Inherited Arrhythmias: Of Channels, Currents, and Swimming Maura M. Zylla, Dierk Thomas  Biophysical Journal  Volume 110, Issue 5, Pages 1017-1022 (March 2016) DOI: 10.1016/j.bpj.2016.02.010 Copyright © 2016 Biophysical Society Terms and Conditions

Figure 1 ECG trace of a patient with LQTS and a healthy individual. (A) ECG trace from patient with LQTS (lead I). The QT interval (blue line), from the beginning of the Q-wave (arrow, Q), marking of the start of electrical activation of the ventricular muscle, to the end of the T-wave (T), representing regression of electrical activation, is severely prolonged. (B) ECG trace from a healthy individual (lead I). The QT interval is within the normal range of <440 ms. Note the difference between the QT interval in the ECG from the patient in (A) and that of the healthy individual. To see this figure in color, go online. Biophysical Journal 2016 110, 1017-1022DOI: (10.1016/j.bpj.2016.02.010) Copyright © 2016 Biophysical Society Terms and Conditions

Figure 2 The action potential of a ventricular cardiomyocyte. The different phases of the action potential and the respective ion channels involved are depicted. The respective genes encoding for the ion channels are shown in parentheses. Note the KCNQ1- and hERG-channels (mainly active during repolarization), which are affected in certain subtypes of LQTS. Also note the SCN5A-channels, which play a role in Brugada syndrome and familial sick sinus syndrome (active during depolarization). Red (phase 0), depolarization period; yellow (phase 2), plateau-phase; green (phases 3 and 4), repolarization period and resting membrane potential. To see this figure in color, go online. Biophysical Journal 2016 110, 1017-1022DOI: (10.1016/j.bpj.2016.02.010) Copyright © 2016 Biophysical Society Terms and Conditions

Figure 3 Conduction system of the heart. An electrical impulse is generated by the sinoatrial (SA) node or sinus node (1). Electrical activity then spreads across the atria, which causes contraction of atrial myocardium (2 and 3). After passing the AV node, electrical activation is propagated to excite the ventricular myocardium via bundle branches and Purkinje fibers (4 and 5). To see this figure in color, go online. Biophysical Journal 2016 110, 1017-1022DOI: (10.1016/j.bpj.2016.02.010) Copyright © 2016 Biophysical Society Terms and Conditions

Figure 4 Example of self-terminating TdP tachycardia. Normal sinus rhythm (marked by blue line) is disrupted by a short period of TdP tachycardia” (red line), which is self-terminating and followed, again, by normal sinus rhythm (blue line). To see this figure in color, go online. Biophysical Journal 2016 110, 1017-1022DOI: (10.1016/j.bpj.2016.02.010) Copyright © 2016 Biophysical Society Terms and Conditions