Search PubMed⌕ Search

Biomedical subjects

T van der Werf

Publications and source records attributed to T van der Werf.

At least 19 recordsLinked to original sources
PubMed2006

Dutch survey of coronary artery fistulas in adults: congenital solitary fistulas.

AIMS: Congenital coronary artery fistulas are frequently identified in adult and pediatric populations and they have been associated with various clinical and morphological features. The purpose of this study was to define the clinical and coronary angiographic morphological characteristics of adult patients with congenital solitary CAFs in the Dutch Registry. METHODS AND RESULTS: Fifty-one patients with angiographically documented CAFs were reviewed for clinical evaluation, used non-invasive and invasive diagnostic tools and treatment modalities. Unilateral CAFs were predominant (80%) and 84% of the patients were symptomatic. The most common presenting symptom was angina pectoris (57%). Angina pectoris was present in a quarter of the patients in the absence of coronary artery disease (CAD). Significant CAD was present in 49% of the patients. Twenty-nine percent of the CAFs showed aneurysmal formation, underlying their potential hazard of rupture. Myocardial infarction occurred in 18% of the patients. In 27% of CAFs multiplicity of the origin was found and nearly all fistulas were tortuous (97%). Treatment modalities were conservative medical in 70%, percutaneous transluminal embolisation in 5% and surgical ligation in 25% of the cases. Multiple micro-fistulas from the coronary arteries to the left ventricle were excluded from the study. CONCLUSION: In this national survey series, congenital solitary CAFs can be presented with typical angina pectoris in the absence of obstructive CAD. Fistula-related coronary artery was infrequently involved in the development of ipsilateral myocardial infarction. Tortuousity and multiplicity of the CAFs may determine, for the individual patient, the choice of the currently available treatment modalities.

Adult↗
PubMed2005

Dutch survey of congenital coronary artery fistulas in adults: coronary artery-left ventricular multiple micro-fistulas multi-center observational survey in the Netherlands.

BACKGROUND: Congenital coronary artery-left ventricular multiple micro-fistulas (CA-LVMMFs) in adults are rare anomalies. They may cause angina pectoris and myocardial infarction in association with normal coronary arteries. METHODS AND RESULTS: From the medical databases of a Dutch Survey of coronary artery fistulas in adult cardiology population (30,829 patients), we identified 20 patients with CA-LVMMFs out of 71 fistula-subjects between 1996 and 2003. Clinical files and individual coronary angiograms were reviewed and analysed. There were 13 females and 7 males with a mean age of 67.3 years (range 49-82). The main presenting symptoms were angina pectoris and dyspnea in 70% of the patients. The ECG showed pathologic changes in 75%. Exercise tolerance test and 201-thallium stress scintigraphy were positive for myocardial ischemia in 29% and 50%, respectively of the tested patients. In the absence of significant atherosclerotic coronary artery disease, ipsilateral to the fistulas, myocardial infarction was documented in 15% of the patients. Chest X-ray revealed cardiomegaly in 38% of the patients. Congestive heart failure was documented in 10% of the patients. Uni-, bi- and multilateral fistulas were present in 50%, 45% and 5%, respectively. The origin was the LCA in 71% and the RCA in 29% of the fistulas. The majority (97%) originated from the mid or distal segments of the coronary vessels. Among those patients, the coronary arterial tree had single, dual, and triple vessel disease in 25%, 15% and 5%, respectively. Angiographic anatomy precludes surgical intervention; they were all followed by conservative medical management. CONCLUSIONS: Coronary artery-left ventricular multiple micro-fistulas are found more often in female patients. Furthermore, they originated from the distal segment of the coronary arteries. Coronary artery-left ventricular multiple micro-fistulas, in the presence of normal coronary arterial tree, may often lead to angina pectoris and coronary insufficiency.

Adult↗
PubMed2003

[Resuscitations in the hospital: reporting using the Utstein-style form and a study of 183 patients in the St. Radboud University Medical Center, Nijmegen, the Netherlands, between 1997-2000].

