ACS

• Acute coronary syndrome


  An emergent situation characterised by an acute onset of myocardial ischaemia that result in myocardial death, if definitive interventions do not occur promptly
• Spectrum of acute coronary syndrome

  • Unstable angina
  • NSTEMI
  • ST-segment elevation myocardial infarction (STEMI)
• Angina pectoris


  Chest pain caused by myocardial ischaemia, a symptom of coronary artery disease
• Angina is usually caused by atherosclerotic disease
• Factors associated with typical angina pain

  • Physical exertion
  • Exposure to cold
  • Eating a heavy meal
  • Stress or any emotion provoking situation
• Stable angina


  Predictable and consistent pain that occurs on exertion and is relieved by rest and/or nitroglycerine
• Unstable angina


  Symptoms increase in frequency and severity, may not be relieved with rest or nitroglycerine
• Severe angina that persists for more than 5 minutes, worsens in intensity, and is not relieved by one nitroglycerin tablet is a medical emergency
• Variant angina (Prinzmetal angina)


  Pain at rest with reversible ST elevation, thought to be caused by coronary artery vasospasms
• Silent ischaemia


  A situation in which objective evidence of ischaemia is seen on an ECG but the person does not complain of chest pain
• 1/3 of patients with heart attack do not report chest pain as a symptom
• Locations of angina pain

  • Beneath sternum, radiating to neck and jaw
  • Upper chest
  • Beneath sternum, radiating down left arm
  • Epigastric
  • Epigastric radiating to inner neck, jaw and arm
  • Left shoulder aspect of both arms
  • Intrascapular
• Duration of angina pain

  • Less than 5 min (stable)
  • Less than 5 minutes or worsening symptoms without relief from rest or sublingual nitroglycerine indicates preinfarction symptoms (unstable)
• Quality of angina pain

  • Sensation of pressure or heavy weight on the chest
  • Feeling of tightness, like a vise
  • It feels like there's a tight band around the ribs or rib cage area
  • Visceral quality (deep, heavy, squeezing, aching)
  • Burning sensation
  • Shortness of breath with a feeling of suffocation
  • Most severe pain ever experienced
• Radiation of angina pain

  • Medial aspect of left arm
  • Jaw
  • Left shoulder
  • Right arm
• Factors that provoke angina pain


  • Exertion or exercise
  • Exercising after a large heavy meal
  • Emotional upset (Fright, anger...etc.)
• Medication relief


  Usually within 45 seconds to 5 minutes after sublingual nitroglycerin administration
• Women experience a variety of different symptoms before an acute MI and during the event
• Women's early warning symptoms of MI can occur as early as one month before the event
• Recognition and publicity about the fact that many women do not experience crushing chest pain is important to avoid trivialising women's symptoms
• Angina symptom equivalents


  Unexplained shortness of breath, breaking out in a cold sweat, or sudden fatigue, nausea or lightheadedness
• Objectives of medical management of acute coronary syndrome

  • Reducing oxygen demand
  • Increasing oxygen supply to the myocardium
• Pharmacological therapy for acute coronary syndrome

  • Nitrates
  • Beta-blockers
  • Calcium channel blocker
  • Anti-platelets
  • Anticoagulant
• Mechanisms that can block the coronary artery and are responsible for the acute reduction in oxygen delivery to the myocardium

  • Plaque rupture
  • New coronary artery thrombosis
  • Coronary artery spasms next to the ruptured plaque
• Descriptions used to identify myocardial infarction

  • The type: NSTEMI, STEMI
  • The location of the injury to the ventricular wall: Anterior, inferior, posterior or lateral wall
  • The point in time within the process of infarction: Acute, evolving or old
• Classification of myocardial infarction based on ST-segment deviation

  • STEMI
  • NSTEMI
  • Unstable angina
• Transmural myocardial infarction


  Involves all three cardiac layers; the endocardium, the myocardium, and the epicardium. A transmural (full; thickness) MI usually provokes significant ECG changes. This is also described as Q-wave MI
• Not every acute MI produces a recognisable series of Q-waves on 12 lead ECG. Some patients who had a demonstrated Q-wave on a 12-lead ECG as a result of an acute MI lose the Q-wave months later
• 12 lead ECG changes indicative of myocardial infarction

  • Ischaemia is indicated by T-wave inversion
  • Injury is indicated by ST segment elevation
  • The ST segment may be elevated above or depressed below the baseline, depending on whether the tracing is from a lead facing toward or away from the infracted area and depending on whether epicardial injury occurred
• Epicardial injury causes ST elevation
• Correlation among ventricular surfaces, ECG leads & coronary arteries

  • Inferior: II,III,aVF
  • Lateral: V5-V6,I,aVL
  • Anterior: V2-V4
  • Septal: V1-V2
  • Anterolateral: V1-V6,I,aVl
  • Posterior: V1-V2, V7- V9 Direct
  • Example: Anterior wall MI results from occlusion of the proximal LAD
• Posterior wall infarction


  Infero-basal (posterior) infarctions usually occur in conjunction with an inferior or lateral infarction. Posterior wall is supplied by circumflex artery in most patients, in some patients by the RCA. Because NO leads of a standard 12 lead ECG directly view the posterior wall of the LV, additional chest leads may be used (V7 to V9) may be used to view the heart's posterior surface
• Indicative changes of a posterior wall infarction include ST-segment elevation in these leads
• Clinical manifestations of myocardial infarction

  • Chest pain or discomfort not relieved by rest or nitroglycerine
  • Tachycardia-because of sympathetic stimulation
  • Bradycardia-due to decreased contractility and impending cardiogenic shock
  • Hypotension-due to decreased contractility
  • S3,S4 and new onset murmur-If left ventricular dysfunction is present
  • Shortness of breath, Dyspnoea, Tachypnoea and crackles if MI has caused pulmonary congestion
  • Decreased urine output may indicate cardiogenic shock
  • Cool, clammy, diaphoretic and pale appearance due to sympathetic stimulation may indicate cardiogenic shock
  • Nausea, indigestion and vomiting
  • Anxiety, restlessness and lightheadedness may indicate increased sympathetic stimulation or a decreased contractility and cerebral oxygenation
  • Fear or feeling of impending doom, or denial that anything is wrong
  • ST-segment and T wave changes
• Atypical presentation


  Refers to uncharacteristic signs and symptoms that are experienced by some patients: older adult, diabetics, women, patients with prior cardiac surgery
• Tachycardia


  Because of sympathetic stimulation
• Bradycardia


  Due to decreased contractility and impending cardiogenic shock
• Hypotension


  Due to decreased contractility
• S3, S4 and new onset murmur

  If left ventricular dysfunction is present
• Clinical Manifestation of MI

  • Chest pain or discomfort not relieved by rest or nitroglycerine
  • Tachycardia
  • Bradycardia
  • Hypotension
  • S3, S4 and new onset murmur