A New Method of External Cardiac Massage to Improve Diastolic Augmentation and PrGlong Survival Time Takahira Ohomoto, M.D., Isamu Miura, M.D., and Souji Konno, M.D. mechanical method adapted from manual closed-chest massage and the machine used t o compress the abdomen. A small device was constructed that improves the hemodynamics of coronary and carotid flow. The technique, which has been termed the countermassage method, consists of abdominal compression followed by chest compression of the standard type with the complete maneuver being carried out 70 to 90 times per minute. The abdomen is compressed between 78 and 82% of each cycle; the chest is compressed a quarter-cycle after abdominal compression begins and lasts 27 to 30% of each cycle. The sequence of compression is controlled automatically. Cardiac output during use of the countermassage device can be augmented to 3 times the levels obtainable through conventional mechanical or manual massage. Coronary and carotid flows can be improved 2 and 1.4 times, respectively, compared with flows obtained by conThe closed-chest cardiac massage method advo- ventional methods; these are equivalent to norcated by Kouwenhoven [51 is practical because it mal flows (Fig 1). may be carried out in any place at any time by The need for clinical treatment of circulatory virtually anyone. It is widely applied during insufficiency or arrest due to serious arrhythmia emergency cardiac resuscitation. A device based and ventricular fibrillation or to atrioventricular on the manual massage principle is currently block accompanying acute myocardial infarction being popularized, but survival with it has been has increased greatly in the past twenty years. unsatisfactory on the whole, and it seems to be Successful administration of treatment such as least effective in ischemic heart disease [6,8,12]. defibrillation or pacing within the 15 minutes of Analysis of the unsatisfactory results with resuscitation time permitted by the original conventional cardiac massage techniques led us closed-chest cardiac massage has been difficult. to develop a mechanical adaptation incorporat- The countermassage method has added 15 to 20 ing the principles of both the conventional minutes to this critical period.
ABSTRACT Experiments were performed on 50 dogs to determine the reason for unsatisfactory survival rates following closed-chest cardiac massage and to help develop new means for increasing survival following acute myocardial infarction and other causes of cardiac arrest. A new technique, named the countermassage method, was subsequently developed. Coronary and carotid flows after use of countermassage following cardiac arrest were increased 1.4 and 2 times, respectively, in contrast to flows obtained during manual closed-chest cardiac massage. These increases brought flows up to normal levels. We also tried to determine whether survival could be extended by this method to facilitate clinical treatment such as defibrillation or placing a temporary pacemaker catheter under fluoroscopic control, which are hard to accomplish during the brief time permitted by conventional closed-chest cardiac massage.
From The Heart Institute of Japan, Tokyo Women’s Medical College, Tokyo, Japan. We gratefully acknowledge the assistance of Professor Kiichi Tsuchiya, Waseda Institute of Technology, in manufacturing the cardiopulmonary resuscitator discussed in our study. Accepted for publication Jan 7, 1975. Address reprint requests to Dr. Ohomoto, The Heart Institute of Japan, Tokyo Women’s Medical College, 10 Kawadacho, Shinjuku-ku, Tokyo, Japan.
284
Materials and Methods Fifty adult mongrel dogs weighing from 10 to 30 kg were anesthetized intravenously with pentobarbital (15 mg per kilogram of body weight). An endotracheal tube was inserted, and the dogs were ventilated with a positive- and negativepressure respirator. Ascending aortic pressure,
285
Ohomoto, Miura, and Konno: Method of External Cardiac Massage
r
Hemodynamic comparisons were made, and long-term hemodynamic function with the manual, conventional mechanical, and countermassage methods was measured (Fig 2). Prior to the experimental study, control values for cardiac function were recorded. Ventricular fibrillation was produced with 15 volts of direct current applied for 1or 2 seconds using an electrode catheter inserted into the right ventricle through the femoral vein. In the control study, 5 dogs had massage for 30 minutes under optimal conditions that had been determined in advance for both the conventional mechanical and the countermassage machines (Table 1).Manual massage was administered by 3 persons alternating every 5 minutes to avoid 0 .. .. .. .. individual fatigue. . . . . .. .. .. The compression frequency of both the coni i -: Countermassage ; ; ; . . ventional mechanical and countermassage 0 CONTROL CONVENTIONAL COUNTERmachines was 70 to 90 cycles per minute. The MASSAGE MASSAGE compression time ratio for the conventional Fig I. Coronary and carotid flows b y the machine (time of compressionitime of comprescountermassage method are 100% and9Oo/0 those of sion and decompression, or SmlT) was 0.27 to a natural cardiac beat, respectively, and are 2.0 and 0.30. The compression time ratio of the coun1.4 timesgreater than f l o w rates attainable w i t h manual or conventional mechanical massage. termassage machine (SclT) was 0.78 to 0.82. The compressive phase-shift angle of the counterright atrial pressure, inferior vena caval pres- massage machine to the conventional machine sure, carotid flow, left circumflex coronary artery was -90 degrees. This indicates that for the most flow, and cardiac contractions were determined. effective coronary and carotid flows, chest comA flow probe was inserted to measure coronary pression with the conventional machine should flow, and in order to correct for the error due to be started a quarter-cycle following compression change in position of the probe during massage, of the abdomen (Fig 3). The compressive strokes it was fixed to pericardium which lay vertical to of both the conventional and the countermassage machine averaged about 40 mm. the axis of the coronary arteries. *O0
-j
:
:
:
:
:
:
:
:
:
n(:
Fig2. System of external cardiac nzassage f o r a fibrillating canine heart.
