Metabolic disturbances induce malignant heart arrhythmias in rats

Abstract

OBJECTIVES: Metabolic disturbances are considered to condition the occurrence of malignant heart arrhythmias and negatively infl uence the chances of a patient to survive. To test this assumption, a model of metabolic syndrome was selected in which rats were receiving a diet resembling that of the westernized population. BACKGROUND: Metabolic syndrome is a comorbidity of major cardiovascular risk factors (dyslipidemia, hypertension, impaired glucose tolerance or insulin resistance, diabetes mellitus, and obesity), all facilitating cardiovascular complications leading to morbidity and mortality of patients. METHODS: Hearts were isolated and perfused according to Langendorff. Global ischemia was induced in the hearts and arrhythmia occurrence in reperfusion was monitored. All hearts were stimulated with the electrocardio-stimulator to test the electrical inducibility of heart arrhythmia. RESULTS: Isolated hearts from rats with the metabolic syndrome were more susceptible to ventricular arrhythmias. The high-fat diet increased the occurrence of malignant heart arrhythmias in rats with metabolic syndrome to an even greater extent. All subjects with metabolic syndrome were sensitive to ventricular tachyarrhythmia with signifi cantly decreased threshold to its induction in cardio-stimulation. CONCLUSIONS: These results indicate that metabolic syndrome patients may be more sensitive to the occurrence of malignant heart arrhythmias following myocardial infarction or other heart diseases (Tab. 1, Fig. 2

Monotherapy of experimental metabolic syndrome: II. Study of cardiovascular effects

“…To study myocardial susceptibility to dysrhythmias we used the ex vivo model of cardiac burst pacing for initiation and persistence of malignant re-entry dysrhythmias (Merrilat et al , 1990 ; Kihara & Morgan, 1991 ; Simor et al , 1997 ; Tribulová et al , 2002 ; Liptak et al , 2017 ). Using this model we demonstrated the decreased stimulating threshold and increased incidence of sustained ventricular dysrhythmias.…”

“…Myocardial susceptibility to persistent dysrhythmias was determined by induction of the 2 minute lasting sustained ventricular tachycardia (VT) or ventricular fibrillation (VF). Time to restore sinus rhythm by stop flow after sustained dysrhythmias was considered as the ability of myocardium to recovery electrical activity (Tribulova et al , 2002 ; Liptak et al , 2017 ).…”

Linking Arrhythmias and Adipocytes: Insights, Mechanisms, and Future Directions

“…For example, even a short period of HFD in gerbils can lead to radical inflammation and apoptosis causing cardiac remodeling (Sahraoui et al, 2016). Rats fed a high fat diet had an increased incidence of malignant ventricular tachyarrhythmias (Liptak et al, 2017) in the setting of induced ischemia. Furthermore, atria from rats fed high fat diet showed upregulation of transforming growth factor-β1 and matrix metalloproteinase-2 (atrial fibrosis pathway proteins), gap junction remodeling with alterations and distribution of connexin 40 (Cx40) and Cx43, broadened interstitial space, and myocyte disarray, and increased apoptotic cell death (Meng et al, 2017).…”

Integrating Evidence of the Traditional Chinese Medicine Collateral Disease Theory in Prevention and Treatment of Cardiovascular Continuum

“…Metabolic syndrome is an independent predictor of AF associated with the left atrial low voltage zone ( Dinov et al, 2014 ). Furthermore, MS is also associated with the increased risk of ventricular arrhythmia (VA) ( Fernández-Sada et al, 2017 ; Liptak et al, 2017 ) and was reported to contribute to a higher recurrence rate of outflow tract VA after catheter ablation ( Sardu et al, 2014 ). However, the underlying role of MS in the occurrence and development of such arrhythmia remains unclear.…”