A user-friendly method of cardiac venous system visualization in 64-slice computed tomography

Morphometric Characterization of Human Coronary Veins and Subvenous Epicardial Adipose Tissue-Implications for Cardiac Resynchronization Therapy Leads

Subvenous epicardial fat tissue (SEAT), which acts as an electrical insulation, and the venous diameter (VD) both constitute histomorphological challenges for optimal application and lead design in cardiac synchronization therapy (CRT). In this study, we characterized the morphology of human coronary veins to improve the technical design of future CRT systems and to optimize the application of CRT leads. We retrospectively analyzed data from cardiac computed tomography (CT) of 53 patients and did studies of 14 human hearts using the postmortem freeze section technique and micro CT. Morphometric parameters (tributary distances, offspring angles, luminal VD, and SEAT thickness) were assessed. The left posterior ventricular vein (VVSP) had a mean proximal VD of 4.0 ± 1.4 mm, the left marginal vein (VMS) of 3.2 ± 1.5 mm and the anterior interventricular vein (VIA) of 3.9 ± 1.3 mm. More distally (5 cm), VDs decreased to 2.4 ± 0.6 mm, 2.3 ± 0.7 mm, and 2.4 ± 0.6 mm, respectively. In their proximal portions (15 mm), veins possessed mean SEAT thicknesses of 3.2 ± 2.4 (VVSP), 3.4 ± 2.4 mm (VMS), and 4.2 ± 2.8 mm (VIA), respectively. More distally (20-70 mm), mean SEAT thicknesses decreased to alternating low levels of 1.3 ± 1.1 mm (VVSP), 1.7 ± 1.1 mm (VMS), and 4.3 ± 2.6 mm (VIA), respectively. In contrast to the VD, SEAT thicknesses alternated along the further distal vein course and did not display a continuous decrease. Besides the CRT responsiveness of different areas of the LV myocardium, SEAT is a relevant electrophysiological factor in CRT, potentially interfering with sensing and pacing. A sufficient VD is crucial for successful CRT lead placement. Measurements revealed a trend toward greater SEAT thickness for the VIA compared to VVSP and VMS, suggesting a superior signal-to-noise-ratio in VVSP and VMS.

Temporal changes of the diameter of the coronary sinus during the cardiac cycle

INTRODUCTION

Currently, there are no studies that analyse the changes in the cardiac venous system that are dependent on the phase (RR interval) of reconstruction. The aim of the study was to assess the size of the coronary sinus at two measurement sites depending on the phase of the heart cycle.

METHODS

Fifty patients were included. Cardiac computed tomography was performed in all of the patients due to a suspicion of coronary artery disease (typical indications) using a dual-source Siemens Somatom Force scanner. The "MM reading" presets were used to measure the coronary sinus ostium (measurement 1) and the coronary sinus trunk, which is close to the great cardiac vein (measurement 2) in millimetres. All of the calculations were performed on axial scans using 0%-100% and a 256 × 256 matrix.

RESULTS

The largest CS was found at the 30%, 40% and 50% RR interval-this phenomenon occurred in 37 of the 50 cases (74%). The CS was largest in the 30% phase (9/50 cases; 18%), in the 40% phase (17/50 cases; 34%) and in the 50% phase, and it was the largest in 11 of the 50 cases (22%). There were also no gender-related differences.

CONCLUSIONS

The size of the coronary sinus varies with the phase of the heart cycle. At the 40% phase, it is largest in most cases.

Cardiac resynchronization therapy update: evolving indications, expanding benefit?

Cardiac resynchronisation therapy (CRT) is an effective intervention for appropriately selected patients with heart failure, but exactly how it works is uncertain. Recent data suggest that much, or perhaps most, of the benefits of CRT are not delivered by re-coordinating left ventricular dyssynchrony. Atrio-ventricular resynchronization, reduction in mitral regurgitation and prevention of bradycardia are other potential mechanisms of benefit that will vary from one patient to the next and over time. Because there is no single therapeutic target, it is unlikely that any single measure will accurately predict benefit. The only clinical characteristic that appears to be a useful predictor of the benefits of CRT is a QRS duration of >140 ms. Many new approaches are being developed to try to improve the effectiveness of and extend the indications for CRT. These include smart pacing algorithms, better pacing-site targeting, new sensors, multipoint pacing, remote device monitoring and leadless endocardial pacing. Whether CRT is effective in patients with atrial fibrillation or whether adding a defibrillator function to CRT improves prognosis awaits further evidence.

