Adv. Cardiol., vol. 20, pp. 72-78 (Karger, Basel 1977)
Integrated Medical-Surgical Treatment of Pre-Infarction Syndrome ROBERT J. FLEMMA and BERNARD STALLER
The management of unstable angina requires a close cooperation and communication between cardiologist and surgeon to reduce the hazards at all stages of this experience for the patient. A definition of unstable angina in our hands may differ from others, but it establishes the ground rules of this discussion. Some might feel our criteria are too liberal for unstable angina as they see it at their institution. Our criteria have been established in conjunction with our cardiologists. Foremost is the clinical history of change in the anginal pattern or the onset of new angina. These alone are usually not the hallmarks of the unstable patient, but the consensus with experienced cardiologists who also consider the electrocardiographic findings, which mayor may not be present, stress testing, and the angiography, is a unanimous decision that this patient is changing for the worse rapidly and that it is unadvisable that the patient be allowed to leave the hospital for his own safety. As you know, Milwaukee cardiologists are not timid nor alarmists. Their experience is based on 7,000-8,000 patients undergoing cardiac catheterization. The average patient delay between coronary catheterization and indicated surgery in the ordinary stable angina patient is four to six weeks, while in this group all were kept in the hospital for a waiting period of zero to seven days following catheterization. I point this out only to show that it reflects a heightened concern among experienced cardiologists. Most of the patients had EKG evidence of ischemia either at our hospital or at the referral source with EKGs being sent along with the patient. Angiography confirms highly stenotic lesions, the vast majority in the left coronary system. Stress testing was used, but in no systematic manner, on these patients.
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:28:50 PM
The Medical College of Wisconsin, Milwaukee, Wisc., and st. Lukes Hospital, Milwaukee, Wisc.
73
FLEMMA/STALLER
Table I_ Unstable angina - med ical phase Management Admit to CCU Bed rest Sedation Oxygen NItri t es
Pro panolo l (,f necessary )
Stabilize _ _ _ _ _ _ _ _ _ _ - - - - - - - - Fall to stabilize Decision I Decisio n I 24- 48 h --- - -/ I Enzymes + EKG -Potential surgical candidate (yes-no) --- Notify surgeon _ Balloon pump ' No Infarct
t
/
'" Yes -.
No Drug therapy Decision II
Angiogram /
-------r\JOoperatlOn
~ration
Ste, oids Angi ograph y / -----DecISion II Urgent or emergent Non-operative OperatIve Intervention
w ithin days
Table I shows the medical phase of the management of unstable angina. acter, the goals of the medical phase in the treatment of unstable angina are to restore the balance between myocardial oxygen supply and demand. The patient is admitted to a coronary care unit, he is placed at bed rest, sedated (morphine if necessary), oxygen is administered by nasocatheter, nitrates are given and propanolol administered if necessary. It is not at all unusual that the patients require propanolol for relief of their angina and to stabilize their angina. Also, one of the points that many people have forgotten is that besides slowing the heart rate to restore the supply/demand ratio to the myocardium, propanolol is a sedative and a tranquilizer, Indeed, it was first introduced as a tranquilizer. Over the next 24-48 h, the patient will follow one of two courses. If the patient stabilizes, angina is relieved and arrhythmias (if associated with the angina) have settled down. We then arrive at what we call decision I level. Is the patient a potential surgical candidate? In making this decision, our cardiologists frequently begin the interaction with the surgeon at this point if there is any question concerning operability. The patient might not be a surgical candidate because of vital organ dysfunction, brain damage, or any other illness such as cancer. Few patients are turned down, but they may be based on the above criteria. Once the patient has been identified as a potential surgical candidate, the surgeon is notified of the time of catheterization and possible operation is discussed. Depending upon the severity of the anginal pattern prior to stabilization, and EKG which may have shown inverted T waves that have not reverted to
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:28:50 PM
It is safe to say that with the patient undergoing this change in his anginal char-
74