I
1
Conventional Massage Machine Counter Massage Machine
,
1
Aortic Pressure .......... Venous Pressure--.
..
//I
Coronary flow.^^--Carotid Flow.............. ECG ..........
essure Reaulator
286 The Annals of Thoracic Surgery Vol 21 No 4 April 1976
Table 1. Optimal Driving Conditions for Cardiac Massage Machines Control Variables
Optimal Conditions
Driving frequency (cpm) SmiT
70-90 0.274.30 0.78-0.82 -90 3040 40
SciT Driving phase-shift angle (degrees) Stroke of conventional machine (mm) Stroke of countermassage machine (mm)
Counter position
Abdomen ~~
SmlT = compression time ratio for conventional massage machine; SciT = compression time ratio for countermassage machine (see text for explanation).
Cardiac stimulants were used to compare the long-term hemodynamic effects of each method. A solution combining 100 ml of lactated Ringer's, 100 ml of 7 % sodium bicarbonate injection, and 1 mg of epinephrine was injected directly into the right atrium, 0.2 mlikgimin during the manual and conventional mechanical massages and 0.04 ml/kg/min during countermassage. After a 30-minute massage, 100 to 200 wattseconds of D-c defibrillation was applied, and supplementary massage was carried out if additional shocks were necessary.
Results The hemodynamics of each 30-minute massage are shown in Figure 4. With manual massage, lack of hemodynamic stability was noted which Fig3. For the most effective hemodynamics, compression by the conventional machine should be started one quarter-cycle following compression of the abdomen.
\hest compression
ABDOMINAL COMPRESSOR
V
one cycle
t
(bdominal compression (a quarter-cycle before chest compression) 1
-90"
1
1
1
1
0" t90" +180°t2700
A
(Phaseshift
was largely attributable to operator fatigue. Coronary and carotid flows dropped substantially within 10 to 15 minutes. The cardiac output was limited to a third to a quarter of normal due to regurgitation of cardiac blood to the venous system through valves deformed during compression [lo]; the peak aortic pressures were high, but mean aortic pressures were low. For the first 15 minutes after massage was begun, mean aortic and venous pressure differences were minimal. Afterward venous pressure began to show an inverse relationship to mean aortic pressure and eventually rose to 2 times the control value, indicating that manual massage was ineffective after 15 minutes. Figure 4 also shows the effect of the conventional mechanical massage machine: For the first 15 minutes hemodynamics were stable, with a slight difference between aortic and venous pressures. However, after 15 minutes coronary and carotid flows decreased just as with manual massage, and the effects were ultimately the same. In the countermassage method, hemodynamic function was satisfactory throughout the 30-minute period of application. Coronary and carotid flows approximated the control value of a normal cardiac beat. Although venous pressure was relatively high (40 mm Hg), the aortic-venous pressure difference was kept above 15 mm Hg, which means that circulation was achieved under stable conditions. The long-term hemodynamics of closed-chest massage combined with cardiac stimulants are shown in Figure 5. Note that hemodynamic function after defibrillation was unstable during manual massage (Fig 5a). It is also worth mentioning that while blood pressure rose initially
287 Ohomoto, Miura, and Konno: Method of External Cardiac Massage
- 1I t
P120
-E loot
9\
!i . .-C
a
Manual massage
60
0
5
0
01 D u r a t i o n of massage
(rnin)
Conventionol Mossoge
0
- 1601
:
E 100 l
-
10
30
20
D u r a t i o n of m a s s a g e
f140h
Counter
(rnin)
massage
-E 120
U
"
-
c
01
O
K
0
I
10
I
I
20
D u r a t i o n of massage
I
I
30 ..
