A Glossary of Heart Disease Terms
Murmur: Turbulent blood flow across a heart valve that creates a "swishing" sound heard by a stethoscope. This sound can be due to a valve being too tight, leaky or occur from a congenital abnormality to the heart, such as a hole or stricture.
Myocardial Biopsy (Cardiac biopsy): An invasive procedure to obtain a small piece of heart muscle tissue that is sent to a laboratory for analysis.
Myocardial Infarction (Heart attack): See heart attack (above).
Myocarditis: Inflammation of the myocardium (heart muscle). May feel like a heart attack and appear to be one, until further testing is done.
Myocardium: Heart muscle.
Myomectomy: A surgical procedure to remove abnormally thickened heart muscle. Myomectomy is used to treat people with idiopathic hypertrophic subaortic stenosis (IHSS) or HOCM, thereby relieving the obstruction to blood flow in the left ventricle during contraction.
Nitroglycerin: A medication used to relax and dilate the blood vessels (vasodilator), improving blood flow. Nitroglycerin works very quickly and is the most common vasodilator used to treat angina.
Non-Q-Wave MI (NSTEMI or non-ST-elevation MI): A heart attack that does not cause changes known as "Q-waves" on the electrocardiogram (ECG). However, other changes on the ECG are often seen. In addition, chemical markers in the blood indicate that damage has occurred to the heart muscle. In non-Q-wave MI, a clot may block the coronary artery for a period of time, and then break up by itself or collateral circulation may help to restore blood flow. The size of damage is fairly small; therefore, overall function of the heart is usually maintained, unless there have been multiple events.
Nuclear Scan: Nuclear imaging is a method of producing images by detecting radiation from different parts of the body after the administration of a radioactive tracer material.
Obesity: Excess fat due to eating more calories than used. It is usually defined by having a body mass index (BMI-see above) of 25 or higher.
Off Pump Heart Surgery: Heart surgery done without the use of the cardiopulmonary bypass machine.
Pacemaker: A small electronic device is implanted under the skin and sends electrical impulses to the heart muscle to maintain a suitable heart rate and to prevent slow heart rates.