RyR2 inhibition with dantrolene is antiarrhythmic, antifibrotic, and improves cardiac function in chronic ischemic heart disease
biorxiv(2022)
摘要
Background Ventricular tachycardia (VT) is responsible for sudden death in chronic ischemic heart disease (CIHD) patients. The cardiac ryanodine receptor (RyR2) releases Ca2+ from the sarcoplasmic reticulum (SR) and links electrical excitation to contraction. RyR2 hyperactivity has been widely documented in CIHD and may contribute to VT risk and progressive LV remodeling.
Objective To test the hypothesis that targeting RyR2 hyperactivity plays a mechanistic role in VT inducibility and progressive heart failure in CIHD that can be prevented by the RyR2 inhibitor dantrolene.
Methods CIHD was induced in C57BL/6J mice by left coronary artery ligation. Four weeks later, mice were randomized to either acute or chronic (6 weeks via osmotic mini-pump) treatment with dantrolene or vehicle. VT inducibility was assessed by programmed stimulation in vivo and in isolated hearts. Electrical substrate remodeling was assessed by optical mapping. Ca2+ sparks and spontaneous Ca2+ releases were measured in isolated cardiomyocytes. Cardiac remodeling was assessed by histology and qRT-PCR. Cardiac function and contractility were assessed by echocardiography.
Results Compared to vehicle, acute dantrolene treatment reduced VT inducibility and improved LV contractility in vivo . Optical mapping in isolated hearts demonstrated reentrant VT prevention by dantrolene, which normalized the shortened refractory period (VERP) and prolonged action potential duration (APD), preventing APD alternans. In single CIHD cardiomyocytes, dantrolene normalized RyR2 hyperactivity and prevented spontaneous SR Ca2+ release. Chronic dantrolene treatment reduced peripheral muscle strength but had no adverse effects on body weight or mortality. Chronic dantrolene not only reduced VT inducibility but also reduced peri-infarct fibrosis and prevented the progression of LV dysfunction in CIHD mice.
Conclusion RyR2 hyperactivity plays a mechanistic role for VT risk, infarct remodeling, and contractile dysfunction in CIHD mice. Our data provide proof of concept for the anti-arrhythmic and anti-fibrotic efficacy of dantrolene in CIHD.
What is New?
Clinical Implications
### Competing Interest Statement
The authors have declared no competing interest.
* AF
: Atrial Fibrillation
APD
: Action Potential Duration
CIHD
: Chronic Ischemic Heart Disease
CPVT
: catecholaminergic polymorphic ventricular tachycardia
DAD
: delayed afterdepolarization
EMG
: Electromyogram
FS
: Fractional shortening
ICD
: implantable cardioverter-defibrillator
PSAX
: parasternal short-axis
PSLX
: parasternal long-axis
LV
: Left ventricle/ventricular
LVEDd
: Left ventricular end-diastolic dimension
LVESd
: Left ventricular end-systolic dimension
LVEF
: Left ventricular ejection fraction
MI
: Myocardial Infarction
mVcfc
: mean velocity circumferential fiber shortening
PES
: Programmed electrical stimulation
RV
: Right ventricle/ventricular
RyR2
: Ryanodine Receptor 2
SR
: Sarcoplasmic reticulum
SCD
: Sudden cardiac death
VT
: Ventricular Tachycardia
VF
: Ventricular Fibrillation
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关键词
dantrolene,chronic ischemic heart disease,cardiac function
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