acute coronary syndromes michelle welsford, md, frcpc fall recertification 2004

Acute Coronary Syndromes

Michelle Welsford, MD, FRCPCMichelle Welsford, MD, FRCPC

Fall Recertification 2004Fall Recertification 2004

ACS Overview

DefinitionPathophysiologyRisk FactorsClinical FeaturesAssessmentManagement

ACS Definition

Myocardial ischemia: insufficient blood supply to the heart muscle that results from coronary artery disease

ACS: Any group of symptoms compatible with myocardial ischemia.

Represent a continuum of the same disease process:– Angina– Unstable angina– Non-ST elevation MI– STEAMI

ACS Pathophysiology

All ACS - sudden ischemia that cannot be differentiated initially

Three common events:– Plaque rupture– Thrombus formation– Vasoconstriction

Lipid Core

Fibrous Cap

Lumen

ACS Pathophysiology

Plaque rupture

Thrombus formation - Fibrin cross-linking

Thrombus formation - Platelet aggregation

Risk Factors

HypertensionHyperlipidemiaDiabetes mellitusSmokingFamily historyMales and post-menopausal

womenAdvancing age

Clinical Features

Typical

Atypical – 25% of all AMIs – Pleuritic or sharp/stabbing CP– Palpable CP (10-33% AMI)– Arm pain only– Indigestion – SOB only (40% in elderly)– “Dizziness” (5% AMI)– Nausea – Syncope

Assessment – Examination

Exam usually normal (85%) May have:

– Diaphoresis – Extra heart sounds

(S3, S4 or rubs)– Dysrhythmias– Evidence of new or

worsening heart failure– Hypotension

Assessment – EKG

12-lead EKG– May be normal in ACS– May be nonspecific: ST or T wave ischemic changes– May be suspicious for injury: ST elevation

STEAMI– Fibrinolytic checklist

EKG - AMI Diagnosis

AMI Diagnosis:– At least 2 of 3 criteria

Clinical history suggestive of AMI EKG criteria Laboratory diagnosis

EKG criteria– ST elevation 1 mm or more in 2 anatomically

contiguous leads– OR BBB

EKG - Contiguous Leads

I aVR V1 V4

II aVL V2 V5

III aVF V3 V6

Limb Leads Chest Leads

EKG - AMI Imitators

Causes of ST elevation– AMI– LVH– BBB– Ventricular beats – PVCs – Pericarditis– Early repolarization– Others

EKG Practice 1

EKG Practice 2

EKG Practice 3

EKG Practice 4

Management – Prehospital

Prehospital– Oxygen– ASA– Nitro– Morphine– Dysrhythmia treatment

Medication Defibrillation

– 12-lead EKG with notification of receiving hospital

– Prehospital thrombolysis– Triage to PCI facility

Management – Hospital

Hospital– Oxygen, ASA, Nitro,

Morphine– Dysrhythmia management– Anticoagulation - heparin – Reperfusion

Fibrinolysis PCI - percutaneous

coronary intervention

History/Assessment Risk factorsEKG Medical Management

ACS Management Summary

Questions ?