An annotation-independent algorithm based on electrogram characteristics to guide the identification of ventricular tachycardia isthmuses in patients with structural heart disease.

BACKGROUND: Criteria such as electrograms voltage or late potentials have been largely utilized in the past to help identify areas of substrate maps that are within the ventricular tachycardia (VT) isthmus; yet their specificity and positive predictive value are quite low. The Lumipoint fractionation tool of the Rhythmia system illuminates regions with fractionated electrograms irrespective of their timing and annotation. We aimed to ascertain whether the use of this tool can rapidly identify areas within VT isthmuses from substrate maps. METHODS: Thirty patients with structural cardiomyopathy in whom a complete right ventricular-paced substrate map and a full reconstruction of the diastolic isthmus during VT could be obtained were enrolled. The VT isthmus border was projected on each substrate map to verify whether the areas illuminated by Lumipoint fell within those borders. The behavior of the electrograms detected at the illuminated areas of the substrate maps was studied during a right ventricular drive train and extra stimulus protocol: if the near field potentials showed a delayed conduction after a single extra stimulus, defined as a minimum of 10 ms increase of the time interval between the far field and the near field activation measured during the drive train, the electrogram was said to have a "decremental" behavior. RESULTS: The logistic analysis showed that areas with fractionated electrograms illuminated by the Lumipoint software and showing the greatest decremental behavior fell within the VT isthmus borders (OR = 1.66, CI: 1.41-1.75, p<0.001; OR=1.57 CI: 1.32-1.72, p<0.001, respectively) with a sensitivity, specificity, and positive predictive value of 87%, 96%, and 97%, respectively. CONCLUSIONS: Fractionated electrograms illuminated by the automated Lumipoint software on right ventricular-paced substrate maps showing the greatest decremental behavior fall within the VT isthmus borders with a probability of 0.97, irrespective of their timing, annotation, or voltage, without any need for subjective assessment of their involvement in slow conduction areas.

Platelet inhibition with orodispersible ticagrelor in acute coronary syndromes according to morphine use: the TASTER study final results.

AIM: To date, it is still unknown whether orodispersible tablet (ODT) ticagrelor might represent a suitable way to reach a proper antiaggregation in acute coronary syndrome (ACS) patients receiving morphine. Aim of the present study was to evaluate platelet inhibition with 180 mg ticagrelor loading dose (LD) administered as ODT compared with standard coated tablet ticagrelor formulation in ACS patients undergoing percutaneous coronary intervention (PCI) according to morphine use. METHODS AND RESULTS: One-hundred and 30 patients presenting with STEMI or very high-risk NSTE-ACS were randomly assigned to receive ODT or standard ticagrelor LD. Potential morphine-ticagrelor interaction was assessed by stratified randomization according to morphine use. Platelet reactivity was evaluated by Platelet Reactivity Units (PRU) VerifyNow™ 1, 2, 4, and 6 h after ticagrelor LD. The primary endpoint was residual platelet reactivity 1 h after LD across the two ticagrelor formulation and according to morphine use. Safety endpoints were major bleedings and other in-hospital ticagrelor administration-related adverse events. One hour after LD, PRU median value was higher in morphine-treated patients (N = 32) as compared with patients not receiving morphine (N = 98; PRU = 187 [70-217]) vs. 73 [7-187]; P = 0.012). In patients with morphine, 1-h PRU values were similar between study groups (192 [114-236] vs. 173 [16-215] in ODT and standard tablet ticagrelor, respectively). Similarly, in patients without morphine, 1-h PRU values were not significantly different between study groups (69 [8-152] vs. 110 [6-193] in ODT and standard tablet ticagrelor, respectively). Platelet reactivity appeared similar in the 2 study arms at 2, 4, and 6 h after LD. No significant difference was observed among patients with or without morphine regarding in-hospital adverse events or drug side-effects, even if a reinfarction due to acute stent thrombosis was observed in a patient treated with morphine. CONCLUSIONS: There was no difference between ODT and standard ticagrelor tablets in terms of post-LD residual platelet reactivity, percentage of platelet inhibition or safety regardless to morphine use.

Outcomes of single­lead VDD pacemakers in atrioventricular blocks: The OSCAR study.

BACKGROUND: VDD pacemakers are regarded as a second choice in patients with atrio-ventricular blocks mainly due to the potential failure of atrial sensing, leading to a loss of atrio-ventricular synchrony. This single-centre study aimed to evaluate the prevalence of loss of atrial sensing and its potential determinants in patients with VDD pacemakers. METHOD: 142 patients with an implanted VDD device underwent long-term follow-up with clinical evaluation, electrocardiogram, device interrogation and echocardiogram. RESULTS: Over a long follow-up period [median 110 (68-156) months], 17 patients (12%) in sinus rhythm presented loss of atrial sensing. This was most often intermittent, but three patients required a permanent switch to VVI mode. ECG showed higher prevalence of interatrial blocks (50% vs 26.6%, p = 0.057) and longer P wave duration (116 ± 19 vs 105 ± 15 ms, p = 0.019) in patients with loss of atrial sensing. Echocardiography revealed larger left atrial (LA) volumes (p < 0.05) in patients with loss of atrial sensing, and lower LA ejection fraction (0.40 vs 0.47, p = 0.0037) and expansion index (0.63 ± 0.26 vs 0.90 ± 0.31, p = 0.003). P wave duration on ECG proved to be independently associated with loss of atrial sensing on multivariable analysis (OR 1.062, 95% CI 1.015-1.110; p = 0.008). The prevalence of atrial fibrillation and subsequent switch to VVI mode was high (16%). CONCLUSIONS: In the long-term follow-up, the loss of atrial sensing is present in 12% of patients with implanted VDD pacemakers. ECG and echocardiographic parameters may serve as screening tools for the detection of atrial myopathy which is associated with the loss of atrial sensing.