Activation mapping from the coronary sinus may be limited by anatomic variations

Anatomical considerations of percutaneous transvenous mitral annuloplasty: a novel procedure for treatment of functional mitral regurgitation

Percutaneous transvenous mitral annuloplasty (PTMA) has evolved as a latest procedure for the treatment of functional mitral regurgitation. It reduces mitral valve annulus (MVA) size and increases valve leaflet coaptation via compression of coronary sinus (CS). Anatomical considerations for this procedure were elucidated in the present study. In 40 formalin fixed adult cadaveric human hearts, relation of the venous channel formed by CS and great cardiac vein (GCV) to MVA and the adjacent arteries was described, at 6 points by making longitudinal sections perpendicular to the plane of MVA, numbered 1-6 starting from CS ostium. CS/GCV formed a semicircular venous channel on the atrial side of MVA. Based on the distance of CS/GCV from MVA, two patterns were identified. In 37 hearts, the venous channel at point 2 was widely separated from the MVA compared to the two ends and in three hearts a nonconsistent pattern was observed. GCV crossed circumflex artery superficially. GCV or CS crossed the left marginal artery and ventricular branches of circumflex artery superficially in 17 and 23 hearts, respectively. As the venous channel was related more to the left atrial wall, PTMA devices probably exert an indirect traction on MVA. The arteries crossing deep to the venous channel may be compressed by PTMA device leading to myocardial ischemia. Knowledge of the spatial relations of MVA and a preoperative and postoperative angiogram may help to reduce such complications during PTMA.

Measurement of the ventriculoatrial interval from the coronary sinus during para-Hisian pacing may fail to distinguish ventriculoatrial nodal conduction from conduction over a septal accessory pathway

BACKGROUND

Para-Hisian pacing (PHP) helps differentiate retrograde conduction over an accessory pathway (AP) from retrograde conduction over the atrioventricular (AV) node. This study examined a potential limitation of this technique, focusing on the measurement of the ventriculoatrial (V-A) interval from the coronary sinus (CS) during PHP.

METHODS

Our subjects were 9 patients undergoing electrophysiological studies before successful catheter ablation of a posteroseptal AP. During PHP, retrograde conduction occurred over an AP when the pacing stimulus to atrium (S-A) interval recorded near the AP remained unchanged whether the His bundle (HB) was captured or not (pattern 1), or when a loss of HB capture was associated with an increase in the S-A interval and no change in the V-A interval near the AP (pattern 2).

RESULTS

Patterns 1 and 2 were observed in 5 (56%) and 2 (22%) patients, respectively. However, in the remaining 2 patients (22%), loss of HB capture during PHP was associated with an increase in the S-A interval (as in pattern 2), whereas the V-A interval near the AP could not be measured because no ventricular electrogram was visible on the CS recording (pattern 3); therefore, the presence of AP could not be confirmed by PHP. In patterns 2 and 3, the atrial activation sequence remained unchanged whether the HB was captured or not.

CONCLUSIONS

PHP may not be able to discriminate between a retrograde septal AP and AV nodal conduction in patients whose proximal CS recording shows no visible ventricular electrogram.

Trans-Coronary-Venous Interventions

The coronary venous system is routinely targeted during electrophysiological measurements or cardiac resynchronization therapy. However, several novel interventional techniques require coronary venous catheterization and visualization as well as transvenous delivery of devices and/or therapeutic agents. Recent reports suggest the possibility of a transvenous approach for the interventional treatment of refractory angina and mitral valve regurgitation. In addition, the coronary venous system has been used as a route for the delivery of stem cells in patients with left ventricular dysfunction due to ischemic heart disease. We review the potential value of using a coronary venous approach in association with recent therapeutic developments in the interventional treatment of structural and ischemic heart disease. We will also discuss techniques related to coronary venous catheterization.

Percutaneous mitral annuloplasty through the coronary sinus: an anatomic point of view

OBJECTIVE

We assessed the anatomic relationships among the mitral annulus, coronary sinus, and circumflex artery in human cadaver hearts.

METHODS

Percutaneous posterior mitral annuloplasty has been proposed to treat functional mitral regurgitation on the basis of the proximity of the coronary sinus to the mitral annulus. However, concern remains about the ability to perform a trigone-to-trigone posterior annuloplasty and the potential for compromise of the circumflex coronary artery. Ten hearts were studied after injection of expansible foam into the coronary sinus and circumflex artery. The mitral annulus perimeter, posterior intertrigonal (T1-T2) and intercommissural (C1-C2) distance, and coronary sinus projection on the native annulus (S1-S2) were measured. The spatial geometry of the coronary sinus was correlated with the circumflex artery route and the distance with the native mitral annulus.