(rnin)
Fig4. Hemodynamic effects of each type o f massage in the same animal. W i t h the countermassage method, mean aortic and carotid flo7os uiere improvedto about double the levels with manual massage.
after defibrillation due to the effects of the stimulating agents, this did not last. After 80 minutes, on the average, all the dogs died from congestion in various internal organs (especially the liver and hearf muscle) as shown by postmortem examination. Hemorrhage in lung tissue was also noted. Hemodynamic data up to the twenty-seventh day from animals resuscitated by the conventional mechanical method are
shown in Figure 5b. Three of 5 dogs had died from pulmonary hemorrhage and 1 other dog was noted at postmortem examination to have slight congestion in both liver and lung. All 5 dogs undergoing countermassage survived. The hemodynamic data on these dogs after 9 days' survival are shown in Figure 5c. In these animals, hemodynamic data during the 30 minutes of massage and after defibrillation were approximately equal to control values. Survival studies on the dogs treated with drugs are detailed in Table 2. The results of another group of studies on survival after defibrillation are shown inTable 3. So that the effects of massage alone could be ascertained, no pharmacological agent was used in this group during any massage. In the group receiving manual massage we succeeded in defibrillating 2 dogs after 30 minutes of massage, but the other 3 could not be successfully defibrillated. With conventional mechanical massage, 2 of 3 dogs developed bradycardia and a prolonged QRS time; both died after several minutes of attempted supplementary massage after defibrillation. From these results we concluded that longterm massage using the manual or conventional mechanical methods is not effective and that survival can only be accomplished within the first 15 minutes of massage. Defibrillation should be carried out as quickly as possible. In our experience, survival exceeding 15 minutes among humans with a fibrillating heart, especially when accompanied by acute myocardial infarction, has been extremely rare. With the countermassage technique, despite 40 minutes of massage, 5 of 6 animals were successfully defibrillated and for the most part stabilized after defibrillation. In another set of experiments, each kind of massage was carried out for 5 minutes in the same animal. In spite of the fact that manual and conventional mechanical massage were carried out under the relatively favorable conditions present just after fibrillation, the hemodynamic results obtained were poor. By contrast, during the countermassage period both mean aortic and carotid flows were improved to about double the levels with manual massage, even though countermassage was not started until after this group
288 The Annals of Thoracic Surgery Vol 21 No 4
(a)
0
10
Manual
20
30
Time
April 1976
massage
40
50
(rnin)
60 70
80
-6 2001 (b) Conventional Massage E -E i w Lr - - c o n v ~ E\ L
I
-i
I \
Time
(min)
Time
(min)
2501
Fig 5. Hemodynamics of long-term survival studies using cardiac stimulants: ( a ) Manual massage was ineffective, and all animals died with severe congestion of various internal organs. ( b ) Animals receiving conventional mechanical massage showed slight improvement, with 3 of 5 dying from pulmonary hemorrhage. ( c ) With the countermassage technique all 5 animals survived. On the ninth day 1 was killed for histological examination.
had already undergone two other forms of massage and had experienced 10 minutes of poor circulation.
Comment The closed-chest cardiac massage recommended by Kouwenhoven [51 in 1960 has been the most
practical method of preparation for defibrillation up to this point, primarily because it is the only one designed especially for use outside the hospital. However, Stephenson's study [91 of 5,076 patients from 50 facilities revealed that only 819 survived, a rate of 16%. The primary factor in successful resuscitation is the amount of time that has elapsed before resuscitation begins. When more than 4 minutes have passed since the moment of circulatory arrest, Stephenson showed that the survival rate with either closed or open cardiac massage is only 4%. It is therefore absolutely necessary to start cardiac resuscitation within 3 minutes; after this time irreversible changes begin to occur in the brain. The cardiac muscle itself will not undergo irreversible changes for about 10 to 15 minutes, which means that if cerebral circulation is adequately maintained, cardiac massage can prolong the survival time from 3 to 15 minutes before defibrillation is accomplished. The next most important factor in resuscitation is the environment where it is carried out. According to Stephenson [9] the survival rate is relatively high (50%) in the closely controlled atmosphere of places such as the operating room, intensive care unit, and coronary care unit; but it is as low as 21% in other parts of the hospital and drops even further outside the facility. If a patient begins to fibrillate outside the hospital, it is most difficult to transport and defibrillate him within 15 minutes, and an alternative way to prolong survival time is needed. Survival depends largely upon the kind and severity of the causative disease. The survival rate in ischemic heart disease with acute myocardial infarction is as low as 14% even when the patient is treated in an optimal environment like the coronary care unit, according to William and William [12] and Miura [6]. Eliot and Vyden [21 showed that cardiac arrest can be caused by the downward displacement of a cardiac pacemaker (electrical failure), decrease of cardiac contractility (power failure), or hypoxia caused by hypoventilation. It is evident that cardiac arrest is induced by coronary insufficiency, and the existing hypoxia of cardiac muscle makes it difficult to survive this condition. In ischemic heart disease, then, the time limit
289 Ohomoto, Miura, and Konno: Method of External Cardiac Massage
Table 2 . Survival Studies Using Drugsa in 15 Dogs
Method Manual
massage
Conventional massage
Counter-
massage
Drug Inject. Speed
Sex & Weight (kg)
Massage Time (min)
0.2
M, M, F, M, M, M, M, M, M, M, M, M, M, M, M,
30
(mlikgim in)
0.2
0.04
19 15 12
17 26
23
12
30
18 20 20
15
20 20 17 20
30
Result Died (3 hr) Died (1hr) Died (defib) Died (3 hr) Died (1 hr) Died (1hr) Died ( I h hr) Killed (12 days) Killed (27 days) Died (1 day) Killed (9 days) Killed (30 days) Killed (10 days) Killed (5 days) Alive (more than 1 yr)
“Solution consisting of 100 ml of lactated Ringer’s, 100 ml of 7% sodium bicarbonate injection, and 1 mg of epinephrine.
