Evaluation of platelet reactivity using P2Y12 reaction units in acute coronary syndrome with essential thrombocythemia: A case report

AbstractEssential thrombocythemia (ET) has been reported to cause acute coronary disease. However, the efficacy of anti-platelet therapy for ET is unclear since there are individual differences in the platelet function of ET patients. Here we report a case of a 62-year-old man with ET who was admitted to our hospital because of acute coronary syndrome. He underwent coronary angioplasty. Dual anti-platelet therapy with aspirin (81mg/day) and clopidogrel (75mg/day) was subsequently initiated. We evaluated platelet reactivity in P2Y12 reaction units, and subsequently determined anti-platelet drugs and corresponding doses.<Learning objective: Essential thrombocythemia (ET) is a myeloproliferative disorder that causes acute coronary disease. As there are individual differences in the platelet function of patients with ET, the efficacy of anti-platelet therapy for these patients varies. Evaluation of platelet reactivity using P2Y12 reaction units is useful in determining appropriate anti-platelet drugs and corresponding doses.

Anatomical consideration for safe pericardiocentesis assessed by three-dimensional computed tomography: Should an anterior or posterior approach be used?

AbstractBackgroundThe efficacy of epicardial catheter ablation for ventricular tachycardia has been reported. However, the safest anatomical method for pericardial puncture has not been determined.MethodsThirty patients who underwent 3-dimensional computed tomography (3D-CT) preceding catheter ablations for atrial fibrillation were enrolled in this study. We used the skin surface 1cm below the xiphisternum as the puncture site. For the anterior approach, the attainment site was the pericardium of the mid portion of right ventricular anterior site, and for the posterior approach it was the pericardium of the inferior ventricular site. The distance and the angle between the 2 sites were measured using 3D-CT.ResultsFor the anterior approach, the distance was 54±11mm and the needle angle was 37±11° toward the left scapula and 34±12° towards the back of the body. For the posterior approach, the distance was 56±10mm and the corresponding needle angles were 60±9° and 86±13°. The distance correlated with BMI for the anterior and posterior approaches (anterior approach: r2=0.43, P<0.001; posterior approach: r2=0.49, P<0.001). Liver existed along the pathway of the posterior approach in 11 (37%) of 30 patients, and through in 2 (18%) of 11 patients. The liver and lung were not located along the pathway of the anterior approach in any patients.ConclusionsPerforming subxiphoid pericardiocentesis is anatomically safer via the anterior approach than via the posterior approach

Intra-cardiac echocardiography guided catheter ablation of a right posterior accessory pathway in a patient with Ebstein׳s anomaly

AbstractWe report a case of Ebstein׳s anomaly in which radiofrequency catheter ablation of an accessory pathway was successfully performed under intra-cardiac echocardiography. A 50-year-old woman was referred to our hospital for radiofrequency catheter ablation of a paroxysmal supraventricular tachycardia. A 12-lead surface electrocardiogram revealed ventricular pre-excitation associated with type B Wolff–Parkinson–White syndrome. In the baseline electrophysiological study, an orthodromic atrioventricular reciprocating tachycardia with a right posterior accessory pathway was induced. A phased-array intra-cardiac echo probe was positioned in the right atrium to visualize the atrioventricular junction. The key structures for catheter ablation, such as the atrialized right ventricle, atrioventricular junction, and tricuspid valve, were clearly visualized on intra-cardiac echocardiography. Radiofrequency current was successfully delivered at the atrioventricular junction, where a Kent potential was recorded. During a 6-month follow-up period, the patient was free from arrhythmias. The findings in this case suggest that phased-array intra-cardiac echocardiography is useful for ablation of right-sided accessory pathways in patients with Ebstein׳s anomaly

Topographic variability of the left atrium and pulmonary veins assessed by 3D-CT predicts the recurrence of atrial fibrillation after catheter ablation

AbstractBackgroundCatheter ablation (CA) is an established therapy for atrial fibrillation (AF). However, the assessment of anatomical information and predictors of AF recurrence remain unclear. We investigated the relationship between anatomical information on the left atrium (LA) and pulmonary veins (PVs) from three-dimensional computed tomography images and the recurrence of AF after CA.MethodsSixty-seven consecutive AF patients (mean age: 62±10 years, median AF history: 42 (12; 60) months, mean LA size: 41±7mm, paroxysmal: 56%) underwent CA and were followed for 19±10 months. The segmented surface areas (antral, posterior, septal, and lateral) and dimensions (between the anterior and posterior walls, the right inferior PV and mitral annulus [MA], the right superior PV and MA, the left superior PV and MA, and the mitral isthmus) of the LA were evaluated three dimensionally using the NavX system. The cross-sectional areas of the PVs were also evaluated.ResultsAfter the follow-up period, 49 patients (73%) remained free from AF. A multivariate analysis showed that the diameter of the mitral isthmus and cross-sectional area of the right upper PV were associated with AF recurrence (odds ratio: 1.070, CI: 1.02–1.12, p=0.001; odds ratio: 0.41, CI: 0.21–0.77, p=0.006).ConclusionEnlargement of the mitral isthmus and a smaller right superior PV cross-sectional area were associated with AF recurrence

