Metabolic syndrome (MetS) is a disease that has a complex etiology. It is defined as the co-occurrence of several pathophysiological disorders, including obesity, hyperglycemia, hypertension, and dyslipidemia. MetS is currently a severe problem in the public health care system. As its prevalence increases every year, it is now considered a global problem among adults and young populations. The treatment of choice comprises lifestyle changes based mainly on diet and physical activity. Therefore, researchers have been attempting to discover new substances that could help reduce or even reverse the symptoms when added to food. These attempts have resulted in numerous studies. Many of them have investigated the bioactive potential of polyphenols as a “possible remedy”, stemming from their antioxidative and anti-inflammatory effects and properties normalizing carbohydrate and lipid metabolism. Polyphenols may be supportive in preventing or delaying the onset of MetS or its complications. Additionally, the consumption of food rich in polyphenols should be considered as a supplement for antidiabetic drugs. To ensure the relevance of the studies on polyphenols’ properties, mechanisms of action, and potential human health benefits, researchers have used laboratory animals displaying pathophysiological changes specific to MetS. Polyphenols or their plant extracts were chosen according to the most advantageous mitigation of pathological changes in animal models best reflecting the components of MetS. The present paper comprises an overview of animal models of MetS, and promising polyphenolic compounds whose bioactive potential, effect on metabolic pathways, and supplementation-related benefits were analyzed based on in vivo animal models.

Introduction: A dual-chamber pacemaker (DDD/R) for a sinus node disease is sometimes referred to as a physiological pacemaker as it maintains atrioventricular synchrony, however several clinical trials have proved its inferiority to a nonphysiological single-chamber ventricular back-up pacing. Patient concerns: A subject of the study is a 74-year-old woman with a sick sinus syndrome (SSS) and a previously implanted physiological DDD/R pacemaker. The SSS was diagnosed because of patient's very slow sinus rhythm of about 36 bpm, and due to several episodes of dizziness. After the DDD/R implantation the percentage of atrial pacing approached 100%, with almost none ventricular pacing. Diagnoses: Sick sinus syndrome, complete Bachmann's bundle block, atrial fibrillation, atrial flutter. Interventions: The patient was previously implanted with a physiological DDD/R pacemaker. Several years after the implantation, the atrial fibrillation was diagnosed and the pulmonary vein isolation was then performed by cryoablation. During the follow-up after pulmonary vein isolation, the improvement of mitral filling parameters was assessed using echocardiography. Shortly thereafter the patient developed the persistent paroxysm of a typical atrial flutter which was successfully terminated using a radiofrequency ablation. No recurrence thereof has been observed ever since (24 months). Outcomes: The atrial electrode of the pacing system was implanted within the low interatrial septal region that resulted in a reduced P-wave duration compared to native sinus rhythm P-waves. The said morphology was deformed because of the complete Bachmann bundle block. That approach, despite a nonphysiological direction of an atrial activation, yielded relatively short P-waves (paced P-wave: 179 ms vs intrinsic sinus P-wave: 237 ms). It also contributed to a significantly shorter PR interval (paced PR: 204 ms vs sinus rhythm PR: 254 ms). Conclusions: The authors took into consideration different aspects of alternative right atrial pacing sites. This report has shown that in some patients with a sinus node disease, low interatrial septal pacing can reduce the P-wave duration but does not prevent from the development of atrial arrhythmias.