Phase resetting in human stem cell derived cardiomyocytes explains complex cardiac arrhythmias
Fig 2
PVC dynamics in a patient with frequent PVCs and corresponding simulations of the modulated parasystole model.
(A) A segment of the patient’s electrocardiogram (top) and associated inter-beat intervals (bottom). N denotes a sinus beat, V an ectopic beat (premature ventricular complex, PVC). The sinus cycle length is denoted by ts, the ectopic cycle length by te and ϕ is the phase of the sinus beat in the ectopic cycle. Intervals are color-coded: NN (blue circle), NV (red square), and VN (green diamond). (B) A representation of the phase response curve of the ectopic focus, inferred from sequences of bigeminy (alternating sinus and ectopic beats, black dots) and trigeminy (two sinus beats between ectopic beats, gray dots) (see S2 Text). (C) Sections of patient ECG recordings (left) and simulations of the modulated parasystole model (right), at five different ratios between sinus and ectopic cycle lengths (). The locking ratio of the model is given in parentheses in the form N:M, denoting N sinus cycles per M ectopic cycles.