OBJECTIVE: To evaluate the completion of the Utstein-style forms after cardiopulmonary resuscitation (CPR) in the St Radboud University Medical Center, Nijmegen (UMCN), the Netherlands, and to assess the outcomes of the CPR attempts. DESIGN: Retrospective, descriptive. METHOD: All Utstein-style forms used in the UMCN during the period 1 January 1997-31 December 2000 were examined. The data were supplemented with information from medical records. Resuscitation events initiated in the hospital were included, with the exception of those in the coronary care and intensive care units. RESULTS: 222 forms were completed, 183 of which related to in-hospital resuscitations: 104 men and 79 women with a median age of 65 years: (P25-P75: 49-75). On 148 forms (81%), the patient name, patient identifier and date of collapse were all reported. The cause of collapse was noted in 131 cases (72%). Cardiac condition during CPR was recorded in 126 cases (69%). The Glasgow coma score 10 minutes after CPR was recorded in 41 cases (22%), and 24 hours after CPR in 15 cases (8%). Information regarding follow-up was provided on 27 forms (15%): in all cases this concerned unsuccessful resuscitation. However, medical records revealed that CPR was initially successful in 105 patients (57%), and that 55 patients (30%) eventually survived to discharge. CONCLUSIONS: The variables on the Utstein-style form relating to the acute phase were poorly completed, and even fewer variables were completed for later phases. CPR was successful in 57% of the patients, and 30% left the hospital alive.

Aged↗
PubMed1999

Acquired coronary cameral fistulas: are these collaterals losing their destination?

BACKGROUND: The majority of coronary cameral fistulas (CCFs) are congenital in origin. On the other hand, acquired coronary cameral fistulas, having various etiopathogenic origins, are increasingly recognized. HYPOTHESIS: The aim of this study was to assess the possible involvement of coronary atherosclerosis in the pathogenesis of acquired coronary cameral fistulas. METHODS: Between 1993 and 1996 coronary cameral fistulas were detected in seven adults patients with coronary atherosclerosis (n = 4) and following myocardial infarction (n = 3) with a mean age of 59.3 years (range 40-77). They were analyzed at our hospital. RESULTS: Myocardial infarction (MI) was documented in six patients and was localized at the same territory of the fistula-related artery in three of them. All patients remained asymptomatic after the detection of the fistula. Five patients had associated cardiac disorders. Two patients were treated conservatively with medical therapy. Coronary artery bypass grafting (CABG) was performed in three patients. One patient died while awaiting CABG. Thirty-four adult cases with acquired CCFs were collected from the current literature. The right coronary artery was the origin of the fistula in 37% and they terminated into the right heart-side in 72% of cases. They remained asymptomatic in 62% of cases. CONCLUSIONS: It could be concluded that acquired CCFs may complicate the course of severe atherosclerosis or myocardial infarction in certain adult patients. The symptomatology and treatment strategy is comparable in the congenital and acquired types. The distribution of involvement of the right or left coronary arteries is equally divided in both the acquired and congenital types. Further studies are needed to investigate the precipitating factors for the occurrence of and incidence of acquired CCFs in patients with severe atherosclerosis or post-MI subjects.

Adult↗
PubMed1998

Comparison of coronary flow velocity and regional myocardial perfusion for functional evaluation of coronary artery disease in the setting of angioplasty.

Two essentially different methods for physiological evaluation of coronary artery disease were compared in the setting of angioplasty and related to quantitative coronary angiography. Forty-five patients, referred for percutaneous transluminal coronary angioplasty (PTCA), were examined by digital subtraction angiography (DSA) and by coronary flow velocity measurements distal to the target stenosis. Before PTCA, hyperemic mean transit time (HMTT) was correlated with % area stenosis r = 0.56*, coronary flow velocity reserve (CFVR) r = 0.58* and with CFVRN (CFVR normalized to a mean blood pressure of 100 mmHg) r = 0.68*. The correlation between CFVR and % area stenosis was r = 0.72* (*P < 0.001). After PTCA, all correlations between these measurements disappeared. HMTT and CFVR remained abnormal in 18% and 32 % of the patients, respectively. Pre-PTCA, distal coronary flow velocity measurements were reasonably well related to the assessment of regional myocardial perfusion. Flow velocity parameters, however, were better related to angiographic stenosis parameters. After PTCA, HMTT showed a more consistent improvement compared to CFVR. Flow velocity measurements appear to be more useful for the evaluation of local coronary stenoses, whereas the assessment of regional myocardial perfusion by DSA may be used for a more general evaluation of vessel territories.

