Atrioventricular Block: 2nd Degree, 2:1 fixed ratio block

ECG Features

Figure 1: ECG Strip[1]

A second degree, 2:1 fixed ratio atrioventricular (AV) block occurs when the ratio of P-waves: QRS complexes in a second degree heart block is fixed at 2:1.[2]

Table 1: ECG Characteristics[2][3]

ECM Features

Figure 2: ECM Analysis, Record 231[4][5]

ECM Examples

2nd Degree, 2:1 AV Block with Right Bundle Branch Block

Figure 3: Record 231[4][5]

Additional Information


  1. AV block: 2nd degree, “fixed ratio” blocks [Online image]. (2011). Retrieved July 19, 2016, from
  2. AV block: 2nd degree, “fixed ratio” blocks. (n.d.). Retrieved July 27, 2016, from
  3. Second Degree Heart Block Type II. (n.d.). Retrieved July 27, 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).