Severe methemoglobinemia after transesophageal echocardiography.

Methemoglobinemia, an increased concentration of methemoglobin in the blood, is an altered state of hemoglobin whereby the ferrous form of iron is oxidized to the ferric state, rendering the heme moiety incapable of carrying oxygen. This can cause hypoxia, cyanosis, or even death. Severe methemoglobinemia resulting from oral benzocaine spray before endoscopic procedures has been reported as a rare complication.

Prevalence of renal artery stenosis requiring revascularization in patients initially referred for coronary angiography.

To evaluate the prevalence of clinically significant renal artery stenosis (RAS) in patients referred for coronary angiography, we analyzed data on 2,439 consecutive patients. Patients underwent selective renal angiography in conjunction with coronary angiography if refractory hypertension (blood pressure > 140/90 on two drugs) or flash pulmonary edema was present. A total of 1,089 renal arteries of 534 patients were evaluated.

Safety of therapeutic beta-blockade in patients with coexisting bronchospastic airway disease and coronary artery disease.

Atherosclerotic coronary artery disease and bronchospastic airway disease frequently coexist in older patients. There are substantial data suggesting reduced mortality with the use of beta-adrenergic blocking drugs in patients with symptomatic coronary artery disease, especially patients who have postmyocardial infarction and/or severe coronary artery disease associated with left ventricular dysfunction. Conversely, the use of beta-adrenergic blocking drugs (even selective beta(1)-adrenergic blocking drugs) has the potential of exacerbating bronchospasm.

Acute and long-term results after intra-arterial thrombolysis of occluded lower extremity bypass grafts using recombinant tissue plasminogen activator for acute limb-threatening ischemia.

Occlusion of lower extremity vascular bypass grafts results in acute limb-threatening ischemia. The underlying cause of graft failure generally is distal anastomosis stenosis, and relief of culprit stenosis is a required to maintain long-term patency. Of the three thrombolytic agents used for prolonged infusion to accomplish fibrinolysis, streptokinase was the first to be used and is limited owing to the antigenicity that precludes repeated use.

Safety and efficacy of combined use of low molecular weight heparin (enoxaparin, lovenox) and glycoprotein IIb/IIIa receptor antagonist (eptifibatide, integrelin) during nonemergent coronary and peripheral vascular intervention.

Coronary and peripheral intervention requires intraprocedural anticoagulation to prevent intraluminal thrombosis. Traditionally, unfractionated heparin (UFH) is administered during the procedure to achieve activated clotting time (ACT) of 300 to 400 seconds. When the intravenous IIb/IIIa antagonists are also used, the recommended ACT is 250 to 300 seconds because higher anticoagulation (ACT, 300-400 seconds) is accompanied by an unacceptable bleeding complication rate without added benefits.