Adult↗
PubMed1997

Functional evaluation of lipid-lowering therapy by pravastatin in the Regression Growth Evaluation Statin Study (REGRESS)

BACKGROUND: Lipid-lowering therapy during 2 years in the Regression Growth Evaluation Statin Study (REGRESS) was associated with less progression of coronary atherosclerosis in the pravastatin group compared with the placebo group. The effect of lipid-lowering therapy on the functional state of the coronary circulation is less well known. The purpose of this study was to evaluate this effect. METHODS AND RESULTS: In a substudy of REGRESS, 69 patients were randomized to pravastatin or placebo. Thirty-seven of these patients were allocated to the medical management stratum. Quantitative coronary angiography, regional myocardial perfusion, exercise testing, and classification of angina pectoris were assessed at baseline and after 2 years of therapy. Regional myocardial perfusion was assessed by digital subtraction angiography after intracoronary papaverine with video-densitometric calculation of the hyperemic mean transit time (HMTT) of contrast. In the medical management stratum, regional myocardial perfusion was assessed in 31 regions in the pravastatin group and 25 regions in the placebo group. The change in HMTT in the pravastatin group was -0.18 seconds (-5%) and in the placebo group +0.52 seconds (+18%), a difference of 0.70 seconds (P=.004). The mean difference in change in classification of angina pectoris (scale, 1 to 4) between pravastatin and placebo was 0.7 (P=.03) in favor of the pravastatin-treated patients. The change in HMTT was correlated with the change in exercise time (r=-.65, P=.002). CONCLUSIONS: In patients with symptomatic coronary artery disease, treatment with the HMG-coenzyme A reductase inhibitor pravastatin during 2 years resulted in a preserved regional myocardial perfusion, whereas patients on placebo deteriorated. The classification of angina pectoris improved only in patients receiving pravastatin. In lipid-lowering therapy, the evaluation of myocardial perfusion by assessment of the HMTT reveals a combined measure of functional and structural changes in the coronary circulation.

Adult↗
PubMed1997

Coronary arteriovenous fistulas: collective review and management of six new cases--changing etiology, presentation, and treatment strategy.

We considered it worthwhile to review the literature of the last decade (1985-1995) to answer the question whether the etiology and the clinical picture of coronary arteriovenous fistulas (CAVFs) have changed. Furthermore, new therapeutic modalities such as percutaneous transcatheter embolization have been developed. We tried to define the place of these techniques in the therapeutic arena. Clinical presentation and management of six patients with eight congenital CAVFs and 76 subjects with 96 congenital and acquire I CAVFs taken from a review of the recent literature are presented. Sixty-three review subjects (78%) were treated medically with one fatal case. Ligation of the fistula was achieved by surgical techniques in 10% of review subjects, while percutaneous transcatheter embolization (PTE) was performed in nine patients (12%). Percutaneous transcatheter embolization techniques are being increasingly used in the treatment of CAVFs. The etiology of CAVFs has a tendency to show alterations toward the acquired pathogenesis. In 64% of the review subjects the fistula was congenital in origin, and in 36% it had an acquired cause. Among the patients of the current review, the clinical presentations were 55% asymptomatic, 34% chest pain (anginal or atypical), and 13% congestive heart failure. The CAVFs of our six patients are all congenital in origin. In the current review, the clinical presentation showed a trend toward increasing chest complaints (34%) compared with the review (10%) published in the mid 1970s. This may be due to a higher mean age, and hence increased concurrent coronary artery disease due to aging compared with the review population of two decades ago.

