Investigation of coronary venous anatomy by retrograde venography in patients with malignant ventricular tachycardia

Study of coronary sinus anatomy during levophase of coronary angiography

BACKGROUND

Coronary sinus (CS) imaging has recently gained importance due to increasing need for mapping and ablation of electrophysiological arrhythmias and left ventricular (LV) pacing during cardiac resynchronization therapy (CRT). Retrograde venogram is the current standard for imaging CS and its tributaries.

AIM

To evaluate CS anatomy during levophase of routine coronary angiography to aid LV lead implantation during CRT.

METHODS

In this prospective observational study, 164 patients undergoing routine coronary angiography for various indications (Chronic stable angina-44.5%, acute coronary syndrome- 39.5%, Dilated cardiomyopathy-11%, atypical chest pain-5%) were included. Venous phase (levophase) of left coronary injection was recorded in left anterior oblique - cranial and right anterior oblique -cranial views. Visibility of coronary veins, width and shape of CS ostium, angulations of proximal CS with body of CS were noted. Presence, size, take-off angle and tortuosity of posterolateral vein (PLV), anterior interventricular veins (AIV) and middle cardiac vein (MCV) were also noted.

RESULTS

During levophase, visibility grade (Muhlenbruch grade) for coronary veins was 3 in 74% and 2 in 26% of cases. Visibility of CS did not correlate with body mass index. The diameter of CS ostium was < 10 mm, 10-15 mm and > 15 mm in 48%, 42% and 10% of patients respectively. Proximal CS was tubular in 136 (83%) patients and funnel-shaped in 28 (17%) patients. Sharp take-off angulation between ostium and body of CS was seen in 16 (10%) patients. Two or more PLV were present in 8 patients while PLV was absent in 52 (32%) patients. Angle of take-off of PLV with body of CS was favourable (0°-45°) in 65 (40%) patients. The angle was 45°-90° in 36 patients and difficult take-off angle (> 90°) was seen in 8 patients. Length of PLV reached distal third of myocardium in 84 cases and middle third in 11 cases. There was no tortuosity in 79 cases, a single bend in 29 cases and more than 2 bends in 4 cases. Thirty nine (24%) patients had other veins supplying posterior/Lateral wall of LV. There was a single vein supplying lateral/posterior wall in 31 (19%) patients. Diameter of MCV and AIV was significantly larger in patients with absent PLV as compared to patients with a PLV.

CONCLUSION

Levophase study of left coronary injection is effective in visualization of the CS in almost all patients undergoing coronary angiography and may be an effective alternative to retrograde venogram in patients with LV dysfunction or LBBB.

Comparison of noise-optimized linearly blended images and noise-optimized virtual monoenergetic images evaluated by dual-source, dual-energy CT in cardiac vein assessment

BACKGROUND

The coronary venous system is frequently used as an entry route to the heart and treatment modalities for many cardiac diseases and many procedures. Consequently, evaluation of the coronary venous system and understanding cardiac vein anatomy is crucial.

PURPOSE

To determine the optimal image set in a comparison of noise-optimized linearly blended images (F_0.6) and noise-optimized virtual monoenergetic images (VMI+) evaluated by dual-energy computed tomography (DECT) for cardiac vein assessment.

MATERIAL AND METHODS

Thirty-four patients (mean age 58.2 ± 14.2 years) who underwent DECT due to chest pain were enrolled. Images were post-processed with the F_0.6, and VMI+ algorithms at energy levels in the range of 40-100 keV in 10-keV increments. Enhancement (HU), noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were objectively measured at two points in the great cardiac vein by consensus of two radiologists. Two blinded observers evaluated the subjective image quality of the great cardiac vein on a 4-point scale.

RESULTS

HU, noise, and SNR peaked at 40 keV VMI+ (P < 0.05) among 50-100 keV VMI+. CNR peaked at 100 keV VMI+; however, there were no significant differences compared to CNR images processed at 40-90 keV VMI+. HU and noise were significantly higher in 40 keV VMI+ than F_0.6 images; however, both SNR and CNR were significantly higher in F_0.6 images. An assessment of subjective vein delineation revealed that F_0.6 images had the highest scores.

