TY - JOUR
T1 - Temperature regulates the arrhythmogenic activity of pulmonary vein cardiomyocytes
AU - Chen, Yi Jen
AU - Chen, Yao Chang
AU - Chan, Paul
AU - Lin, Cheng I.
AU - Chen, Shih Ann
PY - 2003
Y1 - 2003
N2 - Temperature plays an important role in the electrophysiology of cardiomyocytes. Pulmonary veins (PVs) are known to initiate paroxysmal atrial fibrillation. The effects of temperature on the arrhythmogenic activity of rabbit single PV and atrial cardiomyocytes were assessed using the whole-cell clamp technique. PV cardiomyocytes had different beating rates at low (22-25°C), normal (38-39°C) and high (40-41°C) temperatures (0.9 ± 0.1, 3.2 ± 0.4, 6.4 ± 0.6 Hz, respectively; p <0.001). There were different action potential durations and incidences of delayed afterdepolarization in PV cardiomyocytes with pacemaker activity (31, 59, 63%; p <0.05), PV cardiomyocytes without pacemaker activity (16, 47, 60%; p <0.001), and atrial myocytes (0, 0, 21%; p <0.05). However, oscillatory afterpotentials were only found in PV cardiomyocytes with pacemaker activity at normal (50%) or high (68%) temperatures, but not at low temperatures (p <0.001). Both PV and atrial cardiomyocytes had larger transient inward currents and inward rectified currents at high temperatures. Additionally, PV cardiomyocytes with and without pacemaker activity had larger pacemaker currents at higher temperatures. This study demonstrated that PV cardiomyocytes have an increase in arrhythmogenic activity at high temperatures because of enhanced automaticity, induced triggered activity, or shortening of action potential duration.
AB - Temperature plays an important role in the electrophysiology of cardiomyocytes. Pulmonary veins (PVs) are known to initiate paroxysmal atrial fibrillation. The effects of temperature on the arrhythmogenic activity of rabbit single PV and atrial cardiomyocytes were assessed using the whole-cell clamp technique. PV cardiomyocytes had different beating rates at low (22-25°C), normal (38-39°C) and high (40-41°C) temperatures (0.9 ± 0.1, 3.2 ± 0.4, 6.4 ± 0.6 Hz, respectively; p <0.001). There were different action potential durations and incidences of delayed afterdepolarization in PV cardiomyocytes with pacemaker activity (31, 59, 63%; p <0.05), PV cardiomyocytes without pacemaker activity (16, 47, 60%; p <0.001), and atrial myocytes (0, 0, 21%; p <0.05). However, oscillatory afterpotentials were only found in PV cardiomyocytes with pacemaker activity at normal (50%) or high (68%) temperatures, but not at low temperatures (p <0.001). Both PV and atrial cardiomyocytes had larger transient inward currents and inward rectified currents at high temperatures. Additionally, PV cardiomyocytes with and without pacemaker activity had larger pacemaker currents at higher temperatures. This study demonstrated that PV cardiomyocytes have an increase in arrhythmogenic activity at high temperatures because of enhanced automaticity, induced triggered activity, or shortening of action potential duration.
KW - Action potential
KW - Atrial fibrillation
KW - Triggered activity
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U2 - 10.1159/000072381
DO - 10.1159/000072381
M3 - Article
C2 - 12928594
AN - SCOPUS:0042423726
VL - 10
SP - 535
EP - 543
JO - Journal of Biomedical Science
JF - Journal of Biomedical Science
SN - 1021-7770
IS - 5
ER -