TSH Testing in Cardiac Murmur Evaluation

Standard Evaluation of Cardiac Murmurs

The American College of Cardiology/American Heart Association recommends echocardiography for asymptomatic patients with diastolic murmurs, continuous murmurs, holosystolic murmurs, late systolic murmurs, or murmurs associated with ejection clicks 2, 4
The American College of Cardiology/American Heart Association indicates echocardiography for patients with heart murmurs and symptoms/signs of heart failure, myocardial ischemia, syncope, thromboembolism, or infective endocarditis 3, 4
Asymptomatic patients with grade 3 or louder midpeaking systolic murmurs should undergo echocardiography, as recommended by the American College of Cardiology/American Heart Association 2, 4
Echocardiography can be useful for murmurs associated with abnormal cardiac physical findings or abnormal ECG/chest X-ray, according to the American College of Cardiology/American Heart Association and Circulation 3, 5
The American College of Cardiology/American Heart Association does not recommend echocardiography for patients with grade 2 or softer midsystolic murmurs identified as innocent or functional by an experienced clinician 3, 5

Hyperthyroidism is associated with increased risk of atrial arrhythmias and can increase heart rate, left ventricular mass, and cardiac contractility, as reported by JAMA 6
Subclinical hyperthyroidism with TSH <0.1 mIU/L is associated with a 3-fold increased risk of atrial fibrillation in individuals over 60 years, according to JAMA 6

TSH testing should be considered in patients with cardiac murmurs when there are clinical features suggestive of thyroid dysfunction, such as tachycardia, tremor, weight changes, heat/cold intolerance, as recommended by JAMA 6
New-onset atrial fibrillation detection, particularly in older adults, is an indication for TSH testing, according to JAMA 6
Patients with risk factors for thyroid disease along with cardiovascular symptoms should undergo TSH testing, as suggested by JAMA 6