BACKGROUND AND PURPOSE: In drug research using the rat Langendorff heart preparation, it is possible to study left ventricular (LV) contractility using an intraventricular balloon (IVB), and arrhythmogenesis during coronary ligation-induced regional ischaemia. Assessing both concurrently would halve animal requirements. We aimed to test the validity of this approach. EXPERIMENTAL APPROACH: The electrocardiogram (ECG) and LV function (IVB) were recorded during regional ischaemia of different extents in a randomized and blinded study. KEY RESULTS: IVB-induced proarrhythmia was anticipated, but in hearts with an ischaemic zone (IZ) made deliberately small, an inflated IVB reduced ischaemia-induced ventricular fibrillation (VF) incidence as a trend. Repeating studies in hearts with large IZs revealed the effect to be significant. There were no changes in QT interval or other variables that might explain the effect. Insertion of an IVB that was minimally inflated had no effect on any variable compared with 'no IVB' controls. The antiarrhythmic effect of verapamil (a positive control drug) was unaffected by IVB inflation. Removal of an inflated (but not a non-inflated) IVB caused a release of lactate commensurate with reperfusion of an endocardial/subendocardial layer of IVB-induced ischaemia. This was confirmed by intracellular (31) phosphorus ((31) P) nuclear magnetic resonance (NMR) spectroscopy. CONCLUSIONS AND IMPLICATIONS: IVB inflation does not inhibit VF suppression by a standard drug, but it has profound antiarrhythmic effects of its own, likely to be due to inflation-induced localized ischaemia. This means rhythm and contractility cannot be assessed concurrently by this approach, with implications for drug discovery and safety assessment.
BACKGROUND AND PURPOSE: In drug research using the rat Langendorff heart preparation, it is possible to study left ventricular (LV) contractility using an intraventricular balloon (IVB), and arrhythmogenesis during coronary ligation-induced regional ischaemia. Assessing both concurrently would halve animal requirements. We aimed to test the validity of this approach. EXPERIMENTAL APPROACH: The electrocardiogram (ECG) and LV function (IVB) were recorded during regional ischaemia of different extents in a randomized and blinded study. KEY RESULTS: IVB-induced proarrhythmia was anticipated, but in hearts with an ischaemic zone (IZ) made deliberately small, an inflated IVB reduced ischaemia-induced ventricular fibrillation (VF) incidence as a trend. Repeating studies in hearts with large IZs revealed the effect to be significant. There were no changes in QT interval or other variables that might explain the effect. Insertion of an IVB that was minimally inflated had no effect on any variable compared with 'no IVB' controls. The antiarrhythmic effect of verapamil (a positive control drug) was unaffected by IVB inflation. Removal of an inflated (but not a non-inflated) IVB caused a release of lactate commensurate with reperfusion of an endocardial/subendocardial layer of IVB-induced ischaemia. This was confirmed by intracellular (31) phosphorus ((31) P) nuclear magnetic resonance (NMR) spectroscopy. CONCLUSIONS AND IMPLICATIONS: IVB inflation does not inhibit VF suppression by a standard drug, but it has profound antiarrhythmic effects of its own, likely to be due to inflation-induced localized ischaemia. This means rhythm and contractility cannot be assessed concurrently by this approach, with implications for drug discovery and safety assessment.
Authors: F J Chorro; J Canoves; J Guerrero; L Mainar; J Sanchis; E Soria; L M Such; A Rosado; L Such; V López-Merino Journal: Pacing Clin Electrophysiol Date: 2000-11 Impact factor: 1.976
Authors: Robert J Sidell; Mark A Cole; Nicholas J Draper; Martine Desrois; Robin E Buckingham; Kieran Clarke Journal: Diabetes Date: 2002-04 Impact factor: 9.461
Authors: Hans Erik Bøtker; Derek Hausenloy; Ioanna Andreadou; Salvatore Antonucci; Kerstin Boengler; Sean M Davidson; Soni Deshwal; Yvan Devaux; Fabio Di Lisa; Moises Di Sante; Panagiotis Efentakis; Saveria Femminò; David García-Dorado; Zoltán Giricz; Borja Ibanez; Efstathios Iliodromitis; Nina Kaludercic; Petra Kleinbongard; Markus Neuhäuser; Michel Ovize; Pasquale Pagliaro; Michael Rahbek-Schmidt; Marisol Ruiz-Meana; Klaus-Dieter Schlüter; Rainer Schulz; Andreas Skyschally; Catherine Wilder; Derek M Yellon; Peter Ferdinandy; Gerd Heusch Journal: Basic Res Cardiol Date: 2018-08-17 Impact factor: 17.165
Authors: Louise M Hesketh; Catherine D E Wilder; Niraja N Ranadive; Georgia Lytra; Patrisia Qazimi; Jade S Munro; Nakita Ahdi; Michael J Curtis Journal: Sci Rep Date: 2020-05-21 Impact factor: 4.379
Authors: D Ryan King; Rachel L Padget; Justin Perry; Gregory Hoeker; James W Smyth; David A Brown; Steven Poelzing Journal: Sci Rep Date: 2020-10-14 Impact factor: 4.379