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An interim visual display system for continuous monitoring of the ECG in coronary care units
Annotations A new method blood pressure
for measurement in clinical shock
The measurement of blood pressure by the usually employed indirect methods in various circulatory shock states may sometimes be quite difficult and even inaccurate.’ This is due to the fact that the brachial artery pulsations and Korotkoff’s sounds are greatly diminished in these conditions. Often there is a discrepancy in the blood pressure readings obtained by two different observers and sometimes no sounds may be heard at all in presence of significant blood pressure levels demonstrable by direct arterial cannulation. Comparison between auscultatory pressures in the arm and direct arterial readings taken with a needle inserted into the femoral artery frequently reveals that the direct femoral pressure is considerably higher than the pressure recorded in the arm by the auscultatory method.2 Under these circumstances indirect auscultatory method may be grossly inaccurate so a direct method of blood pressure recording is required to follow these critically ill patients. By employing a slightly modified technique for the indirect measurement of blood pressure by auscultatory method, we have often been able to get blood pressure readings in situations where no such measurements could be obtained by the use of the usual standard method. This is accomplished by inserting the diaphragm piece of the stethoscope under the lower edge of the blood pressure cuff over the brachial artery and then leaving it there during the subsequent rapid inflation and gradual deflation of the cuff. By using the stethoscope in this position, the Korotkoff’s sounds became clearer and more audible compared to the absent or muffled sounds that are heard in the same patients when the stethoscope is applied below the cuff in the antecubital space. In regard to the accuracy of these measurements, we recently had the opportunity to compare blood pressure readings obtained by this method with simultaneous direct measurements obtained through a
An interim monitoring
needle into the brachial artery, in two patients in shock in whom the Korotkoff’s sounds were not heard at all by the use of standard auscultatory method. The direct systolic arterial pressure in both of these patients was 85 to 90 mm. Hg. The simultaneous blood pressure readings in opposite arm with the modified auscultatory method were within 5 mm. Hg of the direct arterial pressure measurements taken on multiple occasions. Furthermore, the blood pressure recorded in this way was always slightly less than the direct arterial pressures. We are convinced that by this technique fairly reliable blood pressure recordings can be obtained without resort to arterial puncture in situations where the conventional method of taking blood pressure is not of much help. This technique, although no substitute for a direct arterial pressure measurement, should be employed in situations where the blood pressure is unobtainable by the standard methods and where an arterial puncture is not desirable. Mohammad Zahir, M.D.* Lawrence Gould, M.D.** Medical Service, Bronx Veterans Administration Hospital 130 West Kingsbridge Rd. Bronx, N. Y. 10468 *Fellow **Chief,
in Cardiology. Cardiac Cardiac Section.
Section.
REFERENCES 1. American Heart Association: Recommendations for human blood pressure determination by sphygmomanometers, 1967. 2. Cohn, J. N., and Daddario, R. C.: Mechanism of disappearance of Korotkoff’s sounds in clinical shock, Circulation 32 (Suppl. 11):69, 1965.
visual dispiay system for continuous of the ECG in coronary care units
Although it is now common practice to monitor the electrocardiogram (ECG) of patients with acute myocardial infarction on a continuous basis in order to detect transient rhythm disturbances, there has been no significant change in the physical
572
of
format of the presentation of the ECG to assist monitoring personnel to perform their function better. The usual variety of rate meters, alarm units, and oscilloscopes now in widespread use was not engineered as a system to provide ease and
Annotations
accuracy under the conditions of continuous monitoring. In the future, undoubtedly, monitoring will be accomplished automatically by computers: in the interim, it will continue to be done by nursing or other specially trained personnel. For the present we are causing the ECG to be displayed on a storage oscilloscope where the image is retained for several seconds, thus lessening the chance of overlooking
573
solitary events and permitting more time for study of the ECG wave form. In practice, a 5 inch storage display oscilloscope is used (Model 601 storage display unit, Tektronix, Inc., Portland, Ore.). Each sweep is incremented with a stair-step generator. After an arbitrary number of steps the traces are automatically erased requiring 200 msec. In the event of an alarm or
Fig. 1. Left, top to bottom: The oscilloscope sweep is incremented in from left-to-right and from top to bottom in continuous fashion Right, t@: In the hold and nonstore mode, the previous ECG conventional form. Middle: A variety of arrhythmias is displayed. storage of about 3.5 seconds of information before erasure.
