First experience with a vendor-neutral three-dimensional mapping system for cardiac magnetic resonance-guided electrophysiological procedures: a case report.

Background: Fluoroscopy-guided catheter ablation has become the gold standard for treatment of cardiac arrhythmias. High resolution electro-anatomical mapping systems have become fundamental to perform these procedures. Recently, interventional cardiac magnetic resonance (iCMR) has been proposed as an alternative for fluoroscopy to guide atrial flutter ablations. The clinical experience with iCMR and dedicated three-dimensional mapping systems is growing. NorthStar is currently the first available vendor-neutral mapping system. Case summary: We performed a real-time CMR-guided cavotricuspid isthmus (CTI) catheter ablation (CA) on a 69-year-old man using a novel mapping system (NorthStar Mapping System, Imricor Medical Systems, MN, USA). Starting from the CMR imaging, a pre-rendered segmentation model was loaded on NorthStar and used to guide the catheters, display voltage and activation maps, show mapping and ablation points. NorthStar can also take full control of the CMR scanner (i.e. start/stop sequences for anatomical information, tissue characterization, and catheter visualization) and communicate with the recorder/stimulator system (Advantage-MR EP, Imricor Medical Systems, MN, USA). With comparable procedural time to standard fluoroscopy-guided CA, CTI bidirectional block was achieved, without any complication. Discussion: Using the NorthStar Mapping System, we managed to achieve a successful CMR-guided CTI ablation without any complication. Its further use should be explored, especially in more complex arrhythmias where a substrate-guided ablation is critical, as it could significantly improve results in terms of arrhythmia recurrence.

Proning the extracorporeal membrane oxygenation plus Impella: a case report.

Background: The prone position is recommended as supportive therapy in patients with moderate-to-severe acute respiratory distress syndrome (ARDS). However, little is known about prone position ventilation in patients with cardiogenic shock supported by extracorporeal membrane oxygenation (ECMO) plus Impella (ECPELLA) developing ARDS. Case summary: A 66-year-old man with severe left ventricular dysfunction was admitted to a non-academic ECMO centre for a high-risk coronary artery bypass grafting. He developed post-cardiotomy shock needing ECMO support. To improve left ventricular unloading, an Impella was inserted 2 days later. One day later, he developed ARDS and needed prone position ventilation with ECPELLA in situ. After 4 weeks, he was discharged from the intensive care unit. Discussion: Previous studies demonstrated that prone positioning could help avoid an additional venous cannula in veno-arterial ECMO patients, which is associated with mechanical complications. In this case, there was a promising role for unloading the left ventricle with Impella during veno-arterial ECMO and, for proning, the patient with cardiogenic shock developing ARDS during ECMO support without the need for an extra venous cannula.

Right Ventricular Dysfunction in Patients With Concomitant Tricuspid Regurgitation Undergoing Transcatheter Aortic Valve Implantation.

BACKGROUND: This study investigated the impact and predictive factors of concomitant significant tricuspid regurgitation (TR) and evaluated the roles of right ventricle (RV) function and the etiology of TR in the clinical outcomes of patients with severe aortic stenosis undergoing transcatheter aortic valve implantation (TAVI).Methods and Results: We assessed grading of TR severity, TR etiology, and RV function in pre- and post-TAVI transthoracic echocardiograms for 678 patients at Keio University School of Medicine. TR etiology was divided into 3 groups: primary TR, ventricular functional TR (FTR), and atrial FTR. The primary outcomes were all-cause and cardiovascular death. At baseline, moderate or greater TR was found in 55 (8%) patients and, after adjustment for comorbidities, was associated with increased all-cause death (hazard ratio [HR] 2.11; 95% confidence interval [CI] 1.19-3.77; P=0.011) and cardiovascular death (HR 2.29; 95% CI 1.06-4.99; P=0.036). RV dysfunction (RVD) also remained an independent predictor of cardiovascular death (HR 2.06; 95% CI 1.03-4.14; P=0.042). Among the TR etiology groups, patients with ventricular FTR had the lowest survival rate (P<0.001). Patients with persistent RVD after TAVI had a higher risk of cardiovascular death than those with a normal or recovered RV function (P<0.001). CONCLUSIONS: The etiology of TR and RV function play an important role in predicting outcomes in concomitant TR patients undergoing TAVI.

The Predictive Power of the 14-51 Ng/L High Sensitive Troponin T (hsTnT) Values for Predicting Cardiac Revascularization in a Clinical Setting.

