The Low-Flow-Mediated Arterial Constriction in the Upper Limbs of Healthy Human Subjects are Artery Specific and Handedness Independent

Low-flow-mediated constriction (LFMC) has been used to assess resting endothelial function in peripheral conduit arteries. The literature describes discrepancies in the behaviour of radial versus brachial artery in response to low-flow state, the reasons for which were not addressed in a systematic and scientific way. Moreover, the influence of handedness on observed LFMC responses has not been investigated. The present study aimed at systematic measurement and comparison of the LFMC responses in radial and brachial arteries of both dominant and non-dominant arms of healthy human volunteers. We also investigated the physiological factors associated with differential LFMC response of radial versus brachial artery in the same group of subjects. Longitudinal B mode ultrasonographic cine loops of radial and brachial arteries were acquired at baseline and after producing distal circulatory arrest. Cine loops were screen grabbed and analyzed later using automated edge detection algorithms to measure end-diastolic diameters. Distal circulatory arrest was produced over the proximal forearm (for the brachial artery) and over the wrist (for the radial artery) at 250 mm Hg for 5 min after baseline measurements. Results suggested that arterial location (p = 0.0001) and baseline diameter (p < 0.0021) emerged as independent predictors of LFMC response. Differences in the LFMC responses are handedness independent and could be attributed to the arterial location along with the differences in their baseline diameters.

[Myocardial ischemia without coronary obstructions: MINOCA-INOCA. Review for decision making]

One in every four coronarographies performed to study myocardial ischemia shows coronary angiographic stenosis less than 50%. This data triggered an increasing interest in the medical community. The American Society of Cardiology recently published a position paper about the pathophysiology, diagnosis and treatment of this entity. Our group performed a narrative review reflecting the opinion of cardiology experts from different centers in Argentina. It aims physiopatologic and diagnostic aspect to understand the current approach in patients with MINOCA (myocardial infarction with non-obstructive coronary arteries) e INOCA (demonstrated angina and ischemia but without coronary lesions that justify this syndrome).

Real-Time Cineangiography Visualization of Cerebral Aneurysm Rupture in an Awake Patient: Anatomic, Physiological, and Functional Correlates

Intracranial aneurysms are common and, on a population-based perspective, are a major cause of morbidity and mortality as a result of mass effect or rupture. Cerebral angiography is the primary technique used for the diagnosis of cerebral aneurysms, and the imaging data have additional utility for planning medical, endovascular, or surgical treatments. An extremely rare periprocedural complication of cerebral angiography is rupture of the aneurysm, either as a chance phenomenon or as a result of some physiologic change or mechanical effect. We report on a single awake, alert patient who experienced intraprocedural aneurysm rupture that was recorded in real time during diagnostic cerebral angiography and subsequently proved fatal. Rupture occurred shortly after the completion of contrast material injection into a semi-open vascular bed and appeared to be temporally unrelated to any supranormal change in systemic physiology. No therapeutic endovascular procedure was planned or attempted. From the high-quality sequential, frame-by-frame images, and electronic sedation and anesthesiology records, plus our own real-time observations (G.L., W.L.L.), we were able (for educational purposes) to reconstruct the time course of rupture of the aneurysm, the velocity and pattern of blood escaping the aneurysm and entering the subarachnoid space, and other physiologic and functional correlates (blood pressure changes, alterations in consciousness) that may be critical to our understanding of the mechanism and consequences of aneurysm rupture.

Comparative Study between Perfusion Changes and Positive Findings on Coronary Flow Reserve

BACKGROUND

Functional assessment of coronary artery obstruction is used in cardiology practice to correlate anatomic obstructions with flow decrease. Among such assessments, the study of the coronary fractional flow reserve (FFR) has become the most widely used.

OBJECTIVE

To evaluate the correlation between FFR and findings of ischemia obtained by noninvasive methods including stress echocardiography and nuclear medicine and the presence of critical coronary artery obstruction.

METHODS

Retrospective study of cases treated with systematized and standardized procedures for coronary disease between March 2011 and August 2014. We included 96 patients with 107 critical coronary obstructions (> 50% in the coronary trunk and/or ≥ 70% in other segments) estimated by quantitative coronary angiography (QCA) and intracoronary ultrasound (ICUS). All cases presented ischemia in one of the noninvasive studies.

RESULTS

All 96 patients presented ischemia (100%) in one of the functional tests. On FFR study with adenosine 140 g/kg/min, 52% of the cases had values ≤ 0.80. On correlation analysis for FFR ≤ 0.80, the evaluation of sensitivity, specificity, positive and negative predictive values, accuracy, and ROC curve in relation to the stenosis degree and length, and presence of ischemia, no significant values or strong correlation were observed.

CONCLUSION

Coronary FFR using a cut-off value of 0.80 showed no correlation with noninvasive ischemia tests in patients with severe coronary artery obstructions on QCA and ICUS.

Does the use of additional X-ray beam filtration during cine acquisition reduce clinical image quality and effective dose in cardiac interventional imaging?

The impact of spectral filtration in digital ('cine') acquisition was investigated using a flat panel cardiac interventional X-ray imaging system. A 0.1-mm copper (Cu) and 1.0-mm aluminium (Al) filter added to the standard acquisition mode created the filtered mode for comparison. Image sequences of 35 patients were acquired, a double-blind subjective image quality assessment was completed and dose-area product (DAP) rates were calculated. Entrance surface dose (ESD) and effective dose (E) rates were determined for 20- and 30-cm phantoms. Phantom ESD fell by 28 and 41 % and E by 1 and 0.7 %, for the 20- and 30-cm phantoms, respectively, when using the filtration. Patient DAP rates fell by 43 % with no statistically significant difference in clinical image quality. Adding 0.1-mm Cu and 1.0-mm Al filtration in acquisition substantially reduces patient ESD and DAP, with no significant change in E or clinical image quality.

4D-cine CT imaging of a bicuspid pulmonary valve

A 71-year-old woman underwent diagnostic workup for progressive shortness of breath. Transthoracic echocardiography showed a dilated main pulmonary artery (MPA) and an anomalous configuration of the pulmonary valve. CT revealed a bicuspid pulmonary valve (BPV) and confirmed MPA dilation. Further congenital abnormalities were excluded. An isolated finding of BPV is rather rare. To our knowledge we present the first 4-dimensional CT images of a BPV. As in this case, 4-dimensional cine cardiac CT may be helpful to reveal the underlying cause of MPA dilation.

