A condition caused by partial or complete occlusion of one or more of the coronary arteries, resulting in abrupt reduction in coronary blood flow to a segment of the myocardium, oftentimes secondary to thrombus. The condition is commonly known as a "heart attack" or myocardial infarction (MI).

Myocardial infarction arises from any condition resulting when the oxygen supply to the myocardium cannot keep pace with demand. Conditions that may lead to MI include: coronary heart disease, coronary artery emboli, coronary artery spasm, and severe hematologic and coagulation disorder. Risk factors that increase an individual's vulnerability to MI include: family history of MI, hypertension, smoking, elevated serum triglyceride, cholesterol, and low-density lipoprotein (LDL). Additional risk factors include: low-level high-density lipoprotein (HDL); diabetes mellitus, obesity, poor dietary practice, sedentary lifestyle, aging, stress, or Type A personality, and use of oral contraceptives.

At times, prodromal (premonitory) symptoms are experienced as actual events, but at other times no early warning signs are noted. Prodromal symptoms can be characterized as increasing angina, shortness of breath, and fatigue. Acute MI produces symptoms of deep, substernal, visceral pain (internal aching or pressure), often with radiation to the shoulder, neck, back, jaw, teeth, or left arm. Nausea and vomiting, sweating, and shortness of breath may accompany the symptoms. One-third of the MIs are clinically unrecognized, and representative of silent MIs.

The functional abilities of cardiac patients can be classified in terms of metabolic equivalents (METs). The classification is generally as follows:

To determine the limitations on patient's functional abilities, the METs are considered in accordance with what symptoms are exhibited when the activities are carried out. For example, if a patient is performing activity at the 2 to 4 MET level and experiences dyspnea, fatigue, dizziness or fainting, the patient is considered to have low functional abilities.

• Light to medium housework is 2 to 4 METs

• Heavy housework or yard work is approximately 5 to 6 METs

• Strenuous activity would be 7 to 10 METs, etc.

Echocardiogram may show ventricular wall hypokinesia (impairment of movement). A series of 12-lead electrocardiograms (EKGs), creatine phosphokinase (CPK), and troponin levels; pyrophosphate and thallium scans; and ventriculography tests can detect ischemic (insufficient blood supply) episodes and may indicate the specific area of heart involved.

Stabilization is the first priority. Treatments vary depending upon the diagnosed underlying causes. Possible treatments include, but are not limited to: reduction in myocardial oxygen demands; increased myocardial oxygen supply through use of medications; tissue plasminogen activator (TPA); and anticoagulant drugs. Percutaneous transluminal coronary angioplasty (PTCA) or pacemakers constitute additional treatment measures.

Residual effects range from a permanent reduction in activity levels to complete freedom of activity. Functional impairment and the prognosis depend on the size and location of the infarct.

• May be entitled to special monthly compensation where the Veteran has a single service-connected disability rated as 100% with additional service-connected disability or disabilities independently ratable at 60% or more, which are separate and distinct from the 100% service-connected disability and involves different anatomical segments or bodily systems. See  38 CFR 3.350(i)(1) – Special Monthly Compensation (SMC).

• This disease shall be granted service connection although not otherwise established as incurred in or aggravated by service if manifested to a compensable degree within the applicable time limits under 38 CFR 3.307 following service in a period of war or following peacetime service on or after January 1, 1947, provided the rebuttable presumption provisions of 38 CFR 3.307 are also satisfied [38 CFR 38 CFR 3.309 .  [Disease subject to presumptive service connection], 38 CFR 3.309 (a) [chronic disease].

• If a Veteran is a former prisoner of war, this disease shall be service connected if manifest to a degree of disability of 10 percent or more at any time after discharge or release from active military, naval, or air service even though there is no record of such disease during service, provided the rebuttable presumption provisions of 38 CFR 3.307 are also satisfied [38 CFR 3.309 (c) Disease subject to presumptive service connection].

• If a Veteran was exposed to an herbicide agent during active military, naval, or air service, this disease shall be service-connected if the requirements of 38 CFR 3.307(a)(6) are met even though there is no record of such disease during service, provided further that the rebuttable presumption provisions of 38 CFR 3.307(d) are also satisfied. [38 CFR 3.309(e)]

Notes

• Evaluate cor pulmonale, which is a form of secondary heart disease, as part of the pulmonary condition that causes it.

• One MET (metabolic equivalent) is the energy cost of standing quietly at rest and represents an oxygen uptake of 3.5 milliliters per kilogram of body weight per minute. When the level of METs at which breathlessness, fatigue, angina, dizziness, or syncope develops is required for evaluation, and a laboratory determination of METs by exercise testing cannot be done for medical reasons, a medical examiner may estimate the level of activity (expressed in METs and supported by specific examples, such as slow stair climbing or shoveling snow) that results in those symptoms.

• For this general formula, heart failure symptoms include, but are not limited to, breathlessness, fatigue, angina, dizziness, arrhythmia, palpitations, or syncope.

• The rating criteria for cardiovascular conditions underwent full-scale revision effective on November 14, 2021 and January 12, 1999.  A regulatory change was effective August 13, 1998, updated criteria for cold injury residuals under 38 CFR 4.104, DC 7122.  The changes are not considered liberalizing and should not be used as the basis for reduction unless the disability has actually improved.