Cardiac signals and the interference of reward on attention and inhibitory control

Interoceptive responses can act as potent cues to cognition and behavior; discrete cardiac signals can shape emotional and motivational adaptation towards reward-related cues, but also affect response inhibition. Novel addiction perspectives posit an interoceptive basis for the interplay between reward processing and inhibitory control, but there is a lack of behavioral evidence for this relationship. In this registered report we extend on previous findings to examine how reward cues interact with cardiac-facilitated attention and motor inhibition. Across two sessions, a sample of 35 social drinkers will complete a visual search task (VST) and two instances of a stop signal task (SST). In each task, alcohol or neutral cues will be presented as targets or distractors respectively. In the VST, target stimuli will be presented synchronized with participants’ cardiac phase (systole vs. diastole), examining how cardiac signals support alcohol attentional biases. In a modified SST, Go cues will appear synchronized with cardiac phase while alcohol or neutral cues appear as distractors, examining how cardiac signals increase reward interference in inhibitory control. Finally, in another instance of the SST, Stop signals will appear synchronized with cardiac phase, examining whether interoceptive signals can improve inhibitory control in the presence of reward cues. We hypothesize, at systole, higher attentional biases and interference in inhibitory control for alcohol cues, and that Stop signals can facilitate response inhibition. These results can provide evidence for the role of cardiac signaling in alcohol attentional biases and inhibitory control, extending our understanding of the interoceptive components of addiction.

Choosing the Adaptive Cardiac Phase for Assessing Cardiac Dimensions Using Cardiac Computed Tomography for Heart Disease

Background Choosing a suitable cardiac cycle to measure cardiac chamber dimensions and wall thickness can be a more accurate assessment of cardiovascular disease. Methods Cardiac CT was performed on 137 patients for suspected coronary disease. The parameters of left atrium (LA), left ventricle (LV), right atrium (RA), and right ventricle (RV), as well as the wall thickness of LV were measured in different cardiac phases. The general linear mixed model was used to analyze differences in different phases and the correlation between these parameters and traditional risk factors. ROC analysis was performed to estimate LA enlargement. Results The dimensions of LA, RA, and LV wall thickness achieved the maximum at the phase of 35–45%, and those of LV and RV, at 95–5%. Whereas, the changes of LA-B (antero-posterior diameter), LV-D1 (basal dimension), RA-B (minor dimension) and RV-D2 (mid cavity dimension) were relatively more stable during the cardiac cycle. The maximum LA-B diameter(95%CI 36.92,38.48mm), LV-D1 diameter(95%CI 44.36,45.83mm), RA-B diameter(95%CI 48.75,50.61mm), and RV-D2 diameter(95%CI 30.83,32.84mm) and the maximum interventricular septum thickness( 95%CI 10.79,11.51mm) was acquired. Heart rate (HR) and smoking were potential indicators of LVD2 (mid cavity dimension), while HR and LV myocardial mass were potential indicators of LVD3 (apical-basal dimension). In phase 45%, the cut-off value of LA-B was 37.12mm has high sensitivity of 90.9% for predicting LA enlargement. Conclusion Cardiac chamber dimensions and wall thickness vary with the cardiac phase. Choosing the adaptive cardiac phase for evaluating these parameters obtained by cardiac CT could provide a more accurate clinical measurement. Trial registration retrospectively registered.

Assessment of thoracic aorta in different cardiac phases in patients with non-aorta diseases using cardiac CT

