pulse rate- 36-40 per minute; Rhythm-regular; Volume-high; Tension-high. (ii) Condition of arterial wall may be sclerosed; Character-may be collapsing. (iii) The pulse is a fixed pulse. (iv) Carotid artery may show carotid dance at a rate of 36-40 per minute. (v) Jugular veins- show auricular pulsations at a rate of 72 per minute. (vi) Auscultation of mitral area- the intensity time which is called canon sound. (vii) E.C.G. will be the diagnosis.
[The gravest danger of complete heart block is Stokes-Adam’s Syndrome.]
Ques. 3 What is the treatment of Heart Block case?
Ans. Complete heart block in acute myocardial infarction requires treatment to prevent undue bradycardia or asystole.
- Steroids in some cases may be given.
- Tablet Neoepinine 20 mgm. I tablet every 4 hourly sublingually.
- Isoprenaline, as an intravenous infusion.
- Curative (Homoeopathic Remedies).
- CACTUS GR. – Violent palpitation worse lying on left side, iron band feeling, constricting, stitching pain in heart, pulse feeble irregular, quick, low blood pressure.
- DIGITALIS – The least movement causes violent palpitation and sensation as if heart would cease beating if he will move. Very slow pulse, intermits, sudden sensation as if heart stood still hypertrophy, cardiac failure with cardiac dropsy.