Conduit Flow Compensates for Impaired Left Atrial Passive and Booster Functions in Advanced Diastolic Dysfunction.

BACKGROUND: Quantification of left atrial (LA) conduit function and its contribution to left ventricular (LV) filling is challenging because it requires simultaneous measurements of both LA and LV volumes. The functional relationship between LA conduit function and the severity of diastolic dysfunction remains controversial. We studied the role of LA conduit function in maintaining LV filling in advanced diastolic dysfunction. METHODS: We performed volumetric and flow analyses of LA function across the spectrum of LV diastolic dysfunction, derived from a set of consecutive patients undergoing multiphasic cardiac computed tomography scanning (n=489). From LA and LV time-volume curves, we calculated 3 volumetric components: (1) early passive emptying volume; (2) late active (booster) volume; and (3) conduit volume. Results were prospectively validated on a group of patients with severe aortic stenosis (n=110). RESULTS: The early passive filling progressively decreased with worsening diastolic function (P<0.001). The atrial booster contribution to stroke volume modestly increases with impaired relaxation (P=0.021) and declines with more advanced diastolic function (P<0.001), thus failing to compensate for the reduction in early filling. The conduit volume increased progressively (P<0.001), accounting for 75% of stroke volume (interquartile range, 63-81%) with a restrictive filling pattern, compensating for the reduction in both early and booster functions. Similar results were obtained in patients with severe aortic stenosis. The pulmonary artery systolic pressure increased in a near-linear fashion when the conduit contribution to stroke volume increased above 60%. Maximal conduit flow rate strongly correlated with mitral E-wave velocity (r=0.71; P<0.0001), indicating that the increase in mitral E wave in diastolic dysfunction represents the increased conduit flow. CONCLUSIONS: An increase in conduit volume contribution to stroke volume represents a compensatory mechanism to maintain LV filling in advanced diastolic dysfunction. The increase in conduit volume despite increasing LV diastolic pressures is accomplished by an increase in pulmonary venous pressure.

Ser194Leu DSG2 mutation, associated with arrhythmogenic left ventricular cardiomyopathy and ventricular tachycardia.

INTRODUCTION: Arrhythmogenic cardiomyopathy (AC) is an inherited cardiomyopathy characterized by fibro-fatty replacement of cardiomyocytes, leading to life-threatening ventricular arrhythmia and heart failure. Pathogenic variants of desmoglein2 gene (DSG2) have been reported as genetic etiologies of AC. In contrast, many reported DSG2 variants are benign or variants of uncertain significance. Correct genetic variant classification is crucial for determining the best medical therapy for the patient and family members. METHODS: Pathogenicity of the DSG2 Ser194Leu variant that was identified by whole exome sequencing in a patient, who presented with ventricular tachycardia and was diagnosed with AC, was investigated by electron microscopy and immunohistochemical staining of endomyocardial biopsy sample. RESULTS: Electron microscopy demonstrated a widened gap in the adhering junction and a less well-organized intercalated disk region in the mutated cardiomyocytes compared to the control. Immunohistochemical staining in the proband diagnosed with AC showed reduced expression of desmoglein 2 and connexin 43 and intercalated disc distortion. Reduced expression of DSG2 and Connexin 43 were observed in cellular cytoplasm and gap junctions. Additionally, we detected perinuclear accumulation of DSG2 and Connexin 43 in the proband sample. CONCLUSION: Ser194Leu is a missense pathogenic mutation of DSG2 gene associated with arrhythmogenic left ventricular cardiomyopathy.

Radiological findings in poisoning by synthetic cannabinoids adulterated with brodifacoum.

