Contribution of increased minimal coronary resistance and attenuated vascular adaptive remodeling to myocardial ischemia in patients with systemic hypertension and ventricular hypertrophy

This study assessed the impact of coronary vascular adaptive remodeling and coronary vascular reactivity on myocardial ischemia in patients with hypertension and left ventricular hypertrophy. Myocardial ischemia is associated with impaired endothelium-independent vasodilation of resistance coronary arteries and increased minimal coronary resistance. These changes may occur in association with lumen reduction caused by attenuated adaptive remodeling in response to plaque accumulation.     

Effects of flecainide on the electrophysiological properties of atrial vulnerability in humans.

The aims of this study were to evaluate the changes in the electrophysiological characteristics of the right atrium after the administration of flecainide and to clarify whether flecainide has a selective effect on human atrial tissue. Electrophysiological measurements were made in 38 patients, before and after intravenous administration of flecainide (2 mg/kg per 10 min). The effective refractory period of the right atrium (ERP-A), maximum conduction delay (Max.CD), repetitive atrial firing zone (RAFZ), fragmented atrial activity zone (FAAZ), and conduction delay zone (CDZ) were studied in the patients who were divided into 2 groups based on whether repetitive atrial firing (RAF) was induced in the baseline study. Flecainide significantly prolonged the ERP-A (202+/-22 to 238+/-33 ms, p<0.001) and shortened Max.CD (77+/-17 to 63+/-32 ms, p<0.05) in the patients with RAF, but not in those without RAF in the baseline study. After flecainide administration, there were significant reductions in the RAFZ (43+/-22 to 13+/-19 ms, p<0.0001), FAAZ (51+/-22 to 28+/-26 ms, p<0.001) and CDZ (70+/-21 to 48+/-30 ms, p<0.01) in the patients with RAF. However, atrial fibrillation (AF) was induced by stimulation after flecainide in 2 patients without RAF in the baseline study. There was a significant negative correlation between the ERP-A in the baseline study and the change in the ERP-A upon flecainide administration (r=0.45, p<0.01). Flecainide may preferentially activate the substrate for AF and RAF, but that action is mainly based on the electrophysiological characteristics found in the baseline study.     

Predictive factors for postoperative tachyarrhythmia after thoracoscopic esophagectomy and the usefulness of landiolol hydrochloride for its treatment

Background

Tachyarrhythmia after esophagectomy is a severe complication that should not be underestimated because of its negative impact. The aims of this study were to clarify the cause and impact of postoperative tachyarrhythmia after thoracoscopic esophagectomy. Additionally, we analyzed the usefulness of landiolol administration for postoperative tachyarrhythmia.

Methods

We evaluated the predictive factors for tachyarrhythmia onset after surgery and its clinical impact in 127 patients who underwent thoracoscopic esophagectomy with extended lymphadenectomy. Moreover, we analyzed the efficacy of landiolol for postoperative tachyarrhythmia.

Results

Tachyarrhythmia developed in 38 of the 127 patients. Multivariate analysis showed that advanced age, heart disease, and hyperlipidemia were associated with postoperative tachyarrhythmia. Hyponatremia, hypoalbuminemia, and leukocytosis on postoperative day 3 were significantly associated with tachyarrhythmia onset. The incidence of all complications and respiratory complications, including pneumonia, was significantly higher in patients with than in those without tachyarrhythmia. The mortality rate in the tachyarrhythmia group tended to be higher than that in the nontachyarrhythmia group. Landiolol as a treatment for tachyarrhythmia immediately decreased heart rate and safely reduced subsequent respiratory complications.

Conclusion

In elderly patients with cardiac disease or hyperlipidemia, surgeons should be alert for the occurrence of tachyarrhythmia after esophagectomy. Postoperative tachyarrhythmia is a marker of morbidities with particular emphasis on respiratory complications. However, it can be adequately managed by landiolol, resulting in fewer respiratory complications. Landiolol might be a safe and convenient agent for managing postoperative tachyarrhythmia after thoracoscopic esophagectomy, resulting in lower mortality and morbidity rates.