normality of the size of the aorta has, to my knowledge, never been before expressed.

CONCLUSIONS

1. The borders of the ascending, transverse and descending aorta can be percussed accurately.

2. The topography of the aorta must be revised because the ascending vena cava has been included in the measurements of the transverse diameter of the aortic arch.

3. The right border of the vena cava extends 0.5 to 1 cm. beyond the right border of the sternum.

4. The right border of the ascending

aorta is adjacent to or slightly to the right of the mid-sternal line.

5. The transverse diameter of the arch of the aorta corresponds to a line drawn from or near the mid-sternal line and ending approximatively 0.5 cm. to the left of the left border of the sternum.

6. The size of the normal aorta is dependent upon the stature, position of diaphragm and the chest conformation of the individual.

7. The correlation of the normal size of the aorta and the ascending vena cava to the size of the sternum is generally constant and is the only practical determinator of the size of the normal aorta.

CHAPRON, ROBERT: Etude anatomo-radiologique des vaisseaux de la base du coeur. Masson & Cie Edit., Paris, 1922.

DELHERM ET CHAPRON: Jour. of Radiologie et d'Electricité, July, 1923. DIELTLEN: Die Röentgen untersuchung von

Herz, Gefassen und Perikard, Lehrbuch von Roentgenkunde, Leipzig, 1915.

FOSSIER, A. E.: Size of the normal heart. Jour. Amer. Med. Assoc., June 21, 1924, lxxxii, 2016-2021.

GRANGER, AMEDEE: Radiology, July, 1924. GROEDEL: The examination of the heart

by the roentgen rays. Archives of the Roentgen Ray and Allied Phenomena, April, 1908. Coeur et gros vaisseaux injectés in situ sur des cadavres. (9th Congress of the German Society of Radiology.) Berlin,

March 29, 1913.

JAUGEAS: Précis de radiodiagnostic. Sec

ond edition, 1918.

LERCH, OTTO: Deutsch. Arch. f. klin. Med., December, 1912. Internat. Clin., Ser

ies 25, iv, 1915. Arch. Diagnosis, ix, 1, January, 1916. LEWALD, LEON T.: The relation of the heart, pericardium, and the heart valves to the anterior chest wall. Arch. Surg., January, 1923. LUTEMBACHER, R.: Examin du coeur en clinic. Masson et Cie, 1921. MARTIN, C. L.: Roentgen-ray study of the great vessels, Jour. Amer. Med. Assoc., March 31, 1920, Ixxiv.

MORRIS: Human anatomy.
PIERSOL: Human anatomy.

POIRIER: Traité d'anatomie humaine.
SOBOTTA: Atlas and Text Book of Human
Anatomy.
THOYER-ROZAT: Contribution a l'étude
anatomo-radiologique de l'aorta, de
l'artère pulmonaire et de la veine cave
supérièure. Thèse Paris, 1919.
VAQUEZ ET BORDET: The heart and the
aorta, Yale University Press, 1920.
Radiologie des vaisseaux de la base du
coeur, 1920.

WEIL, A.: Eléments de radiologie. Second edition, 1920.

TH

HE report of this interesting case appears warranted, not only because of the unusual disturbance in the cardiac mechanism, but also because this appears to be the only instance in which this sequence of events has ever occurred.

The patient, a man, aged fortynine years, came to the Mayo Clinic October 18, 1924, complaining of attacks of rapid heart action occurring suddenly and terminating suddenly, which had been present since February, 1923. Up to that time he had been in apparently good health, with no complaints referable to the cardiovascular system. He had had no significant previous illnesses, and emphatically denied venereal infection. He used coffee and tobacco moderately but did not use alcohol or drugs. A few months before his visit to the Clinic, the attacks had begun to be very much more frequent, occurring as often as seven or eight times a day, and lasting from a few minutes to several hours. Treatment had been carried out during the entire period without cessation of the attacks of paroxysmal tachycardia. There was an associated feeling of pressure in the upper abdomen, a sense of constriction in the throat, and dizziness, and occasionally during the severe

ANNALS OF CLINICAL MEDICINE, VOL. III, No. 8

attacks, momentary loss of consciousness.

The patient's color was good, and there was no evidence of cyanosis. All the teeth had been extracted. The tonsils were small and apparently normal. The thyroid gland was not enlarged. Examination of the heart between the attacks showed that the area of dulness extended 4 cm. to the right, and 10.5 cm. to the left of the midsternal line. The rhythm was occasionally interrupted by premature contractions; there were no murmurs. The general examination, otherwise, except for a moderate degree of peripheral arteriosclerosis, was unimportant. The systolic blood pressure was 135, and the diastolic, 95. The urinalyses were negative. The hemoglobin was 74 per cent; the erythrocytes, numbered 4,740,000, and the leukocytes, 7000. The blood Wassermann reaction by the Kolmer method was negative. The eye-grounds were normal on examination. X-ray studies of the chest were negative.

COURSE

The attacks lasted for four days after hospitalization, but did not recur during the subsequent period of observation, which lasted twenty-two days.