Does a heart murmur due to rheumatoid arthritis (RA) show on an electrocardiogram (ECG)?

ECG Does Not Detect Heart Murmurs from Rheumatoid Arthritis

An electrocardiogram (ECG) cannot detect or "show" a heart murmur from rheumatoid arthritis or any other cause—murmurs are audible sounds detected by auscultation, while ECG records electrical activity of the heart. However, the ECG may reveal indirect consequences of the underlying cardiac pathology that causes the murmur, such as ventricular hypertrophy or conduction abnormalities 1.

Understanding the Distinction

The ECG and physical examination serve complementary but fundamentally different diagnostic roles:

• Murmurs are acoustic phenomena detected by stethoscope during physical examination, representing turbulent blood flow across abnormal valves or cardiac structures 1
• ECG records electrical signals and can only detect arrhythmias, conduction defects, chamber enlargement patterns, and ischemic changes 1
• The absence of ventricular hypertrophy, atrial enlargement, or conduction abnormalities on ECG provides useful negative information but does not exclude significant valvular disease 1

Cardiac Involvement in Rheumatoid Arthritis

Rheumatoid arthritis commonly affects the heart, with mitral regurgitation occurring in up to 80% of patients:

• Mitral valve involvement is the most frequent cardiac manifestation, causing mitral regurgitation that produces a systolic murmur 2
• Aortic regurgitation occurs in approximately 33% of RA patients, producing a diastolic murmur 2
• Pericarditis affects 13-23% of patients and may cause pericardial friction rubs 2, 3
• These valvular abnormalities often remain subclinical and are detected only through imaging 2, 4

What ECG Can Show in RA Cardiac Disease

While ECG cannot detect the murmur itself, it may reveal secondary cardiac changes:

• ST segment and T wave abnormalities are the most common ECG findings in RA patients with cardiac involvement 3
• Conduction disturbances and arrhythmias occur in approximately 50% of RA patients, though at rates similar to age-matched controls 5
• Ventricular hypertrophy patterns may develop with chronic valvular disease 1
• Abnormal ECG findings in a patient with a heart murmur should prompt echocardiography 1

The Appropriate Diagnostic Approach

Echocardiography, not ECG, is the definitive test for evaluating heart murmurs in RA patients:

• Echocardiography is recommended (Class I) for any patient with a diastolic murmur, continuous murmur, holosystolic murmur, or grade 3 or louder systolic murmur 1
• Transesophageal echocardiography is more sensitive than transthoracic echocardiography for detecting valvular abnormalities in RA, particularly mitral valve disease 2
• ECG and chest X-ray provide complementary information about chamber size, rhythm, and conduction but should not delay echocardiography when indicated 1
• A normal ECG does not exclude significant structural heart disease or valvular pathology 1

Clinical Implications

The high prevalence of cardiac involvement in RA warrants a low threshold for echocardiographic evaluation:

• Cardiac disease is the leading cause of death in RA patients, often remaining subclinical until advanced 3, 4
• Duration of RA disease correlates with abnormal echocardiographic findings 3
• Modern imaging modalities, particularly cardiac magnetic resonance, can identify early asymptomatic cardiac abnormalities 6, 4
• Any RA patient with a newly detected murmur, regardless of symptoms, should undergo echocardiography to characterize the valvular lesion and assess ventricular function 1, 2