normal, the surgeon will be standing by with his pump team for possible surgery should catheterization lead to a deterioration of the patient's condition. Angiography is carried out at which point decision II is made. No operation would be recommended if the patient had diffuse disease and poor left ventricular function which is deemed to be scar rather than ischemic myocardium. If the patient has proximal lesions and a reasonable ventricle, i. e. at least two of the four walls moving, and there are threatening lesions in vessels which go to the viable segments of the myocardium, the patient will be programmed for surgical intervention. Again, a close cooperation between the cardiologist and surgeon is necessary to decide quickly as to whether the patient is a candidate for revascularization or not. In the group that fails to stabilize, decision I again comes at the end of 24-48 h. If the patient's enzymes and EKG still show that the patient is in an ischemic pattern rather than having truly infarcted, the decision is made as to whether the patient is a potential surgical candidate. At our institution, we have not used the balloon pump as a method of reducing oxygen demand on the myocardium. There are institutions that have used this method and this is merely another way to bring the patient's oxygen demand/supply ratio into balance. It is important that the surgeon be notified early and that he partake in this decision. Indeed, if one is going to have a balloon pump program for this, one must have many house officers, which more commonly exist in medical programs than in thoracic surgery programs today. However, if one does not use the balloon pump, and this has been the common practice in our institution, I would highly recommend that at this point the patient be given 30 mg/kg of Solu-Medrol for stabilization of the myocardium while angiography is being carried out. Angiography is performed at this point since the surgeon has been notified and the patient is persistently unstable. Surgical preparation is a bit more advanced, in that the operating room has been forewarned and a cardiac anesthesiologist is available. The surgeon with his team and pump technicians are standing by and a heart-lung machine is set up in the operatin room so that the patient may be taken directly from the catheterization laboratory to the operating room. I feel strongly that the most critical phase in the patient's care will occur between the time angiography until the time when he is placed on cardiopulmonary bypass, and for this reason, the medical and surgical areas blend together (table II). If the patient has not received steroids as yet, we like to give the patient steroids for stabilization of the myocardium preoperatively as well as during the period of intraoperative procedures where the aorta is cross-clamped.
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:28:50 PM
FLEMMA/STALLER
Integrated Medical-Surgical Treatment of Pre-Infarction Syndrome
75
Table II. Unstable angina surgical phase
Urgent
Emergent -------Steroids Propanolol Avoid tachycardia Avoid hypertenSion Heparinize Immediately
~
Cannulation DIStal anastomoSis - - - - - - - -
Most critical viable leSion first
- - - - - - . . . Stable·no EKG changes Proximal anastomosis
and then progress Myocardial Protection Hypothermia 30 'C LV venting Hemodilution
Propanolol is continued. We do not discontinue this medication. It may exert its beneficial effects in preventing arrhythmias and the bradycardia effect may help bring oxygen supply/demand into line. Our anesthesiologists feel that two of the most important aspects of the preoperative portion of the surgical treatment of unstable angina are the avoidance of tachycardia and of hypertension, which in general cause a marked increase in myocardial oxygen demand and can precipitate ventricular fibrillation, arrhythmias, hypotension and cardiac arrest. Therefore, we do continue the propanolol in low doses (up to 40 mg every 6 h). Our anesthesiologists bring a high degree of skill to this critical period even if it is only 5-10 min duration. It is a period when if the heart stops, you may sustain irreversible brain damage and despite a successfully performed operation, still have a disastrous outcome. We heparinize the patients immediately after the skin incision, cannulate immediately, and in most of the patients who are unstable, carry out the distal coronary anastomosis and perfuse the heart immediately with oxygenated blood through the vein graft. We occasionally carry out the proximal anastomoses on the aorta prior to going on bypass, even though the patient has been heparinized, thereby shortening the pump run. We do this occasionally in some of the very old patients to keep pump runs at a minimum. However, the vast majority receive the distal anastomosis first. Also, this is an excellent period for the use of the side-to-side, end-to-side or 'jump' graft to keep perfusion time at a minimum.