Physician-received scatter radiation with angiography systems used for interventional radiology: comparison among many X-ray systems

Radiation protection for interventional radiology (IR) physicians is very important. Current IR X-ray systems tend to use flat-panel detectors (FPDs) rather than image intensifiers (IIs). The purpose of this study is to test the hypothesis that there is no difference in physician-received scatter radiation (PRSR) between FPD systems and II systems. This study examined 20 X-ray systems in 15 cardiac catheterisation laboratories (11 used a FPD and 9 used an II). The PRSR with digital cineangiography and fluoroscopy were compared among the 20 X-ray systems using a phantom and a solid-state-detector electronic pocket dosemeter. The maximum PRSR exceeded the minimum PRSR by ~12-fold for cineangiography and ~9-fold for fluoroscopy. For both fluoroscopy and digital cineangiography, the PRSR had a statistically significant positive correlation with the entrance surface dose (fluoroscopy, r = 0.87; cineangiography, r = 0.86). There was no statistically significant difference between the average PRSR of FPDs and IIs during either digital cineangiography or fluoroscopy. There is a wide range of PRSR among the radiography systems evaluated. The PRSR correlated well with the entrance surface dose of the phantom in 20 X-ray units used for IR. Hence, decreasing the dose to the patient will also decrease the dose to staff.

Coronary artery perforation successfully treated with tris-acryl gelatin microsphere embolisation

We describe a case of coronary artery perforation in a 76-year-old man, successfully treated by tris-acryl gelatin microsphere embolisation. This novel interventional embolic material is used in interventional radiology for arterial embolisation. We believe that this is the first report of its use for a coronary artery perforation.

Use of dynamic computed tomography to evaluate pre- and postoperative aortic changes in AAA patients undergoing endovascular aneurysm repair

PURPOSE

To utilize dynamic computed tomographic angiography (CTA) on pre- and postoperative endovascular aneurysm repair (EVAR) patients to characterize cardiac-induced aortic motion within the aneurysm neck, an essential EVAR sealing zone.

METHODS

Electrocardiographically-gated CTA datasets were acquired utilizing a 64-slice Philips Brilliance CT scanner on 15 consecutive pre- and postoperative AAA patients. Axial pulsatility measurements were taken at 2 clinically relevant levels within the aneurysm neck: 2 cm above the highest renal artery and 1 cm below the lowest renal artery. Changes in aortic area and diameter were determined.

RESULTS

Significant aortic pulsatility exists within the aneurysm neck during the cardiac cycle. Preoperative aortic area increased significantly, with a maximum increase of up to 12.5%. The presence of an endograft did not affect aortic pulsatility (p=NS). Postoperative area also changed significantly during a heart cycle, with a maximum increase of up to 14.5%. Diameter measurements demonstrated an identical pattern, with significant pre- and postoperative intracardiac pulsatility within and above the aneurysm neck (p<0.05). An increase in maximum diameter change up to 15% was evident.

CONCLUSION

Patients undergoing EVAR experience aortic diameter changes within and above the aneurysm neck. The presence of an endograft does not abrogate this response to intracardiac pressure changes. Static CT imaging may not adequately identify patients with large aortic pulsatility, potentially resulting in endograft undersizing, stent-graft migration, intermittent type I endoleaks, and poor patient outcomes. The current standard regime of 10% to 15% oversizing based on static CT may be inadequate for some patients.

P-wave duration and dispersion in patients with coronary slow flow and its relationship with Thrombolysis in Myocardial Infarction frame count

AIM

P-wave dispersion (PD), and duration has been reported to be associated with inhomogeneous and discontinuous propagation of sinus impulses. The aim of this study was to investigate the PD in patients with coronary slow flow (CSF) phenomenon.

METHODS

Study population included 48 patients with angiographically proven normal coronary arteries and slow coronary flow in all 3 coronary vessels (group I, 36 men; mean age, 54 +/- 9 years) and 32 subjects with angiographically proven normal coronary arteries without associated slow coronary flow (group II, 24 men, mean age, 53 +/- 10 years). Coronary flow rates of all patients and control subjects were documented by Thrombolysis In Myocardial Infarction (TIMI) frame count. All patients in group I had TIMI frame counts greater than 2 SD above those of control subjects (group II). The mean TIMI frame count for each patient and control subject was calculated by adding the TIMI frame counts for each major epicardial coronary artery and then dividing the obtained value into 3. The maximum and minimum P-wave duration (P(max) and P(min)) and PD were measured from the 12-lead surface electrocardiogram. Echocardiographic examination was also performed.

RESULTS

There was no statistically significant difference between the 2 groups with respect to age, sex, hypertension, diabetes mellitus, hyperlipidemia, and cigarette smoking (P > .05). P-wave dispersion and P(max) of patients with CSF were found to be significantly higher than those of control subjects (39.4 +/- 17 vs 21.2 +/- 10 milliseconds and 121.6 +/- 17.1 vs 104.3 +/- 10.4 milliseconds, respectively; P < .0001). Moreover, we found a significant positive correlation between both P(max) and PD with mean TIMI frame count (r = 0.836 and r = 0.806, respectively; P < .0001).

CONCLUSIONS

P-wave dispersion and P-wave duration both were found to be greater in patients with CSF than in controls.

Renal frame count: a quantitative angiographic assessment of renal perfusion

Renal perfusion may be measured by a variety of noninvasive methods; however, there is no objective angiographic method to assess renal perfusion. We measured the renal frame count (RFC) in 26 patients (50 kidneys) with normal renal function and normal renal angiograms and 9 patients (15 kidneys) with renal artery fibromuscular dysplasia (FMD) and normal renal function. The mean age of the patients with normal renal arteries was 61.5 +/- 9.5 (range, 47-82 years) and the mean age of patients with FMD was 72.5 +/- 9.2 (range, 54-86 years; P = 0.005). There was no correlation between the age and RFC in both the normal renal artery group and the FMD group. The mean RFC for the normal renal arteries was 20.4 +/- 3 (95% CI = 19.5-21.2), which was significantly lower than the FMD group's mean RFC of 26.9 +/- 9.9 (95% CI = 21.4-32.4; P = 0.0001). RFC is an objective angiographic measure to quantify renal perfusion. Compared to normal renal arteries, those with FMD had significantly increased RFC consistent with decreased perfusion.

Angiographic views used for percutaneous coronary interventions: a three-dimensional analysis of physician-determined vs. computer-generated views

The goal of this study was to determine the severity of vessel foreshortening in standard angiographic views used during percutaneous coronary intervention (PCI). Coronary angiography is limited by its two-dimensional (2D) representation of three-dimensional (3D) structures. Vessel foreshortening in angiographic images may cause errors in the assessment of lesions or the selection and placement of stents. To date, no technique has existed to quantify these 2D limitations or the performance of physicians in selecting angiographic views. Stent deployment was performed in 156 vessel segments in 149 patients. Using 3D reconstruction models of each patient's coronary tree, vessel foreshortening was measured in the actual working view used for stent deployment. A computer-generated optimal view was then identified for each vessel segment and compared to the working view. Vessel foreshortening ranged from 0 to 50% in the 156 working views used for stent deployment and varied by coronary artery and by vessel segment within each artery. In general, views of the mid circumflex artery were the most foreshortened and views of the right coronary artery were the least foreshortened. Expert-recommended views frequently resulted in more foreshortening than computer-generated optimal views, which had only 0.5% +/- 1.2% foreshortening with < 2% overlap for the same 156 segments. Optimal views differed from the operator-selected working views by > or = 10 degrees in over 90% of vessels and frequently occurred in entirely different imaging quadrants. Vessel foreshortening occurs frequently in standard angiographic projections during stent deployment. If unrecognized by the operator, vessel foreshortening may result in suboptimal clinical results. Modifications to expert-recommended views using 3D reconstruction may improve visualization and the accuracy of stent deployment. These results highlight the limitations of 2D angiography and support the development of real-time 3D techniques to improve visualization during PCI.

