<prompt> Which of the following is not a positive ionotropic agent: September 2007DobutamineDopamineDiltiazemAmrinone  <response>: Ans. C: Diltiazem Positive inotropic agents increase myocardial contractility, and are used to suppo cardiac function in conditions such as decompensated congestive hea failure, cardiogenic shock, septic shock, myocardial infarction, cardiomyopathy, etc. Examples of positive inotropic agents include Berberine Bipyridine derivatives-Amrinonelnamirone, Milrinone Calcium sensitisers-Levosimendan Cardiac glycosides-Digoxin Catecholamines-Dopamine, Dobutamine, Dopexamine, Epinephrine adrenaline, Isoprenaline isoproterenol, Norepinephrine noradrenaline Eicosanoids-Prostaglandins PDE inhibitor-Enoximone, Milrinone, Theophylline Glucagon Negative inotropic agents decrease myocardial contractility, and are used to decrease cardiac workload in conditions such as angina. Beta blockers Calcium channel blockers Diltiazem Verapamil Clevidipine Class IA antiarrhythmics such as Quinidine, Procainamide, disopyramide Class IC antiarrhythmics such as Flecainide 