OBJECTIVES: Severe coagulopathy due to consumption of synthetic cannabinoids adulterated with brodifacoum, a long-acting anticoagulant, is an emerging worldwide hazard. Here, we review the spectrum of imaging findings in adulterated cannabinoid poisoning. MATERIALS AND METHODS: In this retrospective study, we used the Israeli Poison Information Center database to identify patients with cannabinoid-associated coagulopathy who presented to the Rambam Health Care Campus, where most patients were treated during an outbreak in northern Israel between September 2021 and June 2022. All relevant imaging studies for these patients were reviewed. We estimated the sensitivity of findings for cannabinoid-associated coagulopathy. Associations between a continuous variable and a dichotomous outcome were assessed with the Mann-Whitney U test. RESULTS: We identified 48 patients (mean age 40 years ± 9 [SD], 43 males) with 54 hospitalizations due to cannabinoid-associated coagulopathy. Symptomatic hemorrhage was documented in 50 (93%) cases at presentation, most of whom (78%) had hemorrhage from multiple systems. The most common bleeding site was the genitourinary collecting system, with a characteristic sign of suburothelial bleeding in 16/18 of performed abdominal CTs (sensitivity 89% [CI 65-99%] for cannabinoid-associated coagulopathy). Intramural bowel hematomas were noted in 70% (7/10) of CTs of patients with gastrointestinal bleeding. Incidental bleeding sites were identified on imaging in 24% of patients. An increased number of bleeding sites was associated with need for vasopressors (difference in bleeding sites 3.00 [95% CI 0.99-4.00], p = 0.026). CONCLUSION: CT plays a key role in the diagnosis and work-up of adulterated cannabinoid-associated coagulopathy. Characteristic signs include suburothelial hemorrhage and intramural bowel hematomas. CLINICAL RELEVANCE STATEMENT: Recognition of radiological signs of adulterated synthetic cannabinoid-associated coagulopathy is critical for optimizing outbreak control on the public health level and ensuring timely treatment on the individual patient level. KEY POINTS: • Severe coagulopathy due to consumption of synthetic cannabinoids adulterated with brodifacoum, a long-acting anticoagulant, is an emerging worldwide threat. • Characteristic imaging signs include suburothelial bleeding, intramural bowel hematomas, and rare incidental bleeding sites. • Imaging has a pivotal role in optimizing outbreak control and ensuring timely and appropriate treatment.

Comparison Between Echocardiography and Cardiac Computed Tomography in the Evaluation of Diastolic Dysfunction and Prediction of Heart Failure.

Recent data indicate that left atrial (LA) function assessment by cardiac computed tomography (CT) is closely related to diastolic dysfunction (DD). Therefore, we aimed to perform a direct comparison between CT and echocardiography for diagnosis of advanced DD and prediction of future heart failure or cardiovascular death. We identified 340 patients who had both spiral cardiac CT and a proximate echocardiogram. LA total emptying fraction (LATEF), a measure of global LA function, was automatically calculated from CT data, as a surrogate for diastolic function and was compared with echocardiographic grades of diastolic function. The area under the receiver operating characteristic curve for LATEF to differentiate between advanced DD (grades 2 and 3) and all other grades was 0.84 (0.79 to 0.88). Over a median of 4 years, 69 events (admissions for heart failure and cardiovascular deaths) occurred. By multivariate Cox analysis, LATEF <40% provided incremental prognostic information after adjustments for advanced DD by echocardiography (hazard ratio 2.15, 95% confidence interval 1.13 to 3.94). There was a significant interaction (p = 0.03) between LATEF and echocardiography-based diastolic grades. Stratified analyses within the diastolic function groups revealed that LATEF <40% was equivalent to echocardiography in predicting events in the subgroup with advanced DD by echocardiography (p = 0.20) but was associated with a significantly higher event rates in patients with normal filling pressures (p = 0.0001) or indeterminate diastolic function (p = 0.04) by echocardiography. In conclusion, LA function derived from CT can accurately detect advanced DD diagnosed by echocardiography and has additive value to echocardiography-derived DD.

Left atrial function by cardiac computed tomography is a predictor of heart failure and cardiovascular death.