Three-dimensional trajectory assessment of an IVUS transducer from single-plane cineangiograms: a phantom study

The recovery of the three-dimensional (3-D) path of the transducer used during an intravascular ultrasound (IVUS) examination is of primary importance to assess the exact 3-D shape of the vessel under study. Traditionally, the reconstruction is done by simply stacking the images during the pullback, or more recently using biplane angiography to recover the vessel curvature. In this paper, we explain, how single-plane angiography can be used with two projection models, to perform this task. Two types of projection geometry are analyzed: weak-perspective and full-perspective. In weak-perspective projection geometry, the catheter path can be reconstructed without prior transducer depth information. With full-perspective projection geometry, precise depth location of reference points are needed in order to minimize the error of the recovered transducer angle of incidence. The transducer angulation reconstruction is based on the foreshortening effect as seen from the X-ray images. By comparing the measured to the true transducer length, we are able to get its incidence angle. The transducer trajectory is reconstructed by stitching together the different estimated angulations obtained from each image in a cineangiogram sequence. The method is described and validated on two helical vessel phantoms, giving on average a reconstructed path that is less than 2 mm distant from the true path when using full-perspective projection.

Increased thrombolysis in myocardial infarction frame count in patients with myocardial infarction and normal coronary arteriogram: a possible link between slow coronary flow and myocardial infarction

BACKGROUND

Thrombolysis in myocardial infarction (TIMI) frame count is a simple clinical tool for assessing quantitative indexes of coronary blood flow. This technique counts the number of cineangiographic frames from initial contrast opacification of the proximal coronary artery to opacification of distal arterial landmarks. We hypothesized that patients with normal coronary artery (NCA) and myocardial infarction (MI) might have impaired coronary flow. Accordingly, we assessed the TIMI frame counts of patients with NCA and MI and compared to patients with NCA and without MI.

MATERIALS AND METHOD

This retrospective study included consecutive patients with MI and who were found to have normal coronary angiograms performed between 1999 and 2003. Fifty patients (group I) with NCA and MI were enrolled in the study. Fifty consecutive patients with NCA and without MI were also enrolled in the study as control group (group II). Mean time interval between MI and coronary angiography was 6 +/- 2 days.

RESULTS

There were statistically significant differences between groups I and II in respect to gender (11 females (22%) versus 22 females (44%), p = 0.003, respectively) and smoking status (62% (31/50) versus 38% (19/50), p = 0.02). Comparison of TIMI frame counts between two groups revealed that group I patients had significantly higher TIMI frame counts than group two patients for all three coronary arteries (LAD: 40 +/- 12 versus 23 +/- 7, Cx: 47 +/- 14 versus 27 +/- 7, RCA: 36 +/- 10 versus 26 +/- 10, respectively, p < 0.001 for all). Smokers were significantly younger when compared to non-smokers (44 +/- 5 years versus 51 +/- 9 years, p = 0.008, respectively). TIMI frame counts of smokers did not significantly differ from those of non-smokers in group I patients. There were statistically significant differences between smokers and non-smokers in group II patients regarding TIMI frame counts for all three coronary arteries (LAD: 29 +/- 7 versus 18 +/- 3, LCX: 34 +/- 10 versus 22 +/- 4, RCA: 34+ /- 13 versus 20 +/- 4, respectively, p < 0.001 for all).

CONCLUSION

We have shown that patients with MI and NCA have higher TIMI frame counts for all coronary arteries when compared to patients without MI and NCA. Absence of difference between smokers and non-smoker in the myocardial infarction group in respect to TIMI frame count, has suggested that smoking does not lead to further increase of TIMI frame counts. On the other hand, in patients without MI and with NCA, smokers have higher TIMI frame counts than non-smokers have.

Relation between the TIMI frame count and the degree of microvascular injury after primary coronary angioplasty in patients with acute anterior myocardial infarction

OBJECTIVE

To investigate the relation between thrombolysis in myocardial infarction (TIMI) frame count (TFC) and coronary blood flow velocity (CBFV) parameters reflecting the degree of microvascular injury in patients with acute myocardial infarction.

RESULTS

TFC and CBFV were measured after primary coronary angioplasty in 103 consecutive patients with their first anterior wall acute myocardial infarction. TFC correlated inversely with the averaged peak velocity (r = -0.43, p < 0.0001). However, TFC did not correlate significantly with diastolic deceleration time and with the averaged systolic peak velocity (r = -0.16, p = 0.22, and r = -0.23, p = 0.16, respectively). The patients were divided into two groups according to presence (35 patients) or absence (68 patients) of systolic flow reversal. There was no significant difference in TFC between the two groups (29 (16) v 25 (13), p = 0.20).

CONCLUSIONS

These findings suggest that the TFC reflects epicardial CBFV. However, it is not accurate enough to assess the degree of microvascular injury after primary coronary angioplasty.

A study to validate the method based on DIMOND quality criteria for cardiac angiographic images

A method based on image quality criteria (QC) for cine-angiography was developed to measure the quality of cine-angiograms (CA). A series of 30 CA for left ventriculography (LV) and left and right coronary angiography (LCA, RCA) have been scored and 172 readings were obtained. Standard deviation of quality scores indicated the reproducibility of the method. Each part of CA was examined separately, giving scores for LV, LCA and RCA and a total score (TS), with clinical (C) and technical (T) criteria defined and examined separately. In 83% of the studies TS was >0.8 and with standard deviation from 0.02 to 0.21. In general, LV had a lower score and greater disagreement compared with RCA and LCA. Disagreement was greater in T, compared with C. In conclusion, these results indicate that QC, translated into a scoring system, yields reproducible data on the quality of cardiac images.

Angiographic morphologic characteristics in pulmonary atresia with intact ventricular septum

OBJECTIVE

To determine the morphological and functional changes in the right ventricle in pulmonary atresia with intact ventricular septum (PAIVS) for assessing the candidates for the different therapeutic procedures currently available.

METHODS

Thirty-one patients underwent cineangiocardiographic study with axial projections. Their ages ranged from 1 to 50 days (x = 9.6), and 28 of them were studied during the first month of life. The statistical analysis comprised the following: chi-square test, Kruskal-Wallis test for the mean and standard deviation, multiple regression, and the 95% confidence interval (95%CI) was calculated. The significance level adopted was alpha < or =0.05.