Adolescent↗
PubMed1996

Is noninvasive determination of pulmonary artery pressure feasible using deceleration phase Doppler flow velocity characteristics in mechanically ventilated children with congenital heart disease?

Noninvasive determination of pulmonary hemodynamics is important for the management of congenital heart disease complicated by pulmonary hypertension. Flow deceleration is less influenced by right ventricular function and would allow more accurate estimation of pulmonary hemodynamics than acceleration. Respiratory influences on pulmonary blood flow are exaggerated by mechanical ventilation. Doppler-derived pulmonary artery (PA) blood flow velocity characteristics were therefore compared with pulmonary hemodynamic parameters in 42 mechanically ventilated children, aged 0.2 to 14.8 years (mean +/- SD 6.7 +/- 4.9). Mean PA pressure ranged from 11 to 47 mm Hg (21 +/- 9 mm Hg). Pulmonary hypertension was present in 14 patients. Significant differences were found between patients with and without pulmonary hypertension in maximal velocity (1.03 +/- 0.22 vs 0.88 +/- 0.18 m/s), acceleration time (119 +/- 39 vs 136 +/- 29 ms), maximal acceleration (17.6 +/- 6.4 vs 13.1 +/- 4.0 m/s2), mean acceleration (9.3 +/- 2.6 vs 6.7 +/- 2.0 m/s2), and mean deceleration (4.5 +/- 1.0 vs 3.8 +/- 0.8 m/s2). In contrast to our hypothesis of the deceleration phase-derived parameters, only maximal deceleration correlated with PA pressure. Acceleration parameters showed closer relations with PA pressures, but correlations were generally low and did not permit accurate prediction of PA pressure (SEE 5 to 11 mm Hg), PA resistance (SEE 1.14 U. m2) or PA driving force (SEE 7 mm Hg). An analysis that took respiratory phase into account did not improve correlations. Measurement of mean acceleration, maximal deceleration, and rate-corrected preejection period permitted for accurate discrimination between the presence or absence of pulmonary hypertension, with positive and negative predictive values being 92% and 90%. In mechanically ventilated children with congenital heart disease, accurate noninvasive PA pressure assessment is not possible. Accurate predictions for the presence of pulmonary hypertension can be made by measurement of both acceleration and deceleration parameters.

Adolescent↗
PubMed1996

[No sex differences observed in thrombolysis treatment in acute myocardial infarct but they are found in contraindications and complications].

OBJECTIVE: To detect possible differences between men and women in thrombolytic treatment after acute myocardial infarction. DESIGN: Retrospective chart study. SETTING: University Hospital Nijmegen, the Netherlands. METHOD: The data were studied of all patients diagnosed at discharge as 'myocardial infarction' during the period July 1992 to December 1993, with comparison of men and women. RESULTS: There were 181 patients with myocardial infarction: 53 women (29%) and 128 men (71%). At the time of diagnosis, the women on average were 9 years older than the men. Of these patients, 24 women (45%) and 66 men (52%) were treated with a thrombolytic agent. In 30% of the cases in both men and women, the main reason not to give a thrombolytic agent was exceeding the time limit of 6 hours after the first symptoms. In addition, thrombolysis was refrained from because of contraindications in 23% of the women and in 17% of the men. In women, an 'inconclusive' ECG was an important reason for not giving thrombolysis. There was a difference between the numbers of women and men who developed complications after thrombolysis (25% as against 8%); in women these complications were mostly haemorrhages. 25% of the women and 15% of the men died in hospital. CONCLUSION: Women with a myocardial infarction were given thrombolytic treatment about as often as men. There were sex differences regarding the contraindications to thrombolysis and the complications after thrombolysis.

Acute Disease↗
PubMed1996

LDL-Apheresis Atherosclerosis Regression Study (LAARS). Effect of aggressive versus conventional lipid lowering treatment on coronary atherosclerosis.