OBJECTIVES: We sought to evaluate cardiac CT angiography (CCTA)-based assessment of left atrial (LA) function as a predictor of hospitalizations for heart failure (HF) and cardiovascular (CV) mortality. METHODS: LA function was evaluated using automatic derivation of LA volumes to calculate LA total emptying fraction (LATEF) in 788 consecutive patients with normal sinus rhythm who had undergone spiral CT scans. The relationship between LATEF evaluated by CCTA and the composite endpoint of admission for HF or CV mortality was analyzed using Cox models. RESULTS: During a median follow-up of 4 years, there were 100 events, 62 HF hospitalizations, and 38 cardiovascular deaths. Mean LATEF was 30.7 ± 10.7% and 40.5 ± 11.2% in patients with and without events, respectively (p < 0.0001). A high LATEF (upper tertile > 46%) was associated with a very low event rate (3.5% at 6 years [95% CI 1.7-7.1%]). The adjusted HR for HF or CV mortality was 4.37 (95% CI 1.99-9.60) in the lowest LATEF tertile, and 2.29 (95% CI 1.03-5.14) in the middle tertile, relative to the highest tertile. For the endpoint of HF alone, adjusted HR for the lowest LATEF tertile was 5.93 (95% CI 2.23-15.82) and for the middle tertile 2.89 (95% CI 1.06-7.86). The association of LATEF with outcome was similar for patients with both reduced and preserved left ventricular (LV) ejection fraction (Pinteraction = 0.724). Reduced LATEF was associated with a high event rate, even when coupled with normal LA volume. CONCLUSION: CCTA-derived LA function is a predictor of HF hospitalization or CV death, independent of clinical risk factors, LA volume, and LV systolic function. KEY POINTS: • Left atrial function can be automatically derived from cardiac CTA scans. • Cardiac CTA-derived left atrial function is a predictor of hospitalization for heart failure and cardiovascular death. • Evaluation of left atrial function could be useful in identifying patients at risk of heart failure.

New technique: removal of embedded esophageal partially covered stent by endoscopic sub-stent space dissection.

Both fully (FCSEMS) and partially (PCSEMS) covered self-expandable metal stents are used for the endoscopic management of leaks, perforations, and fistulas. PCSEMS have lower migration rates as their uncovered flanges allow for anchorage into the surrounding tissue, but this consequently makes them difficult to be removed, with reported cases of esophageal perforation during the removal of the embedded PCSEMS. Stent-in-stent technique is mostly used, where a FCSEMS is placed co-axially into an existing PCSEMS causing pressure necrosis and facilitating subsequent removal of both stents. This technique, although effective, is expensive, requiring the use of a second stent. In this report, we describe a series of 3 patients with embedded PCSEMS removed by a new endoscopic technique, i.e., endoscopic sub-stent space dissection, without using a second stent.

Accuracy of Diastolic Function by Cardiac Computed Tomography Relative to Echo-Doppler: Additive Clinical and Prognostic Value.

OBJECTIVES: We aimed to assess the agreement between cardiac computed tomography (CT) and echo for diagnosing advanced diastolic dysfunction (DD) and to assess the prognostic value of CT-based parameters. METHODS: One hundred one consecutive patients who had both CT and echo-Doppler within 1 month were included. Diastolic function was assessed by CT using a previously validated method, based on left atrial volume changes, and compared with echocardiography grades 0 to 3. Patients were followed up for a combined outcome of cardiac death and hospitalization for heart failure. RESULTS: By operating characteristic curve analysis, the best CT-based parameter for predicting advanced DD based on echo was left atrial total emptying fraction. Left atrial total emptying fraction <36% had sensitivity/specificity of 76%/86%. Agreement between echo and CT for detecting advanced (grades 2/3) DD was substantial (κ = 0.62, P < 0.0001). By Cox multivariate analysis, left atrial total emptying fraction was a powerful independent predictor of outcome at 3 years (hazard ratio, 8.0 [2.2-28.4]; P < 0.0001). CONCLUSIONS: Computed tomography-based assessment of DD has a good agreement with echo-Doppler-based results. Left atrial total emptying fraction seems to have a strong prognostic value.

Assessment of mitral regurgitation by 3-dimensional proximal flow convergence using magnetic resonance imaging: comparison with echo-Doppler.

To test the feasibility of assessing mitral regurgitation (MR) severity using cardiac magnetic resonance (CMR) 4D velocity vectors to quantify regurgitant volume (RVol) by analysis of the proximal flow convergence, compared to Doppler based proximal isovelocity surface area (PISA) and CMR volume-based methods. In a prospectively designed study, 27 patients with various grades of MR underwent CMR and echo-Doppler on the same day. By CMR, multiple slices were obtained parallel to the mitral valve by phase-contrast imaging, using 3D velocity vectors, as well as short-axis cine images for left and right ventricular volume measurements. Using dedicated software developed in our laboratory, the perimeter of the proximal flow convergence region was semi-automatically measured for each temporal phase, and for each short-axis slice. The CMR-PISA RVol was calculated as the sum of PISA perimeters throughout systole, multiplied by slice width. For comparison, CMR-volumetric RVol was calculated by 2 methods: Volumetric (difference between left and right ventricular stroke volumes) and Flow-based (stroke volume -aortic flow). Echo-PISA RVol was calculated by echo-Doppler based PISA method. RVol by CMR-PISA correlated highly with echo-PISA (r = 0.87) and with CMR-volumetric (r = 0.86) and CMR-flow (r = 0.72). For comparison Doppler-RVol and CMR-volume-based RVol had r = 0.83. On average CMR-PISA was 16 ± 25 ml less than echo-PISA, but 12 ± 22 ml larger than CMR-volumetric RVol. The observed 3D shape of the PISA envelope by 4D-CMR resembled a hemiellipsoid rather than a hemisphere. This feasibility study suggests that CMR-based 4D-PISA may be able to assess MR severity quantitatively without any geometric assumptions.

