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Biomedical subjects

A C Moulijn

Publications and source records attributed to A C Moulijn.

At least 19 recordsLinked to original sources
PubMed1992

Intraoperative assessment of the mitral valve: transesophageal Doppler echocardiography vs. left ventricular filling of the flaccid heart.

Several methods can be used for the intraoperative assessment of residual mitral regurgitation (MR) following reconstruction of the mitral valve. The aim of this study was to compare the reliability of two of these methods: left ventricular filling of the arrested heart with saline (LVF) and intraoperative transesophageal Doppler echocardiography (TEE). Reliability was assessed by comparing LVF and TEE to postoperative left ventricular angiography (LVA) in 27 patients. LVF, TEE and LVA grading of MR was 0-4. Correlations, as measured by the Kappa statistic, were as follows: LVF-LVA: K = 0.33 (95% confidence interval (CI): 0.06-0.59), TEE-LVA: K = 0.48 (95% CI: 0.20-0.77), LVF-TEE: K = 0.43 (95% CI: 0.20-0.67). Considering LVF and TEE as predictors of LVA gradings above 2, sensitivities were 0.4 and 0.6, respectively. Specificities were 1.0 for each method. In conclusion, we found TEE in the beating heart not to be significantly more reliable in the prediction of residual MR than LVF in the flaccid heart.

Adult↗
PubMed1992

Prognostic value of biventricular function in hypotensive patients after cardiac surgery as assessed by transesophageal echocardiography.

In patients after cardiac surgery, hypotension, defined as a mean arterial pressure less than 65 mmHg despite adequate filling pressures and positive inotropic medication, poses a problem. In addition, it is often difficult to determine whether these patients have suffered irreversible myocardial injury or if they are likely to recover. In this study, left and right ventricular function, as assessed by transesophageal echocardiography (TEE), was related to mortality both (1) quantitatively, using fractional area change (FAC), and (2) qualitatively, using a segmental wall motion analysis, which assigned a score to myocardial wall segments, in order to determine whether this technique can be used to predict survival. Mortality rate was very high in patients with biventricular and especially right ventricular failure (FAC less than 35%). Left and right ventricular wall motion abnormality indices were significantly better in survivors compared to nonsurvivors, but no distinct cut-off value could be determined. A wall motion index derived from only 6 segments at the mid-papillary muscle level was found to be as reliable as one based on 16 segments of the entire left ventricle. Thus, TEE provided information about the degree of left and right ventricular dysfunction by using a single cross-section at the papillary muscle level. It identified patients at high risk of death, ie, those with compromised right and biventricular function.

Adult↗
PubMed1992

Treatment of intractable ventricular fibrillation with prompt circulatory support using a biventricular assist device in pigs--an experimental study.

Refractory ventricular fibrillation (VF), intractable to conventional therapy, can be converted into a stable cardiac rhythm by immediate ventricular volume unloading using a form of mechanical circulatory assist (MCA). We investigated the efficacy of MCA in a controlled animal study in which 20 pigs were subjected to intermittent occlusions (5 times) of the left descending coronary artery (5 min. occlusion + 10 min. reperfusion). 12 of the 20 animals (60%) developed 14 events of VF. 64% of VF developed during reperfusion (p less than 0.05). Countershock was attempted up to eight times and was successful in 5 of the 14 events (36%) (primary defibrillation, PD). When conversion was not achieved, total biventricular bypass was instituted. Mean perfusion time between countershock attempts was 24.4 +/- 15.3 min. All animals (n = 9) with cardiac assistance were successfully defibrillated (secondary defibrillation, SD), (p less than 0.05). Hemodynamic parameters after SD were not significantly different from those after PD (p greater than 0.05). Survival rate following PD was 66.6%. Six animals were ultimately weaned from cardiac assistance following SD. Three others died of progressive cardiogenic shock in the six hour follow-up period following SD. These non-survivors had a significantly longer VF time than the survivors (41.7 +/- 10.4 vs. 15.8 +/- 8.0, p less than 0.05). Overall survival after SD was the same as that for PD: 66.6% (p greater than 0.05). These results show that prompt conversion of VF into a stable cardiac rhythm is a prerequisite to recovery.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[No consequences of prolonged drainage following open heart surgery on the incidence of postoperative pericardial effusion].