CONCLUSION

F_0.6 images were superior to VMI+ and provided the optimal image set for cardiac vein assessment.

Giant coronary sinus aneurysm misdiagnosed as an extracardiac mediastinal tumor

Coronary sinus aneurysm is a rare heart anomaly. Herein, we report a rare case with giant coronary sinus aneurysm misdiagnosed as an extracardiac mediastinal tumor. The preoperative diagnostic imaging failed to diagnose the correct location of the tumor and a simple resection was planned. It turned out to be coronary sinus aneurysm intraoperatively and required cardiopulmonary bypass support for the resection.

Planning and guidance of cardiac resynchronization therapy-lead implantation by evaluating coronary venous anatomy assessed with multidetector computed tomography

OBJECTIVES

We sought to evaluate the utility of multidetector computed tomography (MDCT) in preoperative planning of cardiac resynchronization therapy (CRT) device implantation.

BACKGROUND

Variation in coronary venous anatomy can affect optimal lead placement and may warrant preimplantation visualization prior to CRT lead placement.

METHODS

Prospective randomized enrollment of 29 patients (17 males; mean age at implant 66.7 ± 12.8 years) was undertaken. Patients were randomized to preimplantation MDCT (GE^® 64-detector Lightspeed, n = 16) or no MDCT. Implantation was planned based on three-dimensional coronary venous reconstruction as visualized in the CT group. Measurement of coronary sinus (CS) angulation, CS ostial (os) diameter, right atrial (RA) width, volume, and height was undertaken prior to implant. Intraoperative CS lead implantation times (introduction, cannulation, and left ventricular [LV] lead positioning), procedure time, fluoroscopy time, and venogram contrast volume were measured to determine if there was a difference between patients who underwent preimplant CT scan and those who did not.

RESULTS

CS os diameter (mean = 13.8 ± 2.9 cm) was inversely correlated with total fluoroscopy time (r = −0.57, P = .008), and total procedure time, but this correlation was not statistically significant (r = −0.36, P = 0.12). RA width (mean = 52.8 ± 9.9 cm) was associated with a shorter total procedure time (r = −0.44, P = .047) and LV lead positioning time (r = −0.33, P = .012). There were no statistically significant differences between the CT group and the non-CT group with respect to total intraoperative and fluoroscopy times or venogram contrast volumes. Total procedure time was longer in the CT group but the difference was not statistically significant (94 ± 27.2 vs. 74.7 ± 26.6; P = .065).

CONCLUSION

Noninvasive visualization of the coronary venous anatomy before CRT implantation can be used as a guide for lead placement. While no significant differences were noted between the two groups with respect to intraoperative variables, CS os diameter and RA width inversely correlated to a shorter procedure time and LV lead positioning time, respectively. Further clinical trials regarding the utility of MDCT to visualize coronary venous anatomy prior to CRT implantation for procedural planning and lead placement guidance are warranted.

Optimization of free-breathing whole-heart 3-dimensional cardiac magnetic resonance imaging at 3 tesla to identify coronary vein anatomy and to compare with multidetector computed tomography

OBJECTIVE

This study optimizes use of 3-T magnetic resonance imaging (MRI) to delineate coronary venous anatomy and compares 3-T MRI with multidetector computed tomography (MDCT) measurements.

METHODS

The study population included 37 consecutive subjects (22 men, 19-71 years old). Whole-heart contrast-enhanced MRI images at 3 T were acquired using segmented k-space gradient echo with inversion recovery prepared technique. The MDCT images were obtained using nonionic iodinated contrast.

RESULTS

The coronary sinus and great cardiac, posterior interventricular, and anterior interventricular veins were visualized in 100% of cases by both MRI and MDCT. Detection of the posterior vein of the left ventricle and the left marginal vein by MRI was 97% and 81%, respectively. Bland-Altman plots showed agreement in ostial diameter measured by both modalities with correlation coefficients ranging from 0.5 to 0.76. Vein length and distances also agreed closely.

