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STEMI Bonner County EMS System Continuing Medical Education October 2010

Objectives •

Review the Patient Care Guidelines for Chest Pain (5000) and STEMI (5010) at all provider levels.

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Review the pathophysiology of Acute Myocardial Infarction.

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Define STEMI and discuss the role of prehospital care in improving patient outcomes.

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Introduce the Bonner County STEMI Program.

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Discuss the roles of all of the prehospital care team in the case of a STEMI Alert.

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Demonstrate 12-lead ECG lead placement.

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Begin familiarization with the Lifepak 12 and the Lifepak 15.

Definitions •

Acute Coronary Syndromes - Result from acute obstruction of a coronary artery. Consequences include unstable angina, acute myocardial infarction (AMI), and sudden cardiac death.

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Coronary Artery Disease - A major cause of illness and death, coronary artery disease (CAD) begins when hard cholesterol substances - plaques - are deposited within a coronary artery.

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Atherosclerosis - A process of progressive thickening and hardening of the walls of medium and large arteries as a result of fat deposits on their inner lining.

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Ischemia - Insufficient blood flow to tissue - usually localized due to a mechanical obstruction.

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Infarction - An area of tissue death due to lack of oxygen.

More Definitions •

Angina - Chest pain due to an inadequate supply of oxygen to the heart muscle. The pain is typically severe and crushing in nature with a feeling of being just behind the sternum.

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Acute Myocardial Infarction - The interruption of blood supply to a part of the heart, with the subsequent death of heart muscle tissue. The most common cause is occlusion of a coronary artery.

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Electrocardiogram (ECG) - A recording of the electrical activity of the heart.

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STEMI - ST-Elevation Myocardial Infarction.

Demographics •

Number one killer of adults worldwide.

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In the United States, approximately 1.5 million heart attacks occur annually.

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Myocardial infarctions result in death for 400,000 to 500,000 people every year, with about half dying before they reach the hospital.

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Acute Coronary Syndrome should be considered in men older than 30 and women older than 40 years of age (younger in diabetics).

Pathophysiology •

The physiologic process that can result in an Acute MI begins decades earlier, with a progressive thickening and hardening of the coronary arteries resulting from fat deposits on their inner lining.

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This is known as Atherosclerosis.

Pathophysiology • Plaque continues to build and the coronary artery walls continue to thicken over the years. • The coronary arteries become progressively more blocked, resulting in decreased blood flow to the myocardium.

Ischemia • The coronary arteries supply oxygenated blood to the entire heart muscle. • As blood flow to the heart muscle is decreased, it becomes progressively more oxygen-starved. • This is called ischemia.

Angina • Angina may be described as a vague, troublesome ache or area of discomfort, or may rapidly become a severe, intense crushing sensation.

• Angina is typically triggered by exertion or strong emotion, usually persists for no more than a few minutes and subsides with rest or medication, eg Nitroglycerin.

Angina

Infarction • If the coronary artery becomes completely occluded, the flow of blood - and oxygen to the heart muscle below the blockage ceases. • Without oxygenated blood, this area of myocardium dies. • This is known as infarction.

Infarction • Once an infarct occurs, the heart muscle is permanently damaged. • The patient is now at risk for further heart damage, lifethreatening arrythmias, heart failure, cardiogenic shock, cardiac arrest and death.

Signs and Symptoms

Signs and Sypmtoms

Signs and Symptoms

Signs and Symptoms

Signs and Symptoms

Cardiac Conduction System • Cardiac muscle is unique in that it has the ability to generate its own electrical current. • This is known as automaticity. • The state of the heart’s electrical functioning can be measured and evaluated on an electrocardiogram (ECG).

Normal ECG

Normal ECG • In an uninjured heart, the ST Segment of the ECG is flat. • But ischemic or necrotic heart cells are incapable of transmitting electricity and this will show as changes on the ECG.

S-T Elevation •

As ischemia progresses to infarction, there may be a marked elevation in the S-T Segment of the patient’s ECG.

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This is known as S-T Elevation and indicates that there is significant injury to the heart muscle.

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STEMI stands for S-T Elevation Myocardial Infarction

PCI • The definitive treatment for most STEMI patients is a procedure called Percutaneous Coronary Intervention, or PCI.

• PCI is performed by an interventional cardiologist in a Cardiac Catheterization Lab.

PCI • During the procedure, a catheter with a balloon and a metal stent is inserted through the patient’s femoral artery. • When the area of the affected coronary artery is reached, the balloon is inflated the expand the stent and allow blood flow to resume.

Coronary Artery Stents

Minutes = Muscle • Time is of the essence for STEMI patients. • The more time goes by with a coronary artery occlusion, the more heart muscle is lost. • Prehospital care providers at all levels have a vital role to play in improving the outcomes of patients with STEMI.

STEMI Alerts

Bonner County STEMI Program • Working in close cooperation with Bonner General Hospital, Kootenai Medical Center and Heart Clinics Northwest, the Bonner County EMS System has developed a progressive STEMI Alert Protocol. • BCEMS System paramedics have received additional advanced training in STEMI recognition and treatment and now have more tools available to them to stabilize patients with suspected STEMI. • Starting November 2010, patients in Bonner County with suspected STEMI will be transported directly to the Cardiac Cath Lab at KMC, where a highly skilled team will be standing by to assume care of the patient.

The Prehospital Care Team • Every link in the chain of care of the patient with suspected STEMI is vital to the patient’s survival, from the Emergency Medical Dispatcher to the First Responder to the EMT to the Advanced EMT to the Paramedic. Everyone has a key role to play. • Recognition that the patient may be having a serious cardiac event is the first step. • A superior assessment, accurate vital signs, appropriate initial treatment, a concise but detailed update to incoming units and a calm, professional scene presence are all critically important to a successful outcome.

The 12-lead ECG • The 12-lead ECG is a key diagnostic tool in determining whether a patient with chest pain may have a suspected STEMI. • Every prehospital provider in Bonner County will have the opportunity to become comfortable with the Lifepak monitor and 12-lead placement.

Lead Placement • Correct placement of the ECG electrodes is key to obtaining an accurate, diagnostic ECG tracing.

• Assisting with placement of the 12lead on patients presenting with chest pain is an important link in the chain of prehospital care.

Lead Placement • Clark Fork Valley Ambulance pilot program - 12-lead placement and acquisition before the paramedic arrives on scene. • BCEMS System paramedics and instructors will provide initial and ongoing training on the 12lead.