Dataset DOI: 10.5061/dryad.hmgqnkb06

Description of the data and file structure

This dataset contains cardiac cellular electrophysiology (action potentials and ionic currents) data in separate Excel sheets with individual cell data and group statistics. The dataset is structured to follow the sequence of data presented in the Figures in the article entitled Complex Antiarrhythmic Effects of Empagliflozin in Non-ischemic HFrEF Cardiomyocytes, and to ease navigation between the uploaded data files. For a full description of the materials and methods, including experimental procedures and instrumentation, please refer to the article on the Frontiers in Pharmacology website.

Files and variables

File: Fig1_data_AP.xlsx

Description: This file contains action potential (AP) data from murine and rabbit ventricular myocytes with heart failure with reduced ejection-fraction (HFrEF). Cells were treated with vehicle (0.1% DMSO, 3 hours), empagliflozin (3 minutes or 3 hours), and cariporide (3 hours). During recordings, cells were steady-state paced at 1 Hz. “Panel A” section provides representative APs (membrane voltage in millivolts [mV] over time in milliseconds [ms]) in murine ventricular cardiomyocytes isolated 8 weeks after transverse aortic constriction (TAC)-induced HFrEF or sham surgery. “Panel B” section provides representative APs (in millivolts over time) in rabbit ventricular cardiomyocytes with HFrEF induced by combined volume- and pressure-overload and from healthy age-matched controls. “Panel C” section provides data on fifty consecutive action potential duration at 90% repolarization (APD₉₀) values (in milliseconds) used to calculate short-term variability of APD₉₀ (STV, in milliseconds) in TAC and sham mice. “Panel D” section provides data on fifty APD₉₀ values (in milliseconds) used to calculate STV in HFrEF and healthy control rabbits. “Panel E” section provides data on APD₉₀ (in milliseconds) and STV (in milliseconds) in TAC and sham mice. “Panel F” section provides data on APD₉₀ (in milliseconds) and STV (in milliseconds) in HFrEF and healthy control rabbits. “Panel G” section provides data on resting membrane potential (RMP, in millivolts) and maximal upstroke velocity (dV/dt_max in Volts per second) in TAC and sham mice. “Panel H” section provides data on RMP (in millivolts) and dV/dt_max (in Volts per second) in HFrEF and healthy control rabbits.

Variables

• Action potential duration at 90% repolarization (APD₉₀, in milliseconds)
• Cariporide (Cari)
• Empagliflozin (Empa)
• Heart failure with reduced ejection fraction (HFrEF)
• Maximal upstroke velocity (dV/dt_max, in Volts per second)
• Resting membrane potential (RMP, in millivolts)
• Short-term variability of APD₉₀ (STV, in milliseconds)
• TAC (transverse aortic constriction)

File: Fig2_data_DAD.xlsx

Description: This file contains data on action potential (AP) alternans and delayed afterdepolarizations (DADs) from murine and rabbit ventricular myocytes with heart failure with reduced ejection-fraction (HFrEF). Cells were treated with vehicle (0.1% DMSO, 3 hours), empagliflozin (3 minutes or 3 hours), and cariporide (3 hours). “Panel A” section provides data on the frequency-dependence of AP duration at 90% repolarization (APD₉₀, in milliseconds) and the threshold frequency for alternans onset in murine ventricular cardiomyocytes isolated 8 weeks after transverse aortic constriction (TAC)-induced HFrEF or sham surgery. “Panel B” section provides data on the frequency-dependence of APD₉₀ (in milliseconds) and the threshold frequency for alternans onset in rabbit ventricular cardiomyocytes with HFrEF induced by combined volume- and pressure-overload and from healthy age-matched controls. “Panel C” section provides representative APs at a steady-state pacing frequency of 10 Hz (L, long APD₉₀; S, short APD₉₀) in TAC and sham mice. “Panel D” section provides representative APs at a steady-state pacing frequency of 5 Hz (L, long APD₉₀; S, short APD₉₀) in HFrEF and healthy control rabbits. “Panel E” section provides representative DADs following cessation of tachypacing (10 Hz) in TAC and sham mice. “Panel F” section provides representative DADs following cessation of tachypacing (5 Hz) in HFrEF and healthy control rabbits. “Panel G” section provides data on APD₉₀ alternans magnitude (in milliseconds) and DAD frequency (number of events during 1 minute) in TAC and sham mice. “Panel H” section provides data on APD₉₀ alternans magnitude (in milliseconds) and DAD frequency (number of events during 1 minute) in HFrEF and healthy control rabbits.