RESULTS

The patients were divided into 3 groups according to the angiographic morphology of the right ventricle (RV): group A -- tripartite RV (n=16); group B -- bipartite RV (n=9); and group C -- unipartite RV (n=6). The diameter of the tricuspid valve was 10.28 +/- 2.67 mm (A); 7.82 +/- 3.41 (B); and 5.27 +/- 0.57 (C) (P=0.0005). Pulmonary atresia was of the valvular type in all group A patients and of the infundibular type in all group C patients (P<0.0001). Coronary-cavitary connections were rare (2/16) in group A patients, but occurred in all group C patients (P=0.0006), with retrograde opacity of the aorta (flow from the RV to the aorta) in 2 group A patients and in all group C patients (P=0.0003). Three patients (2 in group C and 1 in group A) had right-ventricular-dependent coronary circulation. Isolated moderate/severe tricuspid regurgitation showed a tendency towards being more frequent in group A (P=0.0525). The angle of the ductus arteriosus with the descending aorta was as follows: 104.06 +/- 8.98 in group A; 79.17 +/- 33.08 in group B; and 39.0 +/- 6.52 in group C (P=0.0016). The correlation between the diameter of the tricuspid valve and the angle of the ductus arteriosus with the descending aorta was 0.6568 (P=0.0002).

CONCLUSION

Because of the heterogeneity of the morphology of the RV in patients with pulmonary atresia with intact ventricular septum, knowledge about all these data is required for selecting candidates for the different therapeutic procedures.

Noninvasive cineangiography by magnetic resonance global coherent free precession

Cardiovascular disease is primarily diagnosed using invasive X-ray cineangiography. Here we introduce a new concept in magnetic resonance imaging (MRI) that, for the first time, produces similar images noninvasively and without a contrast agent. Protons in moving blood are 'tagged' every few milliseconds as they travel through an arbitrary region in space. Simultaneous with ongoing tagging of new blood, previously tagged blood is maintained in a state of global coherent free precession (GCFP), which allows acquisition of consecutive movie frames as the heart pushes blood through the vascular bed. Body tissue surrounding the moving blood is never excited and therefore remains invisible. In 18 subjects, pulsating blood could be seen flowing through three-dimensional (3D) space for distances of up to 16 cm outside the stationary excitation region. These data underscore that our approach noninvasively characterizes both anatomy and blood flow in a manner directly analogous to invasive procedures.

Preload-independent mechanisms contribute to increased stroke volume following large volume saline infusion in normal volunteers: a prospective interventional study

Introduction

Resuscitation with saline is a standard initial response to hypotension or shock of almost any cause. Saline resuscitation is thought to generate an increase in cardiac output through a preload-dependent (increased end-diastolic volume) augmentation of stroke volume. We sought to confirm this to be the mechanism by which high-volume saline administration (comparable to that used in resuscitation of shock) results in improved cardiac output in normal healthy volunteers.

Methods

Using a standardized protocol, 24 healthy male (group 1) and 12 healthy mixed sex (group 2) volunteers were infused with 3 l normal (0.9%) saline over 3 hours in a prospective interventional study. Individuals were studied at baseline and following volume infusion using volumetric echocardiography (group 1) or a combination of pulmonary artery catheterization and radionuclide cineangiography (group 2).

Results

Saline infusion resulted in minor effects on heart rate and arterial pressures. Stroke volume index increased significantly (by approximately 15–25%; P < 0.0001). Biventricular end-diastolic volumes were only inconsistently increased, whereas end-systolic volumes decreased almost uniformly. Decreased end-systolic volume contributed as much as 40–90% to the stroke volume index response. Indices of ventricular contractility including ejection fraction, ventricular stroke work and peak systolic pressure/end-systolic volume index ratio all increased significantly (minimum P < 0.01).

Conclusion

The increase in stroke volume associated with high-volume saline infusion into normal individuals is not only mediated by an increase in end-diastolic volume, as standard teaching suggests, but also involves a consistent and substantial decrease in end-systolic volumes and increases in basic indices of cardiac contractility. This phenomenon may be consistent with either an increase in biventricular contractility or a decrease in afterload.

Correlation of echo-Doppler aortic valve regurgitation index with angiographic aortic regurgitation severity

We assessed aortic regurgitation (AR) severity by utilizing multiple echo-Doppler variables in comparison with AR severity by aortic root angiography. Patients were divided into 3 groups: mild, moderate, and severe. An AR index (ARI) was developed, comprising 5 echocardiographic parameters: ratio of color AR jet height to left ventricular outlet flow diameter, AR signal density from continuous-wave Doppler, pressure half-time, left ventricular end-diastolic diameter, and aortic root diameter. There was a strong correlation between AR severity by angiography and the calculated echo-Doppler ARI (r = 0.84, p = 0.0001). As validated by aortic angiography, the ARI is an accurate reflection of AR severity.

Effective techniques for reduction of radiation dosage to patients undergoing invasive cardiac procedures

The goal of this study was to improve radiation dose reduction techniques in invasive cardiology and after patients' radiation data had approached minimal levels, to evaluate predictors of their radiation exposure resulting from invasive cardiac procedures. Over the course of 1 year (and 1996 procedures) we minimized cinegraphic frames and runs, as well as fluoroscopy time, and trained ourselves to achieve effective fluoroscopy-saving positioning of blinds and filters toward the regions of interest. We were consequently able to reduce the mean dose-area products (DAP) for coronary angiography and angioplasty, combined interventions, high-frequency rotational atherectomy, and excimer laser angioplasty: from levels of 53.9 Gy cm(2), 79.6 Gy cm(2), 112.3 Gy cm(2), 119.4 Gy cm(2), and 168.0 Gy cm(2) as currently reported in the literature, to 12.9 Gy cm(2), 13.3 Gy cm(2), 25.9 Gy cm(2), 33.0 Gy cm(2), and 27.1 Gy cm(2), respectively. The mean DAP due to interventions in acute myocardial infarction was 38.3 Gy cm(2). DAP was influenced by body mass index, complexity of coronary artery disease, tube angulation, documented structure, coronary recanalization, emergency circumstances, and the percutaneous transluminal coronary angioplasty (PTCA) target vessel involved, but not by stent implantation. By favouring radiation-reducing cranial posteroanterior views over standard left anterior oblique views for visualization of the left anterior descending and the diagonal artery, we consequently achieved mean PTCA-DAPs of 10.4 Gy cm(2) and 8.6 Gy cm(2), respectively: levels significantly lower than those for PTCA of the right coronary artery (13.3 Gy cm(2)), left circumflex artery (13.7 Gy cm(2)), and obtuse marginal branch (16.9 Gy cm(2)). In conclusion, enhanced knowledge of radiation dose-reduction techniques significantly reduces patient radiation hazards in invasive cardiology.