a series of steps so that the ECG is displayed before erasure and recycling. is held and the current ECG is displayed in Bottom: Use of a slower sweep speed permits
574
.ir,rrr~. Heart J. April, 1970
Annota.tions
manual hold, an additional sweep is used at the bottom of the screen; erase is inhibited, and a Lissajous pattern is generated. This causes the beam to move too fast to be stored and permits the ECG to be displayed in a repetitive fashion to resemble the conventional trace. The amount of ECG information to be displayed is a function of the sweep speed as well as the number of stair-steps generated. Examples of rhvthm disturbances are shown in Fie. 1. Thev were simulated (“Polyrhythm” simulator, khysio-Control Corp.) to show the ease by which rhythm disturbances can be detected and identified by using the system. The total cost of the entire display system is little more than that of the ordinary system. It is considerably less expensive than monitor systems using video-scan techniques now becoming available. The
A thought
about
donor
There must come a time when a donor heart in a recipient survives long enough so that every atom and every molecule of the heart are replaced by new ones through kinetic metabolic processes of the recipient and of the donor heart. But, are the exchanges in the donor heart programmed by the genes of the donor cells without influence from the recipient? Or, are the programmings which are governed by the recipient’s genes so different from those of the donor heart that once in the recipient and with the passage of sufficient time the donor heart is an entirely different one, all atoms and all molecules being new and organized differently, more like that of the recipient? If different, ho.Kr different and how “foreipn” with time to that of the recipient? It may be possible for the kinetics of exchange among atoms and molecules to produce eventually a new and “nonforeign” organ for the
equipment can be mounted in standard relay-rack enclosures and may be adapted to any physical configuration desired. Since the storage oscilloscope has its own built in “memory,” a memory unit is no longer essential. Permanent records can be obtained easily and economically by using a camera adapted to the storage oscilloscope by the manufacturer (Model C-3OP, Tektronix, Inc.). It was used to obtain the photographs in Fig. 1. Loyal L. Conrad, M.D. Professor of Medicine University of Oklahoma Medical Center Veterans Administration Hospital Robert L. Trendley Coronary Care Unit Project Engineer Oklahoma Regional Medical Program Oklahoma City, Okla.
hearts
recipient with the donor heart as the “base.” Perhaps with a little help, the new molecules and their spatial interrelationships and interactions can be made to resemble the recipient sufficiently to be accepted forever. One can only recall the response of George Bernard Shaw to a critic who accused him of writing a bad play 20 years earlier. Shaw replied that the man who wrote that play no longer existed. It was a different George Bernard Shaw who had written that play, for his physiologist friends had told him that all atoms and molecules of man are completely turned over every 14 years. George Burch, M.D. T. D. Giles, M.D. H. L. Colcolough, M.D. Tulane University School of Medicine New Orleans, La.
Streptokinase therapy in acute major pulmonary embolism *
The feasibility by enzymatic *This
of producing dissolution of thrombi means has been demonstrated in ex-
study was supported Foundation of Australia
by a grant
from the National
Heart
perimental thrombi’J and pulmonary emboli3J in animals, in experimental thrombi in man,6 and in patients with acute venous and arterial thromboembolic disease.6J7 Of the enzymes investigated, only the two plasminogen activators, streptokinase
for measurement in clinical shock
The measurement of blood pressure by the usually employed indirect methods in various circulatory shock states may sometimes be quite difficult and even inaccurate.’ This is due to the fact that the brachial artery pulsations and Korotkoff’s sounds are greatly diminished in these conditions. Often there is a discrepancy in the blood pressure readings obtained by two different observers and sometimes no sounds may be heard at all in presence of significant blood pressure levels demonstrable by direct arterial cannulation. Comparison between auscultatory pressures in the arm and direct arterial readings taken with a needle inserted into the femoral artery frequently reveals that the direct femoral pressure is considerably higher than the pressure recorded in the arm by the auscultatory method.2 Under these circumstances indirect auscultatory method may be grossly inaccurate so a direct method of blood pressure recording is required to follow these critically ill patients. By employing a slightly modified technique for the indirect measurement of blood pressure by auscultatory method, we have often been able to get blood pressure readings in situations where no such measurements could be obtained by the use of the usual standard method. This is accomplished by inserting the diaphragm piece of the stethoscope under the lower edge of the blood pressure cuff over the brachial artery and then leaving it there during the subsequent rapid inflation and gradual deflation of the cuff. By using the stethoscope in this position, the Korotkoff’s sounds became clearer and more audible compared to the absent or muffled sounds that are heard in the same patients when the stethoscope is applied below the cuff in the antecubital space. In regard to the accuracy of these measurements, we recently had the opportunity to compare blood pressure readings obtained by this method with simultaneous direct measurements obtained through a
An interim monitoring
needle into the brachial artery, in two patients in shock in whom the Korotkoff’s sounds were not heard at all by the use of standard auscultatory method. The direct systolic arterial pressure in both of these patients was 85 to 90 mm. Hg. The simultaneous blood pressure readings in opposite arm with the modified auscultatory method were within 5 mm. Hg of the direct arterial pressure measurements taken on multiple occasions. Furthermore, the blood pressure recorded in this way was always slightly less than the direct arterial pressures. We are convinced that by this technique fairly reliable blood pressure recordings can be obtained without resort to arterial puncture in situations where the conventional method of taking blood pressure is not of much help. This technique, although no substitute for a direct arterial pressure measurement, should be employed in situations where the blood pressure is unobtainable by the standard methods and where an arterial puncture is not desirable. Mohammad Zahir, M.D.* Lawrence Gould, M.D.** Medical Service, Bronx Veterans Administration Hospital 130 West Kingsbridge Rd. Bronx, N. Y. 10468 *Fellow **Chief,
in Cardiology. Cardiac Cardiac Section.