Background: high sensitive Troponin T (hsTnT) values between 14−50 ng/L represent a challenge in diagnosing acute coronary syndrome (ACS) at the Emergency Department (ED). The European Society for Cardiology (ESC) recommends a second hsTnT measurement 3 h later to distinguish between ACS and other causes depending on the Δ hsTnT. Our study aims to evaluate the predictive power this approach in a clinical setting by following patients presenting at the ED with hsTnT values 14−51 ng/L. Materials and methods: patients presenting with chest pain or dyspnea and a hsTnT value between 14 and 50 ng/L at the Erasmus MC ED in 2012−2013 were included and retrospectively monitored for 90 days after initial presentation for the occurrence of a cardiac revascularization. Patient records were reviewed according to the standing protocol, which depended on the Δ hsTnT. The "event-group" consists of patients receiving cardiac revascularization within 90 days after the ED visit, whereas the "no event-group" consisted of patients without revascularization. Results: a total of 889 patients patient records were reviewed. After excluding out-of-hospital-cardia-arrests (60), non-cardiological chest pain (373) and incomplete follow-up (100), 356 patients remained for final analysis. In 207 patients, a second hsTnT was actually performed (58%). From these 207 patients, 68 (33%) had a Δ hsTnT ≥7 ng/L. In these patients, 37 (54%) experienced an event within 90 days. In the 139 patients with a Δ hsTnT < 7 ng/L, 23 (17%) presented with an event within 90 days. Conclusion: our study demonstrated a sensitivity of 62%, a specificity of 79%, a positive predicted value (PPV) of 54% and a negative predictive value (NPV) of 83% for using a 3-h Δ hsTnT ≥7 ng/L cut-off, related to risk of an event in 90 days following ED presentation.

Appropriate device selection for transcatheter atrial septal defect closure using three-dimensional transesophageal echocardiography.

Detail morphological evaluation for ASD is essential to achieve successful transcatheter closure. Three-dimensional transesophageal echocardiography (3D-TEE) is emerging, but few studies have comprehensively verified the usefulness of 3D-TEE. We divided 329 patients who underwent transcatheter ASD closure at our university hospital into 157 in the Conventional group evaluated with 2-dimensional transesophageal echocardiography and balloon sizing (BS), and 172 in the 3D-TEE group evaluated with 3D-TEE additionally. We assessed usefulness of 3D-TEE and consider appropriate device selection procedure. Overall, the percentage with re-sizing of device tended to be lower in the 3D-TEE group than in the Conventional group (10.1% vs 6.0%, p = 0.187). Among preprocedural modalities, the device size was mainly decided based on the BS diameter. A logistic regression analysis demonstrated that large atrial septum aneurysms (ASA) were associated with a ≥ 2 mm discrepancy of the BS diameter from the preprocedural 3D-TEE diameter (p < 0.05). Compared to the Amplatzer Septal Occluder, the differences in device size and the preprocedural ASD measurement were greater when using the Occlutech Figulla Flex II Occluder (FFII). Particularly, among the patients implanted with FFIIs, the discrepancies of the device size from the 3D-TEE measurement were greater in patients with large ASA than those with small ASA. Preprocedural 3D-TEE is useful to select the appropriate device size. Particularly, it is necessary to select a much larger device than that derived from the preprocedural 3D-TEE measurement when using FFII in patients with a septal aneurysm.

Serial electrocardiography to detect newly emerging or aggravating cardiac pathology: a deep-learning approach.

BACKGROUND: Serial electrocardiography aims to contribute to electrocardiogram (ECG) diagnosis by comparing the ECG under consideration with a previously made ECG in the same individual. Here, we present a novel algorithm to construct dedicated deep-learning neural networks (NNs) that are specialized in detecting newly emerging or aggravating existing cardiac pathology in serial ECGs. METHODS: We developed a novel deep-learning method for serial ECG analysis and tested its performance in detection of heart failure in post-infarction patients, and in the detection of ischemia in patients who underwent elective percutaneous coronary intervention. Core of the method is the repeated structuring and learning procedure that, when fed with 13 serial ECG difference features (intra-individual differences in: QRS duration; QT interval; QRS maximum; T-wave maximum; QRS integral; T-wave integral; QRS complexity; T-wave complexity; ventricular gradient; QRS-T spatial angle; heart rate; J-point amplitude; and T-wave symmetry), dynamically creates a NN of at most three hidden layers. An optimization process reduces the possibility of obtaining an inefficient NN due to adverse initialization. RESULTS: Application of our method to the two clinical ECG databases yielded 3-layer NN architectures, both showing high testing performances (areas under the receiver operating curves were 84% and 83%, respectively). CONCLUSIONS: Our method was successful in two different clinical serial ECG applications. Further studies will investigate if other problem-specific NNs can successfully be constructed, and even if it will be possible to construct a universal NN to detect any pathologic ECG change.

Position of ST-deviation measurements relative to the J-point: Impact for ischemia detection.

