Related Experiment Videos
Echocardiographic and phonocardiographic characteristics of the Hall-Kaster aortic disc valve prosthesis
Insights
The new Hall-Kaster (H-K) heart valve prosthesis functions rapidly, with its disc opening and closing quickly. Echocardiography effectively visualizes the H-K valve, though its rapid movements challenge precise measurement.
Area of Science:
- Cardiovascular Surgery
- Biomedical Engineering
- Diagnostic Imaging
Background:
- The Hall-Kaster (H-K) valve is a novel tilting disc prosthesis for heart valve replacement.
- Assessing the hemodynamic performance and acoustic characteristics of new prosthetic valves is crucial.
Purpose of the Study:
- To evaluate the functional and acoustic properties of the H-K valve in the aortic position using simultaneous echocardiography and phonocardiography.
- To assess the valve's disc dynamics and its impact on systolic time intervals.
Main Methods:
- Simultaneous M-mode echocardiography and phonocardiography were performed on nine patients with normally functioning H-K aortic prostheses.
- Valve disc opening/closing velocities and sounds were analyzed.
- Systolic time intervals, including pre-ejection period and left ventricular ejection time, were measured.
Main Results:
- The H-K valve disc opening and closing were clearly visualized by echocardiography, demonstrating very rapid movements.
- Quantitative velocity measurements in two patients showed mean opening velocity of 38.8 cm/s and closing velocity of 51.8 cm/s.
- Valve closure produced a distinct, high-frequency sound, while opening sounds were rarely detected. Systolic time intervals were largely within expected ranges, with a trend towards shorter left ventricular ejection times.
Conclusions:
- The Hall-Kaster valve exhibits rapid disc dynamics, well-captured by echocardiography.
- Phonocardiography identifies the valve closure sound, aiding in functional assessment.
- The H-K valve demonstrates acceptable hemodynamic function in the aortic position based on systolic time intervals.
Abstract:
The Hall-Kaster (H-K) valve is a new tilting disc valve prosthesis which has recently been taken in use of heart valve replacement. Simultaneous echo- and phonocardiographic studies were performed in nine patients with a normally functioning H-K prosthesis in the aortic position. The prosthesis is well recorded by a M-mode echocardiogram. The opening and closing of the disc were easily recorded in all cases. The disc itself opened and closed very rapidly, in most cases too rapidly for quantitative assessment. In two cases, mean opening and closing velocity was measured to 38.8 cm/s and 51.8 cm/s, respectively. The opening sound of the prosthesis was rarely identified on the phonocardiogram. The closure of the valve was recorded as a discrete single high frequency sound. Systolic time intervals measured by combined echo- and phonocardiography revealed values for pre-ejection period similar to the predicted values, while the left ventricular ejection time tended to be slightly shorter than expected.