Contractile State of the Left Ventricle in Man
Key result
Patients with left ventricular disease exhibited lower velocity of circumferential fiber shortening (0.22-1.11 vs 1.66-2.71 circumferences/sec) compared to those without LV disease.
Why the study?
How do the mechanical characteristics of left ventricular contraction differ between patients with and without left ventricular disease?
Population
15 patients (6 without left ventricular disease, 9 with left ventricular disease)
Comparison
Simultaneous measurement of left ventricular… vs Patients without left ventricular disease
Design
Cross-sectional
Authors
Discussion
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Implication
Does not support practice change in LV assessment; leaves open whether fiber shortening velocity improves risk stratification.
Key Points
- Quantify the contractile state and mechanical characteristics of the human left ventricle by analyzing instantaneous relationships among wall tension, fiber shortening velocity, and ventricular dimensions.
- Assessed left ventricular dimensional changes via cineangiograms correlated with simultaneous left ventricular pressure measurements.
- Evaluated 15 individuals: 6 without left ventricular disease and 9 with left ventricular disease.
- Calculated the extent and velocity of midwall circumferential fiber shortening alongside instantaneous left ventricular wall tension (stress).
- Circumferential fiber shortening velocity during contraction ranged from 0.22 to 1.11 circumferences/sec in left ventricular disease versus 1.66 to 2.71 circumferences/sec in controls at comparable wall tension (137 to 467 g/cm² vs 175 to 409 g/cm²).
- Shortening velocity of contractile elements at maximum wall tension was 0.11 to 0.87 circumferences/sec in diseased ventricles compared to 1.46 to 2.04 circumferences/sec in controls.
- Wall tension declined rapidly shortly after ejection onset in controls, but fell only slightly with ongoing ejection in patients with left ventricular disease.
Study Design
Type
Observational (n=15)
Structured PICO
How do the mechanical characteristics of left ventricular contraction differ between patients with and without left ventricular disease?
P
Population
15 patients (6 without left ventricular disease, 9 with left ventricular disease)
I
Intervention
Simultaneous measurement of left ventricular dimensional changes from cineangiograms and left ventricular pressure
C
Comparator
Patients without left ventricular disease
O
Outcome
Mechanical characteristics of ventricular contraction (extent and velocity of circumferential fiber shortening, time course of LV wall tension)surrogate
Patients with left ventricular disease exhibit significantly reduced velocity and extent of circumferential fiber shortening compared to normal ventricles.
Cite This Study
Gault et al. (1968) conducted an observational in Left ventricular disease (n=15). Patients with left ventricular disease exhibited lower velocity of circumferential fiber shortening (0.22-1.11 vs 1.66-2.71 circumferences/sec) compared to those without LV disease.