Publications by authors named "Takumi Kasai"

Introduction: Unipolar radiofrequency (RF) ablation using half-normal saline irrigation (UNIP-HNS) and bipolar RF ablation using normal saline irrigation (BIP-NS) are effective to treat arrhythmias from inside thick myocardium. However, differences between these two ablations when using a long application time had not fully been studied.

Methods: UNIP-HNS, BIP-NS and unipolar RF ablation using normal saline irrigation (UNIP-NS) were applied for 120 s (30 W and 20-g contact) to porcine endocardial wall (≧15.

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Introduction: Cold saline application through an irrigation catheter may induce reversible inhibition of submyocardial excitation, which may be used to identify in advance an ideal site for radiofrequency (RF) energy delivery around delicate areas.

Methods: An open irrigation catheter was positioned vertically or parallel with 10-g contact on coronary perfusing porcine hearts and the contacted myocardium was cooled by cold saline at 4°C (20 mL/min). A temperature electrode was inserted 2 mm below the myocardial surface (intra-myocardial temperature at approximately 2 mm below the surface [Temp-BS]).

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Introduction: During radiofrequency (RF) ablation, impedance monitoring has been used to avoid steam-pop caused by excessive intramyocardial temperature (IMT) rise. However, it is uncertain why the impedance decline is related to steam-pop and whether the impedance decline is correlated to IMT.

Methods: Twenty-one bipolar ablations (40 W, 30-g contact, 120 s) were attempted for seven perfused porcine myocardium.

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Article Synopsis
  • RF catheter ablation can create areas of recoverable heart tissue around permanent lesions, and this varies based on the method of energy delivery used.
  • In a study with porcine hearts, different ablation techniques were tested for their effects on the myocardium, revealing that longer ablation times resulted in deeper layers of recoverable tissue.
  • After 40 minutes, all tested methods showed areas of excitation recovery, with the irrigation catheter method having a larger number of recoverable electrodes shortly after the procedure.
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Introduction: Bipolar (BIP) radiofrequency (RF) ablation creates deep myocardial lesions but ideal energy application modes to treat ventricular arrhythmias originating from deep inside the thick myocardium have not been well established. An experimental study was performed to clarify whether high power and long application time BIP ablation were performable by impedance-decline-guide power control (PC) and whether it could create transmural lesions in the thick ventricle with a minimum risk of steam-pop.

Methods And Results: Perfused porcine ventricle (18.

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