Automatic Estimation of Optimal Deployment of Transcatheter Aortic Valve Implantation Using Computed Tomography.

BACKGROUND: A comparison was made between the accuracy of and time saved by using novel automated software for pre-procedural computed tomography (CT) planning before transcatheter aortic valve implantation (TAVI) and manual methods. Preprocedural CT to assess aortic annulus dimensions and predict the optimal C-arm implant angle before TAVI can reduce complications related to incorrect prosthesis sizing and positioning. METHODS: A total of 61 consecutive patients underwent TAVI using either the SAPIEN XT or CoreValve prosthesis. Pre-procedural CT scans were analysed using three methods: automatic; semi-automatic; and manual. For each method, annular dimensions were measured and the optimal implantation angle was predicted. After TAVI the actual post-deployment angle orthogonal to the prosthesis was determined using aortic fluoroscopy. The difference between the predicted angle by CT and the measured post-deployment angle was calculated for each method. RESULTS: For all methods the mean angular difference with the actual post-deployment angle was similar at ~9 ± 7°. There was a significant difference between the SAPIEN XT (6.6 ± 5.8°) and CoreValve (11.5 ± 6.9°, p <0.001) prostheses due to a consistently greater left anterior oblique and caudal angulation for the CoreValve. Although the annular area correlated well among all methods, 'automatic' results were consistently larger than 'manual' results. Interobserver variability was low for all measures. The fully automatic method saved 98 s, and the semiautomatic method 40 s per case. CONCLUSIONS: The use of automatic software enabled a rapid and accurate prediction of implantation angles, though results differed for specific manufacturers. Annular areas were overestimated by the automatic method, and thus required manual adjustments.

Multimodality Image Fusion with PSMA PET/CT and High-Intensity Focused Ultrasound Focal Therapy for Primary Diagnosis and Management of Prostate Cancer: A Planned Research Initiative.

Recent developments in diagnostic imaging herald a new approach to diagnosis and management of prostate cancer. Multimodality fusion that combines anatomic with functional imaging data has surpassed either of the two alone. This opens up the possibility to "find and fix" malignancy with greater accuracy than ever before. This is particularly important for prostate cancer because it is the most common male cancer in most developed countries. This article describes technical advances under investigation at our institution and others using multimodality image fusion of magnetic resonance imaging (MRI), transrectal ultrasound (TRUS), and PSMA PET/CT (defined as the combination of prostate-specific membrane antigen [PSMA], positron emission tomography [PET], and computed tomography [CT]) for personalized medicine in the diagnosis and focal therapy of prostate cancer with high-intensity focused ultrasound (HiFUS).

Pyogenic Granuloma: Possible Cause for Macroscopic Hematuria in Children.

Pyogenic granuloma (PG) is a benign, vascular tumor that is rarely reported in the urinary tract of pediatric population. Herein we present a case of a child followed up for recurrent painless macroscopic hematuria. We performed ureteroscopy, and a whitish lesion was discovered in the upper calyx of the right kidney. The lesion resected endoscopically, and microscopic examination of the lesion was consistent with PG. It is important for pediatricians and urologists to properly recognize PG as a possible source of hematuria in the pediatric population.

Assessment of Diastolic Function in Hypertrophic Cardiomyopathy by Computed Tomography-Derived Analysis of Left Ventricular Filling.

