Pharmacological therapies for acute cardiogenic shock ; Farmakološko liječenje u akutnom kardiogenom šoku

Cardiogenic shock (CS) is a life threatening condition, a state of end-organ hypoperfusion, caused by cardiac failure leading to low cardiac output and inability of cardiovascular system to provide adequate flow of oxygen-rich blood to body-extremities and vital organs. This is a clinical syndrome characterized by a systemic hypotension <90 mmHg, and signs of tissue hypoperfusion, usually as a sequela of an acute myocardial infarction. Cardiogenic shock can also arise from nonischemic causes, like myocarditis, endocarditis and pericardial tamponade. The incidence of cardiogenic shock is in decline, which reflects increased use of coronary reperfusion strategies for MI, including primary percutaneous coronary intervention (PCI) and fibrinolytic therapy which by limiting the infarct size also reduces the risk of shock development. Initial medical treatment includes IVFs, inotropes and vasopressors. Inotropes are divided into subgroups, according to their mechanism of action we distinguish beta-agonists, phosphodiesterase III inhibitors and Ca2+ sensitizers. Inotropes act on heart contractility, vasopressors increase vasoconstriction, consequently causing increase in mean arterial pressure (MAP) and Ca2+ sensitizers, among other pharmacological agents, are used to increase sensitivity of myocardiocytes on intracellular Ca2+ level. Pathophysiology of CS is not fully understood, it is a vicious cycle: when it is caused by infarction, ischemia leads to myocardial dysfunction which causes left ventricular systolic and diastolic dysfunction manifested with elevated left ventricular end diastolic pressure (LVEDP), decreased cardiac output and decreased coronary perfusion. Systemic hypoperfusion causes compensatory vasoconstriction and tachycardia which increases myocardial oxygen demand and subsequently worsens myocardial ischemia. This self-perpetuating cycle leads to progressive myocardial dysfunction and finally to the multi-organ failure unless it is interrupted by an adequate therapy. CS is an emergency condition ...