Chest Pain Review For Dental Emergencies

Abstract

Dental professionals are in front line of taking care of medically compromised patients. One condition that can arise in daily care is chest pain and angina for a highly anxious patient. This review article summaries the pathophysiology, diagnosis, risk factors and complications associated with stable and unstable angina, and myocardial infarct. It is meant to be a summary review to refresh information on this common condition for the dental professionals dealing with these emergencies in dental office. Keywords Chest Pain, Myocardial infarction, Anxiety, Treatment

Chest pain can be a medical emergency in the dental clinic - so you must know all about it!

Chest pain and heart disease is a condition affecting significant part of the population. As dental professionals, we are constantly dealing with anxious patients or patients with cardiac conditions that could present themselves as an emergency in dental office. Understanding Ischemic heart and myocardial infarct and how to manage the patient in dental chair is critical. Ischemic heart disease is notorious for its classic presentation with a crushing retrosternal chest pain in patients with risk factors suggestive of atherosclerosis: HTN, smoking, being a male 55+ years old (or a female 65+ years old), and–of course–hyperlipidemia 1,2,3. There is a continuum of stages from perfectly healthy coronary arterial circulation to ischemic transmural myocardial necrosis (characteristic of ST segment-elevation myocardial infarction, or STEMI) 1,3. When evaluating a patient with a common symptom like abdominal pain or headache, it is crucial to consider the most life-threatening conditions with a common enough epidemiology before worrying about more benign ones, and the evaluation of chest pain is no different. Thus, anyone who presents with chest pain–even in an outpatient setting where the probability of myocardial infarction (MI) is lower relative to the inpatient setting–the patient must at the very least be screened for life-threatening causes of chest pain.

In the case of MI, especially, its presentation can commonly deviate from the classic presentation of a crushing retrosternal chest pain or pressure radiating down the left arm 3. 20% of patients with myocardial infarction present with little to no pain at all, many of whom are diabetics 3. For this reason, there is generally a relatively low threshold for screening of acute coronary syndrome (ACS), which includes unstable angina, non-ST elevation MI (NSTEMI), and STEMI in order of increasing severity of myocardial ischemia respectively.

Stable Angina

Stable angina is a mild form of myocardial ischemia that is characterized by its predictability: Increased demands of the heart due to exercise or emotional stress crossing a certain threshold out of demand to myocardial oxygen supply causing a retrosternal chest discomfort lasting for several minute. This is commonly the condition seen in dental patients especially after local anesthesia injection. While stable angina, in itself, is not all that threatening, it can progress to acute coronary syndrome. Recognition and immediate treatment could alleviate this with minimal steps. Those including oxygen, sublingual nitroglycerine aspirin.

Unstable Angina

Unstable angina is a chest pain that is worse than stable angina brought on with relatively little or no physiologic stress without any irreversible myocardial damage yet. Unstable angina can present clinically as:

1. increasing episodes of chest pain at a lower threshold in a patient already with stable angina,
2. angina pectoris chest pain at rest or with no exertion, and
3. sudden onset of serious angina pectoris without prior progression.

Non-ST elevation MI (NSTEMI)

NSTEMI presents almost identically to unstable angina, but the features may be slightly more severe. Unstable angina and NSTEMI appear identical on electrocardiogram with either T-wave inversions or ST-segment depressions. The only real way to tell the difference is with markers of cardiac necrosis, like cardiac troponins (cTn’s, especially cTnI and cTnC) and creatine kinase MB, where unstable angina has no definitive evidence of necrosis while NSTEMI does. However, untreated unstable angina can progress to NSTEMI or even STEMI as a function of the underlying pathophysiology.

ST elevation MI (STEMI)

It is the most severe type of myocardial ischemia. The classical presentation of a STEMI is

• transmural ischemia and
• necrosis.

This would be visible once 12 lead EKG is obtained. ST segment elevations are acutely to “pathologic” Q waves as remnants. If the artery is only partially occluded, either unstable angina or NSTEMI will manifest as a function of the degree of occlusion. If the thrombus resolves on its own and no findings are observed on EKG, the atherosclerotic plaque may still thicken and eventually lead to an ACS episode.