Related Experiment Videos
Triggered propagated contractions in human atrial trabeculae
M C Daniels1, T Kieser, H E ter Keurs
1Health Sciences Centre, University of Calgary, Alberta, Canada.
Cardiovascular Research
|October 1, 1993
Summary
Triggered propagated contractions, similar to those seen in rats, can be induced in human cardiac trabeculae. These contractions, influenced by calcium levels and temperature, propagate along the muscle, offering insights into cardiac electrophysiology.
Area of Science:
- Cardiology
- Cardiac Electrophysiology
- Muscle Physiology
Background:
- Mechanical stress and rapid release in damaged cardiac tissue can trigger aftercontractions.
- These aftercontractions may propagate and precede arrhythmias.
- Previous studies demonstrated this phenomenon in rat cardiac trabeculae.
Purpose of the Study:
- To investigate if triggered propagated contractions can be elicited in human cardiac tissue.
- To characterize the properties of these contractions in human trabeculae.
Main Methods:
- Human atrial trabeculae were dissected from surgical biopsies.
- Trabeculae were superfused and monitored using video systems, force transducers, and laser diffraction for sarcomere length.
- Triggered contractions were induced using electrical stimulation under specific ionic and temperature conditions.
Main Results:
- Triggered contractions initiated at one end and propagated along the human trabeculae.
- Contraction force increased with extracellular calcium and stimulus number, while latency decreased.
- Propagation velocity ranged from 0.8 to 3.9 mm/s and was influenced by temperature and calcium.
Conclusions:
- Triggered propagated contractions can be successfully elicited in human atrial trabeculae.
- These human contractions share fundamental characteristics with those previously observed in rat ventricular trabeculae.