1 / 41

Myocardial Infarction

Myocardial Infarction. Relationships Among CAD, Stable Angina, and MI. Fig. 33-8. Relationships Among Stable Angina, Unstable Angina, ACS, and MI. Stable angina Myocardial demand > myocardial supply Ischemia is reversible No intimal disruption; no thrombus** Unstable angina

beata
Download Presentation

Myocardial Infarction

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Myocardial Infarction

  2. Relationships Among CAD, Stable Angina, and MI Fig. 33-8

  3. Relationships Among Stable Angina, Unstable Angina, ACS, and MI • Stable angina • Myocardial demand > myocardial supply • Ischemia is reversible • No intimal disruption; no thrombus** • Unstable angina • Myocardial demand > myocardial supply • Ischemia is reversible • Partially occlusive thrombus that stabilize, lyse, or progress to total occlusion**

  4. Relationships Among Stable Angina, Unstable Angina, ACS, and MI • Myocardial Infarction • Myocardial demand > myocardial supply • Non-reversible ischemia leading to cell death • Intimal disruption → arterial spasm & thrombosis • Acute coronary syndrome • Includes both unstable angina and MI because both tend to be caused by intimal disruption and thrombosis • Disruption is oxygen supply is prolonged and not immediately reversible

  5. Myocardial Infarction:Etiology and Pathophysiology • Primary reason is disruption of atherosclerotic plaque → platelet aggregation and thrombus formation • Myocardial cyanosis occurs within the 1st 10 seconds of occlusion  ECG changes • Total occlusion  anaerobic metabolism and lactic acid accumulation

  6. Fig. 33-9

  7. Myocardial Infarction:Etiology and Pathophysiology • Occurs as a result of sustained ischemia, causing irreversible cellular death • Myocardial function is altered • Degree of alteration depends on location and size of infarct

  8. Myocardial Infarction:Etiology and Pathophysiology • Contractile function of the heart stops in the areas of myocardial necrosis • Most MIs involve the left ventricle (LV) • Described by the area of occurrence • Lateral, inferior, posterior, anterior, right ventricular, etc.

  9. Etiology and PathophysiologyHealing Process • Scar tissue is present by day 10 – 14, but is weak • Healed by 6 weeks post MI • Ventricular remodeling • In attempt to compensate for the infarcted muscle, the normal myocardium will hypertrophy and dilate

  10. Myocardial Infarction“Typical” Symptoms • Pain • Chest pain not relieved by rest, position change, or nitrates • Pressure, aching, burning, crushing, squeezing, swelling, or heavy in quality • The hallmark of an MI • Dyspnea, diaphoreses, N & V

  11. Myocardial Infarction“Atypical” Symptoms • Up to 1/3 of patients do not experience chest pain • Dyspnea, nausea/ vomiting, feeling faint or light-headed, and sweating or “fever” • Those without chest pain delay longer in seeking Rx • Up to 10% of MIs are totally asymptomatic (i.e., “silent MI”)

  12. Atypical symptoms more likely to occur among • Women • Elderly • Diabetics • CHF • African Americans

  13. Other Clinical Manifestations Myocardial Infarction • Fever • May  within 1st 24 hours up to 100.4° • May last as long as 1 week • Systemic manifestation of the inflammatory process caused by cell death

  14. Clinical Manifestations Myocardial Infarction • Cardiovascular manifestations indicating complication of CHF •  BP and heart rate initially • Later the BP may drop from  CO •  urine output • Crackles • Hepatic engorgement • Peripheral edema

  15. Complications of Myocardial Infarction • Dysrhythmias • Most common complication • Present in 80% of MI patients • Most common cause of death in the prehospital period

  16. Complications of Myocardial Infarction • Congestive heart failure • A complication that occurs when the pumping power of the heart has diminished

  17. Complications of Myocardial Infarction • Cardiogenic shock • Occurs when inadequate oxygen and nutrients are supplied to the tissues because of severe LV failure • Requires aggressive management

