What are the most commonly missed cardiac diagnoses, particularly in high-risk demographics such as older adults or those with a family history of cardiac disease?

Most Commonly Missed Cardiac Diagnoses

Acute aortic dissection, acute myocardial infarction, and congenital heart disease in adults represent the most frequently missed cardiac diagnoses, with diagnostic errors occurring in 10-15% of cardiovascular cases overall, primarily due to faulty cognition rather than knowledge gaps. 1

Top 10 Most Commonly Missed Cardiac Diagnoses

1. Acute Aortic Dissection/Acute Aortic Syndrome

• Missed or delayed diagnosis occurs most commonly when incorrectly diagnosed as acute coronary syndrome, leading to potentially catastrophic administration of antiplatelet and antithrombin agents 1
• Approximately 40% of chest films lack widened mediastinum, and up to 16% are completely normal, making radiographic absence unreliable for exclusion 1
• High-risk features include abrupt/instantaneous onset pain, severe intensity, ripping/tearing quality, pulse deficit, blood pressure differential between arms, and new aortic regurgitation murmur 1, 2
• Patients without any high-risk features still require consideration of aortic imaging, particularly those over 70 years, with syncope, focal neurologic deficit, or recent aortic manipulation 1

2. Acute Myocardial Infarction

• Missed diagnosis rate ranges from 0.9% to 2.1% of all AMI admissions, with some emergency departments showing rates up to 29% 3, 4, 5
• Lower-volume emergency departments have 2-fold higher odds of missed AMI compared to highest-volume centers 5
• Common misdiagnoses include nonspecific chest pain, gastrointestinal disease, musculoskeletal pain, and arrhythmias 4
• Younger patients and Black patients have significantly higher odds of missed diagnosis 3
• Primary reasons include incorrect ECG interpretation and failure to order appropriate diagnostic tests 4

3. Congenitally Corrected Transposition of Great Arteries (CCTGA)

• The diagnosis is often missed in cardiology practice due to failure to recognize abnormal ventricular position and associated AV valves 1
• Initial diagnosis delayed until adulthood in 66% of patients, with 17% diagnosed after age 60 1
• Patients present with systemic AV valve regurgitation, heart failure, atrial arrhythmias (36% of survivors), or complete heart block (2% per year spontaneous rate) 1
• Dextrocardia should always trigger consideration of this diagnosis 1

4. Hypertrophic Cardiomyopathy

• Most common cause of sudden cardiac death in young people and competitive athletes, yet frequently undiagnosed until catastrophic event 1
• Requires comprehensive annual assessment including family history, echocardiography, 24-48 hour Holter monitoring, and exercise blood pressure response 1
• Family history of premature sudden death, unexplained syncope (particularly exertional), and extreme LVH (≥30mm) are critical diagnostic clues 1
• Only 3% of patients who die suddenly lack any currently acknowledged risk markers 1

5. Arrhythmogenic Right Ventricular Cardiomyopathy

• Among 89 patients diagnosed by general cardiologists after MRI, 73% did not meet diagnostic criteria when reinvestigated at specialist centers 1
• Represents a major source of diagnostic error when imaging is interpreted by non-specialists 1
• Requires expert-level interpretation of cardiac MRI findings 1

6. Cardiac Amyloidosis

• Frequently missed in older adults presenting with heart failure symptoms 1
• Should be suspected in patients with heart failure and preserved ejection fraction, particularly with increased wall thickness 1
• Requires specific consideration during noncardiac disease evaluation including collagen vascular disease assessment 1

7. Familial Dilated Cardiomyopathy

• Up to 30% of idiopathic dilated cardiomyopathy cases are familial, yet family screening is often not performed 1
• Three-generation family history should identify relatives with cardiomyopathy, sudden unexplained death, conduction system disease, and skeletal myopathies 1
• ECG and echocardiogram should be considered in first-degree relatives of patients with dilated cardiomyopathy 1

8. Cardiac Involvement from Chemotherapy/Radiation

• Heart failure may occur years after exposure to anthracyclines or mediastinal irradiation, making temporal association difficult 1
• Cardiotoxic agents include anthracyclines (doxorubicin, daunorubicin), trastuzumab, cyclophosphamide, and mitoxantrone 1
• Total cumulative dose and timing of exposure (before/after age 20 for radiation) should be documented 1
• Mediastinal radiation increases risk of coronary disease, valvular disease, and pericardial disease 1

9. Pulmonary Embolism Misdiagnosed as Cardiac Disease

• Included in 18.7% of 970 autopsies where cardiovascular diseases were misdiagnosed 1
• Presents with chest pain, dyspnea, and hemodynamic instability mimicking acute coronary syndrome or heart failure 1

10. Cardiac Channelopathies (Long QT, Brugada, CPVT)

• Family history of sudden cardiac death, sudden infant death syndrome, or unexplained drowning in first-degree relatives should trigger evaluation 1
• Various medications can cause QT prolongation and torsades de pointes (www.crediblemeds.org) or induce Brugada pattern (www.brugadadrugs.org) 1
• Epilepsy may be misdiagnosed when arrhythmic syncope is the actual cause 1
• Requires detailed medication history including over-the-counter medications and supplements 1

Common Pitfalls Leading to Missed Diagnoses

Cognitive Errors

• Faulty cognition accounts for 34-37% of diagnostic errors in cardiovascular imaging, representing the major cause rather than knowledge deficiency 1
• Clinicians default to intuitive "System 1" thinking with pattern recognition, which is fast but error-prone 1
• Analytical "System 2" thinking—deductive and deliberate—reduces errors by reviewing options systematically 1

Technical and Systematic Factors

• Diagnostic errors more common with rare diseases (odds ratio 9.2) and suboptimal image quality 1
• Non-specialist interpretation shows 44% error rate versus 3% for experts in pediatric echocardiography 1
• Lower-volume centers lack access to advanced diagnostic technologies and consultant expertise 5

High-Risk Demographics Requiring Heightened Vigilance

• Older adults (>70 years) with atypical presentations 1, 6
• Younger patients and Black patients with acute coronary symptoms 3
• Patients with family history of premature cardiac death, cardiomyopathy, or conduction disease 1
• Those with prior chemotherapy, radiation therapy, or cardiotoxic substance exposure 1