2:1 electronic AV block due to inappropriate automatic post­ventricular atrial refractory period extension.

A 16-year-old female with dual-chamber pacemaker (Medtronic Azure XT DR), due to symptomatic third-degree congenital atrioventricular (AV) block, presented to our ambulatory with dizziness and presyncopal episodes preceded by prodromes, occurring over the last few months. The device was programmed in DDD mode with an upper rate of 150 bpm. A head-up Tilt Test (HUTT) revealed the unexpected emergence of 2:1 electronic AV block at a sinus rate of 130 bpm.

Late acquired coronary aneurysm and restenosis after bioresorbable vascular scaffold implantation: a case report.

Background: Although the technology of bioresorbable vascular scaffold (BVS) aroused the peak of interest a few years ago and currently remains available only as part of experimental research, patients who have had BVS implanted should be still carefully monitored to detect possible long-term complications. Case summary: We present the case of a 47-year-old man who had received BVS implantation for ST-segment elevation myocardial infarction. Six years later, computed tomography coronary angiography (CTCA) demonstrated in-segment restenosis in between two newly formed coronary aneurysms at the site of the implanted BVS. The patient received successful optical coherence tomography-guided percutaneous intervention with a new metallic drug-eluting stent implantation. Discussion: Our case demonstrates that coronary aneurysms can be well characterized with CTCA and are often incidentally discovered as they cause no symptoms. The incidence of coronary aneurysm at the site of a previously implanted BVS is not defined, and little is known about the pathophysiology and evolution of these lesions. Therefore, the decision to proceed with conservative management or intervention must be tailored to the clinical conditions of the patient, the anatomy, the rapidity of growth, and the possible thrombotic burden.

Monotherapy with P2Y12-inhibitors after dual antiplatelet therapy: Filling gaps in evidence.

BACKGROUND: Whether P2Y12 inhibitor monotherapy (P2Y12-I) is superior to aspirin following DAPT discontinuation post-PCI remains to be established. METHODS: We updated our prior network meta-analysis where P2Y12-I and aspirin had been compared with DAPT or directly with each other. The focus is specifically on the available direct evidence, now consisting of the three head-to-head comparisons of P2Y12-I and aspirin in event-free PCI patients after DAPT. We include a Trial Sequential Analysis of the direct evidence based on meta-analytical literature. RESULTS: The main finding reveals a 39% significantly lower risk of myocardial infarction with P2Y12-I (RR 0.61, 95% CI 0.47-0.78, p = 0.0001, I2 = 0%) with no difference in bleeding. Trial Sequential Analysis demonstrates clinically meaningful evidence for a reduction in the incidence of myocardial infarction with P2Y12-I that is also supported by statistical significance. CONCLUSIONS: Accruing data highlight that P2Y12-I following DAPT discontinuation after PCI is associated with lower risk for MI and a similar risk for bleeding as compared with ASA. In light of potential limitations to the widespread adoption of life-long P2Y12-I treatment, clinicians should consider identifying selected patients who are expected to derive the highest benefit.

Improved Coronary Artery Visualization Using Virtual Monoenergetic Imaging from Dual-Layer Spectral Detector CT Angiography.

Background: To evaluate if coronary CT angiography (CCTA) monoenergetic reconstructions, obtained with a dual-layer spectral detector computed tomography (DLCT) system, offer improved image quality compared with 120 kVp conventional images without affecting the quantitative assessment of coronary stenoses. Methods: Fifty CCTA datasets (30 men; mean age: 61.6 ± 12.3 years) acquired with a DLCT system were reconstructed using virtual monoenergetic images (VMI) from 40 to 100 keV with 10 keV increment and compared with conventional images. An analysis of objective image quality was performed, evaluating the signal- and contrast-to-noise ratio. For the subjective assessment, two readers used a 5-point Likert scoring system to evaluate sharpness, noise, demarcation of coronary plaques, vascular contrast, and an overall score. Furthermore, coronary stenoses were analyzed for each vessel to describe the diagnostic agreement between monoenergetic images and conventional images. Results: The objective image analysis showed that all reconstructions from 70 keV to 40 keV show higher SNR (from 61.33 ± 12.46 to 154.22 ± 42.91, respectively) and CNR (from 51.45 ± 11.19 to 135.63 ± 39.38, respectively) compared with conventional images (all p < 0.001). The 40 keV monoenergetic images obtained the best average score for sharpness, vascular contrast, and for the overall impression (all with p < 0.001). The detection and grading of stenoses of the coronary arteries with conventional and monoenergetic images at 70 keV and 40 keV showed an overall excellent interobserver agreement (k= 0.81 [0.72-0.91]). Conclusions: The 40 keV virtual monoenergetic images obtained with a DLCT system allow the objective and subjective image quality of coronary CT angiography to be improved.

Coronary angiography using spectral detector dual-energy CT: is it the time to assess myocardial first-pass perfusion?

Coronary computed tomography angiography (CCTA) represents a common approach to the diagnostic workup of patients with suspected coronary artery disease. Technological development has recently allowed the integration of conventional CCTA information with spectral data. Spectral CCTA used in clinical routine may allow for improving CCTA diagnostic performance by measuring myocardial iodine distribution as a marker of first-pass perfusion, thus providing additional functional information about coronary artery disease.