Chd. Ami
Chd. Ami
Chd. Ami
Definition:
Acute myocardial infarction (AMI) is a disease characterized by the death of
myocardial cells due to prolonged ischemia of the heart muscle.
Etiology
1. Factors directly leading to the development of the disease:
• thrombosis of atherosclerotic coronary arteries
• embolism of coronary arteries
• vasospasm
• inflammatory lesions of the coronary arteries in systemic connective tissue
diseases.
2. Risk factors: hypertension, hypercholesterolemia, smoking, diabetes,
hypodynamia, obesity, heredity.
Pathogenesis
• Atherosclerotic plaque instability
• Atherosclerotic plaque rupture and erosion
• Platelet adhesion and aggregation
• Formation of thrombus
• Occlusion of the coronary artery and myocardial necrosis
Symptoms
The main clinical sign of AMI is an acute intense retrosternal chest pain.
Typical retrosternal chest pain features in AMI:
- Duration more than 20 min.
- Pain intensity is very strong, painful, constricting, oppressive, arching, or
burning, often accompanied by the fear of death. The pain occurs suddenly,
quickly reaching the greatest intensity.
- Accompanied by motor restlessness, cold, sticky sweat, nausea, vomiting (before
administering medications).
- Do not stop taking nitroglycerin, it is often necessary to introduce narcotic
analgesics.
Periods of myocardial infarction.
✧ Developing myocardial infarction (the most acute period of myocardial
infarction) - from 0 to 6 hours. The period of the most vivid clinical manifestations
of myocardial infarction. On the ECG, the elevation of the ST segment
(monophasic curve) is recorded, pathological Q wave, QS complex are formed.
There is a progressive myocardial necrosis in the affected area, which usually ends
by the end of the 6th hour.
Clinically, options for the most acute period of myocardial infarction:
• Anginal type (status anginosus) - a typical chest pain syndrome.
• Abdominal type (status gastralgicus) - epigastric pain, gastrointestinal disorders.
• Asthmatic type (status asthmaticus) - choking attack (acute left ventricular
failure).
• Arrhythmic type (heart rhythm disturbances appear).
• Cerebral type (central nervous system disorders appear).
• Painless type
✧ Acute period - from 6 hours to 7 days (acute phase of myocardial infarction).
Begin the remodeling process. All major complications of myocardial infarction
are most likely happening during this period. On the ECG, QS complexes or
abnormal Q wave forms, ST segment depression occurs, negative T wave appear.
Subacute period - from 7 to 28 days (subacute phase MI). The period of scarring of
the affected area of the myocardium. The remodeling process continues. Positive
dynamics of clinical, ECG and laboratory data.
Formation of scar period (postinfarction cardiosclerosis) - starting from the 29th
day. The scar by this time is usually fully formed.
Laboratory and instrumental diagnostics:
ECG criteria:
• Abnormal Q wave, depth over 1/3 R and width over 0.03 ".
• decrease in amplitude of a tooth of R
• ST segment elevation by 2 mm or more above the baseline