Although some patient and office files have been well maintained, many are not well ordered. While the fonds' series do indicate the boxes in which material from a particular series can be found, the contents of those boxes may be highly disorganized and include materials from several series.

Elements of Dr. Segall's patient files are spread across 10 of the fonds' series (Series A, B, C, D, E, F, H, L, R, & T) and are stored in several different formats including 4 x 6'' notes, 4 x 6'' normal heart sound forms, 6 x 12'' clinical history forms, and electrocardiograms. As Dr. Segall explains in "The evolution of the record system,'' located in Box 308, the organization of the patient records found in the fonds and their format were deliberately chosen at different periods in his career to facilitate convenient record keeping and management practices. His need to write notes during home visits throughout his career required him to have a conveniently sized writing pad. Thus, 4 x 6'' paper was selected. The notes recorded on this paper were stored in envelopes of the same size and arranged in alphabetical order. These envelopes (which contain(ed) many of the patient records for Series A D F, L, & T) often also contained cards with mounted sections of electrocardiograms (begun in 1939), 4 x 6'' "normal heart sounds'' standard pattern sheets (first used in 1949), folded 6 x 12'' clinical history forms (first used in 1949), heart sounds diagrams drawn by Dr. Segall on large folded pieces of paper, as well as correspondence between Dr. Segall and other doctors, medical institutions, health insurance companies, and occasionally the patient himself/herself.

Additional 4 x 6'' patient records, containing the same elements as other 4 x 6'' records, are found in two groups of segregated files (Series E and L). These two groups are the records of patients who died of mitral stenosis (Series E) and who were attached to Trans-Canada Airlines (TCA) and ferry command (Series L). Ferry command referred to Canadian pilots who flew North American made aircraft to England during the Second World War. As Dr. Segall explains in "The evolution of the record system,'' the TCA and ferry command patient records provided normal patterns of heart sounds from which he developed a model pattern. This normal model pattern was then used as the standard against which he could compare the heart sounds of other patients.

Dr. Segall's patient records were rearranged three times between when he began keeping patient records in 1926 and when he retired in 1984. The first rearrangement began in 1939 when any files started between 1926 and 1939, which were also consulted after 1939, were segregated from files which were not consulted after 1939. The files which were not consulted after 1939 came to make up Series A, while those consulted after 1939 became Series B. Furthermore, Dr. Segall's office also segregated the files created between 1926 and 1939 of patients who had died. These deceased patients' files are typically marked with a "D'' and are found in Sub-series F/A.

The second rearrangement of patient files occurred in 1969-1970 when Dr. Segall's office segregated all inactive files created or consulted between 1939 and 1969 from those which were still active. As Dr. Segall explains in "The evolution of the record system,'' this rearrangement was precipitated by a reduction in the amount of office space he was able to dedicate to patient files. Following 1969 his patient files were restricted to one filing cabinet. As a result of this rearrangement, inactive files remained in Series B while the active files were transferred to Series C. While Series C was housed in Dr. Segall's patient records filing cabinet, the records of Series B, like those of Series A, were moved off-site (possibly to Dr. Segall's house). In addition, all of the records of patients who had died between 1939 and 1969 were removed from Series B and came to form Sub-series F/B. These patient files are typically marked with the code number "B99''.

The third rearrangement of patient files occurred in 1973 when active files of Series C were transferred to Series D. This rearrangement may have been the result of Dr. Segall's need to maintain only active files in his one office filing cabinet. Series D remained in the office filing cabinet while Series C was transferred off-site. In addition, the records of patients who had died between 1970 and 1973 were also segregated from Series C, creating what has become Sub-series F/C. They are typically marked with the code number "B99''.

A large number of the envelopes of 4 x 6'' patient records are marked with a (a) number, (b) a two or three character alphanumeric code (either A1 to A45, B1 to B99, or C1 to C70), and often (c) one or more two to three digit numerical codes beginning with a number between 1 and 80 followed by a digit between 0 and 9 (1-0 to 80-9). The number (a) corresponds to an electrocardiogram, or the sections of an electrocardiogram not attached to elements of the patient's 4 x 6'' file. (These electrocardiograms are stored as rolls and form Series G. Each electrocardiogram is marked with a number, the name of a patient from whom the electrocardiogram was taken, and the date it was made.) The two or three character alphanumeric code (b) corresponds to a condition listed in the first five drawers of Series M, a Kardex index of particular patients with certain conditions. Attached to each condition in the index is a list of the electrocardiogram numbers, often, but not always, including the numbers for electrocardiograms of the patients whose files bear that particular three character alphanumeric code. The listed electrocardiograms were determined by Dr. Segall to represent manifestations of their corresponding Kardex index condition. The two to three digit numerical codes (c) refer to various cardiac symptoms experienced by the patient. Drawers 6 through 10 of the Kardex index (Series M) contain indexed sections for 80 different cardiac symptoms. Each of the 80 symptoms are further divided into 10 (numbered 0 to 9) different sub-sections (possibly for different variations of each symptom), each of which contains a list of the electrocardiogram numbers, often, but not always, including the numbers for electrocardiograms of the patients whose files bear that particular two to three digit numerical code. The listed electrocardiograms seem to have been determined by Dr. Segall to represent manifestations of the corresponding Kardex index symptoms.