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Biomedical subjects

S Meerbaum

Publications and source records attributed to S Meerbaum.

95 records · Page 6Linked to original sources

Factors affecting penetration of retrograde coronary venous injections into normal and ischemic canine myocardium: assessment by contrast echocardiography and digital angiography.

Ths experimental study described myocardial echo contrast enhancement through coronary venous injections. Retrograde administration of renografin was performed in 15 closed-chest dogs. Two-dimensional echocardiography was used to study myocardial echo contrast enhancement before and after coronary artery occlusion. Digital subtraction venography was used to assess delivery, drainage and shunting of the retrograde injectate. Systolic/diastolic blood pressure in the great cardiac vein measured 7 +/- 3/1 +/- 0.6 mm Hg and increased to 29 +/- 11/5 +/- 3 after coronary sinus occlusion and to 55 +/- 2.3/15 +/- 12 mm Hg during coronary sinus contrast injection. Myocardial contrast echo appearance in a midpapillary left ventricular short axis cross-section was limited to the anteroseptal region, extending to 28.4 +/- 11.3% of the section circumference after great cardiac vein injections and 35.3 +/- 17% after coronary sinus injections (difference NS). After occlusion of the left anterior descending coronary artery, great cardiac vein contrast injections resulted in opacification of 36.6 +/- 9.7% of the section circumference (N.S. vs preocclusion control) and opacified most, but not all asynergic segments. After occlusion of the circumflex coronary artery, myocardial echo contrast uptake was restricted to the septum and the anterior wall. The ischemic and asynergic posterolateral myocardial segments were not opacified. Digital subtraction coronary venography revealed rapid drainage of retrogradely injected contrast to the right atrium, in spite of coronary sinus balloon occlusion via venovenous anastomoses. Retrograde coronary venous contrast injections may help define myocardial regions which are accessible with retrograde coronary venous interventions.

Angiography, Digital Subtraction↗

Experimental evaluation of a new transducer tipped catheter.

The accuracy and fidelity of a new transducer-tipped catheter (Camino Laboratories) was compared in 10 closed chest anesthetized dogs with standard Millar catheters. Simultaneous Camino and Millar measurements of left ventricular pressures and its first derivative (dp/dt) were recorded in control, after Isoprenaline infusion and during left anterior descending coronary artery balloon occlusion, to vary the pressures for comparison. Linear regression analysis comparing the Camino and Millar systems yielded a good correlation, and one way analysis of variance showed no difference between the two catheter readings, thus revealing that the recently developed Camino disposable transducer-tipped catheter provides accurate measurements of left ventricular pressure and its first derivative.

Animals↗

Transducers for myocardial research.

Seven miniaturized transducers to measure force, displacement, and thickness--singly and in combination--in animal experiments are described. The transducers are lightweight and during an open-chest procedure can be inserted within a heartbeat, removed, and reinserted, with minimum trauma. Six or more transducers of various kinds can be used simultaneously without artifacts. For closed-chest experiments a combination force-displacement transducer can be catheter-borne. A trifunctional transducer was used successfully to measure force-displacement thickness in a small area. A single conductor can be added for ECG measurement in the area where the transducer is implanted.

Animals↗