Kinematic and deformation analysis of 4-D coronary arterial trees reconstructed from cine angiograms

In the cardiovascular arena, percutaneous catheter-based interventional (i.e., therapeutic) procedures include a variety of coronary and other vascular system interventions. These procedures use two-dimensional (2-D) X-ray-based imaging as the sole or the major imaging modality for procedure guidance and quantification of key parameters. Coronary vascular curvilinearity is one key parameter that requires a four-dimensional (4-D) format, i.e., three-dimensional (3-D) anatomical representation that changes during the cardiac cycle. A new method has been developed for reconstruction and analysis of these patient-specific 4-D datasets utilizing routine cine angiograms. The proposed method consists of three major processes: 1) reconstruction of moving coronary arterial tree throughout the cardiac cycle; 2) establishment of temporal correspondence with smoothness constraints; and 3) kinematic and deformation analysis of the reconstructed 3-D moving coronary arterial trees throughout the cardiac cycle.

Comparison of coronary artery dynamics pre- and post-stenting

Stents have dramatically improved the treatment of coronary artery disease. Since the implantation of stents changes the geometry and dynamics of the coronary artery, it is reasonable to hypothesize that some of these changes may have an important effect on the development of atherosclerosis by modulating the mechanical environment. In this paper, we presented a method to compare the geometric dynamics of the coronary artery before and after stenting using biplane angiography. Two cases are reviewed and a number of parameters are proposed to describe the longitudinal change of the vessel before and after stenting. This analysis technique has the potential to identify some aspects of stent design and procedure that might improve the success rate with this therapeutic approach.

Virtual coronary cineangiography

The mastering of myocardial infarction diagnosis is traditionally composed of laborious trial- and error-based examination of canonical coronary cineangiographies. In the following article we suggest a system that enables the instructor to generate student-specific cases, thus allowing teaching not only the basic feature searching and stenosis evaluation processes, but also the importance of the correct acquisition viewpoint. With the proposal of the development of the Digital Cardiologist intelligent agent we also envisage the possibility of the student's self-tutoring.

Three-dimensional motion tracking of coronary arteries in biplane cineangiograms

A three-dimensional (3-D) method for tracking the coronary arteries through a temporal sequence of biplane X-ray angiography images is presented. A 3-D centerline model of the coronary vasculature is reconstructed from a biplane image pair at one time frame, and its motion is tracked using a coarse-to-fine hierarchy of motion models. Three-dimensional constraints on the length of the arteries and on the spatial regularity of the motion field are used to overcome limitations of classical two-dimensional vessel tracking methods, such as tracking vessels through projective occlusions. This algorithm was clinically validated in five patients by tracking the motion of the left coronary tree over one cardiac cycle. The root mean square reprojection errors were found to be submillimeter in 93% (54/58) of the image pairs. The performance of the tracking algorithm was quantified in three dimensions using a deforming vascular phantom. RMS 3-D distance errors were computed between centerline models tracked in the X-ray images and gold-standard centerline models of the phantom generated from a gated 3-D magnetic resonance image acquisition. The mean error was 0.69 (+/- 0.06) mm over eight temporal phases and four different biplane orientations.

Improved localization of coronary stents using layer decomposition

Accurate placement and expansion of coronary stents is hindered by the fact that most stents are only slightly radiopaque and hence difficult to see in typical coronary X-ray images. We propose a new technique for improved image guidance of multiple coronary stent deployment using layer decomposition of coronary X-ray image sequences. We hypothesize that layer decomposition can improve the accuracy of localization of the end of a deployed stent. Layer decomposition is used to obtain good quality images of a stent in vitro. The resultant background-subtracted stent images are embedded into other cine X-ray image sequences to form a database of simulated image sequences. For each simulated sequence, the position of the stent edge is estimated from raw and layer-decomposed images using a small region of the original layer image as a template. Layer decomposition reduced median position errors in 33 of 47 image sequences (70%), including 16 of 18 sequences in which the position errors for raw and layer images differed by 5.0 pixels (0.5 mm) or more. Layer decomposition significantly reduces errors in determination of stent edge location in simulated cine X-ray image sequences.

Usefulness of rotational spin for coronary angiography in patients with advanced renal insufficiency

Coronary angiography in patients with advanced renal insufficiency is typically restricted to cases of life-threatening circumstances such as acute myocardial infarction and unstable angina. To gather a large amount of visual information with a minimum number of cine runs, and consequently, with a minimum volume of contrast medium, we rotated the gantry at 40 degrees /s throughout an angle of 120 degrees, from the right toward the left anterior oblique positions. This technique of rotational spin during cinegraphic runs has not yet become established in invasive cardiology. Three experienced cardiologists independently evaluated all coronary segments in rotational versus standard coronary angiography modes for 15 patients, on the basis of an 11-point scale (0 = cardiac spin far better to 10 = standard mode far better). A score of 5 signified that there was no difference in quality between the 2 modes. The arithmetic mean of the assessment values was 4.9 +/- 0.3 for coronary segments, 5.4 +/- 1.3 for coronary lesions, 5.1 +/- 1.4 for bifurcations, and 5.0 +/- 0.1 for coronary flow. The arithmetic means for the volume of contrast medium (25 +/- 4 ml), for the overall dose area product (8.6 +/- 4.5 Gy x cm(2)), and for the number of cine graphic frames (203 +/- 65) for a diagnostic cardiac spin were significantly below published typical values in standard mode. Cardiac spin enables 3-dimensional coronary impression under conditions of adequate image quality and represents a new, useful, and beneficial method in invasive cardiology for applications involving the special indication of advanced renal insufficiency.

Cineangiographic aortic dimensions in normal children

Knowledge of normal aortic dimensions is important in the management of children with aortic disease. So as to define such dimensions, we undertook a retrospective review of clinical data and aortic cineangiograms from 167 subjects without aortic disease having a mean age of 3.67 years, with a range from 0.01 to 14.95 years. Amongst the patients, 56 were without detectable cardiac lesions, 66 patients had mild pulmonary stenosis, 30 were seen with Kawasaki disease, and 15 with small interatrial defects within the oval fossa. Aortograms were available in all. No patient had any hemodynamic derangement that would have affected the aorta during intrauterine life or childhood. Systolic dimensions were measured in the ascending and descending aorta at the level of the carina, at the transverse aortic arch distal to the brachiocephalic, of the left common carotid artery at its origin, at the transverse aortic arch distal to the left common carotid artery, at the aortic isthmus, and of the aorta at the level of the diaphragm. A regression analysis model was used to establish the range of predicted normal values, with their confidence limits, standardizing the values to height as the biophysical parameter having the highest correlation to aortic dimensions. Normal ranges were established for all the levels of measurement. The data should prove useful in identifying abnormalities of the thoracic aorta during childhood, and when assessing the outcomes of interventions.