within which resuscitation can be accomplished is less than 15 minutes, and greater emphasis must be placed on maintaining cerebral and coronary circulation. Closed-chest cardiac massage is not adequate to keep circulation stable because it cannot control the low cardiac output induced by regurgitation of cardiac blood into the venous system. Pulse pressure is minimal after 15 minutes and circulatory volume decreases rapidly, thus leading to cardiac shock. In addition, this method cannot selectively maintain coronary circulation.
In management of ventricular fibrillation, then, the first problem is to mechanize the massage procedure in order to achieve hemodynamic stability. The second step is to increase coronary circulation selectively through diastolic augmentation. Because it incorporates principles from both the conventional mechanical machine, adapted from manual closed-chest massage, and the massage machine that compresses the abdomen, the countermassage method fulfills both needs. In dogs, hemodynamic stability can be main-
Table 3 . Results of Resuscitation Using Massage Alone in 14 Dogs Method Manual massage
Conventional massage Countermassage
Weight (kg) 18
30 23 33 8
Duration of Massage (min) 15
30
30
17 18 12
15 30 30 30 30
25 17
30
15 14 20
13
40
40 40 30
30
Result Cardiac arrest Successful defib Successful defib Pulmonary edema-arrest Cardiac arrest Successful defib Brad ycardia-arrest Bradycardia-arres t Successful defib Bradycardia Successful defib Successful defib Successful defib Successful defib
290 The Annals of Thoracic Surgery Vol 21 No 4
April 1976
tained for only about 15 minutes using manual or conventional mechanical massage, while i t can be supported for as long as 30 to 40 minutes during countermassage. Countermassage also keeps the pulse pressure constant at 15 mm Hg. Pantridge [71 has stated that 60% of acute myocardial infarctions are accompanied by complete atrioventricular block and ventricular arrest within 12 hours. Chiocca [ l l has stated that the incidence of ventricular arrest due to ventricular fibrillation is 74%. In 1940 Wigger [ll]and Gurevich and Yuniev [3] suggested that the maximum time for defibrillation and reestablishment of the cardiac beat is from 1to 1% minutes but can be prolonged to 8 minutes when closed-chest cardiac massage is carried out before defibrillation. Hosler [4] asserted that it is necessary to limit the time of defibrillation strictly and mentioned that cardiac massage should be done before a defibrillation of more than 50 seconds in order to augment the coronary circulation. In our experimental studies of defibrillation that sought to improve the extreme bradycardia or atrioventricular block usually present just after this event, supplementary countermassage was carried out for 10 to 20 minutes with 50% of the drive ordinarily used in the countermassage technique. The cardiac beat was shortly reestablished in sinus rhythm.
