August 23, 2002Acta Physiologica Scandinavica
Cardiomyocyte contractility and calcium handling partially recover after early deterioration during post‐infarction failure in rat
Key result
Coronary artery ligation in rats reduced relative cardiomyocyte shortening from 26% in controls to 11% at 1 week, with partial recovery to 20% at 13 weeks despite progressive heart failure.
Why the study?
Does progression of heart failure after myocardial infarction associate with deterioration of intrinsic cardiomyocyte function in a rat model?
Population
Female Wistar rats
Comparison
Coronary artery ligation vs Sham-operation
Design
Preclinical
Follow-up
13 weeks
Authors
Discussion
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Implication
Questions role of sustained cardiomyocyte contractile decline in driving chronic post-MI HF; leaves open alternative remodeling mechanisms in animal models.
Key Points
- To determine whether the continuous progression of post-infarction heart failure is driven by ongoing deterioration of intrinsic cardiomyocyte contractile function and calcium handling.
- Assessed female Wistar rats at 1, 4, and 13 weeks following left coronary artery ligation or sham surgery.
- Measured cell dimensions, contractility, and calcium transients in isolated left ventricular cardiomyocytes alongside echocardiographic and hemodynamic evaluations.
- Cardiomyocyte fractional shortening fell from 26% in controls to 11% at week 1, then partially recovered to 18% at week 4 and 20% at week 13 post-infarction.
- Time to 50% relaxation prolonged by 31% at week 1 and 20% at weeks 4 and 13, matching transient elevations in diastolic and systolic calcium concentrations that subsided over time.
- Left ventricular end-diastolic pressure rose from 6 mmHg to 24, 25, and 36 mmHg at weeks 1, 4, and 13, accompanied by progressive chamber enlargement and cardiomyocyte hypertrophy.
Structured PICO
Does progression of heart failure after myocardial infarction associate with deterioration of intrinsic cardiomyocyte function in a rat model?
P
Population
Female Wistar rats
I
Intervention
Coronary artery ligation (myocardial infarction model)
C
Comparator
Sham-operation
O
Outcome
Cardiomyocyte function (cell dimensions, contractility, and calcium transients) at 1, 4, and 13 weekssurrogate
Main Result
Absolute Event Rate: 11% vs 26%
In a rat model of post-infarction heart failure, initial deterioration of cardiomyocyte contractile function partially recovers, suggesting chronic HF progression is not driven by further intrinsic cardiomyocyte contractile impairment.
Cite This Study
Loennechen et al. (2002) studied Post-infarction heart failure. Coronary artery ligation vs. Sham-operation was evaluated on Relative cardiomyocyte shortening. Coronary artery ligation in rats reduced relative cardiomyocyte shortening from 26% in controls to 11% at 1 week, with partial recovery to 20% at 13 weeks despite progressive heart failure.