BACKGROUND: Intensive lipid lowering may retard the progression of coronary atherosclerosis. LDL-apheresis has the potential to decrease LDL cholesterol to very low levels. To assess the effect of more aggressive lipid lowering with LDL-apheresis, we set up a randomized study in men with hypercholesterolemia and severe coronary atherosclerosis. METHODS AND RESULTS: For 2 years, 42 men were treated with either biweekly LDL-apheresis plus medication or medication alone. In both groups a dose of simvistatin of 40 mg per day was administered. Baseline (mean+/-SD) LDL cholesterol was 7.8+/-1.9 mmol x L(-1) and 7.9+/-2.3 mmol x L(-1) in the apheresis and medication groups, respectively. The mean reduction in LDL cholesterol was 63% (to 3.0 mmol x L(-1)) and 47% (to 4.1 mmol x L(-1)), respectively. Primary quantitative coronary angiographic end points were changes in average mean segment diameter and minimal obstruction diameter. No differences between the apheresis and medication groups were found in mean segment diameter (-0.01+/-0.16 mm versus 0.03+/-0.16 mm, respectively) or in minimal obstruction diameter (0.01+/-0.13 mm versus 0.01+/-0.11 mm, respectively), expressed as means per patient. On the basis of coronary segment, mean percent stenosis of all lesions showed a tendency to decrease; only in the apheresis group more minor lesions disappeared in comparison to the medication group. On bicycle exercise tests, the time to 0.1 mV ST-segment depression increased significantly by 39% and the maximum level of ST depression decreased significantly by 0.07 mV in the apheresis group versus no changes in the medication group. CONCLUSIONS: Two years of lipid lowering both with medication alone or LDL-apheresis with medication showed angiographic arrest of the progression of coronary artery disease. However, more aggressive treatment induced functional improvement, which may precede anatomic changes.

Adult↗
PubMed1996

Low density lipoprotein apheresis improves regional myocardial perfusion in patients with hypercholesterolemia and extensive coronary artery disease. LDL-Apheresis Atherosclerosis Regression Study (LAARS).

OBJECTIVES: In a randomized study we evaluated the effect of biweekly low density lipoprotein (LDL) apheresis plus simvastatin versus medication alone on regional myocardial perfusion. BACKGROUND: In patients with severe hypercholesterolemia, diet and lipid-lowering drugs are often insufficient to achieve optimal LDL cholesterol values. Low density lipoprotein apheresis is a very effective lipid-lowering therapy. Assessment of regional myocardial perfusion enables evaluation of the functional state of the coronary circulation. METHODS: We studied 42 patients with severe hypercholesterolemia and extensive coronary artery disease who were randomized to diet and simvastatin with or without biweekly LDL apheresis. Regional myocardial perfusion was assessed by digital subtraction angiography with videodensitometric calculation of hyperemic mean transit time (HMTT) of contrast medium at baseline and after 2 years of therapy. RESULTS: Low density lipoprotein cholesterol decreased by 63% (to 3.0 mmol/liter) in the LDL apheresis group and by 47% (to 4.1 mmol/liter) in the medication group. Paired HMTT measurements were assessed in 43 regions in the LDL apheresis group and 35 regions in the medication group. In the LDL apheresis group, regional HMTT decreased over 2 years from 3.35 +/- 1.18 (mean +/- SD) to 2.87 +/- 0.82 s (-14%, p = 0.001), whereas no change in the medication group was observed: 2.95 +/- 1.06 to 2.96 +/- 0.90 s (p = NS). In the patient-based comparison, the mean change in HMTT was -0.45 s (-14%, p = 0.01) in the LDL apheresis group and -0.05 s (-2%, p = NS) in the medication group, respectively. Only exercise-induced ischemia improved in the LDL apheresis group. CONCLUSIONS: Biweekly LDL apheresis plus simvastatin decreased time-averaged LDL cholesterol levels by an additional 31% (1.1 mmol/liter) compared with medication alone. After 2 years of therapy, regional myocardial perfusion improved in the LDL apheresis group and remained unchanged in the medication group. Thus, aggressive reduction of LDL cholesterol has a favorable effect on regional myocardial perfusion and alleviates ischemia.

