OBJECTIVETo analysis the effect of amiodarone on funny current (I(f)) and hyperpolarization-activated cation channel (HCN) gene expressions of the neonatal rat ventricular myocytes.

METHODSVentricular myocytes of 1 - 3 days-old rats were isolated and cultured. The cardiomyocytes were treated by amiodarone (0.01, 0.1, 1, 10, 100 micromol/L) for 3 hours or amiodaron (10 micromol/L) for 0, 0.5, 1, 3, 6 hours. The I(f) and HCN 1 - 4 gene expressions were measured through the whole-cell configuration of the patch-clamp technique and real-time quantitative polymerase chain reaction (real-time PCR) using SYBR Green PCR kit.

RESULTS(1) HCN1, HCN2, HCN3 and HCN4 represented (0.23 +/- 0.01)%, (83.58 +/- 0.04)%, (0.79 +/- 0.01)% and (15.44 +/- 0.01)% of total HCN mRNA, respectively. (2) Amiodaron resulted in a dose-dependent I(f) [(3.1 +/- 0.9)%, (9.7 +/- 2.4)%, (36.7 +/- 5.8)%, (80.3 +/- 1.8)% and (85.9 +/- 3.1)%, respectively at -145 mV, IC(50) (1.32 +/- 0.28) micromol/L], HCN2 [(2.1 +/- 0.8)%, (8.9 +/- 3.6)%, (30.1 +/- 4.2)%, (78.3 +/- 3.6)% and (81.1 +/- 1.9)%, respectively] and HCN4 decrease [(0.5 +/- 0.2)%, (2.1 +/- 2.6)%, (8.8 +/- 3.2)%, (60.1 +/- 4.6)% and (59.6 +/- 6.5)%, respectively]. (3) Amiodaron (10 micromol/L) also induced a time-dependent I(f) [(1.1 +/- 0.1)%, (12.6 +/- 2.3)%, (80.6 +/- 2.2)% and (80.1 +/- 2.1)%, respectively], HCN2 [(1.0 +/- 0.1)%, (9.8 +/- 3.9)%, (82.9 +/- 4.6)% and (83.9 +/- 1.7)%, respectively] and HCN4 decrease [(0.1 +/- 0.1)%, (1.9 +/- 1.1)%, (59.4 +/- 7.8)% and (60.9 +/- 3.1)%, respectively]. However, HCN1 and HCN3 expressions were not affected by amiodaron treatment.

CONCLUSIONCurrent density of I(f) and the expression of HCN2 and HCN4 were decreased by amiodaron which might be the possible antiarrhythmic working mechanisms of amiodaron.

OBJECTIVEIn this randomized prospective single-center study, we compared the efficacy of adjunctive thrombectomy using Diver CE device (Linvatec, Italy) versus Guardwire Plus device (Medtronic, USA) before percutaneous coronary intervention (PCI) in patients with <12 h acute inferior myocardial infarction (AIMI) and Thrombolysis In Myocardial Infarction (TIMI) flow grade 0 to 1. The primary end point was the magnitude of ST-segment resolution after PCI.

METHODSA total of 122 patients (61 in Diver CE group and 61 in Guardwire Plus group) were studied. The magnitude of ST-segment resolution, myocardial blush grade and slow flow or no re-flow 1 h after PCI were measured in study patients.

RESULTSBaseline characteristics were similar between groups: age (59.6 +/- 14 years vs. 60.1 +/- 13 years), males (82% vs. 84%), diabetes (31% vs. 28%), previous coronary artery disease (25% vs. 23%), onset-to-angiogram (350 +/- 185 min vs. 345 +/- 180 min), and glycoprotein IIb/IIIa inhibitor use (11% vs. 13%, all P > 0.05). The magnitude of ST-segment resolution was also similar in these two groups: ST-segment resolution > 70% (57% vs. 59%, P > 0.05). Slow flow/no reflow rate (8% vs. 7%), TIMI flow grade 3 (95% vs. 97%) and myocardial blush grade 3 (70% vs. 72%) post PCI were not different in the groups (all P > 0.05). Left ventricle ejection fraction (0.54 +/- 0.12 vs. 0.53 +/- 0.11), death (3% vs. 3%), re-myocardial infarction (2% vs. 0) and target vessel revascularization (2% vs. 2%) at one month post PCI were comparable (all P > 0.05).

CONCLUSIONEfficacy of removing thrombus burden with Diver CE device or Guardwire Plus device was similar in patients with < 12 h acute inferior myocardial infarction.