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Mechanical alternans in patients with chronic heart failure
1First Department of Internal Medicine, Niigata University School of Medicine, and the Department of Clinical Pharmacology, Niigata College of Pharmacy, Niigata, Japan.
Journal of Cardiac Failure
|June 23, 2001
Summary
Mechanical alternans is common in chronic heart failure patients, affecting 78%. This condition, linked to impaired contractility and reduced ejection fraction, appears to originate early in the cardiac cycle.
Area of Science:
- Cardiology
- Heart Failure Research
- Cardiac Mechanics
Background:
- Mechanical alternans clinical significance in chronic heart failure (CHF) remains unclear.
- This study investigated the prevalence, characteristics, and prognostic value of mechanical alternans in CHF patients.
Purpose of the Study:
- To determine the prevalence of mechanical alternans in patients with chronic heart failure.
- To characterize the features and prognostic implications of mechanical alternans.
- To explore the potential origin of mechanical alternans during the cardiac cycle.
Main Methods:
- Cardiac catheterization with a micromanometer-tipped catheter was performed on 51 patients with dilated cardiomyopathy.
- Mechanical alternans was assessed under basal conditions, during physiologic tachycardia, and with dobutamine stimulation.
- Hemodynamic parameters, including dP/dt, ventricular volumes, and ejection fraction, were analyzed.
Main Results:
- Mechanical alternans was observed in 78% of patients (40 out of 51).
- Alternans correlated with reduced left ventricular ejection fraction and increased ventricular volumes.
- Mechanical alternans was associated with alternating positive dP/dt, suggesting an origin during isovolumetric contraction.
Conclusions:
- Mechanical alternans is highly prevalent in patients with chronic heart failure.
- The findings suggest that the origin of mechanical alternans occurs at or before isovolumetric contraction time.
- Mechanical alternans may serve as a marker for impaired cardiac contractility in heart failure.