CONCLUSIONS

Free-breathing whole-heart 3-dimensional MRI at 3 T provides high-spatial-resolution images and could offer an alternative imaging technique instead of MDCT scans.

Thoracoscopic Epicardial Lead Implantation as an Alternative to Failed Endovascular Insertion for Cardiac Pacing and Resynchronization Therapy

Objective

Numerous anomalies or postprocedural stricture of the venous system prevent optimal endovascular implantation of a pacing lead in more than 10% of patient indicated for permanent pacing or cardiac resynchronization therapy. The purpose of this report was to summarize our experience and immediate postoperative results of thoracoscopic lead implantation as a lesser invasive solution to an unsuccessful endovascular lead insertion.

Methods

From January 2008 to April 2013, 11 epicardial leads were introduced thoracoscopically at our center as a rescue treatment after failed endovascular attempts. Patients were ventilated using a double-lumen endotracheal tube. A 5-mm 30-degree lance thoracoscope was used with either 2 or 3 additional working ports. A screw-in pacing lead (Medtronic Model 5071 Pacing lead, Minneapolis, MN USA) was inserted into the left ventricular epicardium. After the lead placement and assessment for threshold less than 1 V, the lead was brought to the chest wall and tunneled to the pacemaker generator pocket. At the end of the procedure, a small, flexible 14F thoracic drain, was left inside the pleural cavity for the next 24 hours.

Results

There were no mortality or any major surgical complications among these patients. All patients responded to the epicardial lead implantation in terms of appropriate pacing and conductivity. No clinical failure was observed, and no patient required a repeat procedure.

Conclusions

Thoracoscopic lead insertion is safe and easy to perform. We believe it should be offered as the first choice after failed endovascular pacing lead implantation.

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.

[Clinical indications for the use of cardiac MRI. By the SIRM Study Group on Cardiac Imaging]

Cardiac magnetic resonance (CMR) is considered an useful method in the evaluation of many cardiac disorders. Based on our experience and available literature, we wrote a document as a guiding tool in the clinical use of CMR. Synthetically we describe different cardiac disorders and express for each one a classification, I to IV, depending on the significance of diagnostic information expected.

Contemporary and future trends in cardiac resynchronization therapy to enhance response

The rationale for cardiac resynchronization therapy (CRT), expectations in terms of patient benefit, patient selection for CRT, selection of a CRT pacemaker (CRT-P) vs CRT plus implantable cardioverter-defibrillator (CRT-D) platform, and studies evaluating device programming to enhance benefit from CRT are reviewed. The notion of an "optimal" left ventricular (LV) pacing site, the rationale for identifying and avoiding LV pacing in regions of scar, the use of anatomic, hemodynamic, and electrical parameters to identify an optimal LV pacing site, and the potential utility of multisite LV pacing to enhance benefit from CRT are discussed. Finally, the advantages and disadvantages of the various methods for LV lead delivery are reviewed.

Clinical indications for cardiac computed tomography. From the Working Group of the Cardiac Radiology Section of the Italian Society of Medical Radiology (SIRM)

Cardiac computed tomography (CCT) has grown as a useful means in different clinical contexts. Technological development has progressively extended the indications for CCT while reducing the required radiation dose. Even today there is little documentation from the main international scientific societies describing the proper use and clinical indications of CCT; in particular, there are no complete guidelines. This document reflects the position of the Working Group of the Cardiac Radiology Section of the Italian Society of Radiology concerning the indications for CCT.

Usefulness of electroanatomical mapping during transseptal endocardial left ventricular lead implantation

AIM

Failure rate to implant left ventricular (LV) lead transvenously is 4-8% in cardiac resynchronization therapy (CRT) patients. Epicardial lead placement is an alternative method and if not applicable case reports and small series showed the feasibility of endocardial LV lead implantation. Electroanatomical mapping might be a useful tool to guide this procedure.

