Can trapezius muscle pain mimic cardiac pain, such as myocardial infarction?

Can Trapezius Muscle Pain Mimic Cardiac Pain?

Yes, trapezius muscle pain can mimic cardiac pain, but the critical distinction is that musculoskeletal chest pain is positional, reproducible with palpation, and lacks the associated autonomic symptoms that characterize acute coronary syndrome.

Key Distinguishing Features

Characteristics That Suggest Musculoskeletal (Trapezius) Origin

• Pain reproducible by palpation of the chest wall is the hallmark finding indicating musculoskeletal origin and provides the highest diagnostic information against angina in patients without previous coronary artery disease 1
• Positional chest pain (pain that changes with body position or specific movements) is usually nonischemic and musculoskeletal 2
• Sharp, stabbing pain localized to a very limited area is unlikely related to myocardial ischemia 2
• Fleeting chest pain of few seconds' duration is unlikely to be related to ischemic heart disease 2
• Absence of associated autonomic symptoms such as diaphoresis, nausea, vomiting, or dyspnea makes cardiac origin less likely 2

Characteristics That Suggest Cardiac Origin

• Retrosternal chest discomfort described as heaviness, tightness, pressure, constriction, or squeezing that gradually builds over minutes 2
• Diffuse pain over a wide area of the anterior chest wall, not localized to a point 2
• Radiation to left/right arm, neck, jaw, or back 2
• Associated autonomic symptoms: pallor, diaphoresis, cool skin, nausea, vomiting, dyspnea 2
• Triggered by physical exercise or emotional stress, with occurrence at rest indicating acute coronary syndrome 2

Epidemiological Context

Musculoskeletal disorders are actually the most common cause of chest pain in primary care settings, accounting for 43% of cases seen by general practitioners, while cardiac causes represent only 20% 2. However, in emergency department settings, the distribution shifts dramatically, with cardiac causes accounting for 45% and musculoskeletal only 14% 2.

Critical Pitfalls to Avoid

Do Not Rely on These Unreliable Indicators

• Relief with nitroglycerin is NOT diagnostic of myocardial ischemia and should not be used as a diagnostic criterion, as esophageal spasm and other non-cardiac conditions also respond to nitroglycerin 2, 3
• Sharp chest pain does NOT exclude cardiac disease, particularly in women, elderly patients, and those with diabetes who frequently present with atypical symptoms including sharp or positional pain 2, 3
• Location on left or right side of chest does not exclude cardiac origin 2

High-Risk Populations Requiring Extra Vigilance

• Women are at particular risk for underdiagnosis of cardiac disease and may present with atypical symptoms more frequently than men 2, 3, 4
• Elderly patients (>75 years) may present with isolated dyspnea, confusion, or fatigue rather than classic chest pain 2, 4
• Diabetic patients frequently have atypical presentations of cardiac ischemia 2, 4

Mandatory Immediate Evaluation Protocol

For ANY patient presenting with acute chest pain, regardless of suspected etiology:

1. Obtain ECG within 10 minutes to identify ST-segment elevation myocardial infarction 2, 3
2. Measure cardiac troponin as soon as possible after presentation 2, 3
3. Assess for life-threatening conditions including aortic dissection (sudden "ripping" pain radiating to back, pulse differentials), pulmonary embolism (tachycardia >100 bpm, dyspnea, pleuritic pain), and pericarditis (sharp pain worsening supine, improving when leaning forward) 3, 1

When Musculoskeletal Diagnosis is Safe

A musculoskeletal diagnosis can be confidently made when ALL of the following are present:

• Pain is reproducible by palpation of the trapezius or chest wall 1
• Pain is positional or movement-related 2
• ECG is normal 2
• Cardiac troponin is normal 2
• No associated autonomic symptoms (diaphoresis, nausea, dyspnea) 2
• No cardiac risk factors or low-risk designation by clinical decision pathway 2

Special Consideration: Trapezius Muscle Pathophysiology

Chronic trapezius myalgia involves impaired microcirculation in the local muscle with consistently low blood flow and slightly elevated muscle tension, causing nociceptive pain that can be differentiated from neuralgic pain 5. There is a strong association between perceived neck/shoulder pain intensity and trapezius muscle tenderness in office workers 6. However, this chronic musculoskeletal condition presents very differently from acute cardiac pain in terms of onset, associated symptoms, and response to palpation.

Bottom Line for Clinical Practice

Never dismiss chest pain as musculoskeletal without first ruling out cardiac causes through ECG and troponin testing 2, 3. The consequences of missing acute coronary syndrome far outweigh the cost of appropriate testing. When in doubt, delayed transfer to the emergency department for diagnostic testing should be avoided 2.