Biomedical subjects
Publications and source records attributed to E Kreuzer.
Pre-, intra- and postoperative myocardial protection improved the success-rate of open heart surgery. As a part of myocardial preservation, cardioplegia is the most important procedure since it influences significantly the ischemic metabolism of the heart during the operative time.
Ten anesthetized mongrel dogs had a left anterolateral thoracotomy; the left anterior descending coronary artery was then ligated. After 60 min five animals each were treated either with dobutamine (4 microgram/min/kg; for 10 min), or with dobutamine and intraaortic counterpulsation. Combined treatment of cardiogenic shock proved superior. Those five dogs had significantly lower heart rates and dp/dt/p-values. Due to IABP the non-ischemic parts of the left ventricle were better perfused; there was no difference in treatment with regard to ischemic parts. The combined treatment was successfully inaugurated in two patients with cardiogenic shock.
12 patients suffering from a low cardiac output syndrome following aorto-coronary bypass-graft surgery were treated with a combined therapy. The left ventricular afterload was decreased by Urapidil, and a low dose positive inotropic agent, dobutamine, was added. The right and left ventricular filling pressures were kept constant by simultaneous volume replacement. Decreasing the mean arterial pressure by Urapidil alone from 122 +/-5 mm Hg to 90 +/-3mm Hg raised the cardiac index from 1.8 1/m2 x min to 2.71 1/m2 x min. By addition od dobutamine 5 mu/kg BW x min the cardiac index was further increased to 3.4 1/m2 x min. The heart-rate was unchanged. The pressure-rate-product was decreased by 25% with Urapidil alone (p 7E 0.01) and was only slightly increased after addition of dobutamine. It is concluded that in the patients studied, reduction of the mechanical load on the heart by Urapidil in combination with positive inotropic stimulation of the myocardium by dobutamine improved cardiac haemodynamics without a significant detrimental effect on the myocardial oxygen balance.
Explore the source record for details and available documents.
The hemodynamics and the myocardial oxygen consumption during sleep and induction of anesthesia was studied in 10 patients with good left heart function (group I) and in 8 patients with bad left function (group II). Anesthesia was induced with diazepam (0.1 mg/kg BW), fentanyl (0.01 mg/kg BW), etomidate (0.2 mg/kg BW), and pancuronium (0.1 mg/kg BW). Four min after induction under ventilation with mask the cardiac index (CI) in both groups and the whole body oxygen consumption (VO2) diminished in exact the same degree. After intubation in patients of group I the CI and the VO2 decreased further, the arterio-venous oxygen content difference (avDO2) remained constant. In patients of group II the CI decreased to 0.9 1/min x m2, the avDO2 increased to 9.9 Vol%.
The haemodynamic effects of antihypertensive therapy with diazoxide were studied during anaesthesia in 14 patients. Mean arterial pressure decreased after diazoxide from 135 -/+ 14 mm Hg to 98 -/+ 9 mm Hg (p < 0.01) and did not increase within 30 minutes of observation. Cardiac-index increased 23% (p < 0.01) and the heart rate 14%. These parameters reached control values after 30 min of observation. Pulmonary capillary wedge pressure showed no significant variations. The results confirm that diazoxide is an effective antihypertensive drug. the authors conclude that the use of diazoxide is indicated in the perioperative period, when the patient is not under close and invasive observation.
The effects of different doses of pentazocine on circulation and respiration were investigated in 28 patients divided into three groups. The circulatory reactions occurred in two phases. In the first, immediately after the injection, ventilated patients showed vasodilation and therefore a decrease in the peripheral and pulmonary blood pressure due to the reduction in peripheral and pulmonary vascular resistance. In contrast, the second phase is characterized by a vasoconstriction with maximal alterations ten minutes after injection. As a consequence, the peripheral and pulmonary arterial pressure is increased by a raise in peripheral and pulmonary vascular resistance. These circulatory effects were more pronounced in the group receiving the higher dose of pentazocine. In spontaneously breathing patients pentazocine causes ventilatory depression indicated by a decrease in PaO2 and an increase in PaCO2. In these patients pulmonary vascular resistance and pulmonary arterial pressure are increased within the first minute after injection in contrast to the ventilated patients receiving the same dose. These increases are accompanied by the maximum of ventilatory depression. This change can be explained by the pulmonary hypoxic vasoconstriction.
This is an account on combined procedures in 124 patients suffering from arteriosclerotic vessel disease. In order to judge the proceedings and the results the patients were divided up into two groups. in 15 patients (group I) a carotid endarterectomy combined with an aorto-coronary bypass operation was performed; once a subclavian artery stenosis was resected at the same time. One patient of that group died after 31 days (7%). In group II 108 heart valve operations were performed together with a coronary artery revascularisation. Early and late mortality divided up as follows: aortic stenosis 6/44 (14%) respectively 2/44 (5%); aortic insufficiency 1/14 (7%) resp. 0; combined aortic disease 1/8 )13%) resp. 0; mitral stenosis 1/11 (9%) resp. 0; mitral insufficiency 6/26 (23%) resp. 2/26 (8%); combined mitral valve disease 1/2 (50%) resp. 0; three times both valves (aorta, mitral) were replaced without mortality. In our opinion combined procedures, resection of supraaortic artery stenosis respectively cardiac valve operations and aorto-coronary bypass are indicated especially since the functional long-term results are excellent. Though one should consider the high operative risk in patients with mitral insufficiency and combined mitral valve disease.
