This report describes a lethal complication which occurred during retrograde catheterization of the left ventricle across a Björk-Shiley prosthesis. The authors were called upon to testify as experts in malpractice proceedings in this case. After an 8F Sones catheter had been passed through the small side orifice of the prosthesis and three ventriculograms had been carried out, it was apparent that the movement of the tilting disc valve was considerably impaired and that the catheter had become irreversibly trapped. As a consequence the patient died of irreversible left heart failure before an operation could be performed. Consequently passing a tilting disc valve can no longer be considered as completely safe. This procedure should only be used under exceptional circumstances requiring very strict indication. If such an intervention is necessary, then it should only be performed by experienced cardiologists, who should take all possible precautions to reduce risks.

Aortic Valve↗

PubMedDate not supplied

Continuous recording of local myocardial function in normal and ischemic myocardium.

Experiments in anaesthetized open chest dogs are described in which intramyocardial pressure was determined by two methods, both suitable for long time experiments. By means of a Fogarty catheter in connection with a normal transducer the intramyocardial pressure can be measured. With this method the pressure gradient from epicardial to endocardial muscle layers is demonstrated. Insertion of catheter tip manometers leads only to small trauma of the myocardium. This method allows the determination of systolic and enddiastolic tissue pressure together with the dp/dtmax and dp/dtmin. Measurements were performed in normal and in ischemic areas of the myocardium. In the ischemic parts of the myocardium all parameters descline, while in the normal, non ischemic areas the parameters increase, thus demonstrating overactivity, which compensates for the loss of myocardial function in the ischemic parts. The overall function of the heart as a pump remains nearly unaffected. On release of the coronary ligature the negative changes in the ischemic myocardium are rapidly restored. During the phase of reactive hyperemia the parameters measured in the ischemic area even increase above the control values.

Animals↗

PubMedDate not supplied

Cyclosporine increases the intracellular free calcium concentration in electrically paced isolated rat cardiomyocytes.

The effect of cyclosporine on the mean cytoplasmic free calcium concentration in electrically paced single cardiomyocytes from adult rats was studied. Cardiac myocytes were paced by electrical field stimulation with either 2 or 3 Hz in the presence of 5 micrograms/ml cyclosporine or the solvent cremophor. Exposure to cyclosporine during 40 minutes of electrical pacing caused irreversible hypercontracture in most cells, only 22.1% +/- 1.2% (mean +/- SEM) remained rod-shaped versus 64.1% +/- 3.2% in the solvent (p = 0.01). The cytoplasmic free calcium concentration was measured by means of digital image processing of fura-2 fluorescence. Electrical field stimulation increased the cytoplasmic free calcium from 69.7 +/- 5.4 to 124.9 +/- 24.5 nmol/L Ca2+ in the presence of the solvent and from 84.2 +/- 25.4 to 250.1 +/- 55.9 nmol/L in the presence of cyclosporine (p = 0.036 versus solvent). The data provide direct evidence that cyclosporine enhances the cytoplasmic free calcium concentration in single paced rat cardiomyocytes. These findings may be of importance in the consideration of a possible cardiotoxicity of cyclosporine.

Animals↗