OBJECTIVES: Hypertrophic cardiomyopathy (HCM) is characterized by diastolic dysfunction, which is difficult to assess by noninvasive methods. We hypothesized that measurement of simultaneous left ventricular (LV) and left atrial (LA) volume changes by cardiac computed tomography would be useful in the assessment of diastolic function in HCM. METHODS: We studied 21 patients with HCM and 21 age-matched controls. The LA and LV volumes were calculated and early and late diastolic volume changes derived. RESULTS: The HCM patients had significantly larger LA volumes and reduced LA total emptying fraction (30 ± 7% vs 42 ± 6%; P < 0.0001). Conduit volume was increased (30 ± 6 vs 22 ± 4 mL/m; P < 0.0001) and contributed a significantly higher proportion of total LV diastolic filling, suggesting that passive filling of the LV compensates for LA dysfunction, but at the expense of increased pulmonary filling pressure. CONCLUSIONS: This study suggests that simultaneous depiction of computed tomography-derived LV and LA volume changes can characterize diastolic dysfunction in HCM.

Impact of computed tomography image and contact force technology on catheter ablation for atrial fibrillation.

AIM: To investigate the impact of using computed tomography (CT) and contact force (CF) technology on recurrence of atrial tachyarrhythmia after atrial fibrillation (AF) ablation. METHODS: This non-randomized study included 2 groups of patients. All patients had symptomatic recurrent paroxysmal or persistent AF and were treated with at least 1 anti arrhythmic medication or intolerant to medication. The first group included 33 patients who underwent circumferential pulmonary veins isolation (PVI) for AF during 2012 and 2013 guided by CT image integration (Cartomerge, Biosense Webster, Diamond Bar, CA, United States) of left atrium and pulmonary veins into an electroanatomic mapping (EAM) system (CT group) using standard irrigated radiofrequency catheter (ThermoCool, Carto, Biosense Webster, Diamond Bar, CA, United States) or irrigated catheter with integrated CF sensor (Smart Touch, Carto, Biosense Webster, Diamond Bar, CA, United States). The second group included immediately preceding 32 patients who had circumferential PVI by standard irrigated catheter (ThermoCool) using only EAM (Carto) system (EAM group). Linear lesions were performed according to the discretion of operator. RESULTS: Sex, age, and persistent AF were not different between groups. PVI was achieved in all patients in both groups. Linear ablations including cavo-tricuspid isthmus and or roof line ablation were not different between groups. Free of atrial tachyarrhythmia during follow-up of 24 mo was significantly higher among CT group compared to EAM group (81% vs 55%; respectively; P = 0.027). When 11 patients from CT group who had ablation using Smart Touch catheter were excluded, the difference between CT group and EAM became non significant (73% vs 55%; respectively; P = 0.16). Sub analysis of CT group showed that patients who had ablation using Smart Touch catheter tend to be more free of atrial tachyarrhythmia compared to patients who had ablation using standard irrigated catheter during follow-up (100% vs 73%; respectively; P = 0.07). Major complications (pericardial effusion, cerebrovascular accident/transient ischemic attack, vascular access injury requiring intervention) did not occurred in both groups. CONCLUSION: These preliminary results suggest that CT image integration and CF technology may reduce the recurrence of atrial tachyarrhythmia after catheter ablation for AF.

Left-sided cardiac chamber evaluation using single-phase mid-diastolic coronary computed tomography angiography: derivation of normal values and comparison with conventional end-diastolic and end-systolic phases.

OBJECTIVES: With increasing use of prospective scanning techniques for cardiac computed tomography (CT), meaningful evaluation of chamber volumes is no longer possible due to lack of normal values. We aimed to define normal values for mid-diastolic (MD) chamber volumes and to determine their significance in comparison to maximum volumes. METHODS: Normal ranges at MD for left ventricular (LV) volume and mass and left atrial (LA) volume were determined from 101 normal controls. Thereafter, 109 consecutive CT scans, as well as 21 post-myocardial infarction patients, were analysed to determine the relationship between MD and maximum volumes. RESULTS: MD volumes correlated closely with maximal volumes (r = 0.99) for both LV and LA, and could estimate maximum volumes accurately. LV mass, measured at ED or MD, were very similar (r = 0.99). Abnormal MD volumes had excellent sensitivity and specificity to detect chamber enlargement based on maximal volumes (LV 86 %, 100 %, respectively; LA 100 %, 92 %, respectively). CONCLUSION: A single MD phase can identify patients with cardiomegaly or LV hypertrophy with a high degree of accuracy and MD volumes can give an accurate estimate of maximum LV and LA volumes. KEY POINTS: • Traditionally, helical cardiac CT provided clinically important information from chamber volume analysis. • Mid-diastolic left atrial and ventricular volumes correlate closely with maximal volumes. • We derive normal values for mid-diastolic left atrial and ventricular volumes and mass. • A single mid-diastolic phase can be used to identify chamber enlargement and hypertrophy.