In 18 patients undergoing aortocoronary bypass grafting haemodynamic measurements were made before and after hypertensive episodes and intravenous administration of nitroglycerin (NTG). Patients of group I (n = 10) had good left heart function before operation. The mean arterial pressure (MAP) rose during the hypertensive episode from 82 +/- 12 mm Hg to 119 +/- 8 mm Hg (p less than 0.001), the pulmonary capillary wedge pressure (PCWP) increased from 11 +/- 3 mm Hg to 15 +/- 2 mm Hg (p less than 0.05). The cardiac index (CI) was not significantly altered. Infusion of NTG decreased the MAP to 84 +/- 3 mm Hg (p less than 0.001), the PCWP to 9 +/- 3 mm Hg (p less than 0.01). The CI remained unchanged. Patients of group II (n = 8) had poor left heart function before operation. During the hypertensive episode the MAP increased from 77 +/- 15 mm Hg to 115 +/- 6 mm Hg (p less than 0.001), the PCWP from 13 +/- 4 mm Hg to 25 +/- 5 mm Hg (p less than 0.001). The CI decreased from 2.2 +/- 0.3 1/min x m2 to 1.5 +/- 3.41/min x m2. Infusion of NTG decreased the MAP to 83 +/- 4 mm Hg (p less than 0.001), the PCWP to 11 +/- 3 mm Hg (p less than 0.001). The CI rose to 2.3 +/- 0.3 1/min x m2 (p less than 0.01). The authors conclude that NTG is an effective antihypertensive agent. No untoward side effects were noted.
In 12 patients with moderate low-output-syndrome following aortocoronary bypass grafting, the pump function of the left ventricle was improved by sodium nitroprusside (SNP) and dopamine. The cardiac index (CI) on termination of cardio-pulmonary bypass was 2.2 +/- 0.2 1/min.m2 and the pulmonary capillary wedge pressure (PCWP) 20 +/- 3 mm Hg. Folowing infusion of SNP the Cl reached 2.4 +/- 0.2 l/min.m2 (p less than 0.05) and the PCWP was reduced to 13 +/- 3 mm Hg (p less than 0.01). After transfusion of blood the PCWP increased to 18 +/- 2 mm Hg (p less than 0.01), and the CI increased to 2.8 +/- 0.2 l/min.m2 (p less than 0.05). After administration of dopamine the CI was further improved to 3.3 l/min.m2, the PCWP remained constant. The combined therapy with dopamine and SNP is a rational concept to improve the function of the heart in failure following open heart surgery.
There were 51 deaths following cardiac operation in children under one year of age. Nearly all these children were operated upon without using a cardiopulmonary bypass. The commonest cause of death was intra- or postoperative cardiac arrest usually occurring in patients with complex cardiac anomalies. The second most commonest cause was repiratory deficiency. In children between the ages of 2 and 14 years (91 deaths in 1859 patients, i.e. a mortality of 4.64%), the commonest cause of death was cardio-vascular insufficiency usually caused by the operation. In patients with tetralogy of Fallot (147 deaths amongst 709 patients) one must distinguish between right sided and left sided cardiac insufficiency. Here the next commonest cause of death was bronchopneumonia with septicaemia usually as a result of long term artificial respiration. Other causes of death such as haemorrhages and embolic phenomena are much less important. In order to lower the mortality, better postoperative treatment in an intensive therapy unit especially for children undergoing cardiac operations is suggested.
In the period from September 1976 to 1977, aortic or mitral valve replacement was performed in 84 and 34 patients respectively. Cardiogenic shock occurred during or immediately after the operation in 3 and 2 patients respectively (= 8.8% and 2.4%). In spite of the use of intra-aortal counter-pulsation, none of the patients survived the acute event. During the same period, 8 (= 5%) out of 113 patients who had undergone coronary surgery needed intra-aortal counter-pulsation. 4 of them survived the acute left heart failure and at the present time are clinically healthy (N.Y. Heart Association Class II).
Right ventriculotomy with extracorporeal circulation was used for removal of an infected transvenous pacemaker electrode which was firmly attached to the myocardium in a patient with septicemia. Alternative methods and suggestions to prohibit electrode incarceration are discussed.
A case of left-ventricular-right-atrial septal defect secundary to blunt chest trauma is described. The etiology of this type of septal defect, e. g. congenital, following aortic and mitral valve replacement, endocarditis and trauma, is discussed. Early defect closure is recommended in the presence of significant shunt volume.
Explore the source record for details and available documents.
Among a total of 6000 patients of the Herzchirurgische Klinik of the University of Munich, 16 patients had an aneurysm of the sinus of Valsalva. Mostly, this was localized in the right sinus, less often in the non-coronary sinus, and only in one case in the left sinus. In 9 patients the aneurysm had ruptured into the right ventricle or into the right atrium. In 2/3 of the cases the aneurysm was associated with a VSD or an acquired malformation of the aortic valve. The diagnosis in part was based on the typical history with a sudden begin of cardiac symptoms secondary to rupture of the aneurysm; however, the most useful diagnostic procedure was the heart catheterization including an angiogram of the aortic root. Surgical treatment led to good early and late results; there was a low operative risk, and complications were rare; however, the prognosis may be less favorable in the presence of an acquired malformation of the aortic valve.
Explore the source record for details and available documents.
Explore the source record for details and available documents.