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:28:50 PM
Left main stenosis - 3 grafts Bypass all significant lesions Temper operation to patient
FLEMMAjSTALLER
76
In general, we have utilized vein bypass grafts for these patients rather than
spend the time taking down the internal mammary artery. For left main coronary stenosis, we carry out three grafts to the left side. When there is left main stenosis plus other lesions, we bypass all significant lesions. However, we do temper our operation to the patient. An example would be a patient with left main stenosis who is 72 years of age. Three grafts to the left side would be carried out, and if there were additional 50% lesions in small diagonals or marginal arteries, they would be left alone, as we do not try to confer immortality, but rather to relieve the ischemic heart disease in significantly diseased arteries. In a younger 43-year-old patient, we would increase the number of bypass grafts and carry out grafts to less significant lesions in diagonals and marginals so that we would be extending the benefits of revascularization. Myocardial protection utilized at the time of surgery in general consists of hypothermia (30°C), left ventricular venting, and hemodilution.
In 1975, 70 patients fit the criteria that we listed in the beginning for unstable angina; 15 had left main coronary disease. There was one death in
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:28:50 PM
I would like to illustrate with one case report an example of the way this procedure functions. A 55-year-old physician who had previously been in excellent health and had no evidence of coronary disease suddenly within minutes, developed the first angina in his life, tipped over his T-waves and had depression of his ST segments. Marked anterior ischemia was brought under control with propanolol; nitrites and morphine were administered immediately. The patient was referred from another hospital for catheterization and the surgeon was notified at that time. Catheterization was carried out. The lesion in this patient's anterior descending coronary artery can be seen in figure 1. What is of interest is that this is not the usual atherosclerotic obstruction, but rather a plaque that has been elevated. The pressure coming from the proximal portion of the anterior descending continually tends to make this plaque close the anterior descending completely. There were no other lesions in this patient's coronaries except small insignificant plaques throughout the coronary system. He was taken to the operating room immediately and underwent vein bypass grafting. The one goal that was not met in his preoperative period was that the patient did develop hypertension over 200 mm Hg during the induction of anesthesia, and his EKG showed inversion of the T waves. When we opened the pericardium, the anterior myocardium was becoming dusky blue and he immediately underwent a distal anastomosis with resulting pinking up of the anterior wall of the left ventricle. He is now well and is over three years post-operative bypass surgery. There is no evidence of myocardial infarction in this patient and repeated stress tests have not shown any problems. This represents a rather urgent indication for catheterization and surgery in a 55-year-old hypertensive with no previously known coronary disease. We have had one other patient who fit into the same category with the same elevation of a plaque. It is obvious that these patients cannot be temporized with and the entire process must be hurried along in order to prevent a major infarction. We call this the 'hypertensive plaque elevation' syndrome to emphasize the need for rapid diagnosis and therapy.
Integrated Medical-Surgical Treatment of Pre-Infarction Syndrome
77
Fig. I. Lesion (arrow) in a patient's anterior descending coronary artery.
Table III. Unstable angina in 70 patients aged 39-67 (1975) Pts (age 39-67)
Left main
Death
70
15
1
4 2 4 2
1
this group which was technical (table III). What happened was not really a failure of the system, but rather a failure of the surgeon. When closing the chest, we did not recognize that a vein graft was kinked. The patient reached the intensive care unit and suddenly had cardiac arrest. The most important vein graft that this patient had was found to be kinked. This graft occlusion
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:28:50 PM
Complications Peri operative infarction (3 anterior, 1 inferior) CVA Arrhythmia Venous thrombosis (sign.) Balloon assistance
78
FLEMMA/STALLER
R.J. FLEMMA, MD, The Medical College of Wisconsin, Milwaukee, Wise.
(USA)
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:28:50 PM
led to her demise with an anterior infarction. Despite placing another graft, we could not resuscitate this patient even with the balloon pump. There is marked male predominence over females in this group of patients with unstable angina. Four patients suffered peri operative infarctions, three anterior and one inferior. There have been two CVAs (both have recovered totally). Four patients developed arrhythmias, primarily atrial in type, and two patients had significant venous thrombosis problems, one with pulmonary emboli. Balloon assistance was utilized only in that patient who expired. As one can see, this integrated approach does offer a satisfactory management for the treatment of unstable angina. No matter how anyone of us defines unstable angina, the close cooperation and working together of the surgeon, cardiologist and anesthesiologist is the only way that we can treat this problem in a satisfactory manner.
