CARDIOVASCULAR DISEASES

 

MAIN TOPIC

CARDIOVASCULAR DISEASES

SUB TOPIC :- 
Coronary artery disease

Coronary artery disease is the leading cause of death in people over the age of 40 in developed countries. Disease of the coronary arteries is almost always due to artheroma and it's complications, particularly thrombosis ; the common clinical manifestations and pathological condition of CAD are :

Clinical manifestations

• Stable angina
• unstable angina
• myocardial infarction
• heart failure
• arrhythmia
• sudden death

UNDERLYING PATHOLOGY

• Ischaemia due to fixed atheromatous stenosis of one or more coronary arteries.

• Ischaemia caused by dynamic obstruction of a coronary artery due to plaque rupture with superimposed thrombosis and spasm .

• Myocardial necrosis caused by acute occlusion of a coronary artery due to plaque rupture and thrombosis.

• Myocardial dysfunction due to infraction or ischaemia

• Altered conduction due to ischaemia or infarction

• Ventricular arrhythmia, asystole or massive myocardial infarction .

AETIOLOGY

atherosclerosis is the most common etiological factor .

ATHEROSCLEROSIS is a progressive inflammatory disorder of the arterial wall that is characterized by focal lipoid- rich deposit atheroma.

ATHEROSCLEROSIS VASCULAR DISEASE MAY MANIFEST AS :-

• coronary heart disease
• cerebrovascular disease
• peripheral vascular disease
• mesenteric artery occlusion

MAJOR AND MINOR FACTOR FOR ATHEROSCLEROSIS :

MAJOR FACTOR
• Hyperlipidemia
• Hypertension
• Smoking
• diabetes mellitus

MINOR FACTOR
• Male gender
• obesity
• sedentary lifestyle
• stress
• oral contraceptive
• increasing age
• familial genetic factor

PATHOGENESIS

The formation of an atherosclerosis plaque within a coronary artery proceed through a number of stages .

First stage : formation of fatty streak a longitudinal accumulation of liquid with surroundings smooth muscle proliferation .

Second stage : low density lipoprotein (LDL)  enters the endothelium in the area of the fatty streak. The LDL becomes oxidized attracting macrophages that ingest the LDL. These macrophages release factors that recruit more macrophages fibroblast and other infammatory cells .

Final stage : proliferation of smooth muscle cells, connective tissue and lipid become incorporated into the maturing plaque. The formation of a fibrous cap results in narrowing of the artery lumen .

PREVENTION OF CORONARY ARTERY DISEASE CAD

A. PRIMARY PREVENTION

two complementary strategies can be used to prevent artheosclosis in apparently healthy but a risk individuals .

Population strategy : this strategy aims to modify the risk factors in whole population not merely in an individual. This approach is based on the principle that small changes in risk factor levels in total population can acheive the biggest reduction in mortality. The population strategy centers in the following key areas:-

• Dietary modification
     • Reduction of fat intake to 20-30% of total energy
     • reduction of saturated fatty acid
     • increased intake of mixed diet rich in fresh fruit and vegetables
     • avoidance of excessive consumption of alcohol .
     • Do not smoke
     • maintain ideal body weight
     • take regular excercise
    
Targeted startegy : this strategy aims to identify and treat high risk individuals who usually have a combination of risk factor .

B. SECONDARY PREVENTION

The aim of the secondary prevention is to prevent the recurrence and progression of CAD. The key areas of secondary prevention area.
      • Smoking cessation
      • treatment of hyperlipidemia
      • treatment of hypertension
      • control.of diabetes mellitus
      • wight reduction
      • reduction of physical and emotional stress

ANOTHER SUBTOPIC

ANGINA PECTORIS

Angina pectoris is a typical manifestation of symptomatic CAD , characterized by paroxysmal chest pain due to transient myocardial ischemia  . it is due to a discrepancy between myocardial oxygen demand and supply.

CLASSIFICATION OF ANGINA PECTORIS

a. Stable angina or typical or exertional or classical angina : induced by effort relieved by rest .

b. Unstable angina or descendo angina : rapidly worsening angina or angina at rest.

c. Post-infarction angina
d.prinmetals or vasospastic angina or varient angina .
e.nocturnal angina

CAUSES OF ANGINA PECTORIS

1. Coronary artery disease
2. Aortic stenosis
3. Aortic regurgitation
4. Systemic hypertension
5. Severe anaemia

Clinical feature

A.Character of angina

• Site : retrosternal i.e behind sternum
• radiation: pain radiates to neck jaw left shoulder and medial aspect of upper limb .
• character : pressing squeezing strangling constricting a band across the chest a heavy wight n the chest. Patient can't pinpoint or localized the site if pain.
• duration: last 1-3 minutes, never less the 30 sec and more than 15 minutes .
• aggravating factors
        • Exertion
        • emotional
        • cold
        • heavy metal
        • sexual activity
        • anger and irritation
       
• Relieving factor
         • Rest
         • diet

B. breathlessness
C. history of smoking hypertension DM and other sir factors.

On physical examination there may be evidence of :

a. Important risk factors
     • Smoking
     • HTN
     • Hyperlipidemia
     • obesity
     • DM
     • anaemia

b.cardiac manifestation

      • Looks second heart sound
      • gallop rythm
      • cardiomegaly
      • basal crackle

C. Generalized areterial disease
      • Carotid bruit
      • peripheral vascular disease

Differential diagnosis

      • Myocardial infarction
      • pulmonary embolism
      • aortic dissection
      • esophageal spasm
      • pancreatitis
      • pneumonia
     
Grading of angina

Grade I : chest pain on strenuous physical activities.

Grade II : Angina on ordinary physical activities eg.walking uphill or climbing more than one flight of stairs m.

Grade III : Marked limitation of ordinary physical activities or angina on climbing of one fight stairs

Grade IV : angina on any physical activity or at rest.

INVESTIGATION

• CBC
• CHEST XRAY PA VIEW
• SERUM CHOLESTEROL AND LIPID PROFILE

MANAGEMENT

A. General management
       • Stop cigarette smoking
       • control high blood pressure
       • low cholesterol diet
       • control diabetes mellitus
       • reduction of mental stress
       • regular exercise
       • avoid sedentary lifestyle
       • maintain ideal body weight

      
Drugs used in angina
    i) nitrates
         - sublingual nitroglycerin is used for acute attack of angina .it is available in 0.5 mg tablet. It acts within 3 seconds and peak action takes place by 2 minutes
         - oral nitrate - isosorbide dinitrate 5-19 mg 4-6 hourly or
         - isosorbide mononitrate 10-30mg 8-12 hourly.
         - nitroglycerin injection is used when chest pain due to angina does not respond to sublingual or oral nitrate.

    iI) calcium channel blockers
        - nifedipine retard 10-20mg twice daily or
        - diltiazem 30-90mg thrice a day or
        - amlodipine 2.5 -10 mg × daily

    III) beta blockers cardioselective B blocker
          - atenolol 50 -100 mg × orally daily or
          - metoprolol 200mg × daily

    IV) aspirin and clopidegrol
         - aspirin 50 -100 mg daily or
         - clopidegrol 75 mg × daily