Heart Attack in Women: Recognizing Atypical Symptoms

Acute coronary syndrome (ACS) is one of the most common life-threatening emergencies – yet it is significantly more often missed or diagnosed with delay in women than in men. The reason lies less in a lack of expertise and more in a deeply rooted clinical bias: The "classic" picture of a heart attack – crushing chest pain radiating to the left arm – was developed over decades from predominantly male study populations. However, women present with atypical symptoms in up to 30–40% of cases, initially suggesting other differential diagnoses. The consequence: longer door-to-balloon times, less frequent guideline-adherent therapy, and higher in-hospital mortality. As an emergency physician, anesthesiologist, or nurse in an emergency setting, you need to know these sex-specific differences to avoid delaying life-saving decisions.

Epidemiology and the Gender Gap

Cardiovascular disease is the leading cause of death in women in Austria and worldwide. Yet a significant gender gap persists in diagnosis and treatment:

• Women with STEMI reach the catheterization lab on average 15–30 minutes later than men.
• Women less frequently receive guideline-adherent dual antiplatelet therapy.
• 30-day mortality after STEMI is higher in women than in age-matched men – particularly in the age group under 55.
• Women are more frequently discharged from the emergency department with non-cardiac diagnoses (anxiety disorder, musculoskeletal complaints, reflux).

These disparities cannot be explained by biology alone. A major factor is the atypical symptom presentation, which leads to delayed recognition both by the patients themselves and by medical professionals.

Pathophysiological Basis of Sex Differences

The differences in clinical presentation have a pathophysiological basis that extends beyond mere symptom perception:

Coronary Vascular Pathology

While men predominantly develop obstructive atherosclerotic plaques in epicardial coronary arteries, women more frequently exhibit:

• Coronary Microvascular Dysfunction (CMD): Functional disorders of the small coronary vessels without significant epicardial stenoses. Clinically presenting as MINOCA (Myocardial Infarction with Non-Obstructive Coronary Arteries).
• Spontaneous Coronary Artery Dissection (SCAD): Disproportionately affects younger women, frequently peripartum or in association with fibromuscular dysplasia.
• Plaque erosion rather than plaque rupture: The thrombotic mechanism differs – erosions less frequently lead to complete vessel occlusion but more frequently result in NSTEMI presentations.
• Coronary vasospasm (Prinzmetal angina): Occurs more frequently in women and can cause transient ST elevations.

Hormonal Influences

Estrogen has protective effects on the endothelium, vasodilation, and lipid profile. After menopause, cardiovascular risk in women rises steeply. At the same time, pain perception and autonomic regulation change – factors that influence symptom presentation.

Differences in Autonomic Regulation

Women more frequently exhibit vagal symptoms (nausea, vomiting, diaphoresis) during myocardial ischemia and less frequently the typical sympathetically triggered "crushing pain" response.

Symptom Presentation: What "Atypical" Really Means

The term "atypical" is actually misleading – because for women, these symptoms are quite typical. A more accurate designation would be sex-specific presentation. Nevertheless, the term has become clinically established.

Classic vs. Sex-Specific Symptoms

"Classic" (more common in men)	Sex-specific (more common in women)
Retrosternal pressure pain, "elephant on the chest"	Diffuse tightness, pressure in the upper abdomen
Radiation to left arm, jaw	Pain between the shoulder blades, neck, bilateral jaw
Exertion-related angina	Symptoms also at rest, frequently nocturnal
Acute onset	Prodromal symptoms over days to weeks
Diaphoresis with chest pain	Isolated nausea, vomiting, fatigue

The Most Common Symptoms in Women with ACS

1. Dyspnea – often the leading or only symptom, without accompanying chest pain
2. Unusual fatigue – pronounced, new-onset exhaustion that increases over days
3. Nausea and vomiting – frequently misinterpreted as a gastrointestinal cause
4. Upper abdominal / epigastric pain – confused with gastritis, cholecystitis, pancreatitis
5. Back pain – particularly interscapular, frequently without a thoracic component
6. Jaw pain – bilateral, exertion-related, often interpreted as a dental problem
7. Dizziness and presyncope – due to autonomic dysregulation and arrhythmias
8. Restlessness, anxiety, "feeling that something is wrong" – often dismissed as psychosomatic

Prodromal Symptoms

A crucial distinguishing feature: Women report prodromal symptoms in the days and weeks before the acute event significantly more often. These include:

• Increasing, unexplained fatigue
• Sleep disturbances
• Exertional dyspnea with previously tolerated activities
• Intermittent upper abdominal complaints
• General malaise

These warning signs theoretically offer a window for early detection – but are frequently not recognized as cardiac by either the patients themselves or the medical system.

ECG Considerations in Women

The 12-lead ECG remains the cornerstone of initial ACS diagnosis. Here too, there are sex-specific considerations you need to know:

ST-Elevation Criteria

The AHA guidelines define sex-specific thresholds for significant ST elevation:

• Men < 40 years: ≥ 2.5 mm in V2–V3, ≥ 1 mm in all other leads
• Men ≥ 40 years: ≥ 2.0 mm in V2–V3, ≥ 1 mm in all other leads
• Women (all age groups): ≥ 1.5 mm in V2–V3, ≥ 1 mm in all other leads

The lower threshold in women reflects the lower physiological ST elevation. In practice, this means: An ST elevation of 1.5 mm in V2 in a woman has the same diagnostic significance as 2.0 mm in a man.

