Chest pain which is retrosternal in a male over thirty five or a female over 45 is worrisome. Precordial left sided pain also is worrisome but somehave said less so. Diaphoresis, true diaphoresis, not so much sweaty palms is also worrisome. The milieu of the patient, a sense of fear or foreboding on the part of the patient or the patient's family is worrisome. Ask about a prior history, ask about prior risk factors such as obesity, diabetes, angina, ascvd, family history, smoking, triglycerides, industrial exposures, work and stress loads and so in trying to arrive at a presumption of ischemic heart disease. For it is a serious step to embark upon the workup of heart disease.
Myocardial infarction is due to myocardial necrosis. This is due to ASCVD or sometimes cocaine abuse. There are other rare causes.
Onset is associated with activity or inactivity. But unusual stress, fatigue and excessive exertion may be precipitating factors as is exposure to cold. In general there may be a a sudden disparity between the patient's normal and current emotional or effort level.
Incidence of lethal arrhythmia associated with MI peaks in the first hour and levels off during the next eleven hours but persists for up to 48 hours.
EKG findings prompting presumption of acute MI:
The EKG is used to locate the injured myocardium. Localization of the infarction has implications in prognosis and therapy.
INFERIOR MI - reflected in leads II III and AVF. ST elevations and q waves may be present in those leads. Think of right circumflex coronary involvement. Additional findings of ST depression in V1-V4 suggest disease of left anterior descending coronary artery with added morbidity and mortality. Complete Heart Block may occur in inferior wall MI.
ANTERIOR MI - reflected in leads I and AVL
ANTEROSEPTAL MI - reflected in leads V1-V4
ANTEROLATERAL MI - reflected in leads l and AVL termed high lateral
APICAL MI - reflected in leads V5 V6
POSTERIOR MI - Mirror image changes in V1 to V3 : tall R waves. tall upright and symmetric T waves and depressed concave upwards ST segs in V1 to V3