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Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents
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Isolation of Human Atrial Myocytes for Simultaneous Measurements of Ca2+ Transients and Membrane Currents

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Nonalternans repolarization variability and arrhythmia - the calcium connection

Jan Němec1

  • 1Heart and Vascular Institute, University of Pittsburgh.

Journal of Electrocardiology
|September 8, 2016
PubMed

Insights

Nonalternans repolarization variability, distinct from repolarization alternans, occurs in various heart conditions and animal models. Understanding this variability is crucial for diagnosing arrhythmias and requires advanced detection methods.

Area of Science:

  • Cardiology
  • Electrophysiology
  • Computational Biology

Background:

  • Repolarization alternans can precede ventricular arrhythmias, but some arrhythmias lack this precursor.
  • Nonalternans repolarization changes are observed in coronary artery disease and congenital long QT syndrome.
  • Nonalternans repolarization lability is present in animal models of ventricular tachycardia.

Purpose of the Study:

  • To investigate nonalternans repolarization variability as a phenomenon distinct from repolarization alternans.
  • To explore the underlying mechanisms and detection challenges of nonalternans repolarization lability.
  • To determine the potential role of nonalternans repolarization variability in ventricular arrhythmias.

Main Methods:

  • Analysis of ventricular repolarization in patients and animal models.
  • Utilizing optical mapping to investigate cellular mechanisms.
  • Evaluating detection methods for repolarization variability.

Main Results:

  • Nonalternans repolarization variability occurs in diverse cardiac conditions and experimental setups.
  • Intracellular calcium handling heterogeneity is implicated in nonalternans repolarization variability.
  • Signal averaging is ineffective for detecting nonalternans repolarization lability, posing detection challenges.

Conclusions:

  • Nonalternans repolarization variability is a significant factor in cardiac electrophysiology, separate from alternans.
  • Further research is necessary to elucidate the precise role of nonalternans repolarization variability in ventricular arrhythmias.
  • Improved detection methodologies are needed to accurately identify nonalternans repolarization lability.

Keywords:
CalciumLong QT syndromeNonalternans repolarization variability

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