The Thebesian valve and coronary sinus in cardiac magnetic resonance

Purpose

There is no complex research exploring usefulness of cardiac magnetic resonance in the evaluation of the coronary sinus including Thebesian valve, which can be useful before selected electrophysiology procedures.

Methods

One hundred twenty-two patients aged 49.2 ± 17.2 (42 women) were included in the study; 4 of them were excluded. A steady-state free-precession (SSFP) sequence was the basis of the visualization and analysis of the coronary sinus as well as Thebesian valve. In selected cases, dedicated coronary sinus sequences were created. All data were evaluated by experienced cardiac magnetic resonance investigators.

Results

We were able to visualize the coronary sinus by using basic SSFP sequence in all patients, however in four cases in suboptimal quality. Average length of the coronary sinus was 39.73 ± 16.9 mm, average diameter was 9.81 ± 9.3 mm, and average angle of the entrance of the coronary sinus into the right atrium was 111.37 ± 13.8°. The Thebesian valve as the gate of the coronary sinus was found in 56 cases (45.9 %). In 21 patients (17.2 % of all), the valve was porous or almost totally covered the coronary sinus ostium, which can potentially create problems during CS cannulation.

Conclusions

In most of the cases, it is possible to visualize and measure the coronary sinus using cardiac magnetic resonance with SSFP sequence. In selected cases, it is necessary to perform additional dedicated short sequences. Thebesian valve was visualized in almost 50 % of patients.

Coronary venous system in cardiac computer tomography: Visualization, classification and role

The role of the coronary venous system was underestimated for many years. In the last 20 years, a few percutaneous cardiology techniques in which the anatomy of the coronary venous system was significant were developed and are in use. The most important seems to be cardiac resynchronization therapy, which is an invasive method for the treatment of heart failure. Unfortunately, one of the major problems is the significant anatomical variability of the coronary venous system. The description of the selected anatomical structures is only useful in selected cases such as, for example, the obstruction of selected vessels, a huge Thebesian valve, etc. The 3D images can add significant value; however, their usefulness is limited due to the different points of view that are obtained during intra-operational fluoroscopy. After summarizing all of the articles and guidelines, it can be recommended that the visualization of the coronary venous system be performed in certain patients before cardiac resynchronization. The best option is to use tomography with retrospective gating with the optimal reconstruction of cardiac veins that occurs during the diastolic phases.

Normal anatomy and variants of the venous cardiac system in MDCT coronary angiography

Three separate venous systems drain the blood returning from the heart walls. These veins are characterised by remarkable variability in terms of frequency, size and course. The knowledge of cardiac venous anatomy is of primary importance during interventional cardiac procedures that require catheterisation of cardiac veins. Some anatomical variants may hinder or contraindicate access to target veins. Coronary angiography (CA) with multidetector computed tomography (MDCT-CA) and multiplanar reformations (MPR), maximum intensity projection (MIP) and 3D reconstructions provides noninvasive visualisation of normal cardiac veins and anatomical variants. The purpose of this pictorial review is to describe by MDCT-CA the anatomy and main variants of the cardiac venous system.

Preprocedural imaging for patients with atrial fibrillation and heart failure

Various electrophysiological procedures and device implantation has been shown to improve morbidity and mortality in patients with atrial fibrillation (AF) and patients with heart failure (HF). Noninvasive cardiac imaging is used extensively in the preprocedural patient selection and for procedural guidance. In this review, we will discuss the application of preprocedural cardiac imaging in patients with AF prior to pulmonary vein and left atrial ablation as well as insertion of left atrial occluder device. We also discuss the role of noninvasive cardiac imaging in the selection of appropriate HF patients for device therapy as well as their use in guiding implantation of biventricular pacemaker for cardiac resynchronization therapy by assessing left ventricular ejection fraction, coronary venous anatomy, mechanical dyssynchrony and myocardial scar. We describe new research associated with preprocedural imaging in these patient cohorts.

