Zur Pulmonalklappeninsuffizienz

Summary

Thermistors (NTC-Resistors) open the possibility to registrate under a low velotage the accurate temperature of the surrounding blood (Thermodilution method: thermodilution curves for the estimation of cardiac output, regurgitation and enddiastolic ventricular volume) as well as under an increased voltage a qualitative measurement of the volocity of the blood. The blood velocity measurement in the mean pulmonary artery is easy to carry out. A catheter tip, on which a thermistor has been fixed, has to be placed in a free moving position 2–3 cm distal to the pulmonary valves. Under competent valve conditions the over heated thermistor shows a systolic cooling (increased blood velocity) and a diastolic warming up (standstill of the blood stream close to the valves). Under incompetent conditions a systolic forward and diastolic backward stream occur, that means the overheated thermistor shows as systolic and diastolic cooling. If this last mentionned curve was found on a patient, the regurgitation of a cold injectate form the pulmonary artery into the right ventricel has been checked and proved that in all cases a real regurgitation existed.

With help of this technique 447 cardiac patients have been checked and 40 (9%) times incompetent pulmonary valves were found. 23 incompetences existed under 246 acquired valve defects (9,5%), 13 under 201 congenital heart defects (6,5%) and 4 cases were previously operated (pul'monary commissurotomy).

A classification in organic and relative pulmonary incompetences has been tried. Angiocardiography, direct observation under cardiac surgery, postoperativ follow up and behaving under conservative therapy as well as autopsies were used for this classification. For this 31 cases could be used: 5 had an organic valve disease (3 acquired, 2 congential), 3 a idiopathic dilatation of the pulmonary artery, 16 a relative incompetence by pulmonary hypertension and 7 could not be classified.