Pericardial effusion (PE) frequently occurs after cardiac surgery and, in some cases, complicates the postoperative course. This study was performed in order to assess if prolongation of the postoperative drainage period may result in a decreased incidence of PE. For this purpose we studied 100 patients, randomised into two groups. In group I (50 patients) standard drainage of the thorax was performed. In group II (50 patients) the drainage period was prolonged by 24 hours. The amount of fluid drained during the additional period did not correlate with preceding fluid production. Echocardiography performed on the sixth postoperative day revealed a virtually equal incidence of PE in both groups: 26 patients in group I, 29 patients in group II. None of the observed effusions resulted in clinical signs of cardiac tamponade. PE occurred more frequently in patients with more than 60 ml of additional drainage volume (p less than 0.01). We conclude that: (1) prolonging the duration of postoperative drainage does not result in a lower incidence of postoperative PE and (2) the aetiological process causing PE in a number of patients is probably already active during the early postoperative course.

Adult↗
PubMed1991

Late results of 200 repeat coronary artery bypass operations.

To determine the clinical outcome and the long-term results of a second coronary artery bypass operation, we studied preoperative clinical status and catheterization data in 200 consecutive patients over a 9-year period (1979 to 1987) (mean follow up time 34 months, maximum 120). The study group included 169 men and 31 women (mean age 58.4 years [7% greater than 70 years]). Sixty-four percent of patients had severe angina (New York Heart Association class IV), 70% had 3-vessel coronary artery disease and 21% had poor left ventricular function. Reoperation was performed after a mean interval of 58 months after the first procedure. A mean of 3.3 distal anastomoses was placed. The operative mortality rate (30 days) was 7.5%, with additional cardiac morbidity (myocardial infarction, heart failure) in 11.5% of patients. Multivariate analysis showed an increased risk in women (risk ratio 3.6) and in patients with poor left ventricular function (risk ratio 3.1). The cumulative 5-year survival rate was estimated at 84%, with a rate of 77% for patients with poor left ventricular function (difference not significant). The probability of remaining free of a cardiac-related event (myocardial infarction, angioplasty, third operation, cardiac death) was 64% for 5 years. At the end of follow-up, 79% of the surviving patients were in New York Heart Association class I or II and nearly 50% of patients in the fifth year after the reoperation had good functional status. It is concluded that a reoperation is effective but carries an increased, immediate, operative risk.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Artery Bypass↗
PubMed1991

Dispersion of refractoriness in canine ventricular myocardium. Effects of sympathetic stimulation.

In 18 dogs on total cardiopulmonary bypass, the average interval between local activations during artificially induced ventricular fibrillation (VF interval) was measured from extracellular electrograms, simultaneously recorded from up to 32 ventricular sites. VF intervals were used as an index of local refractoriness, based on the assumption that during ventricular fibrillation, cells are reexcited as soon as they have recovered their excitability. In support of this, microelectrode recordings in two hearts during ventricular fibrillation did not show a diastolic interval between successive action potentials. Refractory periods determined at a basic cycle length of 300 msec with the extrastimulus method correlated well with VF intervals measured at the same sites. Thus, this technique allows assessment of spatial dispersion of refractoriness during brief interventions such as sympathetic stimulation. The responses to left, right, and combined stellate ganglion stimulation varied substantially among individual hearts. This was observed both in dogs with an intact (n = 12) and decentralized (n = 6) autonomic nervous system. Individual ventricular sites could show effects of both left and right stellate ganglion stimulation (42% of tested sites) or show effects of left-sided stimulation only (31%) or right-sided stimulation only (14%). In 13% of sites, no effects of stellate stimulation were observed. Apart from these regional effects, the responses could be qualitatively different; that is, within the same heart, the VF interval prolonged at one site but shortened at another in response to the same intervention, although shortening was the general effect and prolongation the exception. Whenever sites responded to stellate ganglion stimulation with a shortening of VF interval, this shortening was approximately 10% for left, right, or combined stimulation, whether the autonomic nervous system was intact or decentralized. In six of 12 hearts in the intact group, there was a distinct regional effect of left stellate ganglion stimulation; in the other six hearts, the effects were distributed homogeneously over the ventricles. In three hearts, the effect of left stellate ganglion stimulation was strongest in the posterior wall, and in the other three hearts, in the anterior wall. The effects of right stellate ganglion stimulation were restricted to the anterior or lateral part of the left ventricle. Dispersion of VF intervals increased after left and combined stellate ganglion stimulation in the intact group and after right stellate ganglion stimulation in the decentralized group, but not significantly in every heart. This points to a marked individual variation with regard to the effects of sympathetic stimulation on electrophysiological properties of the heart.