References 1. Chiocca JC: Cardiac arrest complicating acute myocardial infarction. Med Ann DC 33:411, 1964
2. Eliot C, Vyden JK: Resuscitation after myocardial infarction. JAMA 200:9, 1967 3. Gurevich NL, Yuniev GS: Restoration of regular rhythm in mammalian fibrillating heart. Annu Rev Soviet Med 3:236, 1946 4. Hosler RM: Cardiac resuscitation. Biochem Clin 1:327, 1963 5. Kouwenhoven WB: Closed chest cardiac massage. JAMA 173:1064, 1960 6. Miura I: A review of 207 cases of acute myocardial infarction. Jpn Heart J 2:12, 1970 7. Pantridge JF: Cardiac arrest after myocardial infarction. Lancet 1:807, 1966 8. Pierce JA: Cardiac arrest and deaths associated with anesthesia. Anesth Analg (Cleve) 45:407, 1966 9. Stephenson HE: Cardiac Arrest and Resuscitation. St Louis, Mosby, 1970 10. Tsuchia KI, Tanabe TK: Studies of the cardiac massage machine (11). Rep Waseda Inst Tech (Japan) 58:12, 1972 11. Wigger CJ: The physiologic basis for cardiac resuscitation from ventricular fibrillation: method for serial defibrillation. Am Heart J 20:413, 1940 12. William JG, William FM: Resuscitation for cardiac arrest due to myocardial infarction. Dis Chest 50:173, 1966
Editor’s Note Dr. Ohomoto and his colleagues have stated that the likelihood of human survival after more than 15 minutes of manual or conventional mechanical resuscitation is very small. While the improved perfusion accomplished by the authors with the countermassage technique is certainly desirable, experience with closed-chest cardiac resuscitation in the United States suggests that properly administered resuscitation can be carried out for considerably longer than 15 minutes with hope of survival.
ABSTRACT Experiments were performed on 50 dogs to determine the reason for unsatisfactory survival rates following closed-chest cardiac massage and to help develop new means for increasing survival following acute myocardial infarction and other causes of cardiac arrest. A new technique, named the countermassage method, was subsequently developed. Coronary and carotid flows after use of countermassage following cardiac arrest were increased 1.4 and 2 times, respectively, in contrast to flows obtained during manual closed-chest cardiac massage. These increases brought flows up to normal levels. We also tried to determine whether survival could be extended by this method to facilitate clinical treatment such as defibrillation or placing a temporary pacemaker catheter under fluoroscopic control, which are hard to accomplish during the brief time permitted by conventional closed-chest cardiac massage.
From The Heart Institute of Japan, Tokyo Women’s Medical College, Tokyo, Japan. We gratefully acknowledge the assistance of Professor Kiichi Tsuchiya, Waseda Institute of Technology, in manufacturing the cardiopulmonary resuscitator discussed in our study. Accepted for publication Jan 7, 1975. Address reprint requests to Dr. Ohomoto, The Heart Institute of Japan, Tokyo Women’s Medical College, 10 Kawadacho, Shinjuku-ku, Tokyo, Japan.
284
Materials and Methods Fifty adult mongrel dogs weighing from 10 to 30 kg were anesthetized intravenously with pentobarbital (15 mg per kilogram of body weight). An endotracheal tube was inserted, and the dogs were ventilated with a positive- and negativepressure respirator. Ascending aortic pressure,
285
Ohomoto, Miura, and Konno: Method of External Cardiac Massage
r
Hemodynamic comparisons were made, and long-term hemodynamic function with the manual, conventional mechanical, and countermassage methods was measured (Fig 2). Prior to the experimental study, control values for cardiac function were recorded. Ventricular fibrillation was produced with 15 volts of direct current applied for 1or 2 seconds using an electrode catheter inserted into the right ventricle through the femoral vein. In the control study, 5 dogs had massage for 30 minutes under optimal conditions that had been determined in advance for both the conventional mechanical and the countermassage machines (Table 1).Manual massage was administered by 3 persons alternating every 5 minutes to avoid 0 .. .. .. .. individual fatigue. . . . . .. .. .. The compression frequency of both the coni i -: Countermassage ; ; ; . . ventional mechanical and countermassage 0 CONTROL CONVENTIONAL COUNTERmachines was 70 to 90 cycles per minute. The MASSAGE MASSAGE compression time ratio for the conventional Fig I. Coronary and carotid flows b y the machine (time of compressionitime of comprescountermassage method are 100% and9Oo/0 those of sion and decompression, or SmlT) was 0.27 to a natural cardiac beat, respectively, and are 2.0 and 0.30. The compression time ratio of the coun1.4 timesgreater than f l o w rates attainable w i t h manual or conventional mechanical massage. termassage machine (SclT) was 0.78 to 0.82. The compressive phase-shift angle of the counterright atrial pressure, inferior vena caval pres- massage machine to the conventional machine sure, carotid flow, left circumflex coronary artery was -90 degrees. This indicates that for the most flow, and cardiac contractions were determined. effective coronary and carotid flows, chest comA flow probe was inserted to measure coronary pression with the conventional machine should flow, and in order to correct for the error due to be started a quarter-cycle following compression change in position of the probe during massage, of the abdomen (Fig 3). The compressive strokes it was fixed to pericardium which lay vertical to of both the conventional and the countermassage machine averaged about 40 mm. the axis of the coronary arteries. *O0
-j
:
:
:
:
:
:
:
:
:
n(:
Fig2. System of external cardiac nzassage f o r a fibrillating canine heart.
I
1
Conventional Massage Machine Counter Massage Machine
,
1
Aortic Pressure .......... Venous Pressure--.
