Bronchoscopic Method for Measuring Left Atrial Pressure An Aid to Diagnosis in Mitral Disease

The possibility is examined that measurements from the records of left atrial pressure ob-tained by direct puncture of the left atrium through the bronchoscope might help in the diag-nosis of mitral disease. The left atrial pressure records of 156 patients have been analyzed and the results are presented. IT WAS suggested that the record of left atrial pressure, obtained through the bronchoscope, might help to differentiate be-tween mitral stenosis and mitral regurgitation and also to distinguish those patients in whom the mitral lesion is not the major cause of the symptoms.' The validity of these suggestions has been tested in a series of 156 patients. METHOD The apparatus used was the same as that pre-xviouslv described by Allison and Linden. ` 2 The manometer system was damped only by the punc-turing needle and the degree of damping was 60 to 70 per cent of the critical value. It must be emphasized that in a system of this type no other damping is required. If, to eliminate artifacts, further damping is applied by electric or mechan-ical means, the amplitude of the recorded pres-sure pulse will be reduced, and inaccuracies of an unknown degree will occur. The Patient. At rapid heart rates the records of the left atrial pressure contours are less ac-emirate: (1) because the ratio of the frequency of the impressed force to the natural frequency of the manometer system is large and this causes dis-tortion; and (2) because, in some patients with mitral disease and atrial fibrillation, re(,urcita-tion may occur when the heart rate is slow and iii.,y not be present when the rate is faster.1 In an investigation by this method the fact that the patient does not have a general anesthetic and is aware of the surroundings tends to increase the heart rate. To avoid tachycardia, therefore, it is advisable to give a vagal-stimulating drug such as morphia and withhold any vagal-paralyzing drug such as atropine. If the patient is apprehensive, additional sedation with a barbiturate may be necessary. The most important factors are ade-quate explanation and reassurance of the patient.