Integrated Medical-Surgical Treatment of Pre-Infarction Syndrome ROBERT J. FLEMMA and BERNARD STALLER
The management of unstable angina requires a close cooperation and communication between cardiologist and surgeon to reduce the hazards at all stages of this experience for the patient. A definition of unstable angina in our hands may differ from others, but it establishes the ground rules of this discussion. Some might feel our criteria are too liberal for unstable angina as they see it at their institution. Our criteria have been established in conjunction with our cardiologists. Foremost is the clinical history of change in the anginal pattern or the onset of new angina. These alone are usually not the hallmarks of the unstable patient, but the consensus with experienced cardiologists who also consider the electrocardiographic findings, which mayor may not be present, stress testing, and the angiography, is a unanimous decision that this patient is changing for the worse rapidly and that it is unadvisable that the patient be allowed to leave the hospital for his own safety. As you know, Milwaukee cardiologists are not timid nor alarmists. Their experience is based on 7,000-8,000 patients undergoing cardiac catheterization. The average patient delay between coronary catheterization and indicated surgery in the ordinary stable angina patient is four to six weeks, while in this group all were kept in the hospital for a waiting period of zero to seven days following catheterization. I point this out only to show that it reflects a heightened concern among experienced cardiologists. Most of the patients had EKG evidence of ischemia either at our hospital or at the referral source with EKGs being sent along with the patient. Angiography confirms highly stenotic lesions, the vast majority in the left coronary system. Stress testing was used, but in no systematic manner, on these patients.
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:28:50 PM
The Medical College of Wisconsin, Milwaukee, Wisc., and st. Lukes Hospital, Milwaukee, Wisc.
73
FLEMMA/STALLER
Table I_ Unstable angina - med ical phase Management Admit to CCU Bed rest Sedation Oxygen NItri t es
Pro panolo l (,f necessary )
Stabilize _ _ _ _ _ _ _ _ _ _ - - - - - - - - Fall to stabilize Decision I Decisio n I 24- 48 h --- - -/ I Enzymes + EKG -Potential surgical candidate (yes-no) --- Notify surgeon _ Balloon pump ' No Infarct
t
/
'" Yes -.
No Drug therapy Decision II
Angiogram /
-------r\JOoperatlOn
~ration
Ste, oids Angi ograph y / -----DecISion II Urgent or emergent Non-operative OperatIve Intervention
w ithin days
Table I shows the medical phase of the management of unstable angina. acter, the goals of the medical phase in the treatment of unstable angina are to restore the balance between myocardial oxygen supply and demand. The patient is admitted to a coronary care unit, he is placed at bed rest, sedated (morphine if necessary), oxygen is administered by nasocatheter, nitrates are given and propanolol administered if necessary. It is not at all unusual that the patients require propanolol for relief of their angina and to stabilize their angina. Also, one of the points that many people have forgotten is that besides slowing the heart rate to restore the supply/demand ratio to the myocardium, propanolol is a sedative and a tranquilizer, Indeed, it was first introduced as a tranquilizer. Over the next 24-48 h, the patient will follow one of two courses. If the patient stabilizes, angina is relieved and arrhythmias (if associated with the angina) have settled down. We then arrive at what we call decision I level. Is the patient a potential surgical candidate? In making this decision, our cardiologists frequently begin the interaction with the surgeon at this point if there is any question concerning operability. The patient might not be a surgical candidate because of vital organ dysfunction, brain damage, or any other illness such as cancer. Few patients are turned down, but they may be based on the above criteria. Once the patient has been identified as a potential surgical candidate, the surgeon is notified of the time of catheterization and possible operation is discussed. Depending upon the severity of the anginal pattern prior to stabilization, and EKG which may have shown inverted T waves that have not reverted to
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:28:50 PM
It is safe to say that with the patient undergoing this change in his anginal char-
74