The aim was to evaluate the thoracic aorta in different cardiac phases to obtain the correct cardiac phase for measuring the maximum diameter required to predict aortic disease. Cardiac CT was performed on 97 patients for suspected coronary artery disease. The average diameter of ascending (AAD) and descending aorta (DAD) in the plane of pulmonary bifurcation, in the plane of the sinus junction (AAD [STJ] and DAD [STJ]), descending aorta in the plane of the diaphragm (DAD [Dia]), the diameter of the main pulmonary artery (MPAD), distance from the sternum to the spine (S-SD), and distance from the sternum to the ascending aorta (S-AAD) were assessed at 20 different time points in the cardiac cycle. Differences in aortic diameter in different cardiac phases and the correlation between aortic diameter and traditional risk factors were analyzed by the general linear mixed model. The diameter of the thoracic aorta reached the minimum at the phase of 95–0%, and reached the maximum at 30–35%. The maximum values of AAD, AAD (STJ), DAD, DAD (STJ), and DAD (Dia) were 32.51 ± 3.35 mm, 28.86 ± 3.01 mm, 23.46 ± 2.88 mm, 21.85 ± 2.58 mm, and 21.09 ± 2.66 mm, respectively. The maximum values of MPAD/AAD and DAD/AAD (STJ) were 0.8140 ± 0.1029, 0.7623 ± 0.0799, respectively. The diameter of the thoracic aorta varies with the cardiac phase. Analyzing the changes in aortic diameter, which can be done using cardiac CT, could provide a more accurate clinical measurement for predicting aortic disease.

Influence of cardiac phase on myocardial native T1 values by a segmental approach

Funding Acknowledgements Type of funding sources: None. Background. Native T1 values are usually assessed in the end-diastole to minimize motion artifacts while the systolic data acquisition offers the advantage of a thicker myocardium, with reduced partial-volume effects. Higher myocardial T1 values have been detected in diastole at both 1.5T and 3T but the dependence of this difference on myocardial segments or gender has not been fully explored. Aim. We provided a systematic comparison of myocardial native T1 values in diastole and systole, by considering separately myocardial segments and dividing males and females. Methods. Sixty-one healthy subjects (46.0 ± 14.1 years, 32 males) underwent CMR at 1.5T (Signa Artist; GE Healthcare). Three short-axis slices of the left ventricle acquired in diastole and systole using a Modified Look–Locker Inversion Recovery sequence. Image analysis was performed with a commercially available software package. T1 value was assessed in all 16 myocardial segments and global value was the mean. Results. Table 1 shows the comparison between T1 values calculated from maps obtained in diastole and systole. Systolic T1 values were significantly lower in the basal anterolateral segment, in all medium segments except for the medium inferior segment, and in all apical segments. The percentage difference between diastolic and systolic T1 values was considered to compensate for the higher T1 values in females, and a significantly higher value was detected in females for the majority of medium segments, for all apical segments, and for the global value. Conclusion. The diastolic-systolic discrepancy was more pronounced for the females and at the apical level, supporting the hypothesis that, besides the physiologic variations in myocardial blood volume during the cardiac cycle, the partial volume-effect may be a strong additional contributing factor. Native T1 values should be obtained always in the same cardiac phase to avoid a potential bias in the discrimination between healthy and pathologically affected myocardium.

Cardiac Phase Space Analysis: Assessing Coronary Artery Disease Utilizing Artificial Intelligence

The bridge of artificial intelligence to cardiovascular medicine has opened up new avenues for novel diagnostics that may significantly enhance the cardiology care pathway. Cardiac phase space analysis is a noninvasive diagnostic platform that combines advanced disciplines of mathematics and physics with machine learning. Thoracic orthogonal voltage gradient (OVG) signals from an individual are evaluated by cardiac phase space analysis to quantify physiological and mathematical features associated with coronary stenosis. The analysis is performed at the point of care without the need for a change in physiologic status or radiation. This review will highlight some of the scientific principles behind the technology, provide a description of the system and device, and discuss the study procedure, clinical data, and potential future applications.

