Complications

Despite advances in the management of acute myocardial infarction, complications can and do occur.

Complications of myocardial infarction1,2

Complications  of  myocardial  infarction Table describing different types of complications in myocardial infarction and their manifestation

  • Complications of acute myocardial infarction that develop within the first 2 weeks after onset have been associated with poor outcome.3
  • In recent years, aggressive use of haemodynamic monitoring and interventions that improve myocardial oxygen supply and demand have noticeably altered the prognosis.3
  • Urgent relief of myocardial ischaemia with coronary reperfusion has had the largest impact in improving the results.3
  • Surgical treatment of mechanical and non-mechanical complications of AMI requires prompt decision-making and expeditious implementation.3
  • Persistent left ventricular dysfunction and cardiogenic shock are the most important factors that influence the overall results.3
  • Despite the reduction in mortality from ischaemic heart disease in most Western European countries, sudden cardiac death remains a major problem. More than half of all patients with known ischaemic heart disease die suddenly. The majority of cases are associated with malignant ventricular arrhythmias, usually ventricular tachycardia or ventricular fibrillation.3,4
  • The incidence of primary ventricular fibrillation (in the absence of severe haemodynamic compromise) is highest during the very early stages of acute ischaemia. Even with established infarction, ventricular fibrillation is rare after the first 4 hours.3,4
  • Ventricular tachycardia usually occurs later than 4 hours after symptom onset but is not a stable rhythm. Degeneration of ventricular tachycardia is a frequent cause of ventricular fibrillation that appears more than 1 day after the onset of infarction.3,4
  • Asystole may be a primary arrhythmia or the end result of ventricular fibrillation that has degenerated to an imperceptible amplitude.3,4
  • The main mechanical complications of AMI are ventricular septal rupture, free wall rupture, and ischaemic mitral regurgitation.1,2
  • The incidences of ventricular septal rupture, infarct expansion, free wall rupture and ischaemic mitral regurgitation are quite low, but the contribution of these complications to total mortality from acute myocardial infarction is high.
  • In the chronic phase, negative remodelling and aneurysm formation may occur.5,6
  • The incidence of any degree of infarct expansion is about 30–50% of cases of anterior wall infarction, and in more then 75% of patients dying from myocardial infarction. Infarct expansion is associated with high mortality and complications such as cardiac failure and left ventricular aneurysm formation.5,6
References: 
  1. Brener SJ, Tschopp D. Cleveland Clinic Medical Education, January 2009. Complications of Acute Myocardial Infarction. Available online:  http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/cardiology/complications-of-acute-myocardial-infarction/ Accessed January 2013.
  2. Kondor AK, Yang EH. Medscape online, September 2011. Complications of Myocardial Infarction: Overview of MI Complications. Available online: http://emedicine.medscape.com/article/164924-overview Accessed January 2013.
  3. Bolooki H. Surgical treatment of complications of acute myocardial infarction. JAMA 1990;263(9):1237-1240.
  4. Fuster V, et al. ACC/AHA/ESC guidelines for the management of patients with atrial fibrillation: executive summary. A Report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines and the European Society of Cardiology Committee for Practice Guidelines and Policy Conferences (Committee to Develop Guidelines for the Management of Patients With Atrial Fibrillation): developed in Collaboration With the North American Society of Pacing and Electrophysiology. J Am Coll Cardiol 2001;38(4):1231-1265.
  5. Weisman HF, Healy B. Myocardial infarct expansion, infarct extension, and reinfarction: pathophysiologic concepts.Prog Cardiovasc Dis 1987;30(2):73-110.
  6. Anzai T, et al. C-reactive protein as a predictor of infarct expansion and cardiac rupture after a first Q-wave acute myocardial infarction. Circulation 1997;96(3):778-784.
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