..
//I
Coronary flow.^^--Carotid Flow.............. ECG ..........
essure Reaulator
286 The Annals of Thoracic Surgery Vol 21 No 4 April 1976
Table 1. Optimal Driving Conditions for Cardiac Massage Machines Control Variables
Optimal Conditions
Driving frequency (cpm) SmiT
70-90 0.274.30 0.78-0.82 -90 3040 40
SciT Driving phase-shift angle (degrees) Stroke of conventional machine (mm) Stroke of countermassage machine (mm)
Counter position
Abdomen ~~
SmlT = compression time ratio for conventional massage machine; SciT = compression time ratio for countermassage machine (see text for explanation).
Cardiac stimulants were used to compare the long-term hemodynamic effects of each method. A solution combining 100 ml of lactated Ringer's, 100 ml of 7 % sodium bicarbonate injection, and 1 mg of epinephrine was injected directly into the right atrium, 0.2 mlikgimin during the manual and conventional mechanical massages and 0.04 ml/kg/min during countermassage. After a 30-minute massage, 100 to 200 wattseconds of D-c defibrillation was applied, and supplementary massage was carried out if additional shocks were necessary.
Results The hemodynamics of each 30-minute massage are shown in Figure 4. With manual massage, lack of hemodynamic stability was noted which Fig3. For the most effective hemodynamics, compression by the conventional machine should be started one quarter-cycle following compression of the abdomen.
\hest compression
ABDOMINAL COMPRESSOR
V
one cycle
t
(bdominal compression (a quarter-cycle before chest compression) 1
-90"
1
1
1
1
0" t90" +180°t2700
A
(Phaseshift
was largely attributable to operator fatigue. Coronary and carotid flows dropped substantially within 10 to 15 minutes. The cardiac output was limited to a third to a quarter of normal due to regurgitation of cardiac blood to the venous system through valves deformed during compression [lo]; the peak aortic pressures were high, but mean aortic pressures were low. For the first 15 minutes after massage was begun, mean aortic and venous pressure differences were minimal. Afterward venous pressure began to show an inverse relationship to mean aortic pressure and eventually rose to 2 times the control value, indicating that manual massage was ineffective after 15 minutes. Figure 4 also shows the effect of the conventional mechanical massage machine: For the first 15 minutes hemodynamics were stable, with a slight difference between aortic and venous pressures. However, after 15 minutes coronary and carotid flows decreased just as with manual massage, and the effects were ultimately the same. In the countermassage method, hemodynamic function was satisfactory throughout the 30-minute period of application. Coronary and carotid flows approximated the control value of a normal cardiac beat. Although venous pressure was relatively high (40 mm Hg), the aortic-venous pressure difference was kept above 15 mm Hg, which means that circulation was achieved under stable conditions. The long-term hemodynamics of closed-chest massage combined with cardiac stimulants are shown in Figure 5. Note that hemodynamic function after defibrillation was unstable during manual massage (Fig 5a). It is also worth mentioning that while blood pressure rose initially
287 Ohomoto, Miura, and Konno: Method of External Cardiac Massage
- 1I t
P120
-E loot
9\
!i . .-C
a
Manual massage
60
0
5
0
01 D u r a t i o n of massage
(rnin)
Conventionol Mossoge
0
- 1601
:
E 100 l
-
10
30
20
D u r a t i o n of m a s s a g e
f140h
Counter
(rnin)
massage
-E 120
U
"
-
c
01
O
K
0
I
10
I
I
20
D u r a t i o n of massage
I
I
30 ..
(rnin)
Fig4. Hemodynamic effects of each type o f massage in the same animal. W i t h the countermassage method, mean aortic and carotid flo7os uiere improvedto about double the levels with manual massage.
