After the heart has been ruled out: what causes the pain?

A surprising proportion of emergency consultations for chest pain result in a diagnosis of musculoskeletal pain — after rigorous exclusion of cardiac cause. Studies published in the Annals of Internal Medicine show that 20–50% of acute chest pain has musculoskeletal or psychogenic origin, not cardiac. Among musculoskeletal causes, the pectoralis minor and costochondritis are the most frequent and the most underestimated.

The pectoralis minor muscle is called "the great cardiac mimic" by myofascial medicine. Its trigger points refer pain directly to the precordial region, anterior aspect of the shoulder, and medial aspect of the arm — perfectly replicating the pattern of angina pectoris. The fact that many patients with this pattern undergo electrocardiogram and catheterization with normal results and continue to have pain for years is proof that the pectoralis minor is rarely examined.

Non-cardiac chest pain: dimension of the problem

Relevant share
OF CHEST PAIN IN THE ED
after exclusion of acute coronary syndrome and pulmonary embolism, musculoskeletal and non-cardiac causes represent a substantial proportion of emergency department visits for chest pain
Residual anxiety
FREQUENT AFTER INVESTIGATION
patients with non-cardiac chest pain frequently maintain fear of cardiac disease even after complete investigation — the correct diagnosis has therapeutic value
3–5
SESSIONS USUALLY START RELIEF
clinical series of acupuncture in the pectorals and intercostal points describe symptomatic reduction of musculoskeletal chest pain over a few sessions — individual response varies
Improvement described
IN CLINICAL SERIES
studies and reviews on needling in musculoskeletal chest pain describe significant pain reduction in some patients — the level of evidence is still limited and heterogeneous

How the pectoralis minor generates precordial pain

  1. Chronically anteriorly projected shoulders

    Computer work, steering wheel, and "head forward" posture keep the shoulders in protraction. The pectoralis minor — which connects the coracoid process to ribs 3–5 — is kept chronically shortened.

  2. Neurovascular compression

    The tense pectoralis minor compresses the brachial neurovascular bundle (axillary artery, vein, and brachial plexus) in the subcoracoid space, causing arm numbness in addition to chest pain.

  3. Active trigger points

    The belly of the pectoralis minor develops trigger points that refer pain to the precordial region, anterior shoulder, and medial aspect of the arm — a pattern identical to that of angina.

  4. Associated costochondritis

    Chronic tension of the pectoralis minor at the costal insertions can inflame the chondrocostal junction (costochondritis), adding pain on palpation of costal cartilages 2–5.

  5. Acupuncture in the pectorals

    Dry needling of the pectoralis minor (subcoracoid or axillary access) and acupuncture at intercostal points and ST-17–ST-18 deactivates the trigger points and resolves the subcoracoid compression.

Differentiating causes of chest pain

Myth vs. Fact

MYTH

If the ECG is normal, chest pain is not serious

FACT

A resting ECG can be normal even during evolving acute coronary syndrome. A normal ECG does not exclude cardiac cause — it requires medical evaluation with cardiac enzymes and, if necessary, stress test or catheterization. Never use "normal ECG" as the sole criterion to exclude cardiac cause.

MYTH

Stabbing chest pain cannot be from the heart (heart attack hurts as squeezing)

FACT

Although classic angina is squeezing, some people — especially diabetics and women — have atypical presentations of acute coronary syndrome, including stabbing pain. Any new chest pain deserves medical evaluation, regardless of quality.

MYTH

Costochondritis is a rare disease

FACT

Costochondritis is very common — especially in women between 20–40 years and in athletes. It presents as pain on palpation of the chondrocostal junctions (2nd–5th), worsens with trunk movements and coughing, and responds well to medical acupuncture.

Pattern of musculoskeletal chest pain

Critérios clínicos
08 itens

Signs that point to musculoskeletal origin (after cardiac exclusion)

  1. 01

    Pain reproduced or worsened by palpation of costal cartilages (costochondritis)

  2. 02

    Pain that worsens with trunk movements (rotation, extension) or coughing

  3. 03

    Pain reproduced by pressing the pectoralis minor with the arm in abduction

  4. 04

    Worsens when crossing the arms or pushing (bench press)

  5. 05

    Habitually protracted shoulders (rounded forward)

  6. 06

    Associated arm numbness (subcoracoid compression)

  7. 07

    Stabbing or burning pain — not squeezing (distinction from typical angina)

  8. 08

    Relief with anti-inflammatories (confirms a local inflammatory component)

Treatment protocol (after cardiac exclusion)

Confirmation of cardiac exclusion
Pretreatment

The medical acupuncturist orders or confirms ECG, cardiac enzymes, and prior cardiologic evaluation. Only after exclusion of cardiac, pulmonary, or systemic cause is musculoskeletal treatment started.

Pectoralis minor dry needling
Sessions 1–3

Needling of the pectoralis minor via axillary or subcoracoid approach — a medical technique with precise knowledge of the brachial plexus and axillary artery. Electroacupuncture 4 Hz for pain modulation.

Costochondritis and intercostals
Sessions 4–6

Needling of the affected chondrocostal junctions. Points ST-17, CV-17, PC-6 for the precordial component. Segmental dorsal acupuncture at levels T3–T5.

Postural rebalancing
Sessions 7–8

Treatment of the serratus anterior and rhomboids to correct shoulder protraction. Postural guidance and medical prescription of thoracic opening exercises. Discharge with maintenance program.

Clinical pearl: the pectoralis minor test

Frequently asked questions

FREQUENTLY ASKED QUESTIONS · 04

Frequently Asked Questions

It is not possible to distinguish clinically with safety without medical evaluation. Features suggestive of musculoskeletal cause include: pain reproduced by palpation, worsening with trunk movements, young patient without cardiac risk factors, improvement with NSAIDs. Cardiac alert features: squeezing pain, radiation to the left arm/jaw, shortness of breath, sweating. Any doubt: urgent medical evaluation.

The pectoralis minor is located over the rib cage and the apex of the lung. Needling should be performed by a physician with specific training in thoracic anatomy, with needle direction parallel to the ribs and controlled depth. With appropriate technique, the risk is extremely low. In cases of barrel chest or patients with emphysema, ultrasound guides the procedure safely.

In most cases, yes. Costochondritis is typically self-limited, with spontaneous resolution in weeks to months. Medical acupuncture can contribute to symptomatic relief throughout this process, especially when there are associated trigger points in the pectoralis minor that may be perpetuating chronic traction at the costal insertions.

Yes, with some precautions. Needling at superficial points such as intercostals and pectorals can cause a small hematoma in anticoagulated patients, but it is rarely clinically significant. The physician adjusts the technique (finer needles, local pressure after needling) and evaluates individually. Always inform the physician of all medications in use.