Action Potentials↗
PubMed1990

Intraoperative transesophageal color-coded Doppler echocardiography for evaluation of residual regurgitation after mitral valve repair.

Because mitral valve competence after mitral valve reconstruction is awkward to assess during this procedure, we evaluated in this respect transesophageal color-coded Doppler echocardiography in 23 patients undergoing mitral valve reconstruction for severe mitral regurgitation. Transesophageal echocardiographic examinations were performed after induction of anesthesia but before sternotomy (baseline), after mitral valve repair before decannulation, and at sternal closure, all at similar mean aortic pressure and echocardiographic instrument settings. The degree of mitral regurgitation by transesophageal color Doppler flow mapping was visually quantified on a 5-point scale (0 to 4), pending the left atrial extent of the regurgitant jet. This was compared with the degree of mitral regurgitation by left ventricular cineangiography performed within several weeks after operation and also visually quantified on a 5-point scale (0 to 4), with use of the right anterior oblique projection. There was good correlation between the two methods (r = 0.83; p less than 0.001). We conclude that residual mitral regurgitation, as assessed by transesophageal color flow mapping in the operating room, highly correlates with the ultimate mitral regurgitation by cineangiography. Therefore transesophageal echocardiography can be helpful for evaluation of mitral valve competence during mitral valve reconstruction, and hence, in case of repair failure, allow valve replacement in the same surgical session, thus avoiding reoperation.

Adolescent↗
PubMed1989

Antihypertensive and anti-ischemic effects of nicardipine and nitroprusside in patients undergoing coronary artery bypass grafting.

The efficacy of nicardipine vs nitroprusside in controlling hypertension after sternotomy was compared in 120 patients undergoing coronary artery bypass grafting and anesthetized with fentanyl (100 micrograms/kg). All had good left ventricular function and had been receiving long term oral beta-blocking therapy. Patients were randomly allocated to 1 of 3 groups: group C, the control (n = 40), received no vasodilator; group N (n = 40) received intravenous nicardipine at an initial rate of 3 micrograms/kg/min; and group S (n = 40) received intravenous nitroprusside at an initial rate of 1 microgram/kg/min. Vasodilator infusion was begun before surgery and infusion rates were adjusted to maintain systolic blood pressure between 80 and 120% of postintubation (baseline) values. Additional measurements were obtained before incision and after sternotomy. In groups N and S, arterial blood pressure was effectively controlled in all patients. Before the incision, pulmonary artery pressure decreased in group S and systemic vascular resistance decreased in groups N and S. After sternotomy, mean arterial pressure, heart rate, pulmonary artery pressure, pulmonary capillary wedge pressure, cardiac index and rate-pressure product increased in group C. At this time, pulmonary artery pressure returned to baseline values in group S. In groups N and S, heart rate, cardiac index and rate-pressure product increased, but, compared with baseline values, systemic vascular resistance remained low after sternotomy. Ischemic changes were seen in the electrocardiogram in 11 patients (28%) in group C, 10 patients (25%) in group S and 4 patients (10%) in group N. The concentration of creatine phosphokinase MB was not significantly different in the first 24 postoperative hours in any group.

Aged↗
PubMed1989

How soon should drainage tubes be removed after cardiac operations?

