Diagnostic Performance of Frequency-Domain Optical Coherence Tomography to Predict Functionally Significant Left Main Coronary Artery Stenosis.

AIMS: The aim of this study was to assess the safety and diagnostic efficacy of frequency-domain optical coherence tomography (FD-OCT) in identifying functional severity of the left main coronary artery (LM) stenosis determined by fractional flow reserve (FFR). METHODS AND RESULTS: 101 patients with LM lesion (20-70% diameter stenosis angiographically) underwent FFR measurement and FD-OCT imaging of the LM. The following parameters were measured by FD-OCT in the LM: reference lumen area (RLA), reference lumen diameter (RLD), minimum lumen area (MLA), minimum lumen diameter (MLD), % lumen area stenosis, and % diameter stenosis. The LM lesions were analyzable by FD-OCT in 88/101 (87.1%) patients. FFR at maximum hyperemia was ≤0.80 in 39/88 (44.3%) patients. FFR values were correlated significantly with FD-OCT-derived LM lumen parameters. An MLA cutoff value of 5.38 mm2 had the highest sensitivity and specificity of 82% and 81%, respectively, followed by an MLD of 2.43 mm (sensitivity 77%, specificity 72%) and AS of 60% (sensitivity 72%, specificity 72%) for predicting FFR <0.80. CONCLUSIONS: FD-OCT is a safe and feasible imaging technique for the assessment of LM stenosis. An FD-OCT-derived MLA of ≤5.38 mm2 strongly predicts the functional severity of an LM lesion.

Three-dimensional echocardiographic documentation of pacemaker lead perforation presenting as acute pericarditis.

Myocardial perforation is a rare complication of permanent pacemaker insertion and is usually detected during the first month after implantation. Pericardial effusion often occurs at the same time, and as a consequence may generate difficulties in the diagnostic workup due to the various aetiologies of its origin. Computed tomography has been used for the documentation of lead perforation, but its diagnostic accuracy in comparison to echocardiographic examination has not been validated. We report a case of ventricular perforation causing pericarditis, initially undetected by computed tomography, that was finally diagnosed by means of real-time three-dimensional echocardiography.

High power radiofrequency ablation of incessant atrioventricular re-entrant tachycardia in a patient with a Para-Hisian accessory pathway.

Radiofrequency ablation is the interventional therapy of choice for the definitive cure of patients with tachycardias facilitated by accessory pathways. Ablation of an accessory pathway at sites close to the His bundle is inevitably associated with an increased risk of causing complete atrioventricular block. Here we describe the case of a patient with pre-excitation syndrome and episodes of supraventricular tachycardia, in whom an electrophysiological study identified an accessory pathway so close to the His bundle that discrete sites between the pathway and the His bundle were extremely difficult to find. After a first, unsuccessful attempt at ablation the patient developed incessant supraventricular tachycardia. The accessory pathway was successfully ablated in a second session using high power radiofrequency current, although this entailed a great increase in the risk of causing complete atrioventricular block.