When a spacecraft travels, one of the major problems is reentry into the Earth’s _______.

which of the following effects of drugs for tachyarrhythmias is not correct. A: reduction of automaticity B: slowing down conduction of atrial ventricular node conduction C: elimination of reentry D: prolongation of ERP and APD E: acceleration of autodepolarization of pacemakers

suppression of arrhythmias resulting from a reentry focus is most likely to occur if the drug A: has vagomimetic effects o the AV node B: is a beta-blocker C: converts a unidirectional block to a bidrectional block D: slows conduction through the atria E: has atropine-like effects on the AV node