METHODS AND RESULTS

Four patients had undergone endocardial LV lead implantation after unsuccessful transvenous implantation or epicardial LV lead dysfunction using the transseptal approach. Electroanatomical mapping was used to mark the location of the transseptal puncture. This location point guided the mapping catheter from the subclavian access and facilitated positioning of the LV lead at the adjacent latest activation area of the left ventricle detected by activation mapping. Endocardial active fixation LV leads were successfully implanted in all patients with stable electrical parameters immediately after implantation and over a mean follow-up of 18.3 months (lead impedance 520 ± 177 vs. 439 ± 119 Ω and pacing threshold 0.8 ± 0.2 V, 0.5 ms vs. 0.6 ± 0.1 V, 0.5 ms, respectively). Patients were maintained on anticoagulation therapy with a target international normalized ratio of 3.5-4.5 and did not show any thromboembolic, haemorrhagic events, or infection. Echocardiography showed significant improvement of LV systolic function with marked improvement of the functional status.

CONCLUSIONS

Electroanatomical mapping is a useful technical tool to guide endocardial LV lead implantation. It helps to identify the location of the transseptal puncture and the use of activation mapping might facilitate location of the optimal lead positions during CRT.

Lead positioning strategies to enhance response to cardiac resynchronization therapy

Left ventricular lead position is one of the main determinants of CRT response. There are several approaches in LV lead positioning that include favoring an optimal anatomical position or targeting either the segment with maximal mechanical dyssynchrony or a region with maximal electrical delay. The conventional LV lead implantation faces several technical difficulties that may prevent the obtaining of a stable position and good performance of the LV lead without phrenic nerve stimulation. In addition, implant of the LV pacing lead in areas with myocardial scar may result in less than optimal cardiac resynchronization. Several strategies have been proposed to overcome all these obstacles including multimodality cardiac imaging to help in preprocedural or intraprocedural identification of the latest activated areas of the LV and the potential anatomical constraints. In selected patients, the surgical implant may be a solution to overcome these constraints. In the future, LV endocardial or epicardial multisite pacing may deliver an enhanced response to CRT.

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.

Contrast-enhanced whole-heart coronary MRA at 3.0T for the evaluation of cardiac venous anatomy

This study was designed to evaluate the value of contrast-enhanced whole-heart coronary MRA (CMRA) at 3.0T in depicting the cardiac venous anatomy. In cardiac resynchronization therapy (CRT), left ventricular (LV) pacing is achieved by positioning the LV lead in one of the tributaries of the coronary sinus (CS). Pre-implantation knowledge of the venous anatomy may help determine whether transvenous LV lead placement for CRT is feasible. Images of 51 subjects undergoing contrast-enhanced whole-heart CMRA at 3.0T were retrospectively analyzed. Data acquisition was performed using electrocardiography-triggered, navigator-gated, inversion-recovery prepared, segmented gradient-echo sequence. A 32-element cardiac coil was used for data acquisition. The visibility of the cardiac veins was graded visually using a 4-point scale (1: poor–4: excellent). The paired Student t test was used to evaluate differences in diameters of the ostium of the CS in anteroposterior and superoinferior direction. The cardiac veins were finally evaluated in 48 subjects with three anatomic variations. The diameter of the CS ostium in the superoinferior direction (1.13 ± 0.26 cm) was larger than in the anteroposterior direction (0.82 ± 0.19 cm) (P < 0.05). The mean visibility score of CS, posterior interventricular vein, posterior vein of the left ventricle, left marginal vein, and anterior interventricular vein was 4.0 ± 0.0, 3.4 ± 0.5, 3.4 ± 0.5, 3.0 ± 0.8, and 3.3 ± 0.5, respectively. In conclusion, contrast-enhanced whole-heart CMRA at 3.0T can depict the normal and variant cardiac venous anatomy.

