Tjeerd van der Werf

Solitary coronary artery fistulas: a congenital anomaly in children and adults. A contemporary review.

Congenital solitary coronary artery fistulas (CAFs) in adults are uncommon anomalies, which by themselves may resemble the whole spectrum of cardiac presentations from asymptomatic behavior to life-threatening and catastrophic events with syncope or shock and even sudden death. It may take decades to collect a reasonable series of patients in adults and children. From the literature between 1993 and 2004, 236 patients with CAFs were considered for evaluation. The present review is intended to assist cardiologists who are unfamiliar with congenital CAFs in adults by suggesting clues for decision making regarding diagnosis and management. Dyspnea and chest pain represented a frequent 91/128 (71%) clinical symptom in CAFs in adults while in the pediatric age group the majority were silent 105/133 (79%) and dyspnea and chest pain accounted for only 8% of the symptoms. The diagnostic modalities were mainly cardiac catheterization and coronary angiography. On the other hand, in the pediatric patients, echocardiography and coronary angiography mainly guided the diagnosis. Regarding treatment strategy in the reviewed subjects, percutaneous transluminal embolization was performed in 18% of the pediatric and in only 5% of the adult subjects. Surgical ligation (46% vs. 38%) and conservative medical strategies (36% vs. 24%) were reported in both pediatric and adult groups. Presentations of CAFs vary considerably in both groups. These differences include the diagnostic modalities, spontaneous closure, spontaneous rupture, and management. From this review, it seemed that--but it may be biased--surgical ligation remains the major mainstay for closure of CAFs in adult and pediatric populations. Recommendations are necessary for antibiotic prophylaxis and antiplatelet and/or anticoagulant therapy for prevention of endocarditis and thrombotic events in patients with CAFs associated with coronary artery dilatation or aneurysmal formation of the fistulous tract.

Cardiopulmonary resuscitation on the general ward: no category of patients should be excluded in advance

In this study 91 consecutive CPR cases in 90 patients on general wards were evaluated during 18 months. Fifteen patients (16.5%) could be discharged, which is relatively favourable in comparison to the literature. Children proved to have a better chance to leave the hospital alive than adults (6/18 vs. 9/72; P less than 0.05). No factors with negative predictive value before the cardiopulmonary arrest could be isolated. Even oncological patients, often described as a prognostically poor category, with a success rate of 27% (6/22) did not differ from other categories. Patients with isolated respiratory arrest, ventricular tachycardia or ventricular fibrillation at the arrival of the CPR-team had a better chance to be discharged from the hospital. A rapid decrease in survival was noted if a CPR attempt lasted longer than 10 min (P less than 0.001). When there is no return of vital signs within 30 min the CPR attempt can be stopped. During follow-up period (mean 6 month) 2 of the 15 survivors (13.3%) died from a non-cardiopulmonary cause. It is concluded that no category of patients can be excluded from CPR in advance. Although ultimate success rate for CPR in the general wards will rarely exceed 15%, CPR has to be initiated in most cases of cardiopulmonary arrest.

Mean transit time for videodensitometric assessment of myocardial perfusion and the concept of maximal flow ratio: A validation study in the intact dog and a pilot study in man

SummaryOver the last decade it has become more and more obvious that besides anatomical information about the severity of coronary artery stenoses, information about coronary and myocardial blood flow is necessary to understand the functional significance of these obstructions and to evaluate the result of an intervention. Several methods have been proposed for this purpose, each of these having their particular limitations.In this study a new method is shortly described which allows the accurate calculation of relative maximal myocardial perfusion by ECG-triggered digital radiography (videodensitometry), using mean transit time (Tmn) as time parameter; this technique is based on the original physiologic principles of indicator dilution theory. This method was validated in 8 instrumented dogs in which an excellent linear relation was present between 1/Tmn and flow (r=0.96 ± 0.03). Although this method does not allow assessment of resting flow and therefore coronary flow reserve (CFR), it provides a means for the reliable comparison of maximal myocardial flow in different situations and it is independent of most factors affecting coronary flow reserve.The ratio between maximal flow after and before an intervention is called maximal flow ratio (MFR) and this concept was applied in a pilot study in man to evaluate PTCA results in 10 patients undergoing elective angioplasty. MFR was compared with the result of exercise testing 24 hours before and 10 days after the angioplasty. MFR ≥ 1.5 was always accompanied by reversal of exercise test result from positive to negative.We conclude that the accurate calculation of relative maximal perfusion of the myocardium is possible by videodensitometry and suggest that comparison of maximal flow after and before an intervention can be valuable in man for functional evaluation of the result of the intervention.

