Introduction: Application of the chronic thromboembolic pulmonary hypertension (CTEPH) rule out criteria (manual electrocardiogram [ECG] reading and N-terminal pro-brain natriuretic peptide ... Show moreIntroduction: Application of the chronic thromboembolic pulmonary hypertension (CTEPH) rule out criteria (manual electrocardiogram [ECG] reading and N-terminal pro-brain natriuretic peptide [NTproBNP] test) can rule out CTEPH in pulmonary embolism (PE) patients with persistent dyspnea (InShape II algorithm). Increased pulmonary pressure may also be identified using automated ECG-derived ventricular gradient optimized for right ventricular pressure overload (VG-RVPO). Method: A predefined analysis of the InShape II study was performed. The diagnostic performance of the VG-RVPO for the detection of CTEPH and the incremental diagnostic value of the VG-RVPO as new rule-out criteria in the InShape II algorithm were evaluated. Results: 60 patients were included; 5 (8.3%) were ultimately diagnosed with CTEPH. The mean baseline VG-RVPO (at time of PE diagnosis) was -18.12 mV.ms for CTEPH patients and - 21.57 mV.ms for non-CTEPH patients (mean difference 3.46 mV.ms [95%CI -29.03 to 35.94]). The VG-RVPO (after 3-6 months follow-up) normalized in patients with and without CTEPH, without a clear between-group difference (mean Delta VG-RVPO of -8.68 and - 8.42 mV.ms respectively; mean difference of -0.25 mV.ms, [95%CI -12.94 to 12.44]). The overall predictive accuracy of baseline VG-RVPO, follow-up RVPO and Delta VG-RVPO for CTEPH was moderate to poor (ROC AUC 0.611, 0.514 and 0.539, respectively). Up to 76% of the required echocardiograms could have been avoided with VG-RVPO criteria replacing the InShape II rule-out criteria, however at cost of missing up to 80% of the CTEPH diagnoses. Conclusion: We could not demonstrate (additional) diagnostic value of VG-RVPO as standalone test or as on top of the InShape II algorithm. Show less
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... Show moreBackground: 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. Show less
This thesis provides insight in the impact of congenital and acquired heart diseases on electrophysiology and hemodynamics in the heart, that could help understand the often complex... Show moreThis thesis provides insight in the impact of congenital and acquired heart diseases on electrophysiology and hemodynamics in the heart, that could help understand the often complex pathophysiological mechanisms involved in cardiovascular diseases and might aid in the early detection of patients prone to cardiovascular deterioration. The first part of this thesis shows the value of the electrocardiogram and vectorcardiogram in the assessment of patients with right-sided acquired and congenital heart defects. The 3D vectorcardiographic VG and SA could be valuable in the assessment of patients with right ventricular volume or pressure overload. The second part of this thesis shows significant steps towards clinical utility of 4D flow MRI. Valvular flow quantification with 4D flow MRI, especially in combination with automated valve tracking, has great potential as a future clinical standard. The third part of this thesis provides important insights in intraventricular hemodynamics in Fontan patients. In time to come, knowledge on intraventricular hemodynamics could aid in determining follow-up frequency and the ideal timing of initiation of heart failure management, perhaps even on an individual patient’s level. Moreover, these findings can create a platform for further research in the field of intraventricular hemodynamics in healthy subjects and different patient groups. Show less
Awareness of the involvement of the right ventricle in both common and rare cardiovascular diseases has grown. Recent developments in echocardiography and electrocardiography have contributed... Show moreAwareness of the involvement of the right ventricle in both common and rare cardiovascular diseases has grown. Recent developments in echocardiography and electrocardiography have contributed to further insight into the pathophysiology of the right ventricle as well as its relation to the pulmonary circulation and the left ventricle. Because echocardiography is accessible, non-invasive, and inexpensive it is an ideal technique for the assessment of the right ventricle and can be used for screening patients at risk of right ventricular dysfunction as well as monitor therapeutic responses. Furthermore, advanced echocardiographic techniques such as 2-dimensional speckle-tracking imaging may add to a better understanding of right ventricular mechanics. Integrated application of echocardiographic and electrocardiographic techniques could provide further understanding into the different pathophysiological aspects of right ventricular function. These insights could be used to identify risk factors, prognostic factors and monitor response to therapy through serial assessment in patients at risk for right ventricular dysfunction and failure such as patients with pulmonary hypertension, heart failure and those undergoing cardiac surgery. Furthermore, a better understanding of the mechanisms that lead to right ventricular remodeling may aid to the development of right ventricular specific therapies that improve survival in patients with right ventricular dysfunction. Show less