Choosing The Adaptive Cardiac Phase for Assessing Cardiac Dimensions Using Cardiac Computed Tomography for Heart Disease

Background: Choosing a suitable cardiac cycle to measure cardiac chamber dimensions and wall thickness can be a more accurate assessment of cardiovascular disease.Methods: Cardiac CT was performed on 137 patients for suspected coronary disease. The parameters of left atrium (LA), left ventricle (LV), right atrium (RA), and right ventricle (RV), as well as the wall thickness of LV were measured in different cardiac phases. The general linear mixed model was used to analyze differences in different phases and the correlation between these parameters and traditional risk factors. ROC analysis was performed to estimate LA enlargement. Results:The dimensions of LA, RA, and LV wall thickness achieved the maximum at the phase of 35%–45%, and the dimensions of LV and RV reached the maximum at 95%–5%. Whereas, the changes of LA-B (antero-posterior diameter), LV-D1 (basal dimension), RA-B (minor dimension) and RV-D2 (mid cavity dimension) were relatively more stable during the cardiac cycle. The maximum LA-B diameter(95%CI 36.92,38.48mm), LV-D1 diameter(95%CI 44.36,45.83mm), RA-B diameter(95%CI 48.75,50.61mm), and RV-D2 diameter(95%CI 30.83,32.84mm) and the maximum interventricular septum thickness( 95%CI 10.79,11.51mm) was acquired. Heart rate (HR) and smoking were potential indicators of LVD2 (mid cavity dimension), while HR and LV myocardial mass were potential indicators of LVD3 (apical-basal dimension). In phase 45%, the cut-off value of LA-A with 77.57mm has high specificity.Conclusion: Cardiac chamber dimensions and wall thickness vary with the cardiac phase. Choosing the adaptive cardiac phase for evaluating these parameters obtained by cardiac CT could provide a more accurate clinical measurement.

Heartbeat and Somatosensory Perception

Our perception of the external world is influenced by internal bodily signals. For example, we recently showed that timing of stimulation along the cardiac cycle and spontaneous fluctuations of heartbeat-evoked potential (HEP) amplitudes influence somatosensory perception and the associated neural processing (Al et al., 2020). While cardiac phase affected detection sensitivity and late components of the somatosensory-evoked potentials (SEPs), HEP amplitudes affected detection criterion and both early and late SEP components. In a new EEG study, we investigate whether these results are replicable in a modified paradigm, which includes two succeeding temporal intervals. Only in one of these intervals, subjects received a weak electrical finger stimulation and then performed a yes/no and two-interval forced-choice detection task. Our results confirm the previously reported cardiac cycle and prestimulus HEP effects on somatosensory perception and evoked potentials. In addition, we obtain two new findings: A source analysis in these two studies shows that the increased likelihood of conscious perception goes along with HEP fluctuations in parietal and posterior cingulate regions, known to play important roles in interoceptive processes. Furthermore, HEP amplitudes are shown to decrease when subjects engage in the somatosensory task compared to their resting state condition. Our findings are consistent with the view that HEP amplitudes are a marker of interoceptive (versus exteroceptive) attention and provide a neural underpinning for this view.

Post-Mortem Cardiac Magnetic Resonance for the Diagnosis of Hypertrophic Cardiomyopathy

Background: Post-mortem cardiac magnetic resonance (PMCMR) is an emerging tool supporting forensic medicine for the identification of the causes of cardiac death, such as hypertrophic cardiomyopathy (HCM). We proposed a new method of PMCMR to diagnose HCM despite myocardial rigor mortis. Methods: We performed CMR in 49 HCM patients, 30 non-HCM hypertrophy, and 32 healthy controls. In cine images, rigor mortis was simulated by the analysis of the cardiac phase corresponding to 25% of diastole. Left ventricular mass, mean, and standard deviation (SD) of WT, maximal WT, minimal WT, and their difference were compared for the identification of HCM. These parameters were validated at PMCMR, evaluating eight hearts with HCM, 10 with coronary artery disease, and 10 with non-cardiac death. Results: The SD of WT with a cut-off of > 2.4 had the highest accuracy to identify HCM (AUC 0.95, 95% CI = 0.89–0.98). This was particularly evident in the female population of HCM (AUC=0.998), with 100% specificity (95% CI = 85–100%) and 96% sensitivity (95% CI = 79–99%). Using this parameter, at PMCMR, all of the eight patients with HCM were correctly identified with no false positives. Conclusions: PMCMR allows identification of HCM as the cause of sudden death using the SD of WT > 2.4 as the diagnostic parameter.