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.

Reproducibility of mean transit time for maximal myocardial flow assessment by videodensitometry

In the assessment of myocardial perfusion by ECG-triggered digital radiography, time parameters are calculated from the time density curve (TDC) and related to blood flow.Recently we developed a method which uses mean transit time (Tmn) as time parameter, and which is in accordance with the original principles of indicator dilution theory. In this approach, variability in vascular volume is excluded and Tmn−1, determined at maximal hyperemia, showed an excellent correlation with maximal flow in animal validation studies. For calculation of Tmn, however, a large part of the descending limb of the TDC has to be known for reliable extrapolation, and especially this part of the curve is subject to variability in image quality in man. Therefore we tested reproducibility of Tmn in 30 arteries in 20 patients. Tmn was derived from the TDCs, obtained from paired studies under identical circumstances with an interval of 10 minutes. Satisfactory images could be obtained in all but one patient. Image processing was performed in an identical way in the paired studies. Reproducibility proved to be excellent for all three coronary arteries. The absolute value of the relative differences between the first and second determination was 7±7% for the LAD, 6±3% for LCx and 4±2% for the RCA (mean ± SD). Correlation coefficients between both measurements were 0.97, 0.95 and 0.95 for the respective arteries. Therefore, it is concluded that, using this approach, Tmn at maximal hyperemia can be determined reproducibly in man and used for maximal myocardial flow assessment.

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.

Congenital and Atherosclerotic (Acquired) Coronary Artery Aneurysms: Coronary Angiographic and Morphologic Observations in 10 Patients

Coronary angiographic observations in 10 patients with coronary artery aneurysms (CAAs) are reported. Four patients had atherosclerotic (acquired) and six had congenital CAAs. The mean age of patients with acquired CAAs was higher (64.7 years) compared with the congenital group (53.2 years). Ipsilateral myocardial infarction (MI) occurred in three of four patients with acquired CAAs but MI was not located on the same side as the aneurysm-bearing coronary artery (contralateral) in two patients with the congenital variety. In the patients with congenital CAAs, an aneurysm predilection site was observed in the proximal portion of the aneurysm-bearing vessel. Dual and multiple aneurysms were more common in the acquired CAAs. Although congenital CAAs were sizeable, the small-sized atherosclerotic CAAs developed complications more frequently. During an average follow-up of 7.9 years, only one patient died of a noncardiac cause and another developed recurrent uncomplicated non-Q wave lateral MI. Both subjects had atherosclerotic CAAs. In our series, no rupture or sudden death occurred. Coronary artery bypass grafting (CABG) was performed in three patients with acquired and in one patient with congenital CAAs. In the latter patient, simultaneous ligation of the congenital aneurysm associated with a coronary arteriovenous fistula was performed. Regarding antiplatelet and anticoagulant policy for the whole group, three patients were on aspirin, four were on acenocoumarol, and in another three subjects with congenital CAAs, a medical regimen was followed. Larger series, however, are required in order to elucidate further angiographic characteristics of acquired vs congenital CAAs.

Effect of lipid lowering therapy on myocardial perfusion; results from REGRESS and LAARS

In patients with coronary artery disease, lipid lowering therapy during 2–5 years is associated with less progression of coronary atherosclerosis in comparison to placebo [1, 2, 3, 4, 5, 6]. The effect of lipid lowering therapy on regional myocardial perfusion is less well known. We evaluated the effect of lipid lowering therapy during 2 years on myocardial perfusion by assessment of the hyperemic mean transit time (HMTT) of contrast passage by means of digital subtraction angiography [7,8]. This effect was studied in patients with coronary artery disease with normal to moderately elevated cholesterol levels within a substudy of the REgression GRowth Evaluation Statin Study (REGRESS), and in patients with extensive coronary artery disease and severe hypercholesterolemia in the LDL-Apheresis Atherosclerosis Regression Study (LAARS) [7,9]. The methodologic issues and results of both studies are summarized, and discussed in relation to each other.