The Means-Lerman scratch is an uncommon type of heart murmur

Heart murmur

Murmurs are extra heart sounds that are produced as a result of turbulent blood flow that is sufficient to produce audible noise. Most murmurs can only be heard with the assistance of a stethoscope ....

 which occurs in patients with hyperthyroidism

Hyperthyroidism

Hyperthyroidism is the term for overactive tissue within the thyroid gland causing an overproduction of thyroid hormones . Hyperthyroidism is thus a cause of thyrotoxicosis, the clinical condition of increased thyroid hormones in the blood. Hyperthyroidism and thyrotoxicosis are not synonymous...

. It is a mid-systolic

Systolic heart murmur

Systolic heart murmurs are heart murmurs heard during systole.They can be classified by when the murmur begins and ends, between S1 and S2.Many involve stenosis of the semilunar valves or regurgitation of the atrioventricular valves.-Types:...

 scratching sound best heard over the upper part of the sternum or second left intercostal space

Intercostal space

The intercostal space is the space between two ribs . Since there are 12 ribs on each side, there are 11 intercostal spaces, each numbered for the rib superior to it.-Structures in intercostal space:* several kinds of intercostal muscle...

 at the end of expiration

Exhalation

Exhalation is the movement of air out of the bronchial tubes, through the airways, to the external environment during breathing....

. The murmur results from the rubbing of the pericardium

Pericardium

The pericardium is a double-walled sac that contains the heart and the roots of the great vessels.-Layers:...

 against the pleura

Pleural cavity

In human anatomy, the pleural cavity is the potential space between the two pleura of the lungs. The pleura is a serous membrane which folds back onto itself to form a two-layered, membrane structure. The thin space between the two pleural layers is known as the pleural cavity; it normally...

 in the context of hyperdynamic circulation

Hyperdynamic circulation

Hyperdynamic circulation is abnormally increased circulatory volume. Systemic vasodilation and the associated decrease in peripheral vascular resistance results in decreased pulmonary capillary wedge pressure and decreased blood pressure, often presenting with a collapsing pulse...

 and tachycardia

Tachycardia

Tachycardia comes from the Greek words tachys and kardia . Tachycardia typically refers to a heart rate that exceeds the normal range for a resting heart rate...

, and may mimic the sound of a pericardial rub

Pericardial friction rub

A pericardial friction rub, also pericardial rub, is an audible medical sign used in the diagnosis of pericarditis. Upon auscultation, this sign is an extra heart sound of to-and-fro character, typically with three components, two systolic and one diastolic. It resembles the sound of squeaky...

.

The sign was described by J. Lerman M.D. and J. H. Means M.D. of Massachusetts General Hospital

Massachusetts General Hospital

Massachusetts General Hospital is a teaching hospital and biomedical research facility in the West End neighborhood of Boston, Massachusetts...

in 1932.