Outflow tract ventricular arrhythmia originating from the aortic cusps: our approach for challenging ablation.

BACKGROUND: Ablation of outflow flow ventricular arrhythmia (VA) originating from aortic cusps can be challenging. The aim of this study was to describe our approach for this ablation. METHODS: All patients with outflow VA suspected to originate from aortic cusps according to ECG or after failed ablation from right ventricular outflow tract (RVOT) underwent cardiac CT and radiofrequency ablation. CT image of aortic cusps and coronary arteries was integrated into electroanatomic mapping system by point (left main ostium)-based registration. Ablation was performed at the earliest activation site. RESULTS: Ten patients were included in this case cohort. The ablation catheter was easily maneuvered above and below the aortic valve after registration. Two patients who had previous failed ablation of RVOT focus had successful ablation at right coronary cusp (RCC) and at left coronary cusp (LCC). A patient who had previous failed ablations of RVOT and LCC focuses had successful ablation at RCC-LCC junction. A patient who had previous failed ablation at LCC had successful ablation at RCC-LCC junction. Three patients had successful ablation at RCC-LCC junction, and one patient at LCC. One patient had successful ablation at anterior interventricular vein-great cardiac vein junction. One patient had successful ablation at non-coronary cusp. During follow-up (12-30 months), one patient had recurrence of VA controlled by flecainide. The remaining patients were free of VA without medications. CONCLUSIONS: Catheter ablation of VA originating from aortic cusps is safe and effective. CT image integration into electroanatomic mapping system can be helpful in this challenging ablation.

Assessment of left sided filling dynamics in diastolic dysfunction using cardiac computed tomography.

BACKGROUND: Left ventricular (LV) diastolic dysfunction (DD) often accompanies coronary artery disease but is difficult to assess since it involves a complex interaction between LV filling and left atrial (LA) emptying. OBJECTIVE: To characterize simultaneous changes in LA and LV volumes using cardiac computed tomography (CT) in a group of patients with various grades of DD based on echocardiography. METHODS: We identified 35 patients with DD by echocardiography, who had also undergone cardiac CT, and 35 age-matched normal controls. LV and LA volumes were measured every 10% of the RR interval, using semi-automatic software. From these, - systolic, early-diastolic and late-diastolic volume changes were calculated, and additional parameters of diastolic filling derived. Conduit volume was defined as the difference between the LV and LA early-diastolic volume change. RESULTS: Patients with DD had significantly larger LV mass, and LA volumes, reduced early emptying volumes and increased conduit volume as percent of early LV filling (All p<0.001). LA function, manifesting as total emptying fraction (LATEF), decreased proportionately with worsening grades of DD (p<0.001). LA contractile function was maintained until advanced grade-3 DD. By receiver operating characteristic analysis, LATEF had an AUC of 0.88 to separate between normals and DD. At a threshold of <42.5%, LATEF has 97% sensitivity and 69% specificity to detect DD. CONCLUSIONS: DD is characterized by reduced LA function and an alteration in the relative contributions of the atrial emptying and conduit volume components of early LV filling. In patients undergoing cardiac CT, it is possible to identify the presence and severity of DD.

Direct comparison between coronary computed tomography and invasive angiography for calculation of SYNTAX score.

AIMS: We aimed to test the feasibility of calculating SYNTAX score from coronary computed tomographic angiography (CCTA) compared to from invasive coronary angiography (ICA). METHODS AND RESULTS: SYNTAX score was independently and blindly calculated from CCTA and from ICA in 104 patients, age 57±10, with significant (>50%) stenoses in 1.7±0.7 vessels. The level of agreement was assessed by Cohen's kappa. Agreement between ICA and CCTA for conventional vessel-based analysis (presence of >50% stenosis per vessel) was substantial with kappa=0.66 and sensitivity, specificity and accuracy of 74%, 90% and 80%, respectively. The mean SYNTAX score was 14.2±10.0 by ICA and 10.3±6.9 by CCTA, with a significant underestimation of 3.9±8.2 by CCTA (p<0.001). Weighted kappa was 0.33, indicating only fair agreement. When only good quality CCTA were included, kappa improved to 0.56. Analysis of the cause of the bias showed ICA to identify more lesions per patient (2.2±1.3 vs. 1.7±1.0, p<0.001), while the mean score per lesion was not different (6.4 vs. 5.9, p=ns). CONCLUSIONS: CCTA, despite having a good agreement with ICA by conventional vessel-based analysis, showed only fair agreement for the calculation of SYNTAX score, and cannot be currently used as a substitute for diagnostic ICA for this purpose.

