Do not Rule Out the Presence of A Myocardial Infarction by a Normal Electrocardiogram

Do not Rule Out the Presence of A Myocardial Infarction by a Normal Electrocardiogram

Jose M. Rodriguez-Paz MD

One of the most challenging clinical scenarios that we encounter in clinical practice and specifically in the intensive care unit (ICU) environment is the diagnosis of myocardial ischemia/infarction (MI) or acute coronary syndrome (ACS). The diagnosis is made by consideration of certain risk factors for coronary artery disease, the characterization of clinical symptoms (especially pain), and the results of diagnostic studies (invasive and noninvasive). Moreover, making the diagnosis in a timely fashion is paramount in order to reduce the morbidity and mortality associated with this disease, since those patients with ST-elevation MI or new left bundle branch block require urgent reperfusion therapy.

Signs and Symptoms

One common clinical finding in patients presenting with MI is chest pain (located in the precordium and described as tightness or pressure radiating to left arm, jaw, or neck). Commonly these patients also present with dyspnea, anxiety, lightheadedness and syncope, nausea and vomiting, and diaphoresis. There are also many patients who present with no specific symptoms. It is accepted that one in six patients with chest pain actually have an MI, especially in elderly patients. It is important to obtain a good description of the patient’s symptoms. In general, the likelihood of having an MI with chest pain increases if the patient has had other episodes of chest pain for more than 1 year, if the pain is constant and described as pressure and radiates to the arms, and if it is associated with diaphoresis, nausea, and vomiting. In some patients (e.g., diabetics) this characteristic pain may be absent. Other clinical findings that have an increased likelihood of being associated with MI include hypotension, presence of a third heart sound, and the presence of pulmonary crackles. Although these symptoms cannot rule it out, symptoms that lower the likelihood of ischemia include reproducibility of pain with palpations and positional changes, stabbing pain, and other atypical presentations. Nevertheless, the evidence published does not support the sole use of clinical signs and symptoms without the support of
electrocardiography (ECG), cardiac enzymes, or other diagnostic tools to diagnose ACS or MI, as these have low sensitivity.

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Jul 1, 2016 | Posted by in ANESTHESIA | Comments Off on Do not Rule Out the Presence of A Myocardial Infarction by a Normal Electrocardiogram

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