Circulatory Reactions to Exercise During Convalescence from Infectious „.„......... Disease [ I V.V 1 "* iQIP, OJi. Ii |J0 i HUBERT MANN, M.D. NEW YORK Reprinted from the Archives of Internal Medicine May, 1918, Vol. XXI, pp. 682-694 CHICAGO American Medical Association Five Hundred and Thirty-Five North Dearborn Street 1918 Circulatory Reactions to Exercise During Convalescence from Infectious Disease HUBERT MANN, M.D. NEW YORK CIRCULATORY REACTIONS TO EXERCISE DURING CONVALESCENCE FROM INFECTIOUS DISEASE* HUBERT MANN, M.D. NEW YORK The return of patients to normal after pneumonia, typhoid and typhus fevers and the other infectious diseases is a phenomenon with which we all are familiar clinically, yet convalescence up to the present has not been investigated in any exact or quantitative way. The length of time during which convalescent patients are confined to bed and the resumption of normal life are graduated very differently by different practitioners. In view of this great variation in procedure any accu- rate, or quantitative method by which we could observe the stage of a patient's convalescence would be very desirable. At present the need for such an accurate method of following a patient's convalescence is rendered acute by the military situation. We have in training a great number of young men, many of whom are being attacked by infectious diseases. In the treatment of these patients efficiency demands that their absence from military duties shall be suf- ficient for complete convalescence but shall not be prolonged unduly beyond the proper time. If the proper time for convalescence is to be determined, as it is at present, solely by the opinion of the attending physician, it is highly probable that some soldiers will be returned to active service too soon and some too late. In the former case we may do the patient serious injury; in the latter case we shall have wasted time, attention and hospital accommodation at a time when all of these are in great demand. With these considerations in mind we have con- ducted a series of experiments on patients recovering from acute infections. We have confined our attention to the circulatory system because of the following considerations: Once the original infection has been overcome, the recovery of the patient means really the recovery of the patient's ability to do muscular work, and the recovery of the patient's ability to do muscular work is essentially a circulatory rather than a muscular phenomenon. The ordinary person in health overtaxes his circulation long before he exhausts his skeletal musculature. The con- valescent from infectious disease is limited in his exercise not by what his muscles can do but what his heart can do. This is obvious when we consider that the serious pathologic effects of overexertion, both in health and in disease, are not muscular but circulatory. We cannot * From the cardiographic laboratory of the Mount Sinai Hospital. 4 easily overwork a skeletal muscle, because it has a very efficient safety device—refusal to respond. We can overwork the circulatory system, because refusal to respond adequately on its part does not result in immediate cessation of work. Therefore, it seemed logical to determine the circulatory reactions following muscular work at different periods during convalescence to see if we could discover any change in these reactions which might afford a criterion of the return to normal of the circulation. The patients whose recovery we have followed have all been men between the ages of 21 and 45 years. There are ten cases in our series: seven pneumonias; one pleurisy; one typhoid fever; one typhus fever. Our procedure has been as follows: The pulse rate was taken sev- eral times until it reached a constant figure. The systolic blood pres- sure was read by auscultation (using a mercury sphygmomanometer) until it reached its normal level. Then the patient performed a definite amount of work. The pulse rate was counted for 15 seconds immedi- ately after the work and, at the end of 110 seconds, it was counted again for 20 seconds. From these two figures the rates immediately after exercise and at the end of 120 seconds were calculated. The sys- tolic blood pressure was taken by the method described by Barringer1 and also, in some cases, by the method of Cotton, Rapport and Lewis.2 Our exercises have consisted in sitting up in bed and in flexing and swinging dumb-bells of various weights. We have calculated the work done in foot-pounds. The calculation of work done is fairly accurate and the error is constant for the same patient, so that slight inaccuracies will not vitiate our conclusions. The method of Barringer1 consists in taking the systolic pressure before exercise and then talking three readings after exercise—the first between 25 and 30 seconds; the second between 55 and 60 seconds; the third between 85 and 90 seconds—the endeavor being to make the read- ings as close to 30, 60 and 90 seconds as possible. The method described by Cotton, Rapport and Lewis2 consists in taking the first reading as soon after exercise as possible and in taking numerous read- ings thereafter at very short intervals. These readings, when plotted, give us a curve which shows the variations in the systolic pressure after exercise. For reasons which we give later we have used Barringer's method in the majority of our experiments. Our technic has been standardized during the past four months by testing the circulatory reactions of a number of normal persons and of many patients suffering from cardiac insufficiency. 1. Barringer, T. B., Jr.: Studies of the Heart's Functional Capacity, The Archives Int. Med., 1917, 20, 829. 2. Cotton, T. F.; Rapport, D. L., and Lewis, T.: After Effects of Exercise on Pulse Rate and Svstolic Blood Pressure in Cases of "Irritable Heart," Heart, 1917, 6, 269. 