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Figure 2 Examples of electrocardiogram patterns in affected members. Patient II-19 was a 70-year-old woman with parietal block and left-axis deviation (heart rate [HR]: 64 beats/min, P: 144 ms, PR: 215 ms, QRS: 160 ms). A pacemaker was implanted because of several episodes of syncope. Patient III-2 was a 49-year-old man with a parietal block and undetermined axis (HR: 54 beats/min, P: 150 ms, PR: 244 ms, QRS 128 ms). Patient III-31 was a 48-year-old woman with right bundle branch block (HR: 64 beats/min, P: 153 ms, PR: 205 ms, QRS: 172 ms). Sudden widening of QRS complexes and occurrence of 2-1 atrioventricular block during exercise led to pacemaker implantation. Patient II-20 was a 78-year-old woman with left bundle branch block (HR: 59 beats/min, P: 157 ms, PR: 248 ms, QRS: 196 ms). A pacemaker was implanted after two episodes of syncope.