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Background: Transcatheter mitral valve replacement is a novel therapeutic approach aiming to treat patients with severe mitral regurgitation. This study aimed to evaluate the biological and technical performance of a novel transseptal transcatheter mitral valve replacement system (Cephea Valve Technologies, Santa Cruz, CA) in a preclinical model. Methods: Biological performance and healing response were evaluated following open-heart surgical implantation procedures in 10 sheep utilizing an antegrade transatrial access. Valve performance was assessed with fluoroscopy, echocardiography, and histology at 30 (n=2), 60 (n=3), and 90 days (n=5). Feasibility of transseptal valve delivery and performance was tested acutely in 10 pigs. Results: In the chronic studies, all animals survived without problems until completion of the study. The hemodynamics of the study valves were excellent with low rates of paravalvular leak. There was no left ventricular outflow tract obstruction. Pathological evaluation showed excellent position and condition of the mitral implants without evidence for thrombosis, endocarditis, or excessive calcification. Subsequently, mitral valves were implanted in 10 pigs using a dedicated transseptal delivery system. The implants remained in stable position with excellent hemodynamic profile. Correct valve position and function was confirmed by echocardiography and autopsy. Conclusions: The transseptal delivery of the Cephea transcatheter mitral valve replacement system in an experimental model was feasible and safe. The chronic studies demonstrated a favorable healing response. Further human studies are needed to evaluate the performance of this novel valve system in patients with severe mitral regurgitation.

Cryoballoon ablation is an established treatment for atrial fibrillation (AF). A vital step in the use of Cryoballoon is safe transseptal puncture to access the left atrium (LA). Yet, in the context of cryoballoon ablation, it remains a serious risk for complications. The conventional approach

A 74-year-old man with symptomatic premature ventricular contractions (PVCs) with a right bundle branch block and right inferior axis QRS morphology underwent electrophysiologic testing. During the PVCs, coronary sinus mapping revealed ventricular prepotentials with the earliest activation in the distal great cardiac vein (GCV) where the local ventricular electrograms were smaller in amplitude than the atrial electrograms. The transaortic approach could not reach the earliest activation site within the GCV, but the transseptal catheter ablation successfully eliminated the PVCs on the mitral valve. With catheter ablation of ventricular arrhythmias with pure mitral annular origins, a transseptal approach may be necessary.

Transseptal puncture is performed using a long needle advanced from the femoral approach. A radiofrequency catheter has been developed that delivers a short burst of radiofrequency energy and creates a micro puncture in the interatrial septum. We describe a case in which the distal radiofrequency electrode broke and became embedded in the interatrial septum. (PACE 2010; 33:e57–e58)

In summary, I think it is important to state that transseptal left heart catheterization is a safe procedure when the operator pays meticulous attention to detail. Potential complications can be avoided if the operator: (1) heparinizes the sheath prior to catheterization, (2) fully heparinizes the patient when the catheter and sheath are across the septum, and (3) remembers that the left atrium in these patients is quite small and can be perforated easily by the tapered tip of the transseptal catheter. Transesophageal cardiac ultrasound makes this latter point very clear to anyone doing this procedure.

The incidence of mitral regurgitation and intramyocardial injection of contrast material during left heart catheterization in normal dogs has been investigated, comparing the transseptal with the retrograde aortic approach. A transseptal catheter passed through the mitral valve into the left ventricle almost always caused some regurgitation during injection of contrast material, even in the absence of premature ventricular contractions. There was a 33 per cent incidence of intramyocardial injection when the transseptal catheter was employed. Retrograde aortic catheterization was associated at times with minimal mitral regurgitation when premature ventricular contractions occurred during injection, but significant mitral regurgitation was never produced. In the absence of premature contractions, regurgitation did not occur. Intramyocardial injection of contrast material was not observed in this series when the retrograde aortic catheter was employed.

A new technique for intracardiac phonocardiography of the left side of the heart is described. If a catheter with an inside diameter of 1.75 mm. is used for transseptal left heart catheterization, a microphone catheter with a diameter of 1.50 mm. can be introduced into the left side of the heart through the transseptal catheter. Preliminary results in 25 patients are presented.

1. Teflon tubing is ideally suited for transseptal catheterization because of its low coefficient of friction. 2. Catheterization of the left ventricle can be easily performed with a maneuverable spring guide. 3. A Teflon-tipped cannula and a tough, flexible, Teflon guide are used for percutaneous catheter insertions. 4. Safety measures used in transseptal puncture are described. 5. Simultaneous percutaneous insertion of a retrograde Teflon aortic catheter and the transseptal catheter permit transvalvular gradients to be obtained even when a diseased mitral or aortic valve cannot be crossed.

This report describes our experience with a modified sheath transseptal catheter system. The sheath technique allows for introduction of various catheters into the left heart, including a uniquely designed pigtail catheter intended for use with this system. Fifty-three patients underwent successful transseptal catheterization, 44 of whom had severe native aortic valve stenosis and seven with suspected prosthetic aortic valve dysfunction. The technique provides optimal ventriculographic and hemodynamic information as well as improved access to the left heart in patients with aortic valve disease.