Reconstruction of time-varying 3-D left-ventricular shape from multiview X-ray cineangiocardiograms

This paper reports on the clinical application of a system for recovering the time-varying three-dimensional (3-D) left-ventricular (LV) shape from multiview X-ray cineangiocardiograms. Considering that X-ray cineangiocardiography is still commonly employed in clinical cardiology and computational costs for 3-D recovery and visualization are rapidly decreasing, it is meaningful to develop a clinically applicable system for 3-D LV shape recovery from X-ray cineangiocardiograms. The system is based on a previously reported closed-surface method of shape recovery from two-dimensional occluding contours with multiple views. To apply the method to "real" LV cineangiocardiograms, user-interactive systems were implemented for preprocessing, including detection of LV contours, calibration of the imaging geometry, and setting of the LV model coordinate system. The results for three real LV angiographic image sequences are presented, two with fixed multiple views (using supplementary angiography) and one with rotating views. 3-D reconstructions utilizing different numbers of views were compared and evaluated in terms of contours manually traced by an experienced radiologist. The performance of the preprocesses was also evaluated, and the effects of variations in user-specified parameters on the final 3-D reconstruction results were shown to be sufficiently small. These experimental results demonstrate the potential usefulness of combining multiple views for 3-D recovery from "real" LV cineangiocardiograms.

Right ventricular ejection function assessed by cineangiography--Importance of bellows action

The right ventricular ejection fraction (RVEF) can be shown theoretically as a mathematical function of the percent shortening in the 3 axial dimensions of the right ventricular cavity (the septum-free wall dimension (SF), the anterior-posterior dimension (AP), and the tricuspid valve-apex dimension (TA) or the long axis dimension (LA)). There is a need to decide which mechanism is the most important for the RVEF in cases with neither obvious regional wall motion abnormalities of the left ventricle nor right ventricular overload. Forty-four consecutive subjects (34 males/10 females) were enrolled: 16 had normal hemodynamic parameters without significant coronary artery stenosis, 15 had hypertrophic cardiomyopathy and 13 had dilated cardiomyopathy. Biplane right ventricular cineangiography was performed and the percent shortening of the SF, AP, and TA or LA were measured. The percent shortening in the SF (34.8+/-14.7%) was larger than that of the AP, TA, and LA (23.2+/-8.5, 21.0+/-8.3 and 18.3+/-7.0, respectively; all p<0.001). There was a linear correlation between the percent shortening of each dimension and the RVEF. The 95% confidence interval of the regression equation from the percent shortening of the SF and RVEF was located above those from the other percent shortenings, except for a lower RVEF. These results indicate that systolic shortening of the SF (ie, bellows action) plays an important role in the RVEF except for a lower ejection fraction.

Coronary artery dynamics in vivo

There is considerable evidence that the localization and evolution of vascular disease are mediated, at least in part, by mechanical factors. The mechanical environment of the coronary arteries, which are tethered to the beating heart, is influenced by cardiac motion; the motion of the vessels must be described quantitatively to characterize fully the mechanical forces acting on and in the vessel wall. Several techniques that have been used to characterize coronary artery dynamics from biplane cineangiograms are described and illustrated. There is considerable variability in dynamic geometric parameters from site to site along a vessel, between the right and left anterior descending arteries, and among individuals, consistent with the hypotheses that variations in stresses mediated by geometry and dynamics affect the localization of atherosclerosis and individual risk of coronary heart disease. The few frankly atherosclerotic vessels that have been examined exhibit high torsions in the neighborhood of lesions, an observation which may have etiologic or diagnostic implications.

Compliant design of artificial graft: compliance determination by new digital X-ray imaging system-based method

The development of an artificial graft requires formulation of biomechanical design criteria. The compliance of artifical grafts, based on the intraluminal pressure-internal diameter (Pi-Di) relationship, was measured by a novel method using a digital X-ray imaging system coupled with an edge detection algorithm and a pressure transducer. The Pi-Di values were obtained from digital angiographic images under continuous inflation of a canine femoral artery anastomosed with an expanded poly(tetrafluoroethylene) (ePTFE) vascular graft as a model vessel with a pressurized contrast medium. The Di at Pi using an NIH Image software specially programmed for the entropy filter method, which enables the detection of the edge of the vessel phantoms of the images, was determined. The Pi-Di relationships showed a "J-shape" curve for the artery, a steeper line with a very low pressure-dependent distensibility for the ePTFE graft, and an intermediate curve for the anastomosis protion. The two indices for the vessel compliance, the stiffness parameter (beta value) and the diameter compliance (Cd), both of which were calculated from the Pi-Di relationships, were 10.6 and 6.8%/mmHg x 10(-2) for the artery, 164 and 0.51%/mmHg x 10(-2) for the ePTFE, and 14.4 and 5.5%/mmHg x 10(-2) for the anastomosis portion, respectively. This method can measure compliance at any portions of the sampling vessel in a single experiment on a real-time basis with very high accuracy, compared with conventional methods, and even in cases of intimal thickening and/or connective tissues-adhered vessels, and may serve to provide information on compliant design criteria of artificial and tissue-engineered graft.

Single breath-hold multi-slab and cine cardiac-synchronized gadolinium-enhanced three-dimensional angiography

The rest period of the coronary arteries has been shown to be on the order of 120-160 msec. Restriction of the acquisition window in breath-hold cardiac-synchronized gadolinium-enhanced imaging to this duration limits the amount of sampled k-space data and hence the information when compared with conventional gadolinium-enhanced imaging. Two techniques for gadolinium-enhanced cardiac-synchronized angiography were implemented that acquire additional data during the unused portions of the cardiac cycle. Data acquisition is synchronized with the heart cycle and is restricted to a short period of each heart cycle. In a single breath-hold, a multi-slab acquisition (n = 5) allowed ECG-synchronized imaging of the entire heart or a CINE acquisition (n = 5) provided multiple stacks of images at different phases in the cardiac cycle over a smaller area. Preliminary results acquired in healthy volunteers and patients with aortic disease indicate that additional information can be acquired without an increase in breath-hold duration or a reduction in image quality.

Calcified aneurysms in coronary arteries of a 48-year-old patient

This is a case report of a 48-year-old female patient with a compatible history of Kawasaki disease during childhood, who was admitted to the emergency coronary unit with unstable angina pectoris. Coronary angiography identified two coronary aneurysms, one causing right coronary occlusion and the other causing severe obstruction of the left anterior descending coronary artery. Coronary artery bypass surgery was indicated.

Lack of agreement between left ventricular volumes and ejection fraction determined by two-dimensional echocardiography and contrast cineangiography in postinfarction patients

OBJECTIVE

To assess the agreement between left ventricular (LV) volumes and ejection fraction (EF) determined by two-dimensional echocardiography (2-D echo) and by cineangiography in postinfarction patients.

DESIGN

LV end-diastolic and end-systolic volumes indexed (EDVI and ESVI) to body surface area as well as EF were determined by both methods in all patients.