normal, the surgeon will be standing by with his pump team for possible surgery should catheterization lead to a deterioration of the patient's condition. Angiography is carried out at which point decision II is made. No operation would be recommended if the patient had diffuse disease and poor left ventricular function which is deemed to be scar rather than ischemic myocardium. If the patient has proximal lesions and a reasonable ventricle, i. e. at least two of the four walls moving, and there are threatening lesions in vessels which go to the viable segments of the myocardium, the patient will be programmed for surgical intervention. Again, a close cooperation between the cardiologist and surgeon is necessary to decide quickly as to whether the patient is a candidate for revascularization or not. In the group that fails to stabilize, decision I again comes at the end of 24-48 h. If the patient's enzymes and EKG still show that the patient is in an ischemic pattern rather than having truly infarcted, the decision is made as to whether the patient is a potential surgical candidate. At our institution, we have not used the balloon pump as a method of reducing oxygen demand on the myocardium. There are institutions that have used this method and this is merely another way to bring the patient's oxygen demand/supply ratio into balance. It is important that the surgeon be notified early and that he partake in this decision. Indeed, if one is going to have a balloon pump program for this, one must have many house officers, which more commonly exist in medical programs than in thoracic surgery programs today. However, if one does not use the balloon pump, and this has been the common practice in our institution, I would highly recommend that at this point the patient be given 30 mg/kg of Solu-Medrol for stabilization of the myocardium while angiography is being carried out. Angiography is performed at this point since the surgeon has been notified and the patient is persistently unstable. Surgical preparation is a bit more advanced, in that the operating room has been forewarned and a cardiac anesthesiologist is available. The surgeon with his team and pump technicians are standing by and a heart-lung machine is set up in the operatin room so that the patient may be taken directly from the catheterization laboratory to the operating room. I feel strongly that the most critical phase in the patient's care will occur between the time angiography until the time when he is placed on cardiopulmonary bypass, and for this reason, the medical and surgical areas blend together (table II). If the patient has not received steroids as yet, we like to give the patient steroids for stabilization of the myocardium preoperatively as well as during the period of intraoperative procedures where the aorta is cross-clamped.
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:28:50 PM
FLEMMA/STALLER
Integrated Medical-Surgical Treatment of Pre-Infarction Syndrome
75
Table II. Unstable angina surgical phase
Urgent
Emergent -------Steroids Propanolol Avoid tachycardia Avoid hypertenSion Heparinize Immediately
~
Cannulation DIStal anastomoSis - - - - - - - -
Most critical viable leSion first
- - - - - - . . . Stable·no EKG changes Proximal anastomosis
and then progress Myocardial Protection Hypothermia 30 'C LV venting Hemodilution
Propanolol is continued. We do not discontinue this medication. It may exert its beneficial effects in preventing arrhythmias and the bradycardia effect may help bring oxygen supply/demand into line. Our anesthesiologists feel that two of the most important aspects of the preoperative portion of the surgical treatment of unstable angina are the avoidance of tachycardia and of hypertension, which in general cause a marked increase in myocardial oxygen demand and can precipitate ventricular fibrillation, arrhythmias, hypotension and cardiac arrest. Therefore, we do continue the propanolol in low doses (up to 40 mg every 6 h). Our anesthesiologists bring a high degree of skill to this critical period even if it is only 5-10 min duration. It is a period when if the heart stops, you may sustain irreversible brain damage and despite a successfully performed operation, still have a disastrous outcome. We heparinize the patients immediately after the skin incision, cannulate immediately, and in most of the patients who are unstable, carry out the distal coronary anastomosis and perfuse the heart immediately with oxygenated blood through the vein graft. We occasionally carry out the proximal anastomoses on the aorta prior to going on bypass, even though the patient has been heparinized, thereby shortening the pump run. We do this occasionally in some of the very old patients to keep pump runs at a minimum. However, the vast majority receive the distal anastomosis first. Also, this is an excellent period for the use of the side-to-side, end-to-side or 'jump' graft to keep perfusion time at a minimum.