Common ECG Patterns in Women with ACS

• NSTEMI more common than STEMI: Women disproportionately present with NSTEMI or unstable angina. The ECG may be unremarkable or show only subtle changes.
• ST depressions and T-wave inversions: More common than ST elevations, particularly with diffuse coronary microvascular dysfunction.
• Nonspecific ST/T changes: Often trivialized as "nonspecific" or "positional."
• A normal ECG does not rule out ACS: Up to 6% of all patients with acute myocardial infarction have an initially normal ECG – the proportion is higher in women.

Practical Tip: Serial ECGs

In women with suspicious symptoms and an initially normal finding: serial ECGs every 15–30 minutes. Dynamic ST changes can provide the crucial diagnostic clue, particularly with intermittent vasospasm or evolving thrombi.

Troponin Diagnostics: Sex-Specific Thresholds

High-sensitivity troponin assays (hs-cTnI, hs-cTnT) have revolutionized ACS diagnostics. However, a key point has not yet been widely implemented in clinical practice:

• Women have lower physiological troponin levels than men.
• Sex-specific thresholds (99th percentile) increase sensitivity in women by up to 20%, without substantially reducing specificity.
• A troponin value that is classified as "normal" using a uniform threshold may already be pathological in a woman.

Recommendation: Check whether your laboratory reports sex-specific reference values for hs-troponin. If not, take this factor into account during clinical interpretation.

Risk Stratification and Clinical Pitfalls

HEART Score and Sex-Specific Limitations

The HEART score is a widely used tool for risk stratification of chest pain in the emergency department. Its limitations in women:

• H (History): The history is often classified as "atypical" and scored lower.
• E (ECG): Subtle changes are classified as nonspecific.
• A (Age): Younger women (< 55) are classified as "low risk," even though this group has a high mortality rate with ACS.
• R (Risk Factors): Female-specific risk factors (preeclampsia, gestational diabetes, PCOS, autoimmune diseases) are not included in the score.
• T (Troponin): Without sex-specific thresholds, the criterion loses sensitivity.

The Most Common Misdiagnoses in Women with ACS

• Gastroesophageal reflux / gastritis
• Anxiety or panic disorder
• Musculoskeletal complaints (thoracic spine syndrome)
• Cholecystitis
• Hyperventilation syndrome
• Menopausal symptoms

Red Flags: When You Should Consider ACS

Even without typical chest pain, you should actively consider a cardiac cause in women when:

• New-onset dyspnea without a pulmonary explanation is present
• Autonomic symptoms (nausea, diaphoresis, dizziness) exist without a clear cause
• Cardiovascular risk factors are present (particularly diabetes – diabetic neuropathy masks angina)
• The patient herself expresses the feeling "that something is wrong"
• Exertion-related complaints of any kind are present
• New, unexplained fatigue occurs in combination with any of the above symptoms

Implications for Emergency Care

Prehospital Phase

• 12-lead ECG as early as possible – ideally already by the EMS, with sex-specific interpretation.
• Low threshold for cath lab pre-notification in women with suspicious symptoms, even without classic chest pain.
• Actively ask about symptoms beyond chest pain: "Do you have shortness of breath? Nausea? Pain in your back or jaw? Do you feel unusually exhausted?"

In-Hospital Phase

• Serial ECG and troponin monitoring when clinical suspicion exists, even if the initial findings are unremarkable.
• Use sex-specific troponin thresholds when available.
• Echocardiography as supplementary acute diagnostics: Regional wall motion abnormalities can support the suspicion when ECG and initial troponin are inconclusive.
• Do not discharge too early: In women with intermediate risk, an observational approach (chest pain unit, serial troponins over 3–6 hours) is preferable to rapid rule-out.

ACLS Algorithm: What Changes?

The fundamental ACLS algorithm does not change for women – epinephrine 1 mg IV every 3–5 minutes during arrest, defibrillation for VF/pVT, systematic H's and T's troubleshooting. However:

• Think early about ACS as the cause of arrest in women with unclear etiology. "Coronary Thrombosis" is one of the T's in the ACLS algorithm.
• Consider thrombolysis during arrest with suspected fulminant myocardial infarction, particularly when PCI is not available in a timely manner.
• Takotsubo cardiomyopathy (stress cardiomyopathy) as a differential diagnosis: Predominantly affects postmenopausal women, can mimic STEMI, and may result in cardiogenic shock or arrest.

Checklist for Daily Clinical Practice

The following points will help you actively reduce gender bias in ACS diagnostics:

1. Raise awareness: Women present ACS differently – this is not "atypical" but sex-specifically typical.
2. Ask targeted questions: Not only about chest pain, but about dyspnea, fatigue, nausea, back and jaw pain.
3. Interpret ECGs in a sex-specific manner: Apply the lower ST-elevation threshold in V2–V3 for women.
4. Evaluate troponin in a sex-specific manner: Consider the lower normal values in women.
5. Apply scores critically: The HEART score and similar tools have limitations in women.
6. When in doubt, err on the side of the patient: In case of uncertainty, pursue serial diagnostics, echocardiography, and cardiology consultation rather than premature discharge.
7. Know MINOCA and SCAD: A normal coronary angiogram does not rule out myocardial infarction in women.
8. Expand risk factors: Include pregnancy complications, autoimmune diseases, and hormonal factors in the risk assessment.

Practical Training

Recognizing atypical ACS presentations requires more than theoretical knowledge – it requires clinical practice in realistic scenarios. In the ACLS Refresher Course by Simulation Tirol, you systematically train the differential diagnosis of acute coronary syndrome, sex-specific ECG interpretation, and decision-making in time-critical situations. With high-fidelity simulation and structured debriefing, you can practice exactly the action patterns that make the difference in a real emergency. Find all information about the ACLS Refresher at simulation.tirol.