Myocardial infarction

Myocardial infarction

1. Definition

   • A heart attack occurs when the flow of blood to the heart is blocked, most often by a build-up of fat, cholesterol and other substances, which form a plaque in the arteries that feed the heart
     • Types
       • TYPE 1
         • Spontaneous MI related to plaque erosion and/or rupture, fissuring, or dissection
       • TYPE 2
         • MI related to ischemic imbalance
       • TYPE 3
         • MI resulting in death when biomarker values are unavailable
       • TYPE 4a
         • MI related percutaneous coronary intervention
       • TYPE 4b
         • MI related to stent
       • TYPE 5
         • MI related to CABG

2. Risk factors

   • Age
   • Sex
   • Family History
   • Premature menopause
   • Smoking

3. BMI Scale

4. Pathophysiology

   • Myocardial response to ischemia
     • Coronary artery obstruction
       • blocks the myocardial blood supply
     • The functional consequence
       • is a striking loss of contractility, occurring within a minute or so of the onset of ischemia.
     • Ultrastructural changes
       • these early changes are potentially reversible, and myocardial cell death is not immediate
   • Coronary artery occlusion

5. Symptoms and signs

   • Angina
   • Syncope
   • Dyspnea
   • Profuse sweating

6. Physical findings

   • Vital signs
     • Irregular pulse
     • Elevated blood pressure
     • Increased temperature
   • Chest
     • Wheezing sound
   • Abdomen
     • Hepatoreflux
   • Extremities
     • Peripheral cyanosis
   • Heart
     • lateral displacement of apical impulse and soft S1 sound
     • Mitral regurgitation murmurs
     • Holosystolic murmur

7. Investigations

   • ECG
   • Laboratory Tests
   • Imaging
     • Chest radiography
       • Chest radiography is useful in determining the presence of cardiomegaly, pulmonary edema, pleural effusions, and other criteria of HF

8. Managements

   • Management of angina
     • Goals of this management is to reduce the ratio of oxygen supply to demand, by bringing the coronary blood flow back to normal and decreasing the oxygen consumption of the heart.
     • Nitrates
       • Relaxation of smooth muscle
         • Antiplatelet Aggregation Effect Used for:
           • Acute angina attack  Angina prophylaxis  Unstable angina
     • Beta blockers
       • used if patient has tachycardia or hypertension and has no signs of heart failure
         • Important in prophylaxis of angina and treatment of unstable angina
     • Calcium channel blockers
   • Emergency Medicine
     • Safety and Comfort
       • Oxygen, analgesia, anti-emetic and nitrates.
     • Intravenous access
     • High level of Supervision
     • Resuscitation services
   • Post-Emergency Management
     • Cardioprotective medications
       • Inhibitors of the renin-angiotensin-aldosterone (RAA) system
       • Beta blockers.
       • Statins.
     • Lifestyle modifications and cardiac rehabilitation
   • Angioplasty & Angiography
     • ِAngioplasty is a minimally invasive procedure performed to improve blood flow in the body's arteries and veins and is usually performed in an interventional radiology suite
       • When is it needed?
         • Narrowing of large arteries due to atherosclerosis
         • Peripheral artery disease (PAD)
         • Renal vascular hypertension
     • Angiography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body. This is traditionally done by injecting a radio-opaque contrast agent into the blood vessel and imaging using X-ray based techniques such as fluoroscopy.
   • Lifestyle & Psychological Management
     • lifestyle: Smoking cessation. Safe alcohol consumption. Diet. Regular physical activity. Weight management.
     • Psychological: Educating the patient. Establishing effective communication. Helps in making a collaborative relationship Conducting follow-up assessments.

9. Complications

   • Minutes to hours
     • Arrhythmia Cardiogenic shock Acute left heart failure
   • Few Days
     • Thrombosis and thromboembolic complications Acute pericarditis
   • 5-14 days
     • Rupture of an infarcted area
   • Weeks
     • Dressler s syndrome Ventricular aneurysm

Images and files in the map