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Abstract
A digital minicomputer system has been developed for the on-line real-time estimation
of myocardial contractility from the isovolumetric portion of the left ventricular
pressure wave form. Left-ventricular pressure, its first derivative, aortic pressure,
and the ECG wave forms are digitized at rates of up to 500 Hz by a special terminal
located next to the patient. Data are then sent to a remotely located PDP-11 computer
which calculates the myocardial pressure-velocity relationship for each heartbeat
according to the Maxwell muscle model. The VCE-P curve is extrapolated to zero developed pressure using a modified hyperbolic regression
algorithm to obtain Vmax estimates. Peak VCE, Vmax, peak ![Math Eq]()
, and time-to-peak ![Math Eq]()
are immediately displayed on a CRT console at the bedside. Long-term data storage
for off-line analysis and statistical averaging is provided. The system is employed
in the operating room for evaluation of myocardial contractility after cardiopulmonary
bypass; it can be easily expanded to include multiple patients for application to
the ICU/CCU environment.
, and time-to-peak 
are immediately displayed on a CRT console at the bedside. Long-term data storage
for off-line analysis and statistical averaging is provided. The system is employed
in the operating room for evaluation of myocardial contractility after cardiopulmonary
bypass; it can be easily expanded to include multiple patients for application to
the ICU/CCU environment.To read this article in full you will need to make a payment
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References
- Clinical application of a computer for on-line monitoring of myocardial contractility from left-ventricular pressure curves.Circulation. 1971; XLIV (abst.): II, 143
- Prolonged left-ventricular pressure monitoring by a catheter transducer.Surgery. 1973; 73: 97
- Analog calculation of (dLVP/dt)/LVP.Circulation. 1971; XLIV (abst.): II, 53
- On-line processing of contractility parameters by a digital computer.Circulation. 1971; XLIV (abst.): II, 176
- Myocardial force-velocity relationships in clinical heart disease.Circulation. 1970; XLI: 191
- Isovolumic contraction dynamics in man according to two different muscle models.J. Appl. Physiol. 1972; 33: 409
- Relation of Vamx to different models of cardiac muscle.Circ. Res. 1972; XXX: 34
Article info
Footnotes
☆The work was supported in part by Veterans Administration Research Funds and National Institutes of Health Grant No. HL 14845.
☆☆Presented at the Thirty-fourth Annual Meeting of the Society of University Surgeons, New Orleans, La., 1973.
Identification
Copyright
© 1973 Published by Elsevier Inc.