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:28:50 PM
Left main stenosis - 3 grafts Bypass all significant lesions Temper operation to patient
FLEMMAjSTALLER
76
In general, we have utilized vein bypass grafts for these patients rather than
spend the time taking down the internal mammary artery. For left main coronary stenosis, we carry out three grafts to the left side. When there is left main stenosis plus other lesions, we bypass all significant lesions. However, we do temper our operation to the patient. An example would be a patient with left main stenosis who is 72 years of age. Three grafts to the left side would be carried out, and if there were additional 50% lesions in small diagonals or marginal arteries, they would be left alone, as we do not try to confer immortality, but rather to relieve the ischemic heart disease in significantly diseased arteries. In a younger 43-year-old patient, we would increase the number of bypass grafts and carry out grafts to less significant lesions in diagonals and marginals so that we would be extending the benefits of revascularization. Myocardial protection utilized at the time of surgery in general consists of hypothermia (30°C), left ventricular venting, and hemodilution.
In 1975, 70 patients fit the criteria that we listed in the beginning for unstable angina; 15 had left main coronary disease. There was one death in
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:28:50 PM
I would like to illustrate with one case report an example of the way this procedure functions. A 55-year-old physician who had previously been in excellent health and had no evidence of coronary disease suddenly within minutes, developed the first angina in his life, tipped over his T-waves and had depression of his ST segments. Marked anterior ischemia was brought under control with propanolol; nitrites and morphine were administered immediately. The patient was referred from another hospital for catheterization and the surgeon was notified at that time. Catheterization was carried out. The lesion in this patient's anterior descending coronary artery can be seen in figure 1. What is of interest is that this is not the usual atherosclerotic obstruction, but rather a plaque that has been elevated. The pressure coming from the proximal portion of the anterior descending continually tends to make this plaque close the anterior descending completely. There were no other lesions in this patient's coronaries except small insignificant plaques throughout the coronary system. He was taken to the operating room immediately and underwent vein bypass grafting. The one goal that was not met in his preoperative period was that the patient did develop hypertension over 200 mm Hg during the induction of anesthesia, and his EKG showed inversion of the T waves. When we opened the pericardium, the anterior myocardium was becoming dusky blue and he immediately underwent a distal anastomosis with resulting pinking up of the anterior wall of the left ventricle. He is now well and is over three years post-operative bypass surgery. There is no evidence of myocardial infarction in this patient and repeated stress tests have not shown any problems. This represents a rather urgent indication for catheterization and surgery in a 55-year-old hypertensive with no previously known coronary disease. We have had one other patient who fit into the same category with the same elevation of a plaque. It is obvious that these patients cannot be temporized with and the entire process must be hurried along in order to prevent a major infarction. We call this the 'hypertensive plaque elevation' syndrome to emphasize the need for rapid diagnosis and therapy.
Integrated Medical-Surgical Treatment of Pre-Infarction Syndrome
77
Fig. I. Lesion (arrow) in a patient's anterior descending coronary artery.
Table III. Unstable angina in 70 patients aged 39-67 (1975) Pts (age 39-67)
Left main
Death
70
15
1
4 2 4 2
1
this group which was technical (table III). What happened was not really a failure of the system, but rather a failure of the surgeon. When closing the chest, we did not recognize that a vein graft was kinked. The patient reached the intensive care unit and suddenly had cardiac arrest. The most important vein graft that this patient had was found to be kinked. This graft occlusion
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:28:50 PM
Complications Peri operative infarction (3 anterior, 1 inferior) CVA Arrhythmia Venous thrombosis (sign.) Balloon assistance
78
FLEMMA/STALLER
R.J. FLEMMA, MD, The Medical College of Wisconsin, Milwaukee, Wise.
(USA)
Downloaded by: University of Cambridge 131.111.164.128 - 3/19/2019 4:28:50 PM
led to her demise with an anterior infarction. Despite placing another graft, we could not resuscitate this patient even with the balloon pump. There is marked male predominence over females in this group of patients with unstable angina. Four patients suffered peri operative infarctions, three anterior and one inferior. There have been two CVAs (both have recovered totally). Four patients developed arrhythmias, primarily atrial in type, and two patients had significant venous thrombosis problems, one with pulmonary emboli. Balloon assistance was utilized only in that patient who expired. As one can see, this integrated approach does offer a satisfactory management for the treatment of unstable angina. No matter how anyone of us defines unstable angina, the close cooperation and working together of the surgeon, cardiologist and anesthesiologist is the only way that we can treat this problem in a satisfactory manner.
