Expert Langendorff isolated perfused heart studies

GLP-certified expertise in cardiovascular pharmacology & electrophysiology

Why conduct an isolated perfused heart study?

The ICH S7B guideline recommends greater focus on both the in vitro measurement of ionic currents (using the patch-​clamp technique) and the in vivo assessment of effects induced by the prolongation of the QT interval (using telemetry). The Langendorff isolated perfused heart assay provides rapid, cheap, reproducible and sensitive predictions of QT prolongation. Moreover, this ex vivo study allows the assessment of the effects of a drug on left ventricular cardiac function, cardiac electrical activity and compound accumulation.

Langendorff isolated perfused heart assays

General preclinical study design

Depending on the needs of your study, Langendorff assays can be designed in specific ways. Below you’ll find an example of our general preclinical study design, followed by an example of our study set-up for compound accumulation studies.

Technique

  • Retrograde heart perfusion (Langendorff) at constant pressure with monitoring of hemodynamics and ECGs parameters

Study model

  • Guinea-pig or rat hearts
  • 6 preparations tested and 6 control preparations (as basic design protocol but can be adapted)
  • Options: ischaemic conditions (low coronary flow), chronic pre-​treatment.

Reference products

  • Quinidine
  • Dofetilide

Results

  • Hemodynamics parameters and ECGs parameters

Measured parameters

  • Coronary flow (mL/min)
  • Left ventricular pressure parameters:
    • Developed pressure : maximal systolic pressure – minimal diastolic pressure (mmHg)
    • Max dP/​dt: maximal contraction velocity (mmHg/​sec)
    • Min dP/​dt: maximal relaxation velocity (mmHg/​sec)
    • Heart rate: calculated from ventricular contractions (beats/min)
  • ECG parameters:
    • PR, QRS, RR and QT interval (ms)
    • QTc intervals: Fridericia (QT / (RR)1/3)
  • Clinical cardiology interpretation of the ECG signal, describing events: AV-​block, torsade de pointe, ventricular fibrillation, tachycardia…
Langendorff isolated perfused heart typical result curve

Typical concentration dependent effects of verapamil on LVP parameters.

Langendorff isolated perfused heart study, typical effects of verapamil on LVP parameters

Typical effects of sunitinib on ECGs parameters.

Protocol

  • Electrocardiograms, left ventricular pressure parameters and coronary flow are recorded in hearts perfused at a constant pressure (55 ± 5 mmHg)
  • 3 cumulative increasing concentrations of assay compound
  • Washout period or positive control at the end of the experiment

Langendorff compound accumulation studies

Preclinical study design

Myocardial accumulation of pharmaceutical compounds represents important safety risks, particularly with neuropsychiatric or anticancer drugs. The isolated perfused heart may constitute a rapid and low cost approach to measure compound accumulation.

Technique

  • Isolated Langendorff perfused heart

Study model

  • Guinea-pig or rat hearts
  • 6 preparations tested and 6 control preparations (as basic design protocol but can be adapted)

Measured parameters

  • Coronary flow (mL/min)
  • Left ventricular pressure parameters:
    • Developed pressure : maximal systolic pressure – minimal diastolic pressure (mmHg)
    • Max dP/​dt: maximal contraction velocity (mmHg/​sec)
    • Min dP/​dt: maximal relaxation velocity (mmHg/​sec)
    • Heart rate: calculated from ventricular contractions (beats/min)
  • ECG parameters:
    • PR, QRS, RR and QT interval (ms)
    • QTc intervals: Fridericia (QT / (RR)1/3)
  • Clinical cardiology interpretation of the ECG signal, describing events: AV-​block, torsade de pointe, ventricular fibrillation, tachycardia…
  • Evaluation of the pharmacokinetic profile of through solution analysis at different stages of the time-dependent experiments:
    • Vp : apparent volume of distribution of the deep compartment (mL)
    • Mss: accumulated total amount in the myocardium at steady state (μg)
    • Pss: amount in the deep compartment (μg)

Results

  • Long perfusion of the compound in isolated Langendorff perfused hearts (2h)
  • Time dependent variation of left ventricular pressure and ECG parameters
  • Calculation of pharmacokinetic parameters of accumulation using time-​dependent formulation of the compound at the heart outflow

Protocol

  • Hemodynamics parameters and ECGs parameters
  • Calculation of pharmacokinetic parameters of accumulation using time-​dependent formulation of the compound at the heart outflow

Advice from our expert scientists

Langendorff isolated perfused heart studies remain an ex vivo model deprived of sympathetic and parasympathetic systems. Results obtained using this model should be confirmed in anesthetized animals or via telemetry studies.

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