Open arterial channel
At a fruit an arterial channel — the functioning vessel connecting the place of bifurcation of a pulmonary artery to an aortic arch is lower than an otkhozhdeniye of the left subclavial artery. Owing to high vascular resistance in not finished lungs of a fruit there is a dumping of blood from a pulmonary artery in an aorta in the direction to a placenta where blood is saturated with oxygen.
After the birth the arterial channel ceases to function, however, in some cases, for example, at premature, under the influence of a chronic anoxemia and some other factors, can remain open.
Clinical picture at an open arterial channel
The narrow arterial channel usually occurs at adults. Complaints at patients are absent or they are disturbed by fatigue, heartbeat and an asthma at an exercise stress. Integuments are pale. At an otkhozhdeniya of an arterial channel proksimalny the left subclavial artery the isolated cyanosis of the left hand is possible.
Pulse is high, fast. Arterial pressure at an open arterial channel has considerable scope due to, mainly, decrease in diastolic pressure (sometimes to 0). The small "cordial hump" is sometimes visible.
The apical beat is strengthened. The continuous systolic or systolodiastolic trembling in the second mezhreberye at the left amplifying in a systole is defined. Heart borders at early stages are not expanded, further extend to the left and to the right.
Auskultativno is listened the long rhomboid systolodiastolic "machine" noise which often have continuous character with a maximum at the end of a systole and at the beginning of a diastole and epicenter in the second mezhreberye to the left of a breast. The systolic component of noise is listened over all surface of heart, well carried out to interscapular space, on neck vessels; diastolic — is better listened on the left edge of a breast. Intensity of noise weakens at a natuzhivaniye and amplifies on a breath. In certain cases because of intensity of noise it is impossible to identify cordial tones. Sometimes in a projection of the mitral valve systolic noise of relative mitral insufficiency and diastolic noise of a relative mitral stenosis is listened.
Over time, in process of progressing of heart failure, intensity of noise weakens to short systolic or a full afonichnost, there is a pulsation of cervical veins, increase in a liver, hypostases. In the second mezhreberye to the left of a breast diastolic noise of relative insufficiency of the valve of a pulmonary artery begins to be listened (Graham's noise — Steel).
Treatment of patients with an open arterial channel
In other cases surgical closing of a botallov of a channel is shown. During operation damage of a recurrent nerve with development of paresis of phonatory bands is possible. Use of an intravascular technique with closing of an arterial channel with special "traffic jams" — oklyuder prevents this complication. Contraindication to surgical intervention at an open arterial channel is the IV stage of pulmonary hypertensia.