Pericardial effusion frequently occurs after cardiac operation. Despite its high incidence, the etiological process of postoperative pericardial effusion remains unclear. Residual blood or thrombus has often been suggested as a possible cause, implying that the occurrence of pericardial effusion could be related to the effectiveness of postoperative thoracic drainage. This possible relationship, however, has never been studied. We found that prolonging the duration of thoracic drainage by 24 hours often increases total chest tube output considerably but does not affect the incidence of postoperative pericardial effusion: approximately 55% of 100 patients in this study were shown by two-dimensional echocardiography to have pericardial effusion on the sixth postoperative day, regardless of the duration of postoperative drainage. Because of this, and because a long period of drainage causes discomfort for the patient, mechanical irritation to the heart and the pericardium, and an increased risk of infection, we recommend removing drains as soon as their efficacy has peaked, preferably on the first postoperative day.

Adult↗
PubMed1989

Nicardipine for preservation of myocardial metabolism and function in patients undergoing coronary artery surgery.

The present study was designed to evaluate the myocardial protective effect of nicardipine (NIC) in patients with normal left ventricular (LV) function (control vs. NIC treatment group) and impaired LV function (control vs. NIC treatment group) during extracorporeal circulation for coronary artery surgery. NIC infusions were begun approximately 12 min before aortic cross clamping (AoX) at an infusion rate of 5 micrograms.kg-1.min-1 and maintained for 10 min. Prior to AoX an additional bolus of NIC 5 mg was given. Coronary hemodynamics, myocardial metabolic parameters (continuous thermodilution), and regional LV function (two-dimensional transesophageal echocardiography) were measured. At 15 min after discontinuation of AoX, lactate production was found in the two control groups but not in the two NIC treatment groups. In the control groups, lactate production returned to extraction at sternal closure. At that time regional area ejection fraction (RAEF) had significantly improved in both groups with impaired LV function compared with postintubation (baseline) values. In NIC-treated patients with impaired LV function, however, the percentage improvement in RAEF was significantly greater than that in the control groups. Between the groups, there were no differences in the number of patients requiring inotropic support, pacing, and/or diuretics after bypass or postoperatively. There were no significant differences in postoperative creatine kinase myocardial band release or in the incidence of dysrhythmias, myocardial infarction, or mortality. The results of the present study suggest that NIC iv may be used to provide additional myocardial protection during extracorporeal circulation. In addition, in NIC-treated patients with compromised LV function, this may be associated with a more apparent improvement in RAEF than that seen in nontreated patients.

Aged↗
PubMed1985

Assessment of left ventricular aneurysm resectability by two-dimensional echocardiography.

Mortality of surgical resection of a left ventricular (LV) aneurysm is largely determined by size and function of nonaneurysmal or residual myocardium. A residual myocardial index was determined using 2-dimensional echocardiography (2-D echo) in 56 consecutive patients scheduled for LV aneurysmectomy, and these results were correlated with surgical outcome. The index was calculated using 3 apical cross sections: the 2- and 4-chamber views and the long-axis view. These views were recorded at mutual angles of 60 degrees. In each view the end-diastolic length of normally moving endocardium of the 2 opposite walls was expressed as a fraction of the end-diastolic LV long axis. The index was assessed by averaging the 6 ratios obtained. In 41 survivors the index ranged from 40 to 71% (mean +/- standard deviation 53 +/- 7.8) and in 15 nonsurvivors from 29 to 67% (mean 38 +/- 8.5, p less than 0.01). With 1 exception, this echocardiographic index sharply separated survivors from nonsurvivors. The lower limit to survive aneurysmectomy was 40%.

Adult↗
PubMed1985

A randomized blind study comparing standard heparin and a new low molecular weight heparinoid in cardiopulmonary bypass surgery in dogs.

