Question

When will be R-R interval declared premature?

(a) If it is greater than 85% of the predicted interval

(b) If it is less than 85% of the predicted interval

(c) If it is greater than 75% of the predicted interval

(d) If it is less than 75% of the predicted interval

Answer 1

Right option is (b) If it is less than 85% of the predicted interval

Explanation: In timing classification, the observed R-R interval is compared to an estimate of the expected R-R interval. An R-R interval will be declared premature if it is less than 85% of the predicted interval. Similarly, an R-R interval is long if it is greater than 110% of the predicted value.