after defibrillation due to the effects of the stimulating agents, this did not last. After 80 minutes, on the average, all the dogs died from congestion in various internal organs (especially the liver and hearf muscle) as shown by postmortem examination. Hemorrhage in lung tissue was also noted. Hemodynamic data up to the twenty-seventh day from animals resuscitated by the conventional mechanical method are
shown in Figure 5b. Three of 5 dogs had died from pulmonary hemorrhage and 1 other dog was noted at postmortem examination to have slight congestion in both liver and lung. All 5 dogs undergoing countermassage survived. The hemodynamic data on these dogs after 9 days' survival are shown in Figure 5c. In these animals, hemodynamic data during the 30 minutes of massage and after defibrillation were approximately equal to control values. Survival studies on the dogs treated with drugs are detailed in Table 2. The results of another group of studies on survival after defibrillation are shown inTable 3. So that the effects of massage alone could be ascertained, no pharmacological agent was used in this group during any massage. In the group receiving manual massage we succeeded in defibrillating 2 dogs after 30 minutes of massage, but the other 3 could not be successfully defibrillated. With conventional mechanical massage, 2 of 3 dogs developed bradycardia and a prolonged QRS time; both died after several minutes of attempted supplementary massage after defibrillation. From these results we concluded that longterm massage using the manual or conventional mechanical methods is not effective and that survival can only be accomplished within the first 15 minutes of massage. Defibrillation should be carried out as quickly as possible. In our experience, survival exceeding 15 minutes among humans with a fibrillating heart, especially when accompanied by acute myocardial infarction, has been extremely rare. With the countermassage technique, despite 40 minutes of massage, 5 of 6 animals were successfully defibrillated and for the most part stabilized after defibrillation. In another set of experiments, each kind of massage was carried out for 5 minutes in the same animal. In spite of the fact that manual and conventional mechanical massage were carried out under the relatively favorable conditions present just after fibrillation, the hemodynamic results obtained were poor. By contrast, during the countermassage period both mean aortic and carotid flows were improved to about double the levels with manual massage, even though countermassage was not started until after this group
288 The Annals of Thoracic Surgery Vol 21 No 4
(a)
0
10
Manual
20
30
Time
April 1976
massage
40
50
(rnin)
60 70
80
-6 2001 (b) Conventional Massage E -E i w Lr - - c o n v ~ E\ L
I
-i
I \
Time
(min)
Time
(min)
2501
Fig 5. Hemodynamics of long-term survival studies using cardiac stimulants: ( a ) Manual massage was ineffective, and all animals died with severe congestion of various internal organs. ( b ) Animals receiving conventional mechanical massage showed slight improvement, with 3 of 5 dying from pulmonary hemorrhage. ( c ) With the countermassage technique all 5 animals survived. On the ninth day 1 was killed for histological examination.
had already undergone two other forms of massage and had experienced 10 minutes of poor circulation.
Comment The closed-chest cardiac massage recommended by Kouwenhoven [51 in 1960 has been the most
practical method of preparation for defibrillation up to this point, primarily because it is the only one designed especially for use outside the hospital. However, Stephenson's study [91 of 5,076 patients from 50 facilities revealed that only 819 survived, a rate of 16%. The primary factor in successful resuscitation is the amount of time that has elapsed before resuscitation begins. When more than 4 minutes have passed since the moment of circulatory arrest, Stephenson showed that the survival rate with either closed or open cardiac massage is only 4%. It is therefore absolutely necessary to start cardiac resuscitation within 3 minutes; after this time irreversible changes begin to occur in the brain. The cardiac muscle itself will not undergo irreversible changes for about 10 to 15 minutes, which means that if cerebral circulation is adequately maintained, cardiac massage can prolong the survival time from 3 to 15 minutes before defibrillation is accomplished. The next most important factor in resuscitation is the environment where it is carried out. According to Stephenson [9] the survival rate is relatively high (50%) in the closely controlled atmosphere of places such as the operating room, intensive care unit, and coronary care unit; but it is as low as 21% in other parts of the hospital and drops even further outside the facility. If a patient begins to fibrillate outside the hospital, it is most difficult to transport and defibrillate him within 15 minutes, and an alternative way to prolong survival time is needed. Survival depends largely upon the kind and severity of the causative disease. The survival rate in ischemic heart disease with acute myocardial infarction is as low as 14% even when the patient is treated in an optimal environment like the coronary care unit, according to William and William [12] and Miura [6]. Eliot and Vyden [21 showed that cardiac arrest can be caused by the downward displacement of a cardiac pacemaker (electrical failure), decrease of cardiac contractility (power failure), or hypoxia caused by hypoventilation. It is evident that cardiac arrest is induced by coronary insufficiency, and the existing hypoxia of cardiac muscle makes it difficult to survive this condition. In ischemic heart disease, then, the time limit
289 Ohomoto, Miura, and Konno: Method of External Cardiac Massage
Table 2 . Survival Studies Using Drugsa in 15 Dogs
Method Manual
massage
Conventional massage
Counter-
massage
Drug Inject. Speed
Sex & Weight (kg)
Massage Time (min)
0.2
M, M, F, M, M, M, M, M, M, M, M, M, M, M, M,
30
(mlikgim in)
0.2
0.04
19 15 12
17 26
23
12
30
18 20 20
15
20 20 17 20
30
Result Died (3 hr) Died (1hr) Died (defib) Died (3 hr) Died (1 hr) Died (1hr) Died ( I h hr) Killed (12 days) Killed (27 days) Died (1 day) Killed (9 days) Killed (30 days) Killed (10 days) Killed (5 days) Alive (more than 1 yr)
“Solution consisting of 100 ml of lactated Ringer’s, 100 ml of 7% sodium bicarbonate injection, and 1 mg of epinephrine.
within which resuscitation can be accomplished is less than 15 minutes, and greater emphasis must be placed on maintaining cerebral and coronary circulation. Closed-chest cardiac massage is not adequate to keep circulation stable because it cannot control the low cardiac output induced by regurgitation of cardiac blood into the venous system. Pulse pressure is minimal after 15 minutes and circulatory volume decreases rapidly, thus leading to cardiac shock. In addition, this method cannot selectively maintain coronary circulation.
