Biomaterial Database

Transmural distribution of intramyocardial pressure measured by micropipette technique. 1985

F W Heineman, and J Grayson

A technique is presented for measuring intramyocardial pressure (IMP) in beating hearts using the servo-nulling pressure transducer equipped with polyethylene micropipettes (ID less than 12 micron). The static and dynamic response characteristics of the system were tested in a pressurized, saline-filled container as well as in a pressurized, hollow, gelatin cylinder. The system was then used to measure IMP in vivo in the hearts of 12 dogs during stable cardiac performance and with aortic constriction. In vitro response characteristics were found to be satisfactory for accurate reproduction of cardiovascular waveforms. Peak systolic IMP was not found to exceed the simultaneously recorded left intraventricular pressure (LVP). Furthermore, the slope of the regression line relating the IMP to LVP during systole is linearly related (slope 0.98) to the depth of the micropipette tip in the ventricular wall, as normalized to total wall thickness. Diastolic IMP ranged between 1 +/- 1 (minimum during the cardiac cycle) and 4 +/- 2 mmHg (end diastolic) at associated LVP of 2 +/- 2 and 5 +/- 2 mmHg (mean +/- SD), respectively.

UI	MeSH Term	Description	Entries
D008722	Methods	A series of steps taken in order to conduct research.	Techniques,Methodological Studies,Methodological Study,Procedures,Studies, Methodological,Study, Methodological,Method,Procedure,Technique
D011095	Polyethylenes	Synthetic thermoplastics that are tough, flexible, inert, and resistant to chemicals and electrical current. They are often used as biocompatible materials for prostheses and implants.	Ethylene Polymers,Ethene Homopolymers,Homopolymers, Ethene,Polymers, Ethylene
D011312	Pressure	A type of stress exerted uniformly in all directions. Its measure is the force exerted per unit area. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)	Pressures
D003971	Diastole	Post-systolic relaxation of the HEART, especially the HEART VENTRICLES.	Diastoles
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D004864	Equipment and Supplies	Expendable and nonexpendable equipment, supplies, apparatus, and instruments that are used in diagnostic, surgical, therapeutic, scientific, and experimental procedures.	Apparatus and Instruments,Devices,Medical Devices,Device, Medical,Devices, Medical,Equipment,Inventories,Medical Device,Supplies,Device,Instruments and Apparatus,Inventory,Supplies and Equipment
D006321	Heart	The hollow, muscular organ that maintains the circulation of the blood.	Hearts
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013599	Systole	Period of contraction of the HEART, especially of the HEART VENTRICLES.	Systolic Time Interval,Interval, Systolic Time,Intervals, Systolic Time,Systoles,Systolic Time Intervals,Time Interval, Systolic,Time Intervals, Systolic