SGD 1: Acute Myocardial Infarction

PATHOLOGY

Chest Pain An unpleasant sensation in the anterior wall of the thorax –actual or potential tissue damage –mediated by specific nerve fiber to the brain - conscious appreciation may be modified by various factors.

Organ System Character of pain Location of pain Examples Cardiovascular Pressure Tightness Heaviness Retrosternal, radiates to the neck, jaw, shoulders or arms Coronary artery disease Ischemic heart disease Aortic stenosis Pericarditis Hypertrophic cardiomyopathy Pulmonary Sharp Substernal Unilateral or localized Pneumonia or pleuritis Pulmonary embolism Pneumothorax Tumor Gastrointestinal Burning Presents with abdominal pain Retrosternal Substernal Epigastric Gastroesophageal reflux disease Esophageal spasm Peptic ulcer disease Biliary diseases Pancreatitis Musculoskeletal Stabbing Dull ache Superficial Localized Cervical disk disease Arthritis of the shoulder and spine Costochondritis Intercostal muscle cramps

ConditionLocationQualityDurationAggravating or Relieving Factors Associated Symptoms or Signs AnginaRetrosternal region; radiates or occasionally isolated to neck, jaw, epigastrium, shoulder or arms—left common Pressure, burning, squeezing, heaviness, indigestion <2-10 minPrecipitated by exercise, cold weather, or emotional stress, relieved by rest or nitroglycerin; atypical (Prinzmetal’s) angina may be unrelated to activity, often early morning S4, or murmur of papillary muscle dysfunction during pain Rest or unstable anginaSame as angina Same as angina but may be more severe Usually <20 min Same as angina, with decreasing tolerance for exertion or at rest Similar to stable angina, but may be pronounced. Transient cardiac failure can occur Braunwald and Goldman, Primary Cardiology 2 nd ed

ConditionLocationQualityDurationAggravating or Relieving Factors Associated Symptoms or Signs Myocardial infarction Substernal and may radiate like angina Heaviness, pressure, burning Sudden onset, 30 min or longer Unrelieved by rest or nitroglycerin Shortness of breath, sweating, weakness, nausea, vomiting PericarditisUsually begins over sternum or toward cardiac apex and may radiate to neck or left shoulder; often more localized than the pain of myocardial ischemia Sharp, stabbing, knifelike Lasts many hours to days; may wax and wane Aggravated by deep breathing, rotating chest, or supine position; relieved by sitting up and leaning forward Pericardial friction rub Aortic dissection Anterior of chest; may radiate to back Excruciating, tearing, knifelike Sudden onset, unrelenting Usually occurs in setting of hypertension or predisposition such as Marfan’s syndrome Murmur of aortic insufficiency, pulse or blood pressure asymmetry; neurologic deficit Braunwald and Goldman, Primary Cardiology 2 nd ed

Chest Pain (dark red = most typical area, light red = other possible areas)

Atherogenesis Developmental process of atheromatous plaques.

Pathogenesis of Atherosclerosis Fatty Streak Leukocyte recruitment Foam Cell formation Microvessels Plaque evolution

Atherothrombosis Arterial Remodelling Rupture of Fibrous cap Arterial Occlusion More fibrous lesion

Risk Factors Cigarette Smoking HPN (BP> 140/90 mmHg or on antihypertensive medication) Low HDL, Low LDL DM Family Hx of premature CHD –CHD in male first degree relatives<55y/o –CHD in female first degree relatives<65y/o Lifestyle risk factors –BMI = > 30 kg/m² –Physical inactivity –Atherogenic diet Age (male>55y/o, female >65y/o) Sex (Male>Female) Stress Age (55 y/o) Male Occupational stress 40 pack years Heavy alcoholic beverage drinker HPN (2003) Usual BP Highest BP 170/100 Nifedipine 30 mg – irregular intake Family Hx of DM, HPN, Premature CAD

Clinical Features of Angina Described as heaviness, pressure, squeezing, smothering, or choking, and only rarely as frank pain. Levine’s sign – localization of pain by the pain: placing his hand (clenched fist) over the sternum to indicate sqeezing, central, substernal discomfort. Crescendo-decrescendo (2-5 min) Radiates to either shoulder and to both arms (ulnar surface of the forearm and hand). Also arise in or radiate to the back, interscapular region, root of the neck, jaw teeth and epigastrium.

Types of Angina Pectoris

New York Heart Association Functional Classification I.Px have cardiac disease but without the resulting limitations of physical activity does not cause undue fatigue, palpitation, dyspnea or anginal pain II.Px have cardiac disease resulting in slight limitation of physical activity. They are comfortable at rest. Ordinary physical activity results in fatigue, palpitation, dyspnea, or anginal pain.

New York Heart Association Functional Classification III. Px have caridac disease resulting to marked limitation of physical activity. They are comfortable at rest. Less than ordinary physical activity causes fatigue, palpitation, dyspnea, or anginal pain. IV. Px have cardiac disease resulting in inability to carry on any physical activity without discomfort. Symptoms of cardiac insufficiency or of anginal syndrome may be present even at rest. If any physical activity is undertaken, discomfort is increased.

Canadian Cardiovascular Society Classification of Angina I. No angina with ordinary activity. Angina with strenuous, rapid, or prolonged exertion II. Slight limitation of ordinary activity; angina when walking up stairs briskly, or walking on a cold or windy day III. Marked limitation; angina when walking at normal pace up flight of stairs, or walking 1-2 blocks distance IV. Angina on minimal exertion or at rest

WHO Criteria for AMI Classic WHO Criteria: two (probable) or three (definite) of the following criteria are satisfied: Clinical history of ischemic type chest pain lasting for more than 20 minutes Changes in serial ECG tracings Rise and fall of serum cardiac biomarkers such as CK-MB fraction and troponin Revised (2000) Cardiac troponin rise accompanied by either typical symptoms, pathological Q waves, ST elevation or depression or coronary intervention are diagnostic of MI.