Bacterial endocarditis presenting in an adult patient with undiagnosed double-chambered right ventricle.

Double-chambered right ventricle (DCRV) is a rare congenital heart defect often associated with ventricular septal defect and pulmonary stenosis. Cardiac catheterization or magnetic resonance imaging can differentiate between DCRV and Tetralogy of Fallot when echocardiogram is inconclusive. Patients are at an increased risk for bacterial endocarditis.

Extensive fatal intracoronary thrombosis during percutaneous coronary intervention with bivalirudin.

The authors describe 2 cases of extensive intracoronary thrombus formation leading to acute closure of the left main where bivalirudin (Angiomax) was used as the anticoagulant during percutaneous coronary intervention leading to mortality. Both cases had similarity in the cascade of complications of coronary dissection leading to slow flow and prolonged procedure time with compromise of antegrade flow in the coronary artery and a final catastrophic development of extensive intracoronary thrombosis extending into the left main and nonintervened vessel (left anterior descending or circumflex) followed by ventricular fibrillation and death. Bivalirudin has reversible anticoagulant pharmacodynamics because the bivalirudin molecule is cleaved by the thrombin molecule.

Case report series of left atrial thrombus formation in patients on dabigatran therapy.

Dabigatran etexilate mesylate, a direct thrombin inhibitor, has been approved in the United States as an alternative to warfarin for the prevention of stroke and systemic thromboembolism in patients with nonvalvular atrial fibrillation. The authors report 2 cases of development of large left atrial thrombi and unfortunate occurrence of thromboembolic events in patients with chronic atrial fibrillation, despite these patients being compliant with recommended dabigatran therapy. The authors postulate that certain unique pharmacologic characteristics of the drug may be disadvantageous toward providing a therapeutic level of anticoagulation in all patients and may provide an explanation of occurrence of these thrombotic events, namely, (1) a competitive, reversible, and incomplete inhibition of only one coagulation factor (thrombin), as opposed to warfarin that leads to noncompetitive inhibition of multiple coagulation factors, (2) a short half-life (12-17 hours) and linear pharmacodynamics related to drug levels that conceivably causes an hourly variation of the level of anticoagulation, (3) a much lower incidence of supratherapeutic anticoagulation ("overshoot") with dabigatran as compared with warfarin, and (4) a reported increase in the coagulation factors that follows long-term use of dabigatran.

Clinically unrecognized mitral regurgitation is prevalent in lone atrial fibrillation.

Aim: To investigate the prevalence of clinically unrecognized mitral regurgitation (MR) in lone atrial fibrillation (AF).

Methods: We studied the prevalence and severity of MR by transesophageal echocardiography (TEE) in patients with "lone" AF as compared to a matched cohort of patients in normal sinus rhythm (NSR) undergoing TEE for other indications besides recognized valvular heart disease.

Results: A total of 157 subjects (57 in the AF group and 100 in the NSR group) with structurally normal cardiac valves were included in the study.