Second-Degree Block (Type II)
Second-Degree Block (Type II)
Regular; P to P is regular, rate is variable
Regular; until QRS is dropped, rate is less than atrial rate
More P waves than QRS complexes
Unchanged unless aberrant conduction due to premature beat or increased rate, but dropped in a cyclic pattern
PR: 0.12 to 0.20 sec where they can be measured
QRS: variable