Association between changes in coronary artery circulation and cardiac venous retention: a lesson from cardiac computed tomography

To use computed tomography (CT) image data to measure a potential association between the implantation of coronary artery bypass grafts (CABG) and changes in the coronary venous system has not yet been examined. In 112 (aged 59.4 ± 9.0; 45F) patients (pts.), a 64-slice CT angiography was performed. Patients were divided into 2 groups: CABG (56 pts.) and control (56 pts.)—without changes in coronaries. In each case, ten multi-planar reconstructions (MPR) and 3D volume rendering reconstructions using a 2 mm layer with ECG-gating, helical pitch: 12.8; rotation time: 0.4 s and average tube voltage: 135 kV at 380 mA. The visualization of the coronary veins was independently graded by 2 experts trained in CT. In the CABG group, the average number of visible coronary veins was 5.3 ± 1.3, while in the control group it was 3.1 ± 1.1 (p < 0.001). Statistical differences were also observed for the following coronary veins: posterolateral (control 2.1 ± 1.9 vs. CABG 2.9 ± 1.9; p < 0.05), lateral (control 2.2 ± 1.7 vs. CABG 3.1 ± 1.3; p < 0.01) and anterolateral (control 0.5 ± 0.9 vs. CABG 1.3 ± 1.0; p < 0.001). Implantation of CABG influences the coronary venous system. In patients after CABG, the number of identifiable coronary veins is significantly higher as compared to that in subjects without changes in coronaries. This might suggest an association between changes in coronary artery circulation and cardiac venous retention.

Coronary venous retention-a feature in heart failure as evidenced by mean of cardiac computed tomography

BACKGROUND

Whether the functional status of the heart can influence the coronary venous system itself has not yet been examined. In order to answer this question, we used multislice computed tomography (CT) imaging.

PURPOSE

To answer the question of whether the heart failure (HF) is associated with significant anatomical changes in the coronary venous system?

METHODS

In 136 (aged 56.6 ± 11.5) patients, a 64-slice CT was performed. Patients were divided into three groups according their ejection fraction. In each case, nine 3D volume rendering reconstructions, using a 2-mm layer with electrocardiographic-gating, were created at 0% to 90% R-R intervals (step 10%). The visualization of coronary veins (CVs) was graded independently by two experts trained in multislice computed tomography on a 0-5 point scale (0-not visible/lack of vein; 5-smoothly bordered vascular structure).

RESULTS

The average number of visible CVs per case was 3.44 in the HF group and 2.72 in patients with a normal ejection fraction (P = 0.0246). The statistical correlation between a reduction in ejection fraction and the increase in the number of veins was found (r =-0.2446, P < 0.05). For two of seven common variants of the coronary venous system at least two target veins (posterolateral and lateral) for cardiac resynchronization were presented.

CONCLUSIONS

The statistically higher number of veins in patients with heart failure may suggest an association between a failing heart and cardiac venous retention.

Cardiac CT: Imaging of and Through Cardiac Devices

For patients with cardiac devices, cardiac computed tomography (CT) remains the mainstay for imaging due to its superior resolution as compared with echocardiography and nuclear studies and no contraindication to metal as with cardiac magnetic resonance imaging. This review focuses on the evaluation and pitfalls of coronary arterial imaging in patients with devices, such as pacemakers, implantable defibrillators, cardiac resynchronization therapy (CRT), as well as complications such as lead perforation and safety concerns of CT interference. We discuss both pre- and post-procedural CRT assessment for coronary venous imaging and pre-procedural myocardial scar assessment to localize regions of scar and peri-infarct zone to facilitate ventricular tachycardia ablation in patients with devices. We describe potential new research on dyssynchrony and integration with myocardial scar and site of latest activation for patients with or being considered for CRT. We detail the utility of CT for the assessment of proper function and complications in patients with left ventricular assist device implantation.

Non invasive cardiac vein mapping: role of multislice CT coronary angiography

PURPOSE

Coronary venous anatomy is of primary importance when implanting a cardiac resynchronization therapy device, besides, the coronary sinus can be differently enlarged depending on chronic heart failure. The aim of this study is to evaluate the usefulness of Coronary CTA in describing the coronary venous tree and in particular the coronary sinus and detecting main venous system variants.

