In this compilation, the authors present and discuss various aspects of arrhythmias in endurance competitive and leisure-time sportsmen including master athletes based on their extensive experience and international literature. The value of heart rate monitors for evaluating exercise intensity and for diagnosis of arrhythmias is discussed and standard procedure for dealing with suspected arrhythmias useful both for athletes, their coaches or doctors is proposed. Next, the authors focus on recent literature data related to the role of endothelial nitric oxide and inducible nitric oxide in physiological and pathophysiological conditions. Nitric oxide is a free radical which, in reactions with various molecules, causes multiple biological effects. It is exceptionally regulated and extends to almost every cell type and function within circulation. Extracranial carotid artery stenosis is a major cause of stroke and is treated with either carotid endarterectomy (CEA) or percutaneous transluminal angioplasty (PTA) and carotid artery stenting (CAS). In this collection, several types of imaging study have been used to identify complications related to in-stent restenosis, including Doppler ultrasound, computed tomography angiography, digital subtraction angiography, magnetic resonance angiography, intravascular ultrasound, and optical coherence tomography. The authors go on to discuss some recent randomized studies that compared different d rug-eluting balloon catheters (DEB) with drug-eluting stents (DES) used to treat BMS- in-stent restenosis or DES- in-stent restenosis, and the long-term clinical results of those studies. Evidence from controlled clinical studies has suggested that DES and drug-eluting balloon catheters (DEB) provide the best clinical and angiographic results in the treatment of ISR. Following this, the dynamics of the conformation changes in the subdomains of the NC1 hexamer under the influence of sound frequencies distressing them was studied in gelatin (film) and collagen (cardiac aorta/veins endothelium) obtained from pork, using the gravitation mass spectroscopy method (GMS). Continuing, most coronary events are caused by significant stenoses or vulnerable plaques. Recent studies have shown that significant stenoses and vulnerable plaques often coexist. The basic concept that underlies these entities is increased plaque volume. Additionally, recent evidence shows that coronary calcium score and fractional flow reserve are the most accurate methods to assess increased plaque volume, and therefore, have high prognostic value. The main goal of the subsequent study is the application of an immunohistochemistry technique in order to diagnose myocardial ischemia in early stages with a better confidence rate. Sudden cardiac death cases were selected and their findings were qualitatively and quantitatively assessed. The study focuses on the evolution and location of fibronectin in the ischemic cardiomyocytes during process of infarction and remodeling of cardiac scars. Lastly, the authors investigate the incidence of very late in-stent restenosis and risk factors for very late target lesion revascularization (TLR) in patients with sirolimus-eluting stent (SES). Very late SES-TLR was associated with history of hemodialysis and previous PCI with SES for ISR lesion.