Section.
REFERENCES 1. American Heart Association: Recommendations for human blood pressure determination by sphygmomanometers, 1967. 2. Cohn, J. N., and Daddario, R. C.: Mechanism of disappearance of Korotkoff’s sounds in clinical shock, Circulation 32 (Suppl. 11):69, 1965.
visual dispiay system for continuous of the ECG in coronary care units
Although it is now common practice to monitor the electrocardiogram (ECG) of patients with acute myocardial infarction on a continuous basis in order to detect transient rhythm disturbances, there has been no significant change in the physical
572
of
format of the presentation of the ECG to assist monitoring personnel to perform their function better. The usual variety of rate meters, alarm units, and oscilloscopes now in widespread use was not engineered as a system to provide ease and
Annotations
accuracy under the conditions of continuous monitoring. In the future, undoubtedly, monitoring will be accomplished automatically by computers: in the interim, it will continue to be done by nursing or other specially trained personnel. For the present we are causing the ECG to be displayed on a storage oscilloscope where the image is retained for several seconds, thus lessening the chance of overlooking
573
solitary events and permitting more time for study of the ECG wave form. In practice, a 5 inch storage display oscilloscope is used (Model 601 storage display unit, Tektronix, Inc., Portland, Ore.). Each sweep is incremented with a stair-step generator. After an arbitrary number of steps the traces are automatically erased requiring 200 msec. In the event of an alarm or
Fig. 1. Left, top to bottom: The oscilloscope sweep is incremented in from left-to-right and from top to bottom in continuous fashion Right, t@: In the hold and nonstore mode, the previous ECG conventional form. Middle: A variety of arrhythmias is displayed. storage of about 3.5 seconds of information before erasure.
a series of steps so that the ECG is displayed before erasure and recycling. is held and the current ECG is displayed in Bottom: Use of a slower sweep speed permits
574
.ir,rrr~. Heart J. April, 1970
Annota.tions
manual hold, an additional sweep is used at the bottom of the screen; erase is inhibited, and a Lissajous pattern is generated. This causes the beam to move too fast to be stored and permits the ECG to be displayed in a repetitive fashion to resemble the conventional trace. The amount of ECG information to be displayed is a function of the sweep speed as well as the number of stair-steps generated. Examples of rhvthm disturbances are shown in Fie. 1. Thev were simulated (“Polyrhythm” simulator, khysio-Control Corp.) to show the ease by which rhythm disturbances can be detected and identified by using the system. The total cost of the entire display system is little more than that of the ordinary system. It is considerably less expensive than monitor systems using video-scan techniques now becoming available. The
A thought
about
donor
There must come a time when a donor heart in a recipient survives long enough so that every atom and every molecule of the heart are replaced by new ones through kinetic metabolic processes of the recipient and of the donor heart. But, are the exchanges in the donor heart programmed by the genes of the donor cells without influence from the recipient? Or, are the programmings which are governed by the recipient’s genes so different from those of the donor heart that once in the recipient and with the passage of sufficient time the donor heart is an entirely different one, all atoms and all molecules being new and organized differently, more like that of the recipient? If different, ho.Kr different and how “foreipn” with time to that of the recipient? It may be possible for the kinetics of exchange among atoms and molecules to produce eventually a new and “nonforeign” organ for the
equipment can be mounted in standard relay-rack enclosures and may be adapted to any physical configuration desired. Since the storage oscilloscope has its own built in “memory,” a memory unit is no longer essential. Permanent records can be obtained easily and economically by using a camera adapted to the storage oscilloscope by the manufacturer (Model C-3OP, Tektronix, Inc.). It was used to obtain the photographs in Fig. 1. Loyal L. Conrad, M.D. Professor of Medicine University of Oklahoma Medical Center Veterans Administration Hospital Robert L. Trendley Coronary Care Unit Project Engineer Oklahoma Regional Medical Program Oklahoma City, Okla.
hearts
recipient with the donor heart as the “base.” Perhaps with a little help, the new molecules and their spatial interrelationships and interactions can be made to resemble the recipient sufficiently to be accepted forever. One can only recall the response of George Bernard Shaw to a critic who accused him of writing a bad play 20 years earlier. Shaw replied that the man who wrote that play no longer existed. It was a different George Bernard Shaw who had written that play, for his physiologist friends had told him that all atoms and molecules of man are completely turned over every 14 years. George Burch, M.D. T. D. Giles, M.D. H. L. Colcolough, M.D. Tulane University School of Medicine New Orleans, La.
Streptokinase therapy in acute major pulmonary embolism *
The feasibility by enzymatic *This
of producing dissolution of thrombi means has been demonstrated in ex-
study was supported Foundation of Australia
by a grant
from the National
Heart
perimental thrombi’J and pulmonary emboli3J in animals, in experimental thrombi in man,6 and in patients with acute venous and arterial thromboembolic disease.6J7 Of the enzymes investigated, only the two plasminogen activators, streptokinase