RESULTS

The projection of coronary sinus annuloplasty achieves at best a commissure-to-commissure annuloplasty 14.5 (6-24) mm behind each trigone: T1-T2: 74 (56-114) mm, C1-C2: 62.2 (48-80) mm, S1-S2: 59.5 (40-80) mm. The coronary sinus was distant from the native annulus (8-14 mm at the coronary sinus ostium, 13.7-20.4 mm at the middle of the coronary sinus, 6.9-14 mm at the level of the great coronary vein). The circumflex artery was located between the coronary sinus and the mitral annulus in 45.5% of cases.

CONCLUSIONS

This anatomic study highlights the 3-dimensional structure of the coronary sinus and its distance from the native mitral annulus and fibrous trigones. Human anatomic studies are mandatory for the further development of percutaneous mitral repair technology.

In Vivo Analysis of the Anatomical Relationship of Coronary Sinus to Mitral Annulus and Left Circumflex Coronary Artery Using Cardiac Multidetector Computed Tomography

OBJECTIVES

We sought to determine the in vivo anatomical relationships between mitral annulus (MA) and coronary sinus (CS) as well as CS and left circumflex coronary artery using cardiac computed tomography.

BACKGROUND

Percutaneous treatment of mitral regurgitation (MR) by annuloplasty via CS is under development. Success of such treatment depends on the close anatomical proximity of the MA to the CS. The in vivo data regarding this anatomical relationship in humans are scant. We investigated this relationship using contrast multidetector computed tomography.

METHODS

We studied 25 normal individuals and 11 patients with severe MR (3 to 4+) due to mitral valve prolapse. Separation between MA and CS was measured in standard planes, in 4-chamber (4C), 2-chamber (2C), and 3-chamber views. Distance from ostium of CS to the intersection with left circumflex (LCX), and anatomical relation of LCX and CS were determined using 3-dimensional mapping (Philips Brilliance, Philips Medical Systems, Amsterdam, the Netherlands).

RESULTS

There was significant variance of CS to MA separation at all planes. Separation of CS and MA was increased in lateral location (4C) and decreased in posterior location (2C) in the MR group with increase in MA size. Left circumflex artery crossed between CS and MA in 80% of patients. The LCX crossed CS at a variable distance from the ostium of CS (86.5 +/- 21 mm, range 37 to 123 mm)

CONCLUSIONS

There is significant variability in the relation of CS to MA in humans. Coronary sinus to MA distance increases in patients with severe MR and annular dilation, mainly in the posterolateral location. The left circumflex crosses under the CS the majority of times, but with a significant variability in the location where it crosses the CS. These anatomical features should be taken into consideration while selecting percutaneous treatment strategies for mitral valve repair.

A unipolar coronary sinus mapping study of patients with left-sided atrioventricular accessory pathways

So-called unipolar 'PQS pattern' is widely accepted as a hallmark of successful catheter ablation of the left-sided atrioventricular accessory pathway. However, the unipolar nature of the electrogram and the site-dependent appearance of this characteristic pattern are poorly understood. Therefore, unipolar coronary sinus (CS) mapping was performed using a multipolar fine electrode in patients with Wolff-Parkinson-White (WPW) syndrome associated with an antegrade left-sided accessory pathway (case group) and those with a concealed left-sided accessory pathway or atrioventricular nodal reentrant tachycardia (control group) under sinus rhythm and fixed high right atrial, CS ostial, and distal pacing. In both groups, the unipolar CS atrial electrogram showed intrinsic negative deflection (initial positive followed by negative parts) with considerable variation depending on the recording site. This unipolar configuration of the atrial electrogram was not influenced by different activation sequences during pacing at various sites. The case group exhibited a unipolar 'PQS pattern' at successful ablation sites for the left lateral to anterolateral accessory pathway. However, this was not true for the left posteroseptal accessory pathway, possibly because the negative part of the atrial electrogram distorted the 'PQS pattern' as an intervening dip. In conclusion, the site-dependent variations of the unipolar CS atrial electrogram underlie the limited usefulness of the 'PQS pattern' in left posteroseptal accessory pathway localization.

Transcatheter aortic valve implantation and mitral valve repair: state of the art

Surgical replacement of cardiac valves evolved significantly since its first use. Evolution of techniques and valves used was driven by the frequent complications encountered with surgically implanted valves. Transcatheter implantation of valves is a new technique which continues to be under investigation and promises to perform a task with less risk and potentially better outcome. In addition, new techniques are being developed to address minimizing mitral regurgitation. Progress in transcatheter valve implantation and catheter mitral annuloplasty is reviewed in this article.