September 14, 1962
Dear Dr. Kantrowitz:
We have recently encountered a case of stimulation of the left diaphragm synchronous with heart rate following insertion of an internal pacemaker and myocardial electrodes in a patient with complete heart block and recurring Adam-Stokes syndrome. This proved to be a troublesome complication and required phrenic nerve crush on two occasions nine months apart.
As far as we know, this is an unusual complication of internal pacemakers. Its cause is unknown to us. Have you had any experience with this complication, or do you know of a physician or surgeon who has? We would like to collect data on a few instances to help elucidate the pathogenesis of this interesting problem.
If you yourself have experienced such a complication, would you be willing to forward the following data for use in such a study?
1. Age and sex of patient
2. Diagnosis
3. Duration of symptoms
4. Type of pacemaker inserted
5. Relationship of the electrodes to the phrenic nerve and the inter electrode distance
6. Was insulating material interposed between electrodes and the pericardium?
7. Interval between surgery and onsent of symptoms
8. How troublesome was the complication?
9. Management
If you have not had such a complication, this also would be important to know.
Thank you very much.
Sincerely,
Timothy Takaro, M.D.
Chief, Surgical Service