MATERIALS AND METHODS

301 consecutive patients (196 ♂, mean age 63.74 years) studied for coronary artery disease with 64 slice Coronary CTA were retrospectively examined. The acquisition protocol was the standard acquisition one used for coronary artery evaluation but the cardiac venous system were visualized. The cardiac venous system was depicted using 3D, MPR, cMPR and MIP post-processing reconstructions on an off-line workstation. For each patient image quality, presence and caliber of the coronary sinus (CS), great cardiac vein (GCV), middle vein (MV), anterior interventricular vein (AIV), lateral cardiac vein (LCV), posterior cardiac vein (PCV), small cardiac vein (SCV) and presence of variant of the normal anatomy were examined and recorded.

RESULTS

CS, GCV, MV and AIV were visualized in 100% of the cases. The LCV was visualized in 255/301 (84%) patients, the PCV in 248/301 (83%) patients and the SCV in 69/301 (23%) patients. Mean diameter of the CS was 8.7 mm in 276/301 (91.7%) patients without chronic heart failure and 9.93 mm in 25/301 (8.3%) patients with chronic heart failure.

CONCLUSIONS

Coronary CTA allows non invasive mapping of the cardiac venous system and may represent a useful presurgical tool for biventricular pacemaker devices implantation.

Cardiac imaging: Part 2, normal, variant, and anomalous configurations of the coronary vasculature

OBJECTIVE

Noninvasive imaging of the heart and coronary vasculature using CT and MRI is a new and exciting opportunity for radiologists. The purpose of this pictorial essay is to review normal and variant anatomy of the coronary arteries and of several coronary anomalies that may be clinically significant. The coronary veins and artifacts simulating disease will also be briefly covered. This article will help radiologists learn and review normal coronary anatomy, normal variants, and coronary anomalies and recognize pitfalls, such as coronary veins and artifacts, that may be confusing when first encountered.

CONCLUSION

The coronary arteries generally are predictable in their origin, course, and perfusion territories. Standardized reporting systems exist for describing the location of specific lesions, and radiologists who interpret CT and MR coronary images should be aware of and should attempt to integrate these reporting schemes into clinical practice.

Non-invasive evaluation of the coronary venous system in patients with chronic systolic heart failure by 64-detector computed tomography

BACKGROUND

Imaging coronary venous systems to guide transcatheter cardiac interventions are becoming increasingly important, particularly in heart failure patients who are selected for cardiac resynchronization therapy (CRT). Failure of left ventricular (LV) lead placement during the procedure has been attributed to the inability to insert catheters into the coronary sinus and the lack of suitable side branches.

PURPOSE

To comparatively assess the value of a 64-detector MDCT examination in visualizing the cardiac veins and evaluating the morphological characteristics of the coronary venous system in patients with and without chronic systolic heart failure (SHF).

MATERIAL AND METHODS

A 64-detector MDCT examination of the heart was performed in 26 consecutive patients (five women, 21 men; mean age 57.80 ± 12.05 years; range 27-81 years) with chronic SHF. The morphological characteristics of the coronary venous system, such as the diameter, the distances between the venous tributaries, the angle and the tortuosity, were evaluated. The group was compared with a subgroup of 52 subjects without SHF (LV ejection fraction >40%) matched for age, sex, and the risk factors for coronary artery disease.

RESULTS

The coronary sinus (CS), great cardiac vein (GCV), anterior interventricular vein (AIV), and posterior interventricular vein (PIV) were visualized in all 78 individuals. The posterior vein of the left ventricle (PVLV) (63/78), left marginal vein (LMV) (72/78), and the small cardiac vein (SCV) (50/78) were visualized in SHF and control patients (p = NS). The lengths between venous tributaries were higher (p > 0.05) and more dilated (P < 0.001 for CS, GCV, AIV, PVLV, LMV; p = 0.001 for PIV) in the cases with SHF compared with the control population. The angle between the CS-GCV axis and the venous branches was wider (p = 0.02 for LMV and PIV, p = 0.001 for PVLV) and did not have any correlation with the LV diameter in cases with SHF. There was no difference between the SHF and control groups in terms of the tortuosity of PVLV and LMV (p = NS).

CONCLUSION

The study demonstrated an increase in the diameters, lengths, and angulations with the CS-GCV axis of the coronary veins in cases with SHF. A 64-detector MDCT is a feasible tool for non-invasive evaluation of the coronary venous system and may provide considerable information regarding numbers and morphology of coronary veins before percutaneous transcatheter cardiac therapy.

