Nucleoside transporter expression profiles in human cardiac tissue show striking individual variability with overall predominance of hENT1.

Nucleoside transporters (NTs) are integral membrane transport proteins that modulate the flux of nucleosides such as adenosine across cell membranes. Two families of NTs exist, the concentrative NTs (CNTs, SLC28) and the equilibrative NTs (ENTs, SLC29). CNTs and ENTs transport anti-cancer and anti-viral nucleoside analog drugs and ENTs are also targets of drugs used to treat cardiac pathologies. Levels of some NT profiles have been shown to relate to clinical outcomes in the use of nucleoside analog drugs. However, currently, patient NT profile is not assessed prior to pharmacological administration of analog drugs. Here we describe a reliable method to determine a complete individual NT expression profile from human tissue using quantitative real-time PCR. We developed this assay on tissue (right atrial appendage, left internal mammary, aorta) from individuals undergoing cardiac surgery and compared these findings to the NT expression profiles in pooled whole heart tissue (normal and diseased). Data show that hENT1 is the most abundantly expressed NT, with highest expression levels in the aorta. However, NT expression profiles are highly variable among individuals and changes in NT expression between normal and diseased tissues were observed. These data are the first to describe the RNA expression patterns of all seven NT isoforms in the human heart. The methodology described here may be useful for quantitatively characterizing complete NT expression profiles in any human target tissue.

Hypertrophic obstructive cardiomyopathy complicated by ruptured chordae tendinea to the posterior mitral leaflet and severe congestive heart failure.

A 63-year-old woman with hypertrophic obstructive cardiomyopathy developed rapidly progressive fatigue, shortness of breath and congestive heart failure. A transesophageal echocardiogram demonstrated ruptured chordae to the posterior mitral valve leaflet with severe mitral regurgitation. Mitral valve replacement eliminated the outflow gradient. Acute or subacute hemodynamic deterioration in a patient with hypertrophic obstructive cardiomyopathy should lead to a search for associated lesions.

Management of acute severe perioperative failure of cardiac allografts: a single-centre experience with a review of the literature.

BACKGROUND: Early graft failure is associated with high mortality and is the main cause of death within the first 30 days after transplantation. The purpose of the present study was to examine the investigators' experience of severe perioperative acute graft failure and to review the literature. METHODS: Nine of 385 cardiac transplants (2.3%) performed from 1984 through 2005 developed severe perioperative acute graft failure either in the operating room or within 24 h after cardiac transplantation. Four patients had primary graft failure, two had right heart failure secondary to pulmonary hypertension, one had hyperacute rejection, one had accelerated acute rejection and one possibly sustained a particulate coronary embolus intraoperatively. RESULTS: All except the two patients who had right heart failure secondary to pulmonary hypertension received mechanical circulatory support. Three patients were supported with total artificial hearts, two patients received a left ventricular assist device, one patient was supported with extracorporeal life support followed by a right ventricular assist device when the left ventricle recovered, and one patient was supported for several hours with cardiopulmonary bypass. Three patients were retransplanted after mechanical circulatory support, but only one survived. Only one of the nine patients (11%) survived; this patient was supported with a total artificial heart followed by retransplantation. CONCLUSION: The outcome of severe perioperative acute graft failure is very poor. Mechanical circulatory support and retransplantation are not as successful as in other situations. Due to the shortage of donors and poor outcomes, retransplantation for hyperacute rejection is not advisable.

The "hybrid flip-over" technique for anterior leaflet prolapse repair.

Repair of the anterior mitral leaflet or bi-leaflet prolapse is technically more demanding than repair of the posterior mitral leaflet. Although several techniques have been proposed for the repair of anterior mitral leaflet prolapse during bi-leaflet repair, practical challenges remain, including the determination of the appropriate length for artificial chords. Herein we describe a novel and reproducible technique for bi-leaflet mitral valve repair, including those with extensive anterior mitral leaflet prolapse.

Papillary fibroelastoma of the pulmonary valve.

There is a lack of information regarding the diagnosis and management of papillary fibroelastoma of the pulmonary valve due to the rarity of the tumour at this location. A case of pulmonary valve papillary fibroelastoma in a 60-year-old woman is reported and the approach for diagnosis and management is described.

A technique for annular plication to facilitate sliding plasty after extensive mitral valve posterior leaflet resection.

The sliding leaflet technique has been used in mitral valve repair in conjunction with posterior leaflet quadrangular resection to avoid left ventricular outflow tract obstruction secondary to systolic anterior motion of the anterior leaflet of the mitral valve. On occasion, despite the use of the sliding leaflet technique, reattachment of the edges of the posterior leaflet after extensive resection can be challenging because of excessive tension. My colleagues and I present our technique to ensure reattachment of the posterior leaflet without tension after extensive resection.

Ventricular assist devices as a 'bridge to recovery': where do we stand?

The use of ventricular assist devices as a 'bridge to recovery' has a lot to promise. However, we are at a stage where there are more questions than answers. It is still difficult to predict who will be the right candidate and who will have sustained recovery after explantation of the device. In addition, we do not have a universally accepted protocol to wean patients from assist devices. A case that was successfully bridged to recovery with a left ventricular assist device is presented, together with a discussion of the literature. The search for precise markers of recovery should continue and a multicentre prospective study to validate weaning protocols is needed. At present, one should consider all available markers and look at the full clinical picture before allocating a patient to a bridge to recovery destination.