Atrioventricular Block: 1st Degree

ECG Features

Figure 1: ECG Strip[1]

A first degree atrioventricular (AV) block occurs when electrical impulses moving through the AV node are delayed but not blocked.[2] A first degree AV block is present when the PR interval exceeds 0.30 sec.

Table 1: ECG Characteristics[2]

Clinical Significance[3]

  • A first degree heart block does not cause haemodynamic disturbance; thus, no specific treatment is needed.

ECM Features

Figure 2: ECM Analysis, Record 111[4][5]

Additional Information


  1. First Degree Heart Block [Online image]. (2013). Retrieved July 19, 2016, from
  2. First Degree Heart Block. (n.d.). Retrieved July 27, 2016, from
  3. First Degree Heart Block. (n.d.). Retrieved August 8, 2016, from
  4. MIT-BIH Arrhythmia Database. (1980). Retrieved June, 2016, from
  5. Goldberger AL, Amaral LAN, Glass L, Hausdorff JM, Ivanov PCh, Mark RG, Mietus JE, Moody GB, Peng C-K, Stanley HE. PhysioBank, PhysioToolkit, and PhysioNet: Components of a New Research Resource for Complex Physiologic Signals. Circulation101(23):e215-e220 [Circulation Electronic Pages;]; 2000 (June 13).