Postoperative hemorrhage remains a serious complication in cardiopulmonary bypass (CPB) surgery. In our study, alternative anticoagulation with a new low molecular weight (LMW) heparinoid (Org 10172) was compared with a standardized heparin regimen. A preliminary dose-finding study indicated the minimal effective heparinoid dose to be 260 anti-Xa U/kg body weight, which was comparable to the standardized heparin regime, as revealed by similar plasma anti-Xa values. The following randomized open pilot study in 12 mongrel dogs undergoing CPB showed the heparinoid to be as effective as heparin, with an additional advantageous decrease in postoperative blood loss in the Org 10172 group. Our randomized blind study in 16 mongrel dogs undergoing CPB was performed to confirm previous results. Both antithrombotic agents were effective in the prevention of clot formation within the extracorporeal circuit. Hematocrit values and erythrocyte and platelet counts showed no significant intergroup differences. Post-CPB leukocyte counts revealed a significantly more rapid increase in the group given heparinoid (P less than 0.05). In the group given heparin, the expected prolongations of both the thrombin time (TT) and activated partial thromboplastin time (APTT) were noted, whereas in the group given heparinoid, only a transient peak prolongation of the TT after dose administration was revealed, and no significant prolongation of the APTT. Mean anti-Xa plasma levels were similar during CPB, showing a rapid decrease in the group given heparin on protamine administration, as did the APTT. Assessment of the operating field indicated an elevated intraoperative blood loss in the group given heparin. Postoperative blood loss measured over a period of 2.5 hours after closure of the thorax was significantly lower in the group given heparinoid than in the heparinized animals (625 +/- 100.0 ml, mean +/- SD, and 806 +/- 178.2 ml, respectively; P less than 0.05). Our observations suggest that the LMW heparinoid Org 10172 has an increased benefit/risk ratio over standard heparin and is effective in CPB in dogs. Additional investigations in humans should verify the possibility of use of this substance as an alternative means of anticoagulation during CPB in patients in whom heparin is relatively contraindicated.

Animals↗
PubMed1977

Intrathoracic chemodectoma with multiple localisations.

In 1958 a mediastinal tumour was discovered in an asymptomatic woman with a history of vomiting and an oesophageal anomaly which had not been treated. A tumour of the anterosuperior mediastinum in relation to the aortic arch was extirpated and proved to be a chemodectoma or non-chromaffin paraganglioma. At subsequent follow-ups the mediastinum was never normal and the heart size progressively increased, the oesophageal anomaly remaining unchanged. A small opacity appeared in the left lung in 1974. An operation performed in 1975 revealed an osteochondroma in the lung, pericarditis, and an intrapericardial chemodectoma. The oesophagus was not explored. An intrathoracic chemodectoma is rare. The importance of angiography in its diagnosis is emphasised. Malignant degeneration is seldom observed. Therapy is surgical, the tumour being radioresistant. The possibility to be considered in our patient was either relapse of the tumour with degeneration or multiple localisations of the tumour.

Adult↗
PubMed1977

Successful haemodialysis and renal transplantation in a patient with haemophilia A.

A 19-year old male with severe haemophilia A (factor VIII activity less than 1%) developed terminal renal insufficiency and was subsequently dialysed via an external arteriovenous shunt for one year. To prevent bleeding he received cryoprecipitate (2000-2500 units of factor VIII) three times a week during dialysis. After one year of uneventful dialysis he received a kidney graft from a cadaver donor that was matched for the B locus antigens. During the first two weeks after transplantation his factor VIII level was kept at approximately 70% by daily cryoprecipitate infusions. Thereafter he was free from bleeding at a level of 20% with prophylactic cryoprecipitate treatment (1000 units 3 times a week). He was discharged from the hospital five weeks after transplantation with excellent renal function (ECC 75 ml/min). No rejection crisis occurred. His factor VIII requirements remained unchanged after transplantation, indicating that the human kidney does not substantially contribute to the production of clotpromoting factor VIII.

Adult↗
PubMed1976

[Mediastinal chemodectoma (author's transl)].

In 1958 a mediastinal tumor was discovered in an asymptomatic patient. She had previously complained of vomiting and an oesophageal abnormality had been discovered though not treated. The mediastinal tumor was resected and diagnosed as a non chromaffine chemodectoma. In the follow-up the mediastinal image never appeared normal and the heart shadow was enlarged. In 1974 an infiltrate appeared in the left lung. In 1975 the patient was operated : a pulmonary osteochondroma, a pericarditis and an intrapericardial aortopulmonary chemodectoma were discovered. The mediastinal chemodectoma is a rare tumor and its frequency, location and signs are discussed. The importance of angiography for diagnosis is stressed. The authors consider malignant degenerescence to be rare, and the treatment is surgical as the tumor is radioresistant. In the present case there was either a malignant recurrence or multiple focuses with a possible oesophageal location.

Bone Neoplasms↗