| ID | 66 |
|---|---|
| Name | CORONARY (ISCHAEMIC) HEART DISEASES |
| Cause | |
| Signs Symptoms | |
| Diagnosis | |
| Investigations | |
| Management | Management:1.2 Early management of acute myocardial infarction- 1. Immediate hospitalization- if approachable (where defibrillator is available). 2. Rest- absolute bed rest. 3. Oxygen supplement- high-flow oxygen 2-3 litre/minute by nasal catheter should be started immediately. 4. a. Intravenous access should be opened immediately for rapid i.v medication, b. ECG monitoring. 5. Relief of pain- Inj. morphine 10mg or diamorphine 5mg initially i.v slowly is given immediately. In severe cases it may be repeated in smaller doses in every 3-4 hours interval. 6. Antiemetic- Inj. cyclizine 50mg or prochlorperazine (stemetil) 12.5mg i.v stat to prevent vomiting. 7. Oral aspirin 300mg stat (soluble or chewable) and then 75-150mg daily for at least 4 weeks- it improves survival (30% reduction in short-term mortality) & enhances the effect of thrombolytic therapy. 8. L Thrombolytic therapy: Appropriate use of thrombolytic drugs may bring great benefit to the patient, if it can be initiated within first 1-3 hours; 25-50% or greater reduction in mortality rate can be achieved. Even if it can be given within 12 hours of onset of symptoms, there may be a significant reduction in short-term mortality. Inj. Sterptokinase 1.5 million units in 100ml of saline given as an i.v infusion over 60 minutes (half in 20 minutes & rest in 40 minutes). Or, Inj. Alteplase2 (a genetically engineered i.e recombinant tissue plasminogen activator or tPA; it is not antigenic and rarely causes hypotension)- a bolus dose of 15mg given in i.v drip over 90 minutes, followed by 0.75mg/kg (max. 50mg) over 30 minutes, & then 0.5mg/kg (max. 35mg) over 60 minutes. Many hospitals or clinics only use Alteplase where Streptokinase is supposed to be contraindicated. Recently, other two genetically engineered plasminogen activator products are also available, which can be used as alternative of Alteplase viz, Reteplase (rPA), Tenecteplase (INK) N.B: Streptokinase is an antigenic drug, if once it is used, neutralizing antibodies are formed in the circulation, which may persist for 5 years or more. So that, subsequent use of this drug may be ineffective or occasionally may cause serious allergic reaction. Therefore, if it is necessary to use any thrombolytic drug further, it is better to use another drug in the next few years2. ii. Primary percutaneous coronary intervention (PCI): The patients of myocardial infarction in whom thrombolytic therapy is contraindicated or very much hazardous, immediate or primary angioplasty of the infarct-related coronary artery by percutaneous intervention is a safe and effective alternative to thrombolytic therapy, when performed promptly. But, this is not widely available, and only possible in highly specialized and experienced cardiac centres. 9. Intravenous b-blockers: Inj. atenolol 5-10mg given i.v over 5 minutes or metoprolol 5-15mg over 5 minutes in acute attack of myocardial infarction relieves pain, reduces tachyarrhythmias and improves short-term mortality rate if can be administered within 12 hours of onset. It is contraindicated in heart failure, heart block or sinus bradycardia. 10.Nitrates and other agents: Glyceryl trinitrate can be used as first-aid measure in threatened infarction, sublingually 0.3-0.5mg, or as buccal spray about 5 minutes. Intravenous nitroglycerin 0.6-1.2mg/hour or isosorbide dinitrate 1-2 mg/hour are also useful in the treatment of left ventricular failure and the relief of recurrent or persistent ischaemic pain. Routine oral nitrate therapy is not recommended as there is no evidence of higher survival outcome. 11. Monitoring ECG: Continuous monitoring if available. 12. Treatment of complications (if any)- see below. General management: 1. Diet- first 12 hours nothing by mouth, because of risk of vomiting; then bread, milk, biscuit & on 4-5th day normal diet. 2. Milk of magnesia 30ml twice daily to avoid strain at stool. 3. If retention of urine- catheterisation should be done. 4. Antibiotic- to prevent secondary infection. Advice: 1. Allow patient to sit on bed on 2nd day, to walk on 5th day, to go home after a week, 2nd & 3rd week must stay within home & from 12th week can start office work. 2. Reassurance. 3. Advice for exercise gradually & to do his work which are comfortably possible. 4. No contraindication of family life. 5. Reduce weight, if possible. 6. Avoid smoking. 7. If hypertension, control it. |