Delivery of gene and cellular therapies for heart disease

Although there has been considerable interest in the utilization of gene and cellular therapy for heart disease in recent years, there remain critical questions prior to widespread promotion of therapy, and key among these issues is the delivery method used for both gene therapy and cellular therapy. Much of the failure of gene and cellular therapy can be explained by the biological therapy itself; however, certainly there is a critical role played by the delivery technique, in particular, those that have been adapted from routine clinical use such as intravenous and intracoronary injection. Development of novel techniques to deliver gene and cellular therapy has ensued with some preclinical and even clinical success, though questions regarding safety, invasiveness, and repeatability remain. Here, we review techniques for gene and cellular therapy delivery, both existing and adapted techniques, and novel techniques that have emerged recently at promoting improved efficacy of therapy without the cost of systemic distribution. We also highlight key issues that need to be addressed to improve the chances of success of delivery techniques to enhance therapeutic benefit.

Future Developments in Nonsurgical Epicardial Therapies

The unique anatomic position of the pericardium in juxtaposition to central cardiac structures enables it to serve as the ideal vantage point for the delivery of novel cardiovascular therapies. Development of new tools to permit delivery of therapy in the closed pericardial space holds promise for near-surgical access to the heart, without open surgical morbidity. Early observations raise hope for the availability of epicardial leads to enhance cardiac resynchronization therapy designed for subxiphoid nonsurgical percutaneous delivery. Emerging technologies for left atrial appendage ligation may offer new strategies for preventing stroke.

Optimization of acquisition trajectories for 3D rotational coronary venography

OBJECTIVE

Rotational coronary X-ray imaging on C-arm systems provides a multitude of diagnostic projections from the vascular tree with a single contrast agent bolus. The acquisition trajectory is typically limited to a circular arc with a fixed caudo-cranial angulation. This may cause sub- optimal projection directions for specific vessel segments for all acquired views, e.g., those segments orthogonal to the axis of rotation. In this paper, a method is presented to calculate a patient-independent acquisition trajectory with respect to vessel foreshortening and overlap for multiple vessel segments of the coronary tree. This method can be applied to artery as well as vein anatomy.

METHODS

Rotational coronary venograms of 14 patients have been used to generate three-dimensional mesh representations with a semi-automatic two view modeling algorithm. The venous tree is divided into seven different vessel segments. Foreshortening and overlap of every segment are calculated and combined for all patients in a measure called obstruction value. The weighted obstruction values of all vessel segments define a cost function for the entire two-dimensional angular range of the C-arm system. Viterbi's algorithm is used to calculate an optimal trajectory with respect to this cost function. The method is validated by leave-one-out cross-validation on the 14 rotational venography data sets and on simulated venograms of a segmented computed tomography (CT) data set. Projection images with a foreshortening value below 10% and overlap below 20% are rated 'optimal'.

RESULTS

In 12 (85.7%) data sets, 43% more optimal images were acquired using the presented method compared to the standard circular arc trajectory. As well, in 13 (92.8%) data sets 38% more vessel segments can be optimally visualized in the acquired images. The test on the CT data set showed that the resulting average root-mean-square error of the extracted centerline points of the segmented CT data set compared to the error based on the views from the circular arc was reduced from 2.52 to 1.55 mm.

CONCLUSION

In a first test, the method proved to deliver improved image quality by reducing foreshortening and overlap of vessel segments and may therefore also improve the centerline extraction accuracy of the semi-automatic two view modeling method.

Premature ventricular contractions arising from the intramural ventricular septum

A 68-year-old man with symptomatic idiopathic premature ventricular contractions (PVCs) underwent electrophysiological testing. Radiofrequency catheter ablation was unsuccessful at the earliest endocardial ventricular activation site in the left coronary cusp. Epicardial mapping via the cardiac veins was then performed. Balloon-occluded coronary sinus venography revealed the small branches of the anterior interventricular vein. Mapping with a microcatheter revealed the earliest ventricular activation and perfect pace map at the distal portion of the septal perforating branch, suggesting an intramural ventricular septal PVC origin. Catheter ablation was abandoned because of the inaccessibility of the ablation catheter to that site via the venous system.

Unsuccessful left ventricular lead implantation in two first-degree relatives. Is the coronary venous anatomy similar in both cases?