Coronary sinus ostium: the key structure in the heart's anatomy from the electrophysiologist's point of view

There are no research studies that comprehensively analyze, with computed tomography, the coronary sinus (CS) ostium with respect to its importance for some electrophysiological procedures paying special attention to the Thebesian valve (ThebV). Our aim was to evaluate the characteristic features of the CS anatomy, which can be useful for electrophysiologists using multislice computed tomography (MSCT). An additional aim was to create a tomographic classification of ThebV types. Included into the study were 150 patients (aged 59.7 ± 11.4; 105M) (43 with heart failure). Due to the suspicion of coronary artery disease, 64-slice MSCT (Toshiba, Aquilion 64) was performed in all patients. All measurements and the search for the ThebV were performed on multiplanar reconstructions in axial projection at 0.5-mm slice thickness. The average diameter of CS ostium was 14.2 ± 3.5 mm and the angle of entrance of the CS to the right atrium was 112° ± 11°. Seven variants of the ThebV were introduced and six of them were confirmed in this group. The following frequency of variants of ThebV was confirmed: E, 11.3%; D, 10.6%; A1, 8.7%; A2, 7.4%; C, 6.0%; B2, 2.0%. A statistically significant correlation between age and the size of CS ostium was found (r = 0.25; p < 0.05). It is possible to visualize and evaluate the CS including measurements and ThebV evaluation in MSCT. Six anatomical variants of the valve were found. MSCT can potentially provide valuable knowledge before the CS cannulation.

Accuracy and usefulness of fusion imaging between three-dimensional coronary sinus and coronary veins computed tomographic images with projection images obtained using fluoroscopy

AIMS

Coronary sinus (CS) and coronary veins are not delineated by fluoroscopy. The study evaluates the feasibility and accuracy of cardiac tomography (CT) image registration of CS anatomy on fluoroscopic image.

METHODS AND RESULTS

Eighteen consecutive patients underwent contrast-enhanced, ECG-gated CT scanning. Coronary sinus, coronary veins, superior vena cava, the distal portion of the trachea, and of the two main bronchi were reconstructed. These images were then fused over the CS fluoroscopic angiogram. Registration accuracy was verified by assessing the overlap of CS borders both in the CT- and in the fluoroscopy-derived images. The mean distance between the centrelines of the CS was 0.73 mm, with a maximum distance of 2.22 mm. For the first-order branches, mean distance was 0.80 mm with a maximum distance of 2.64 mm. High Lin concordance correlation coefficients were computed (>0.95) for the CS and first-order branch diameters, although the Bland and Altman limits were large. The agreement between the number of vessels identified was moderate with kappa = 0.43.

CONCLUSION

Fusion imaging processing of two different imaging modalities (CT and fluoroscopy) may be feasible and accurate for guiding CRT implantation as it allows constant comprehensive display of CS body and branches. Prospective studies are needed for assessing clinical implications.

Optimal image reconstruction intervals for noninvasive visualization of the cardiac venous system with a 64-slice computed tomography

The purpose of the study was to evaluate in which phase of the cardiac cycle visualization of the cardiac veins could achieve the highest possible quality. In 138 patients (aged 56.6 +/- 10.6; 58F) with a suspicion of CAD, a 64-slice CT (Toshiba Aquilion) was performed. In each case ten 3D volume rendering reconstructions were created from 0 to 90% R-R intervals (step 10%) using a 0.5 mm slice thickness (reconstructions 2.0 mm). An arbitrary score of the quality of images was introduced. In 82 (59.4%) patients optimal image quality was noted at the 40% phase, in 28 (20.3%) at the 30% phase and finally in 14 (10.1%) at the 50% phase. These 3 phases (30/40/50%) were the best option for 124 (89.8% of all) patients. In the rest of the patients the best visualization was obtained in other phases as follows: 60 and 80% for 4 patients (2.9%); 70% for 3 patients (2.3%) and at the 0, 10, 20% one patient at each phase (0.7%). The optimal phases of the cardiac cycle for the visualization of the cardiac venous system are 30 or 40%. Less frequently, an alternative could be the 50% phase.