SETTING

Multicenter trial conducted in five university hospitals.

PATIENTS

63 patients, 61 male, two female, mean age 55.5 +/- 10.4 years, suffering from a recent myocardial infarction. Eighty-one pairs of measurements were available.

METHODS

The results of biplane 2-D echo measures, using apical four-chamber (4C) and two-chamber (2C) views were compared to those of a 30 degrees right anterior oblique cineangiography projection, using either the apical method of discs or the area-length 2-D echo method. Moreover, eyeball EF was estimated at 2-D echo and cineangiography, and was compared to the conventional methods. The agreement between results was assessed by the Bland and Altman method.

RESULTS

The agreement between 2-D echo and cineangiography results was poor. Mean differences (MD) were -21.8 (EDVI, ml/m(2)), -9.5 (ESVI, ml/m(2)), and -0.9 (EF, %), respectively for 2-D echo method of discs versus cineangiography, and -23.2, -9.3, and -5.7 for area-length 2-D echo versus cineangiography. For EF (%), MD was -3.6 for eyeball cineangiography versus cineangiography, -1.3 for eyeball 2-D echo versus method of discs, and +0.30 for eyeball 2-D echo versus area-length 2-D echo, respectively. Two-dimensional echo is likely to underestimate LV volumes compared to cineangiography, especially for largest volumes. Even for EF, discrepancies are large, with a lack of agreement of 21%-25% between conventional methods, but agreement is better between eyeball EF and usual methods.

CONCLUSIONS

Even with modern echocardiographic devices, agreement between 2-D echo and cineangiography-derived LV volumes and EF remains moderate, and both methods must not be considered interchangeable in clinical practice.

A novel technique using biplane cine magnetic resonance imaging to evaluate left ventricular volume in children

The purpose of the study is to determine the feasibility of a novel simplified technique using cine magnetic resonance imaging (MRI) to assess left ventricular (LV) volume and ejection fraction (EF) validated by comparison with biplane LV angiography. Previous MRI studies to assess LV volumes have used multiple axial planes, which are compromised by partial volume effects and are time consuming to acquire and analyze. Accordingly, we developed a simplified imaging approach using biplane cine MRI and imaging planes aligned with the intrinsic cardiac axes of the LV. We studied 20 children (aged 4 months to 10 years) with various heart diseases. The accuracy of cine MRI was compared with that of LV angiography in all patients. LV volumes were calculated using Simpson's rule algorithm, for both MRI and LV angiography. LV volumes determined from MRI were slightly underestimated but correlated reasonably well with angiographic volumes (LVEDV: Y = 0.88X + 1.58, r = 0.99, LVESV: Y = 0.73X + 1.03, r = 0.98). Most importantly, even in patients who had abnormal ventricular curvature such as in tetralogy of Fallot, MRI determined LV volumes correlated well with angiographic values. The MR study was completed within 35 min in all patients. In conclusion, simplified biplane cine MRI, using the intrinsic LV axis planes, permits noninvasive assessment of LV volumes in views comparable to standard angiographic projections and appears practical for clinical use in childhood heart disease since the scan and analysis times are relatively short.

Model-based morphological segmentation and labeling of coronary angiograms

A method for extraction and labeling of the coronary arterial tree (CAT) using minimal user supervision in single-view angiograms is proposed. The CAT structural description (skeleton and borders) is produced, along with quantitative information for the artery dimensions and assignment of coded labels, based on a given coronary artery model represented by a graph. The stages of the method are: 1) CAT tracking and detection; 2) artery skeleton and border estimation; 3) feature graph creation; and iv) artery labeling by graph matching. The approximate CAT centerline and borders are extracted by recursive tracking based on circular template analysis. The accurate skeleton and borders of each CAT segment are computed, based on morphological homotopy modification and watershed transform. The approximate centerline and borders are used for constructing the artery segment enclosing area (ASEA), where the defined skeleton and border curves are considered as markers. Using the marked ASEA, an artery gradient image is constructed where all the ASEA pixels (except the skeleton ones) are assigned the gradient magnitude of the original image. The artery gradient image markers are imposed as its unique regional minima by the homotopy modification method, the watershed transform is used for extracting the artery segment borders, and the feature graph is updated. Finally, given the created feature graph and the known model graph, a graph matching algorithm assigns the appropriate labels to the extracted CAT using weighted maximal cliques on the association graph corresponding to the two given graphs. Experimental results using clinical digitized coronary angiograms are presented.

Application of a 3D display system for biplane cerebral angiography

To improve the total safety for the biplane cerebral angiographic examination, we have developed a new three dimensional (3D) display system. By applying this system, shortening the examination time and reducing the risk of infection and embolization were achieved. We added just one graphic-workstation for 3D reconstruction to an ordinary biplane digital-cine-angiography system. This system can process the images of angiogram extempore in a short time and display the run of arterial vessels to the examiner. Biplane images were taken from the digital-cine-angiography system into the workstation through a video display. Three dimensional positions were calculated and displayed on a CRT monitor. It took from 15 to 45 seconds for the calculation. This system could display instantly the run of arterial vessels from any angle by using the computer mouse. Our system doesn't disturb the examination, but helps us to understand the run of the arterial vessels. This system was useful in cases where the arteries wound their way around or over-lapped each other.

Comparative analysis of early and late angiographic outcomes using two quantitative algorithms in the Balloon versus Optimal Atherectomy Trial (BOAT)

Although substantial intersystem variability has been shown among several commercially available quantitative angiographic (QA) analysis algorithms, no previous study has compared the angiographic findings using 2 different QA systems performed at the same central angiographic laboratory. The purpose of this study was to compare the early and late QA results obtained with the CMS (MEDIS) and ARTREK (ImageComm) QA systems in the Balloon versus Optimal Atherectomy Trial. Directional atherectomy (n = 496) or balloon angioplasty (n = 490) was performed in 986 patients; late QA follow-up was available in 767 patients (77.7%). QA analysis was performed by 2 independent observers using the CMS and ARTREK systems. Correlation between the 2 QA systems for baseline measurements was good (Pearson's R = 0.78), although the CMS system resulted in larger baseline reference diameter (RD) (3.22 +/- 0.45 vs 3.07 +/- 0.40 mm; p <0.0001) and baseline minimal lumen diameters (MLD) (1.05 +/- 0.35 vs 0.92 +/- 0.32; mm p <0.0001) than the ARTREK system. The final and follow-up RD (+0.17 and +0.11 mm, respectively) were also larger using the CMS system. In contrast, the final and follow-up measurements of MLD and percent diameter stenosis were not significantly different using the 2 QA systems. The QA system did not affect the ability to detect a difference in restenosis rates (>50% follow-up diameter stenosis) between the 2 treatment groups (CMS, directional atherectomy [31.8%]; balloon angioplasty [40.5%]; p = 0.013 and ARTREK, directional atherectomy [33.9%], balloon angioplasty [41.3%]; p = 0.036). Only lesion irregularity contributed to the difference in baseline measurements of MLD and percent diameter stenosis. We conclude that important differences in measurements of RD, baseline MLD, and percent diameter stenosis were noted using the CMS and ARTREK systems. Both systems, however, were able to detect a treatment benefit associated with directional atherectomy in BOAT. The comparability of other angiographic systems will require similar evaluation in other studies.