  18. Complications of Myocardial Infarction • Papillary muscle dysfunction • Causes mitral valve regurgitation • Condition aggravates an already compromised LV

  19. Complications of Myocardial Infarction • Ventricular aneurysm • Results when the infarcted myocardial wall becomes thinned and bulges out during contraction

  20. Complications of Myocardial Infarction • Pericarditis • Inflammation of the pericardium • May result in cardiac compression,  LV filling and emptying, and cardiac failure (cardiac tamponade)

  21. Complications of Myocardial Infarction • Dressler syndrome • Characterized by pericarditis with effusion and fever that develops 1 to 4 weeks after MI

  22. Diagnostic StudiesMyocardial Infarction • History of pain • Risk factors • Health history • ECG – characteristic changes of MI • Serum cardiac markers (troponin, CK MB)

  23. Cardiac Markers • Troponin • Muscle protein released into blood after MI • Rises in 3 – 12 hrs; peak at 24 – 48 hrs, returns to baseline in 5 – 14 days • CK MB • Enzymes released into blood after MI • Rises 3 -12 hrs, peaks 24 hr, returns to baseline in 2 – 3 days

  24. Collaborative CareMyocardial Infarction • Fibrinolytic therapy • Percutaneous coronary intervention (PCI), more commonly called PTCA (percutaneous transluminal coronary angioplasty)

  25. PTCA with Stent

  26. Fibrinolytic Therapy • Lyses thrombi (cardiac and others), thus halting progression of MI • Ideally, treatment should occur within 6 hr of onset of MI • Contra-indications • Conditions that put patient at high risk of hemorrhage (Table 33-14) • Prevent and monitor for bleeding

  27. Collaborative CareMyocardial Infarction • Drug Therapy • IV nitroglycerin • Antiarrhythmic drugs • Morphine

  28. Collaborative CareMyocardial Infarction • Drug Therapy • -Adrenergic blockers • ACE inhibitors • Stool softeners

  29. Collaborative CareMyocardial Infarction • Nutritional Therapy • Diet restricted in saturated fats and cholesterol • Low sodium

  30. Nursing ManagementAngina and Myocardial InfarctionNursing Diagnoses • Acute pain • Ineffective tissue perfusion • Anxiety • Activity intolerance • Ineffective therapeutic regimen management

  31. Nursing ManagementAngina and Myocardial InfarctionPlanning • Overall goals: • Relief of pain • No progression of MI • Immediate and appropriate treatment

  32. Nursing ManagementAngina and Myocardial InfarctionPlanning • Overall goals: • Cope effectively with associated anxiety • Cooperation of rehabilitation plan • Modify or alter risk factors

  33. Nursing ManagementAngina and Myocardial InfarctionNursing Implementation: Angina • Acute Intervention • Administration of oxygen • Vital signs • ECG • Pain relief

  34. Nursing ManagementAngina and Myocardial InfarctionNursing Implementation: MI • Acute Intervention • Morphine • Continuous ECG • Frequent vital signs • Rest and comfort

  35. Nursing ManagementAngina and Myocardial InfarctionNursing Implementation: MI • Acute Intervention • Anxiety • Emotional and behavioral reactions • Communicate with family • Provide support

  36. Nursing ManagementAngina and Myocardial InfarctionNursing Implementation: MI • Ambulatory and Home Care • Rehabilitation • Cardiac rehabilitation • Physical exercise

  37. Nursing ManagementAngina and Myocardial InfarctionNursing Implementation: MI • Ambulatory and Home Care • Resumption of sexual activity • Emotional readiness • Physical training

  38. Sudden Cardiac Death • Unexpected death from cardiac causes • Disruption in cardiac function • Abrupt loss of cerebral blood flow

  39. Sudden Cardiac Death • Usually occurs within 1 hour of onset of symptoms • Occurs secondary to natural causes • Accounts for about 50% of all deaths from cardiovascular causes • Mostly caused by ventricular arrhythmias

  40. Sudden Cardiac DeathNursing and Collaborative Management • Implantable cardioverter-defibrillator (ICD)

More Related