Adult↗
PubMed1995

[Acute rheumatic fever in a 33-year-old man].

In a 33-year-old man with an abnormal ECG three weeks after an episode of a sore throat, laboratory investigations revealed signs of a recent streptococcal infection. Mitral valvular and aortic valvular regurgitation were confirmed by echocardiography. The diagnosis of acute rheumatic fever was established according to the Jones criteria.

Adult↗
PubMed1994

Importance of the coronary collateral circulation for the distribution of anterograde and retrograde delivered cardioplegic solution in aortocoronary bypass surgery: a haemodynamic study.

The importance of coronary collateral circulation for homogeneous distribution of anterograde and retrograde delivery of cardioplegia was evaluated in 36 patients undergoing myocardial revascularization. All patients had three-vessel coronary artery disease, with a stenosis of the right coronary artery of at least 80%. The patients were randomized into two groups: group A (n = 19) received anterograde delivered cardioplegic solution and group B (n = 17) received retrograde. Both groups were further subdivided depending on the pathology of the right coronary artery, as evaluated on preoperative coronary angiography. In group A1 (n = 8) and group B1 (n = 7) there was no visualization of collateral circulation from the left to the right coronary artery system, whereas in group A2 (n = 11) and group B2 (n = 10) there was retrograde filling of the right coronary artery by collateral circulation. Right atrial pressure increased significantly (P < 0.05) in group A1 and was elevated in group A2, but not significantly (P = 0.07). By contrast, right arterial pressure decreased in groups B1 and B2. Analysis of the individual differences in the right atrial filling pressure showed a statistical significance between the two subgroups (group B1-1.0(0.5) versus group B2-1.8(1.1), P < 0.05), although the individual decrease of the right ventricular stroke work index was not significant. It is concluded that collateral circulation is important for an adequate distribution of anterogradely delivered cardioplegia and is also beneficial in cases of retrograde delivery.

Adult↗
PubMed1994

Experience and early results of second reoperations for coronary artery disease. Should patent vein grafts be replaced during reoperation?

Reoperation for coronary artery disease has become a routine procedure; however, a second reoperation is exceptional. In this report we describe our experience with 16 patients undergoing a second reoperation for coronary atherosclerosis. The absence of operative mortality is certainly related to the patient selection. The number of patients is still too small to draw major conclusions. Striking, however, is that the first reoperation was usually done for angina because of progression of atherosclerosis in the native coronary system and the second reoperation was done because of graft failure. This experience supports the idea that the replacement of old, even patent, venous grafts and the choice of the best available conduits are of great importance at the first reoperation and may prevent a second reoperation.

Coronary Angiography↗
PubMed1993

[Erroneous diagnosis of lithium poisoning due to use of lithium-heparin bloodletting tubes].

In two male patients, aged 53 and 21 years, lithium intoxication was suspected. The diagnosis was apparently confirmed by blood testing (the lithium concentrations amounted to 3.68 and 1.82 mmol/l, respectively). Retrospectively however it was found that blood sampling tubes with lithium-heparin as the anticoagulant had been used. No lithium intoxication was present in the patients. Clear instructions in writing are necessary to prevent this error.

Adult↗
PubMed1993

Haemodynamic evaluation of retrograde versus anterograde delivery of cardioplegic solution in aortic valve replacement.

A total of 44 patients undergoing isolated aortic valve replacement received either anterograde (20 patients) or retrograde (24 patients), cold St Thomas's Hospital cardioplegia. The patients were similar with respect to age, sex, left ventricular ejection fraction, left ventricular-aortic pressure gradient, cross-clamping time and mean dose of cardioplegia. After surgery, there were no differences in enzyme release, low cardiac output syndrome, rhythm disturbances or clinical outcome between the two groups. Analysis of the postoperative haemodynamic data, however, suggests better preservation of left ventricular contractility with retrograde delivery of cardioplegic solution.

Adult↗