The three-dimensional geometric relationship between the mitral valvar annulus and the coronary arteries as seen from the perspective of the cardiac surgeon using cardiac computed tomography.

OBJECTIVES: Mitral annuloplasty involves sewing a prosthetic ring to the mitral annulus. This involves a risk of damaging the surrounding structures in the left atrioventricular (AV) groove, particularly the left circumflex artery, which may be inadvertently sutured, causing an arterial occlusion. We have used cardiac computed tomography (CT) scans to study the three-dimensional relationship between the mitral valvar annulus and the neighbouring coronary arteries in the AV groove, and to map the distance between the arteries and the annulus. METHODS: We examined cardiac CT scans of two groups of patient: 40 normal subjects, and 30 patients with left ventricular dysfunction and/or mitral regurgitation. The hinge line of the mitral valve, as well as the location of the coronary arteries within the left AV groove, was manually marked on a workstation and three-dimensional coordinates saved in digital format. Dedicated software was developed to calculate the plane of the mitral annulus, and the smallest distance between each point on the annulus and each of the left circumflex and right coronary arteries, called local minima. The global minimum for each heart is defined as the minimum of all local minima. RESULTS: The global minimum for the left circumflex averaged 6.4 ± 2.1 mm, usually involving the proximal portion, just laterally to the left trigone. In three-tenths of patients, the global minimum was <5 mm. This was more common in patients with left dominance, and in the normal subjects. The major component of the line vector between the annulus and circumflex is parallel to the plane of the mitral annulus, while the perpendicular component is usually in an atrial direction. For the dominant right coronary artery (RCA), the global minimum distance to the annulus is 14.7 ± 5.7 mm. In no patient did the RCA approach to within 5 mm with respect to the mitral annulus, albeit that 13% were <10 mm. CONCLUSIONS: In a significant proportion of patients, the left circumflex is in very close proximity to the annulus of the mitral valve. Knowledge of the precise three-dimensional relationships between the structures can be expected to minimize iatrogenic complications.

Influence of attenuation correction on transient left ventricular dilation in dual isotope myocardial perfusion imaging in patients with known or suspected coronary artery disease.

The aim of this study was to assess the effect of attenuation correction (AC) on left ventricular (LV) volumes and LV transient ischemic dilatation (TID) during dual-isotope single-photon emission computer tomographic (SPECT) myocardial perfusion imaging (MPI). Ninety-six patients (mean age 58 ± 11 years, 15% women, 38 patients completed exercise and 58 dipyridamole pharmacologic stress tests) assessed for known or suspected coronary artery disease underwent dual-isotope thallium-201 rest and technetium-99m sestamibi stress SPECT MPI with computed tomography-based AC. The TID ratio was calculated separately for non-AC and AC SPECT MPI studies as the ratio of the LV endocardial volume at stress divided by LV endocardial volume at rest. The mean and range of the gated LV ejection fraction during exercise and pharmacologic stress was 54 ± 12% (29% to 80%) and 58 ± 12% (27% to 80%), respectively. In the exercise stress group, the same mean LV endocardial volumes in non-AC and AC stress (76.4 ± 30 and 76.5 ± 28) and rest (66.3 ± 26 and 66.4 ± 24) studies were found (p = 0.90). There was no statistical difference between the mean exercise TID ratio in non-AC and AC studies (1.27 vs 1.31, respectively, p = 0.10). The same mean LV endocardial volumes in non-AC and AC in pharmacologic stress (79.9 ± 42 and 80 ± 41) and rest (71.4 ± 41 and 72.3 ± 37), respectively, were found (p = 0.50). There was no statistical difference between the mean dipyridamole TID ratio in non-AC and AC studies (1.20 vs 1.17, respectively, p = 0.10). In conclusion, LV volumes and TID indexes obtained on SPECT MPI with exercise or pharmacologic stress using dipyridamole are not affected by AC.