INSIDE THIS ISSUE OF JACC
Inside This Issue of JACC
 |
Clinical Trial
|
|---|
Infusion of Bicarbonate and Acetylcysteine Reduces Contrast Nephropathy During Emergency PCI.
Patients undergoing emergency percutaneous coronary intervention (PCI) are at higher risk for contrast-induced nephropathy (CIN) than those undergoing elective procedures, but the most effective CIN prevention protocols require several hours of pretreatment. The RENO study randomized over 100 patients with acute coronary syndromes undergoing urgent PCI to either standard post-procedure hydration or immediate intravenous hydration with sodium bicarbonate plus N-acetylcysteine (N-AC). Patients treated with intravenous bicarbonate plus N-AC were 12 times less likely to develop CIN and 6 times less likely to develop acute renal failure. This rapid intravenous infusion of sodium bicarbonate and N-AC appears to safely and substantially reduce the risk of CIN for patients undergoing emergency PCI. See page 1283. See figure.
|
Coronary Artery Disease
|
|---|
Isosorbide-5-Mononitrate Causes Endothelial Dysfunction.
Nitrates are widely used for relief of angina, yet there is evidence that prolonged use may lead to tolerance and increased production of free radicals. Thomas and colleagues performed studies in healthy volunteers taking isosorbide-5-mononitrate (IS-5-MN) 120 mg once daily for 7 days. IS-5-MN caused significant blunting of the responses to both acetylcholine and N-monomethyl-L-arginine; this blunting was restored by vitamin C infusion. This study suggests that IS-5-MN causes pronounced endothelial dysfunction, most likely due to increased oxidative stress and free-radical formation. See page 1289. See figure.
|
Heart Rhythm Disorders
|
|---|
Extensive Atrial Scarring After AF Ablation.
Takahashi and colleagues repeated electroanatomical mapping in patients who had previously undergone catheter ablation for atrial fibrillation (AF) using either a standardized, sequential protocol or routine practice. There were significant areas of scar and low voltages in the left atrium (LA) accounting for 31% and 32% of the total LA surface area. Use of the sequential protocol resulted in smaller areas of scarring in the LA. Despite this widespread scarring, LA contraction appeared normal. This study demonstrates that there is widespread scarring and areas of electrical dysfunction after AF ablation procedures but little evidence of hemodynamic or functional compromise. See page 1306.
|
Heart Rhythm Disorders
|
|---|
Adenosine-Insensitive Focal Atrial Tachycardia.
The majority of focal atrial tachycardias (AT) can be terminated with adenosine infusion, suggesting that they result from triggered activity or automaticity. Markowitz and colleagues report that 8% of focal ATs are insensitive to adenosine. Compared to typical AT, adenosine-insensitive ATs showed highly fractionated electrograms with longer durations and lower amplitudes. Adenosine-insensitive AT had electrograms comprising >22% of the tachycardia cycle length compared to <21% for adenosine-sensitive ATs. This study demonstrates features of a new subtype of focal AT that differs from the majority of regular, focal atrial arrhythmias and is most likely the result of small re-entrant circuits. See page 1324. See figure.
Related Article
-
The Reno-Protective Effect of Hydration With Sodium Bicarbonate Plus N-Acetylcysteine in Patients Undergoing Emergency Percutaneous Coronary Intervention: The RENO Study
- Alejandro Recio-Mayoral, Marinela Chaparro, Belén Prado, Rocío Cózar, Irene Méndez, Debasish Banerjee, Juan C. Kaski, José Cubero, and Jose M. Cruz
J. Am. Coll. Cardiol. 2007 49: 1283-1288.
[Abstract]
[Full Text]
[PDF]
Top
Clinical Trial
Coronary Artery Disease
