<prompt> Which of the following abnormality is seen in first-degree hea block?PR interval 140msPR interval 160msPR interval 180msPR interval 200ms  <response>: First-degree AV block PR interval 200 ms is a slowing of conduction through the AV junction. All p waves will be followed by QRS complexNormal PR interval 120-200msHarrison 19e pg: 1472 