0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Thinning of the blood. Carried out prior to an operation so that fewer erythrocytes are lost in the event of loss of blood, or to reduce the risk of thrombosis


Effect on cardiovascular functions

Heart-lung machine

Device commonly used in open-heart surgery to temporarily take over the functions of the heart and lungs. Lowering body temperature to 18 - 30° Celsius (hypothermia) reduces, in particular, cardiac and cerebral oxygen requirements.

Heart attack
myocardial infarction

Gross necrosis of the myocardium due to reduced blood supply and subsequent lack of oxygen following occlusion of the coronary vessels by thrombosis.

Heart block

Disturbance of the heartbeat caused by a disorder in the conduction system resulting in a delay or absence of contraction of the cardiac chambers; AV block, bundle branch block

Heart failure/cardiac insufficiency

Myocardial insufficiency; the heart becomes unable to pump sufficient blood - and therefore oxygen and nutrients - to the organs

Heart murmur

Occurs when the blood flows over an irregular surface or constriction exceeds a critical velocity, e.g. valvular stenosis or the sound of backflow through leaking cardiac valves. Diagnosis with ascultation.

Heart rate

Number of heartbeats per minute

Heart tones

Sounds coming from the heart, caused by movements of the cardiac valves and muscular contractions

Heart transplantation

The diseased heart is removed and replaced by the heart of a deceased donor

Hegar’s dilator

A series of bougies of varying sizes, used in cardiac surgery to calibrate the diameters of valves


Anticoagulant substance

also xenograft

Valve-bearing vascular prothesis (conduit) made of synthetic material (Dacron. Goretex), which contains a cardiac valve made of porcine aorta, or bovine and porcine pericardium

High blood pressure

Increase of blood pressure above certain values

High frequency ablation


Hilum of the lung
root of the lung

Hilum displacement is caused by vascular mutations, e.g. with left-to-right shunt

Hippocratic nails

Condition probably first described by Hippocrates. Features increased convexity of the finger- and toenails due to persistent cyanosis (see also clubbing) the fingernails are curved like the glass of a pocket watch


Heart-lung transplantation


Heart murmur that can be heard throughout systole


Cadaveric valve (pulmonary or aortic). Usually implanted between a ventricle and the pulmonary artery.


Heart transplantation

Hydrops fetalis

Accumulation of fluid in foetal body cavities


Excess of cells in the blood. With long-term cyanosis there is an excess of red blood cells (erythrocytes)


A state of increased rate of metabolic activity


Commonly referred to as high blood pressure; a medical condition in which the blood pressure is chronically raised

Hypertrophic cardiomyopathy

Disease of the heart muscles resulting from dysfunctional contraction of cardiomyocytes

Hypoplastic left heart syndrome

Immaturity of the structures on the left side of the heart


Below-normal temperature; artificially induced hypothermia during heart surgery.

Thymus aplasia

Immaturity/congenital absence of the thymus gland


Low blood pressure or abnormally low tension in the muscle


Deficient arterial oxygenation


Lack of oxygen. Often in connection with dyspnea, anxiety, disorientation, tachycardia and increased blood pressure

Author(s): Kinderherzstiftung, Prof. Dr. Elisabeth Sticker, Hermine Nock
Last updated: 2009-04-28