We reported on two unsuccessful implantations of the left ventricular lead in two first-degree relatives due to inability to cannulate the coronary sinus (CS). The anatomy of the coronary venous system investigated by means of dual source computed tomography showed several similarities in both patients: narrowing of the proximal part of CS and a small number of CS tributaries.

[Optimal electrode placement. What to consider during implantation of a biventricular pacemaker?]

Since the introduction of transvenous left ventricular lead systems nearly a decade ago, resynchronization therapy has gained widespread acceptance and has become a growing field in heart failure therapy. Due to the increasing numbers of implanting centers and physicians, the need for adequate education is increasing. This article describes and illustrates the anatomical background, the technical opportunities and pitfalls, which have to be overcome, to achieve an implanting success rate of 95% to 98%, as can be achieved by well-trained physicians under optimal conditions.

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

BACKGROUND

Previsualization of the cardiac venous system is very important for some techniques, for example, cardiac resynchronization therapy (CRT). The aim of this study was to propose a new, user-friendly method of cardiac venous system visualization in 64-slice computed tomography (CT).

METHODS

In 112 patients (66 M) aged 58 +/- 11 standard deviation, a 64-slice CT with a retrospective electrocardiogram gating was performed due to a suspicion of ischemic heart disease. Special attention was paid to the requirements for image reconstruction useful for CRT.

RESULTS

In 74% of the patients, it was possible to obtain similar images to those during the CRT implantation procedure within anterior-posterior, left anterior oblique, and right anterior oblique views. The coronary sinus was clearly visible in all cases, the ostium measured 12.9 +/- 5.9 mm, and the angle of entrance 99 +/- 12 degrees. In all patients it was possible to demonstrate more than one vein; in 95%, at least one vein was clearly visible in the target area. Among the target veins, the posterolateral vein was visible most frequently (78%) in the cases as well as the lateral vein (78%).

CONCLUSION

The proposed scheme in 64-slice computed tomography enables images to be generated similar to the intraoperative fluoroscopy, which can be useful in techniques where previsualization of the cardiac venous system is recommended.

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.

Noncoronary applications of cardiac multidetector row computed tomography

Multidetector row computed tomography (MDCT) has a high diagnostic accuracy to evaluate coronary artery stenoses. Additionally, the 4-dimensional aspect of cardiac MDCT allows a comprehensive evaluation of cardiac structure and function. Left ventricular volumes and systolic function can be accurately assessed with MDCT, and imaging of myocardial infarction is a promising application of cardiac MDCT. In addition, MDCT may provide anatomical visualization of heart valves. Also, evaluation of anatomy of the pulmonary veins and cardiac venous system render MDCT a valuable tool for the cardiologist performing electrophysiological procedures. In this article, the role of MDCT in the noninvasive evaluation of cardiac structure and function is discussed. An overview of the wide range of noncoronary applications of cardiac MDCT is provided, focusing on the assessment of left ventricular function, valvular heart disease, and cardiac venous anatomy.

Magnetic resonance imaging and computed tomography in assessing cardiac veins and scar tissue

The success of cardiac resynchronization therapy is influenced by several issues including cardiac venous anatomy and myocardial scar tissue. This article discusses non-invasive imaging modalities that could contribute significantly to the selection process of cardiac resynchronization therapy (CRT) candidates: multi-slice computed tomography to depict the coronary sinus tributaries and magnetic resonance imaging to identify scar tissue.

Influence of left atrial and ventricular volumes on the relation between mitral valve annulus and coronary sinus