| Introduction | Ischaemic heart disease is the commonst cause of cardiovascular disability and most important cause of premature death throughout the world. Myocardial ischaemia occurs due to an imbalance between the supply of oxygen & other nutrients and the myocardial demand. This imbalance in supply is due mostly to reduced myocardial blood flow, as a result of obstructive coronary artery disease (CAD). Men are more often affected than women at an average ratio of 4:1. In men, the incidence is at age 50-60 and in women, at age 60-70 years. |
| History | |
| Etiology | Etiology: 1. Obstructive coronary artery disease leading to reduced myocardial blood flow, viz- a. Atheroma or atherosclerosis & its complication b. Thrombosis c. Embolism d. Spasm e. Coronary osteal stenosis d. Coronary arteritis (as in SLE) 2. Decreased oxygenated blood flow, as in- a. Anemia b. Hypotension causing decreased coronary perfusion pressure 3. Increased myocardial demand- a. Thyrotoxicosis b. Myocardial hypertrophy (as a result of aortic stenosis or hypertension) c. Aortic valve disease Risk factors for coronary heart disease: A. Fixed factors- 1. Positive family history. 2. Male gender (men are more often affected). 3. Age - incidence rate increases with age B. Factors strongly associated- 4. Hypertension 5. Hyperlipidaemia (high LDL cholesterol & lower HDL cholesterol) 6. Diet- high fat & low fibre diet & low intake of antioxidant vitamins 7. Diabetes mellitus 8. Cigarette smoking C. Factors weakly associated- 9. Obesity 10. Physical inactivity 11. Elevated blood homocysteine level 12. Hypoestrogenaemia (in women) 13. Chronic infection 14. Contraceptive pill (women) 15. Heavy alcohol consumption 16. Mental stress Clinical manifestations: 1. Angina pectoris 2. Myocardial infarction 3. Heart failure 4. Arrhythmia 5. Sudden death |
| Clinical Features | |
| Preventions | |
| Treatment | Treatment of complications: Arrhythmias: 1. If unusual tachycardia, i.e. pulse rate more than 120/minute- a. b-blockers- Inj. Atenolol 5-10mg i.v over 5 minutes or metoprolol 5-15mg over 5 minutes may reduce tachyarrhythmias. Oral dose may be given after initial acute episode, b. Diuretics- may be helpful, such as frusemide, thiazide etc. 2. Ventricular tachycardia, i.e heart rate usually between 140-220/minute-a. Cardioversion is the treatment of choice. b. Inj. Lignocaine 50-100mg stat i.v slowly, followed by l-2mg/minute in i.v drip. If fails, Procainamide 250-500mg 6 hourly orally. 3. Sinus bradycardia, i.e pulse less than 60/minute with normal B.P-Usually no drug treatment is required. But, if bradycardia with hypotension or with ectopic beat or some degree of heart block- Inj. Atropine sulphate, 1 ampoule (0.6mg) may be given i.v very slowly under caution. 4. Ventricular ectopic beats- ectopic beats require treatment when- a. more than 5/minute. b. there is successive 3 ectopics. c. E.C.G shows ‘R’ on T. In any of these situations, Inj. Lignocaine 50-100mg i.v slowly in 2-3 minutes, followed by l-2mg/minute in i.v drip, if necessary. If failed, then Procainamide 250-500mg 6 hourly orally. 5. Ventricular fibrillation-Immediate cardiac resuscitation & cardioversion, then Inj. lignocaine 200mg in i.v drip at the rate of l-2mg/minute & then quinidine is given to prevent recurrence. 6. Atrial fibrillation- Digitalisation is the treatment of choice. If fails, b-blocker e.g atenolol may be given. If rate is very high, & above treatment fails, cardioversion should be applied. 7. Cardiogenic shock- a. Foot end should be raised. b. O2 supplementation. c. Emergency digitalisation. d. Isoprenaline l-2mg in 500ml of 5% dextrose in aqua as i.v drip. e. Hydrocortisone 200mg i.v stat, repeat 50mg 6 hourly if necessary. |
| Complications | |
| Prognosis | |
| Types | |
| Classification | |
| Observation | |
| Pathology |
© Pakistan Drug Directory. All Rights Reserved.
Designed By: Pakistan Drug Directory Team