5 Barringer believes that a "delayed rise" ("delayed summit," Cotton, Rapport and Lewis) indicates the overtaxing of the cardiac reserve power. A reading at sixty seconds after exercise which is 4 mm. or more higher than the reading at thirty seconds has been taken as indica- tive of a delayed summit. We have generally been able to produce a delayed summit much more pronounced than this minimum. The following typical normal series of tests will illustrate the method of testing and recording. The subject was a normal man, 26 years old, weighing 160 pounds. His systolic blood pressure at rest was................ 130 He swung two 10-pound dumb-bells 10 times (Calculated work = 2,400 foot-pounds) His systolic pressure after work was—at 30 seconds--- 150 at 60 seconds.... 140 at 90 seconds.... 130 In 5 minutes his systolic pressure at rest was constant at 120 He swung two 10-pound dumb-bells 25 times (Calculated work = 6,000 foot-pounds) His systolic pressure, after work was—at 30 seconds.... 152 at 60 seconds.... 152 at 90 seconds___ 144 In 5 minutes his systolic pressure at rest was constant at 125 He swung two 10-pound dumb-bells 30 times (Calculated work = 7,200 foot-pounds) His systolic pressure after work was—at 30 seconds.... 150 at 60 seconds.... 164 (delayed summit) at 90 seconds___ 156 In tabulated form the record reads as follows: 130 120 125 2 X 10 S. 10 (2,400) 2 X 10 S. 25 (6,000) 2 X 10 S. 30 (7,200) 30......... 150 30......... 152 30.......;. 150 (delayed summit) 60......... 140 60......... 152 60......... 164 90......... 130 90......... 144 90......... 156 Graphically the record would appear in Chart 1. We can express the fact that the subject showed a delayed summit after doing 7,200 foot-pounds of work and did not show a delayed summit after 6,000 foot-pounds of work as in Chart 2. We have omitted any mention of the time in which the work is done. Patients soon acquire a regular rhythm in working, the time of each swing being the same (2 to 3 seconds). Thus, the time factor becomes a constant and can be left out of consideration. The accompanying series of charts (Charts 3, 4, 5 and 6) shows the change in reactions of the blood pressure to muscular work during convalescence. It will be observed that all the convalescent patients show the same phenomenon—a progressive increase in the amount of work that can be done without causing a delayed summit of blood pressure. This increase in all cases was synchronous with subjective symptoms of 6 BLOOD PRESSURE IN M M.OF MERCURY seconds 10 20 30 40 50 60 TO "80 AFTER \W0RK w •w Chart 1.—This chart shows a typical series of blood pressure readings after increasing amounts of work. The subject was a normal man 26 years old. Note that after a small amount of work the pressure falls rapidly; after a greater amount of work the return to normal is not so rapid; after a still greater amount of work the blood pressure continues to increase for some time— "delayed summit." The blood pressure before exercise was about 125. POUNDS 8000 7500 7000 6000 5500 5000 4^00 4-000 350c 3000 2000 1500 1000 500 FOOT POUNDS —^H----> —I- Chart 2.—This chart indicates that with 6,000 foot-pounds of work or less there is no delayed summit; with 7,200 foot-pounds of work or more there is a delayed summit; between 6,000 and 7,200 foot-pounds the circulatory reaction to work changes. p$&os 8O00r 8000 7500 7000 65 OO GOOO 5500 5000 ,, ^ 4v! ■f 500 *f000 | P ; v 3500 3000 2500 2000 V>V>Y 1000 M Ki 500 ffiS 1 2 3 t 5 6 7 8 9 10 U 12 13 Chart 4 Charts 3 and 4.—These charts show the change in the circulatory reaction to exercise which takes place during convalescence. Chart 3 is from the patient I. M. in Table 1; Chart 4 is from the patient C. B. in Table 1. DAYS FOOT POUNDS 8000 It'17 DAYS 1 8 S 10 11 12 13 14 15 It IT 18 Chart 6 Charts 5 and 6.—These are like charts 3 and 4. They show the same pro- gressive change in circulatory reactions. Chart 5 is from the patient R. F. in Table 1; Chart 6 is from the patient M. O. in Table 1. 9 improvement and increased activity. Patients R. F. and C. B., who show a late development of this phenomenon, were subjectively weak and improved very slowly before the time at which the objective improvement in the circulatory reactions began. Synchronously with the objective improvement there was marked subjective and clinical improvement. In the cases I. M., C. B., R. F. and M. O., which were followed carefully with daily readings, it will be noted that this change in the circulatory reactions is most marked during a period of a very few days. In the case of I. M. the change in four days was from 1,500 to 6,500 foot-pounds. In the case of R. F., in two days the point at which the delayed summit appeared rose from 500 to 5,000 foot-pounds C. B. rose from 1,500 to about 5,000 foot-pounds in two days. M. C. changed from about 1,000 to above 3,000 in two days. FOOT POUNDS 4000 3500 3000 2500 2000 g mi Ni B it a M 1500 1000 500 TOOT POUNDS! days 1 Z^+Z^JSH 12 37 Chart 7.—This chart shows the circulatory reactions to exercise in a normal woman taken day after day. Note that the daily variation is comparatively slight. Compare with Charts 3, 4, 5 and 6. That this change is not a mere result of the exercises to which the patient is subjected in the process of trying out his circulatory reactions is shown by the control Chart 7. The control was a normal woman not used to exercise. Observe that there is no marked change produced by the amount of exercise necessary to try out her circulatory reactions. Table 1 summarizes our results in this series of patients. When the method of frequent readings is used we obtain a result something like that shown in Chart 8, which is taken from the case R. F. Both the slow readings and the rapid readings are given, and it will be observed that they both give exactly the same conclusions as regards the circulatory reactions. The readings taken at thirty, sixty and ninety seconds with the rapid method compare well with the same readings taken with the infrequent method. We have observed this 10 TABLE 1—Change in Reaction of the Systolic Pressure to Exercise During Convalescence * --- Patient Age Disease Recovery Circulatory Reactions to Exercise Days I. M. 22 Lobar pneu-monia Crisis —9 days 1 1,200 900 2 1.200 1,000 3 1,400 1,120 4 5 2,800 3, 7 1 ■^ -^1- 2 fOl ND '■ KIN r4 *>•«; v 10 r" i»e 1 » 0... ••c / —^ P*"! ••J u f— «-. •— -• -• •f -*