The effect of DICOM on QCA and clinical trials

Almost without any exemption, new cardiac catheterization laboratories are entirely digital without 35 mm cinefilm as the storage medium. In addition, existing laboratories are increasingly converting to the digital world. Aside from the organizational aspects, this has significant implications for the daily diagnostic review process of the procedures, and for the quantitative analysis of selected frames by QCA. The DICOM standard has now been well accepted in the catheterization laboratories. In stead of mechanical cine projectors, a department must decide on so-called DICOM-Viewers or 'digital Tagarno's'. In this paper the effects of DICOM on image quality and therefore on the visual interpretation of these images, as well as on QCA are discussed. Since the digital images can be enhanced, these look sharper than the conventional cinefilm images. However, edge enhancement has an effect on QCA, reason why the digital data must be stored in raw format. With the enormous amounts of digital data produced in a catheterization laboratory, image compression is of great importance. Currently, an international study is being carried out to determine which compression level is still acceptable from a visual interpretation and QCA point of view. Finally, the implications of the digital era on clinical trials are discussed. One of the important conclusions is that one should be encouraged not to switch from cinefilm to digital in the course of a trial, while a mixed population from the beginning is no problem, as long as the proper statistical calculations are carried out. In conclusion, despite the fact that there are still a number of items to be checked and possibly modified in the standard, the existing DICOM standard has succeeded in bringing widespread utilization of QCA in cardiac angiography closer than ever.

Computer evaluation of left ventricular wall motion by means of shape-based tracking and symbolic description

Relevant cardiac pathologies manifest themselves as abnormal movements of left ventricular (LV) myocardial wall. An objective quantification is usually accomplished by computer analysis of temporal sequences of LV contours, as obtained by angiography or echography. However the choice of the reference system for measuring motion is still open to discussion. Simple geometric models cannot deal with the non-uniform myocardial fibre structure, which gives rise to non-rigid movements, asynchronous even in normal subjects. Therefore, a new method, Curvature-Motion (CM), was developed for improving motion assessment. Since LV contour shape and position change smoothly throughout the cardiac cycle, the points of curvature extremes are tracked frame-to-frame and selected by exploiting physiologically-based assumptions; then, the points lying among these landmarks are mapped onto sequential contours, according to local displacements and curvature changes. In this way point-trajectories are allowed to be curvilinear and different in systole and diastole. CM gave no significant differences in estimating the known motion of computer-generated contours (R=0.88), unlike other methods commonly adopted (R<0.80). Moreover, for the evaluation of regional wall motion of a preclassified set of angiographic contours, CM showed a greater specificity (88%) and accuracy (90%) with respect to the centre-line method (respectively 83% and 87%). Finally, a fuzzy logic inference system is proposed for translating significant motion patterns from the quantitative form, as provided by the analysis method, into the linguistic terms used by cardiologists in their clinical examinations. This makes the interpretation of quantitative analysis easier and allows medical users to interact with the system for searching particular properties in a single clinical report as well as in a large database.

[Sublingual isosorbide-5 mononitrate during coronary arteriography. Comparison with sublingual nitroglycerin]

PURPOSE

To evaluate the effect of sublingual isosorbide-5 mononitrate (ISMN) and nitroglycerin (NTG) on luminal diameter of epicardial coronary arteries, mean arterial pressure and deleterious effects.

METHODS

Fifty patients were submitted to cardiac catheterization and coronary arteriography, at baseline, and 5 min after sublingual administration of ISMN, group A (GA) or NTG, group B (GB).

RESULTS

Reference vessel diameter increased in both groups, without statistical significance. In GA and GB, a decrease (1.66 mmHg) and an increase (0.79 mmHg) in mean arterial pressure, respectively, were demonstrated (p = 0.123). There were no deleterious effects with the use of these drugs.

CONCLUSION

Sublingual ISMN is an alternative to administration of NTG during coronary arteriography, and represents a therapeutic alternative to ischemic heart disease treatment.

Simultaneous biplane coronary and pulmonary arteriography: a novel technique for defining the course of an anomalous left main coronary artery originating from the right sinus of Valsalva

We present a novel technique employing biplane cineangiography with simultaneous left coronary and pulmonary angiography to define the anomalous course of the left main coronary artery when it originates from the right sinus of Valsalva. These biplane cinearterlograms clearly define the relationship of the left main coronary artery to the great vessels, allowing confident delineation of the interarterial variant from the other, benign variants. We illustrate the advantages of this technique with two cases in which the course of the anomalous left main coronary artery was incorrectly diagnosed using standard coronary arteriography and magnetic resonance imaging.

Evaluation of patients with diabetes mellitus for coronary artery disease using dobutamine stress echocardiography

BACKGROUND

There is a high prevalence of coronary artery disease (CAD) in patients with diabetes mellitus. Detection of inducible ischaemia using treadmill exercise testing may be limited by the relatively poor inherent predictive accuracy of the test. The purpose of this study was to determine the value of dobutamine stress echocardiography (DSE) for the detection of CAD in patients with diabetes mellitus.

METHODS

Patients with diabetes mellitus referred for cardiac assessment were considered eligible for study. DSE was performed in a standard fashion. Significant CAD was defined as a > 50% luminal diameter stenosis on coronary angiography.

RESULTS

A total of 52 patients (mean age 59 years) with diabetes mellitus were studied prospectively using DSE. Risk factors for CAD included hypertension in 19, family history in 21, hypercholesterolaemia in 14, history of smoking in 38. The sensitivity, specificity, positive and negative predictive values of DSE for detection of CAD were 82, 54, 84 and 50% respectively.

CONCLUSION

The specificity of DSE for CAD in patients with diabetes mellitus is low. Whether this reflects an underdetection of small vessel disease by contrast coronary angiography or whether it relates to test performance is unclear.

A new method for evaluating right ventricular dimensions and volume by cineangiography

The aim of the present study was to establish a new method to evaluate the right ventricular dimensions and volume. Biplane right ventriculography of steep left anterior oblique view (LAO) and right anterior oblique view perpendicular to LAO were performed in 32 patients. The right ventricular volume and ejection fraction calculated from the three axial dimensions of the right ventricular cavity (the septum-free wall dimension, the anterior-posterior dimension, and either the long axis dimension or the tricuspid valve-apex dimension at end-diastole and end-systole) were well correlated to those from Simpson's method. In conclusion, we developed a new method for estimating right ventricular dimensions and volume.