In management of ventricular fibrillation, then, the first problem is to mechanize the massage procedure in order to achieve hemodynamic stability. The second step is to increase coronary circulation selectively through diastolic augmentation. Because it incorporates principles from both the conventional mechanical machine, adapted from manual closed-chest massage, and the massage machine that compresses the abdomen, the countermassage method fulfills both needs. In dogs, hemodynamic stability can be main-
Table 3 . Results of Resuscitation Using Massage Alone in 14 Dogs Method Manual massage
Conventional massage Countermassage
Weight (kg) 18
30 23 33 8
Duration of Massage (min) 15
30
30
17 18 12
15 30 30 30 30
25 17
30
15 14 20
13
40
40 40 30
30
Result Cardiac arrest Successful defib Successful defib Pulmonary edema-arrest Cardiac arrest Successful defib Brad ycardia-arrest Bradycardia-arres t Successful defib Bradycardia Successful defib Successful defib Successful defib Successful defib
290 The Annals of Thoracic Surgery Vol 21 No 4
April 1976
tained for only about 15 minutes using manual or conventional mechanical massage, while i t can be supported for as long as 30 to 40 minutes during countermassage. Countermassage also keeps the pulse pressure constant at 15 mm Hg. Pantridge [71 has stated that 60% of acute myocardial infarctions are accompanied by complete atrioventricular block and ventricular arrest within 12 hours. Chiocca [ l l has stated that the incidence of ventricular arrest due to ventricular fibrillation is 74%. In 1940 Wigger [ll]and Gurevich and Yuniev [3] suggested that the maximum time for defibrillation and reestablishment of the cardiac beat is from 1to 1% minutes but can be prolonged to 8 minutes when closed-chest cardiac massage is carried out before defibrillation. Hosler [4] asserted that it is necessary to limit the time of defibrillation strictly and mentioned that cardiac massage should be done before a defibrillation of more than 50 seconds in order to augment the coronary circulation. In our experimental studies of defibrillation that sought to improve the extreme bradycardia or atrioventricular block usually present just after this event, supplementary countermassage was carried out for 10 to 20 minutes with 50% of the drive ordinarily used in the countermassage technique. The cardiac beat was shortly reestablished in sinus rhythm.
References 1. Chiocca JC: Cardiac arrest complicating acute myocardial infarction. Med Ann DC 33:411, 1964
2. Eliot C, Vyden JK: Resuscitation after myocardial infarction. JAMA 200:9, 1967 3. Gurevich NL, Yuniev GS: Restoration of regular rhythm in mammalian fibrillating heart. Annu Rev Soviet Med 3:236, 1946 4. Hosler RM: Cardiac resuscitation. Biochem Clin 1:327, 1963 5. Kouwenhoven WB: Closed chest cardiac massage. JAMA 173:1064, 1960 6. Miura I: A review of 207 cases of acute myocardial infarction. Jpn Heart J 2:12, 1970 7. Pantridge JF: Cardiac arrest after myocardial infarction. Lancet 1:807, 1966 8. Pierce JA: Cardiac arrest and deaths associated with anesthesia. Anesth Analg (Cleve) 45:407, 1966 9. Stephenson HE: Cardiac Arrest and Resuscitation. St Louis, Mosby, 1970 10. Tsuchia KI, Tanabe TK: Studies of the cardiac massage machine (11). Rep Waseda Inst Tech (Japan) 58:12, 1972 11. Wigger CJ: The physiologic basis for cardiac resuscitation from ventricular fibrillation: method for serial defibrillation. Am Heart J 20:413, 1940 12. William JG, William FM: Resuscitation for cardiac arrest due to myocardial infarction. Dis Chest 50:173, 1966
Editor’s Note Dr. Ohomoto and his colleagues have stated that the likelihood of human survival after more than 15 minutes of manual or conventional mechanical resuscitation is very small. While the improved perfusion accomplished by the authors with the countermassage technique is certainly desirable, experience with closed-chest cardiac resuscitation in the United States suggests that properly administered resuscitation can be carried out for considerably longer than 15 minutes with hope of survival.