Variables

• Action potential duration at 90% repolarization (APD₉₀, in milliseconds)
• APD₉₀ alternans magnitude (difference between long and short APD₉₀, in milliseconds)
• Cariporide (Cari)
• Delayed afterdepolarization (DAD)
• Empagliflozin (Empa)
• Heart failure with reduced ejection fraction (HFrEF)
• TAC (transverse aortic constriction)

File: Fig3_data_EGTA.xlsx

Description: This file contains data on action potential parameters in cardiomyocytes following buffering of intracellular Ca²⁺ concentration using 10 millimol/L ethylene glycol-bis(β-aminoethyl ether)-N, N, N ′, N′-tetraacetic acid (EGTA) in murine and rabbit ventricular myocytes with heart failure with reduced ejection-fraction (HFrEF). “Panel A” section provides data on action potential duration at 90% repolarization (APD₉₀, in milliseconds) and short-term variability of APD₉₀ (STV, in milliseconds) with and without 10 millimol/L EGTA in murine ventricular cardiomyocytes isolated 8 weeks after transverse aortic constriction (TAC)-induced HFrEF or sham surgery. “Panel B” section provides data on APD₉₀ (in milliseconds) and STV (in milliseconds) with and without 10 millimol/L EGTA in rabbit ventricular cardiomyocytes with HFrEF induced by combined volume- and pressure-overload and from healthy age-matched controls. “Panel C” section provides data on the magnitude of APD₉₀ alternans (difference between long and short beats, in milliseconds) at 10 Hz pacing and the frequency of DADs (number of events during 1 minute) following cessation of tachypacing (10 Hz) in TAC and sham mice. “Panel D” section provides data on the magnitude of APD₉₀ alternans (in milliseconds) at 5 Hz pacing and the frequency of DADs (number of events during 1 minute) following cessation of tachypacing (5 Hz) in HFrEF and healthy control rabbits.

Variables

• Action potential duration at 90% repolarization (APD₉₀, in milliseconds)
• APD₉₀ alternans magnitude (in milliseconds)
• Delayed afterdepolarization (DAD)
• Ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA)
• Heart failure with reduced ejection fraction (HFrEF)
• Short-term variability of APD₉₀ (STV, in milliseconds)
• TAC (transverse aortic constriction)

File: Fig4_data_INaL_IK1.xlsx

Description: This file contains data on late Na⁺ current (I_NaL) and inward rectifier K⁺ current (I_K1) densities in murine and rabbit ventricular myocytes with heart failure with reduced ejection-fraction (HFrEF). Cells were treated with vehicle (0.1% DMSO, 3 hours) or empagliflozin (3 hours). Sheet “Panel A” provides representative I_NaL traces (time in milliseconds and current density in amperes per farad) at -40 millivo^t in murine ventricular cardiomyocytes isolated 8 weeks after transverse aortic constriction (TAC)-induced HFrEF or sham surgery. I_NaL was inhibited by tetrodotoxin (TTX, 10 μmol/L) at the end of the experiments, confirming its identity. Sheet “Panel B” provides representative I_NaL traces (time in milliseconds and current density in amperes per farad) in rabbit ventricular cardiomyocytes with HFrEF induced by combined volume- and pressure-overload and from healthy age-matched controls. Sheet “Panel C” provides data on membrane capacitance (in picofarads) and I_NaL density (current amplitude normalized to membrane capacitance) in TAC and sham mice. Sheet “Panel D” provides data on membrane capacitance (in picofarads) and I_NaL density (current amplitude normalized to membrane capacitance) in HFrEF and healthy control rabbits. Sheet “Panel E” provides representative I_K1 traces (time in milliseconds and current density in amperes per farad) at -140 millivolt in TAC and sham mice. I_K1 was inhibited by barium chloride (BaCl₂, 300 μmol/L) at the end of the experiments, confirming its identity. Sheet “Panel F” provides representative I_K1 traces (time in milliseconds and current density in amperes per farad) at -140 mV in HFrEF and healthy control rabbits. Sheet “Panel G” provides data on I_K1 density (current amplitude normalized to membrane capacitance) at -140 millivolts (inward I_K1) and at -40 millivolts (outward I_K1) in TAC and sham mice. Sheet “Panel H” provides data on I_K1 density (current amplitude normalized to membrane capacitance) at -140 millivolts (inward I_K1) and at -4millivoltslt (outward I_K1) in HFrEF and healthy control rabbits.

Variables

• Barium chloride (BaCl₂)
• Empagliflozin (Empa)
• Heart failure with reduced ejection fraction (HFrEF)
• Inward rectifier K⁺ current (I_K1) density (in amperes per farad)
• Late Na⁺ current (I_NaL) density (in amperes per farad)
• TAC (transverse aortic constriction)
•  Tetrodotoxin (TTX)

Code/software

Microsoft Excel can be used to view the data files.