BACKGROUND: There is no consensus about the time instant relative to the J point where ST deviation has to be measured for detection of acute ischemia in the ECG. METHODS: We analyzed 53 ECGs, recorded preceding emergency catheterization of acute coronary syndrome patients with a completely occluded culprit artery (cases), and 88 control ECGs recorded in the cardiology outpatient clinic. ECG-amplitude measurements were made every 10 ms, between 20 ms before till 80 ms after the J point. STEMI-detection algorithms varied from the traditional STEMI criterion (elevations in at least two adjacent ECG leads), via the STEMI equivalent criterion (depressions in V2 and V3), to the most liberal STEMI-detection algorithm in which elevations as well as depressions in two adjacent leads were considered as signs of ischemia. RESULTS: Diagnostic accuracy was highest (93.6%) for the most liberal STEMI-detection algorithm at 10 ms after the J point; sensitivity was 94.3% and specificity was 93.2%. CONCLUSION: The results of our study suggest that STEMI detection close to the J point is optimal.

Performance of ST and ventricular gradient difference vectors in electrocardiographic detection of acute myocardial ischemia.

INTRODUCTION: Serial analysis could improve ECG diagnosis of myocardial ischemia caused by acute coronary occlusion. METHODS: We analyzed ECG pairs of 84 cases and 398 controls. In case-patients, who underwent elective percutaneous coronary intervention, ischemic ECGs during balloon occlusion were compared with preceding non-ischemic ECGs. In control-patients, two elective non-ischemic ECGs were compared. In each ECG the ST vector at the J point and the ventricular gradient (VG) vector was computed, after which difference vectors ΔST and ΔVG were computed within patients. Finally, receiver operating characteristic analysis was done. RESULTS: Areas under the curve were 0.906 (P<0.001; CI 0.862-0.949; SE 0.022) for ΔST and 0.880 (P<0.001; CI 0.833-0.926; SE 0.024) for ΔVG. Sensitivity and specificity of conventional ST-elevation myocardial infarction (STEMI) criteria were 70.2% and 89.1%, respectively. At matched serial analysis specificity and STEMI specificity, serial analysis sensitivity was 78.6% for ΔST and 71.4% for ΔVG (not significantly different from STEMI sensitivity). At matched serial analysis sensitivity and STEMI sensitivity, serial analysis specificity was 96.5% for ΔST and 89.3% for ΔVG; ΔST and STEMI specificities differed significantly (P<0.001). CONCLUSION: Detection of acute myocardial ischemia by serial ECG analysis of ST and VG vectors has equal or even superior performance than the STEMI criteria. This concept should be further evaluated in triage ECGs of patients suspected from having acute myocardial ischemia.

Intra-individual ECG changes over 25 years: How long can elective ECGs be used as reference for acute ischemia detection?

BACKGROUND: The guidelines advocate, in patients with chest pain, comparison of the acute ECG with a previously made, non-ischemic ECG that serves as a reference, to corroborate the working diagnosis of acute coronary syndrome (ACS). Our approach of this serial comparison is to compute the differences between the ST vectors at the J point and 60 ms thereafter (∆ST(J+0), ∆ST(J+60)) and between the ventricular gradient (VG) vectors (∆VG). In the current study, we investigate if reference ECGs remain valid in time. METHODS: We studied 6 elective non-ischemic ECGs (ECG0, ECG1, …, ECG5), 5 years apart, in 88 patients. Within each patient, serial comparisons were done 1) between all successive ECGs, and 2) between each of ECG1, ECG2, …, ECG5 and ECG0, computing, in addition to ∆ST(J+0), ∆ST(J+60) and ∆VG, the difference in heart rates, ∆HR. Additionally, relevant clinical events and the diagnoses associated with each ECG were collected. Linear regression was used to assess trends in ∆ST(J+0), ∆ST(J+60) and ∆VG; multiple linear regression was used to assess the influence of the clinical events and diagnoses on ∆ST(J+0), ∆ST(J+60) and ∆VG. RESULTS: There were no trends in the differences between successive ECGs. Positive trends were seen with increasing time lapses between ECGs: ∆ST(J+0), ∆ST(J+60) and ∆VG increased per year by 0.65 µV, 1.45 µV and 3.69 mV∙ms, respectively. Extrapolation to a time lapse of 0 yielded 50.92 µV, 36.63 µV and 20.91 mV∙ms for the short-term reproducibility of ∆ST(J+0), ∆ST(J+60) and ∆VG, respectively. Multiple linear regression revealed that clinical variables could explain only 10%, 17% and 13% of the variability in ∆ST(J+0), ∆ST(J+60) and ∆VG, respectively. CONCLUSION: With a view on ischemia detection thresholds in the order of magnitude of 58 µV for ∆ST and 26 mV·ms for ∆VG, our study suggests that it is important to have a recent ECG available for the detection of myocardial ischemia, as an "aged" ECG may have lost its validity as a reference.