Table 3

Characteristics of patients with normal and abnormal HV intervals in myotonic dystrophy

Normal HV
interval (n = 18)
Abnormal HV interval (n = 21)p Value
Age (years)44.3  (12)41.7  (12.5)0.50
Sex male (n (%))11 (60.1)12 (57.1)0.8
Onset of the disease (months)103.5 (94.7)164 (105.2)0.07
Brooke score3.9 (3.1)4.6 (2.4)0.41
Symptomatic patients (n (%)) 12 (66.6)11 (52.4)0.36
Abnormal resting ECG (n (%))8 (44.4)15 (71.4)0.09
Size of DNA mutation (kb)2.2 (1.0)3.5 (1.8)0.02
RVEF (%)50.3 (11.4)43 (10.6)0.07
LVEF (%)60.6 (9.4)58.4 (10.9)0.52
QRSD (ms)102.8 (12.3)123.4 (24.6)0.003
LAS 40 (ms)35.3 (8.8)47.5 (12.8)0.001
RPAVN (ms)289.7 (56.6)340 (135.6)0.16
WK point (beats/min)180.6 (30.2)159.8 (38.8)0.07
  • Values are mean (SD) unless stated otherwise.

  • LAS 40, duration of low amplitude signals ⩽ 40 μV; LVEF, left ventricular ejection fraction; RPAVN, refractory period of atrioventricular node; RVEF, right ventricular ejection fraction; WK point, Wenckebach point.