Left atrial anomalous muscular band detected by computed tomography before catheter ablation in a patient with atrial fibrillation

A 65-year-old man was referred to our hospital with persistent atrial fibrillation (AF). Before the ablation procedure, 3-dimensional computed tomography revealed a left atrial anomalous muscular band connecting the posterior side of the left atrial roof and the right edge of the fossa ovalis. During the first ablation procedure, the band interfered with the manipulation of the catheter, resulting in only the left pulmonary vein (PV) being isolated. However, AF recurred. During the second procedure, careful catheter manipulation permitted complete right PV isolation, after which, the patient has not had AF recurrence for more than 3 years

Regional wall motion abnormality at the lateral wall disturbs correlations between tissue Doppler E/e′ ratios and left ventricular diastolic performance parameters measured by invasive methods

BACKGROUND: The impact of regional wall motion abnormality (RWMA) on the accuracy of heart failure with preserved ejection fraction (HFpEF) diagnosis using the E/e′ ratio, which is a non-invasive parameter of left ventricular diastolic performance, is unknown. The purpose of this study was to elucidate the impact of RWMA of the lateral wall (RWMAlat) on the correlation between E/e′ and invasive parameters of left ventricular diastolic performance. METHODS: Three hundred and eight consecutive patients undergoing tissue Doppler imaging and catheterization pressure examination were retrospectively analyzed. E/e′ was calculated as the ratio of early diastolic transmitral flow velocity to mitral annular velocity at the lateral wall. Invasive parameters including left ventricular end-diastolic pressure (LVEDP) and isovolumetric relaxation time constant (τ) were assessed based on the left ventricular pressure study. Correlation coefficients between E/e′ and these invasive parameters were analyzed and compared between cases with RWMAlat and without RWMA. RESULTS: LVEDP and τ correlated well with E/e′ for all 308 patients (r = 0.51 and r = 0.65, respectively). Sixty-two patients had RWMA; the remaining 246 did not have RWMAlat. We confirmed that the presence of RWMAlat weakens both the correlations between E/e′ and LVEDP (r = 0.574 vs. r = 0.381), and E/e′ and τ (r = 0.729 vs. r = 0.461). CONCLUSIONS: Although E/e′ correlates well with parameters of left ventricular diastolic performance assessed by invasive methods, the presence of RWMAlat worsens this correlation. In cases with RWMAlat, careful assessment is required for HFpEF diagnosis because the diagnostic value of the E/e′ ratio could be decreased compared to patients without RWMAlat

Endocardial Substrate Mapping for Monomorphic Ventricular Tachycardia Ablation in Ischemic and Non-Ischemic Cardiomyopathy

We investigated the differences in the endocardial substrates between ischemiccardiomyopathy (ICM) and non-ICM (NICM) by using electro-anatomical mappingand pace-mapping. We studied 18 patients (ICM and NICM, 9 each) withmonomorphic ventricular tachycardia (VT) documented by 12-leads ECG. Low voltagearea was defined by signal amplitude 10 of the 12-leads ECG was regarded as a pace-map match. Andconduction delay during pace-mapping was defined as the stimulus to QRS interval &#8805;40ms. Low voltage area was 53.8 ± 21.5 and 20.8 ± 16.7 cm2 in ICM and NICM patients,respectively (P = 0.002). Pace-mapping was assessed in 6 ICM and 9 NICM. Pace-mapmatch with conduction delay were obtained in all the 6 ICM patients. But in NICMpatients, pace-map match with conduction delay was obtained in 3 patients. Pace-mapmatch sites where conduction delay was not observed were obtained in 5 patients.Pace-map match could not be obtained in 1 patient. We attempted ablation in 6 ICMand 7 NICM patients. Subsequently, VT recurrence was not observed in ICM but itwas observed in 6 of 7 NICM patients (log-rank P = 0.0016). In NICM patients, thearrhythmogenic substrate that represented the abnormal electrogram and conductiondelay was observed less within the endocardial surface when compared with thatobserved in ICM. VT recurrence rate subsequent to endocardial ablation was higher inNICM than in ICM patients