The aim of this study was to evaluate the anatomic relation between the coronary sinus (CS), mitral annulus, and coronary arteries using 64-multislice computed tomography (MSCT) in patients presenting with a wide range of atrial volumes and left ventricular functions to determine the potential clinical use for percutaneous mitral annuloplasty (PMA). The MSCT data of 165 patients (age 63.65 +/- 12.89 years, 67.3% men) were evaluated. The following variables were measured: CS length, CS ostium area, area of the section of CS when it becomes great cardiac vein, area between CS and atrioventricular groove assessed in volume-rendered 3-dimensional images, axial angle measured as the angle between CS and mitral annulus assessed in axial section, mitral valve annulus (MVA) area, left atrium volume, and left circumflex artery/marginal branch-CS relation referring to mitral annulus. The correlation was inversed between the reduction of the axial angle and all following variables: enlargement of both left ventricular end-systolic (r = -0.429, p <0.001) and end-diastolic (r = -0.428, p <0.001) volumes, left atrial volume (r = -0.361, p <0.001), and MVA (r = -0.324, p <0.001). Similarly, there was inverse correlation between the reduction of the area between CS and atrioventricular groove, and enlargement of both left ventricular end-systolic (r = -0.376, p <0.001) and end-diastolic (r = -0.291, p <0.001) volumes, left atrial volume (r = -0.221, p = 0.001), and MVA (r = -0.155, p = 0.019). Of note, circumflex artery was located between CS and MVA in 77% of the patients, but in patients with severe mitral regurgitation CS crossed circumflex/marginal branch artery more frequently (97% of cases). In conclusion, a close proximity of the CS to the mitral annulus but also to circumflex artery is more likely to occur with left atrial and ventricular enlargement. Thus, MSCT should be considered as part of the selection process of potential candidate to PMA to avoid external compression of circumflex artery/marginal branch by the device.

Characterization of human coronary sinus valves by direct visualization during biventricular pacemaker implantation

BACKGROUND

The precise reasons for failure to cannulate the coronary sinus during biventricular device implantation are unknown. Visualization of the coronary sinus ostium during electrophysiology procedures may enhance understanding of how unusual anatomy can affect successful cannulation of the coronary sinus.

OBJECTIVES

The aim of this study was to describe the morphology of valves at the coronary sinus ostium (CSO) visualized directly with an illuminated fiberoptic endoscope during implantation of biventricular devices.

METHODS

The coronary sinus anatomy of one hundred consecutive patients undergoing implantation of biventricular devices was investigated using a fiberoptic endocardial visualization catheter (EVC).

RESULTS

The CSO was clearly visualized in 98 patients using the EVC. A Thebesian valve was seen in 54% of these. Almost all Thebesian valves were positioned at the inferior (61%) or posterior (33%) aspect of the CSO. Only six patients had Thebesian valves that covered more than 70% of the CSO, but all were successfully implanted with a transvenous left ventricular pacing lead after cannulating the coronary sinus under direct visualization.

CONCLUSIONS

Over half of patients undergoing biventricular device implantation have identifiable Thebesian valves. Even valves covering the majority of the ostial area may be traversed using direct visualization and modern catheterization techniques.

Prospective evaluation of the anatomy of the coronary venous system using multidetector row computed tomography

BACKGROUND

Multidetector row computed tomography (MDCT) is a developing technique mainly used to evaluate the coronary arteries, but less attention has been paid to the coronary venous system. However, with the dramatic technological advancement of percutaneous therapies for heart failure or mitral insufficiency, a better knowledge about the anatomy of the coronary venous system may be of great utility. We sought the efficacy of MDCT imaging to delineate the coronary venous system.

METHODS

16 row MDCT scans were performed in 50 consecutive patients (42 men, age 61+/-15 years, all in sinus rhythm). The inter-individual variability in terms of diameter, distance, angle of the main tributaries of the coronary venous system was reported.

RESULTS

The coronary venous system was always visualized. A remnant Thebesian valve was observed in 18 patients, the diameter of the coronary sinus ostium was found 12.2+/-3.6 mm and 15.3+/-3.7 mm respectively in the antero-posterior and supero-inferior directions, the distance between the posterior vein of the left ventricle (PVLV) and the anterior interventricular vein (AIV) was found 108.6+/-15.2 mm with a significant correlation with the mitral annulus diameter (p<.002) and the left ventricular diameter (p<0.01). The left marginal vein (LMV) was more often tortuous when the angle between the LMV and the great cardiac vein was less than 60 degrees (p<0.01).

CONCLUSION

16 row MDCT imaging can be used to investigate non-invasively the coronary venous anatomy and may serve as a useful tool before percutaneous therapies involving the coronary veins.