A Direct Current-Sensing VCO-Based 2nd-Order Continuous-Time Sigma-Delta Modulator for Biosensor Readout Applications.

A second-order voltage-controlled oscillator (VCO)-based continuous-time sigma-delta modulator (CTSDM) for current-sensing readout applications is proposed. Current signals from the sensor can directly be quantized by the proposed VCO-based CTSDM, which does not require any extra trans-impedance amplifiers. With the proportional-integral (PI) structure and a VCO phase integrator, the capability of second-order noise shaping is available to reduce the in-band quantization noise. The PI structure can be simply realized by a resistor in series with the integrating capacitor, which can reduce the architecture complexity and maintain the stability of the system. The current-steering digital-to-analog converter with tail and sink current sources is used on the feedback path for the subtraction of the current-type input signal. All the components of the circuit are scaling friendly and applicable to current-sensing readout applications in the Internet of Things (IoT). The proposed VCO-based CTSDM implemented in a 0.18-µm standard CMOS process has a measured signal-to-noise and distortion ratio (SNDR) of 74.6 dB at 10 kHz bandwidth and consumes 44.8 µw only under a supply voltage of 1.2 V, which can achieve a Figure-of-Merit (FoM) of 160.76 dB.

Atrial high-rate episodes intensify R2CHA2DS2-VASc score for prognostic stratification in pacemaker patients.

Patients with device detected atrial high-rate episodes (AHRE) have an increased risk of MACE. The R2CHA2DS2-VASc, CHADS2, R2CHADS2 and CHA2DS2-VASc score have been investigated for predicting major adverse cardiovascular events (MACE) in different groups of patients. We aimed to evaluate the R2CHA2DS2-VASc score in combination with AHRE ≥ 6 min for predicting MACE in patients with dual-chamber PPM but no prior atrial fibrillation (AF). We retrospectively enrolled 376 consecutive patients undergoing dual-chamber PPM implantation and no prior AF. The primary endpoint was subsequent MACE. For all patients in the cohort, CHADS2, R2CHADS2, CHA2DS2-VASc, R2CHA2DS2-VASc scores and AHRE ≥ or < 6 min were determined. AHRE was recorded as a heart rate > 175 bpm (Medtronic) or > 200 bpm (Biotronik) lasting ≥ 30 s. Multivariate Cox regression analysis with time-dependent covariates was used to determine the independent predictors of MACE. ROC-AUC analysis was performed for CHADS2, R2CHADS2, CHA2DS2-VASc, and R2CHA2DS2-VASc scores and then adding AHRE ≥ 6 min to the four scores. The median age was 77 years, and 107 patients (28.5%) developed AHRE ≥ 6 min. After a median follow-up of 32 months, 46 (12.2%) MACE occurred. Multivariate Cox regression analysis showed that R2CHA2DS2-VASc score (HR, 1.485; 95% CI, 1.212-1.818; p < 0.001) and AHRE ≥ 6 min (HR, 2.125; 95% CI, 1.162-3.887; p = 0.014) were independent predictors for MACE. The optimal R2CHA2DS2-VASc score cutoff value was 4.5 (set at ≥ 5), with the highest Youden index (AUC, 0.770; 95% CI, 0.709-0.831; p < 0.001). ROC-AUC analysis of the four risk scores separately combined with AHRE ≥ 6 min all showed better discriminatory power than the four scores alone (All Z-statistic p < 0.05). In patients with PPM who develop AHRE ≥ 6 min, it is crucial to perform risk assessment with either four scores to further stratify risk for MACE.

Proposed strategies to overcome venous occlusion in the implantation of a cardiac implantable electronic device: A case report and literature review.

This case report describes a successful balloon venoplasty to overcome a total occlusion from the brachiocephalic vein to the superior vena cava in a patient undergoing cardiac resynchronization therapy. It is crucial for implanting physicians to be familiar with strategies to overcome venous occlusion in lead implantation, especially balloon venoplasty, which is an effective and safe approach.

The Ratio of Urine N-Terminal Pro B-Type Natriuretic Peptide to Cyclic Guanosine Monophosphate Predicts Emergency Department Visits for Heart Failure.

INTRODUCTION: Emergency department (ED) visits for decompensated heart failure (HF) are frequent and associated with poor long-term outcomes. Plasma N-terminal pro B-type natriuretic peptide (NT-proBNP) and cyclic guanosine monophosphate (cGMP) are used in diagnosis and prognosis of HF patients, while clinical values of urine NT-proBNP/cGMP ratio have been rarely explored. This study aims to compare the predictive values of urine NT-proBNP/cGMP ratio versus plasma NT-proBNP for ED visits for decompensated HF. METHODS: This prospective study included 126 HF patients with reduced left ventricular ejection fraction (<50%) and without chronic kidney disease. Baseline data included demographics, co-morbidities, and co-medications. Medical records were used to determine the incidence of ED visits for decompensated HF during the 3 months following the last visit. RESULTS: Patients with subsequent ED visits had significantly higher levels of plasma and urine NT-proBNP and urine cGMP in than those without. Multivariate Cox regression analysis disclosed that Lg10urine NT-proBNP/cGMP was an independent risk factor for subsequent ED visits (OR = 3.267; 95% CI: 1.105-9.663; p = 0.032). ROC analysis revealed an Lg10urine NT-proBNP/cGMP ratio optimal cut-off value of 0.1706 (AUC, 0.700; 95% CI: 0.543-0.857; p = 0.036) for predicting subsequent HF-related ED visits. CONCLUSION: A single measurement of urinary NT-proBNP/cGMP ratio is predictive of subsequent ED visits for decompensated HF. This noninvasive and easy measurement may be a clinically useful tool for identifying a subset of patients at higher risk of ED visits.

Case report: A rare complication after the implantation of a cardiac implantable electronic device: Contralateral pneumothorax with pneumopericardium and pneumomediastinum.

Cardiac implantable electronic devices (CIED) including pacemakers (PM), implantable cardioverter defibrillators (ICD), and cardiac resynchronized therapy (CRT) have become the mainstay of therapy for many cardiac conditions, consequently drawing attention to the risks and benefits of these procedures. Although CIED implantation is usually a safe procedure, pneumothorax remains an important complication and may contribute to increased morbidity, mortality, length of stay, and hospital costs. On the other hand, pneumopericardium and pneumomediastinum are rare but potentially fatal complications. Accordingly, a high degree of awareness about these complications is important. Pneumothorax almost always occurs on the ipsilateral side of implantation. The development of contralateral pneumothorax is uncommon and may be undetected on an initial chest radiograph. Contralateral pneumothorax with concurrent pneumopericardium and pneumomediastinum is much rarer. We describe a rare case of concurrent right-sided pneumothorax with pneumopericardium and pneumomediastinum after left-sided pacemaker implantation and highlight the risk factors, management, and possible ways to prevent the complications.

A 0.8-µW and 74-dB High-Pass Sigma-Delta Modulator With OPAMP Sharing and Noise-Coupling Techniques for Biomedical Signal Acquisition.

This work presents a third-order high-pass sigma-delta modulator (HPSDM) for biomedical signal acquisition. The operational amplifier (op-amp) sharing and noise-coupling techniques are adopted to reduce the required quantity of op-amps and add a noise-shaping order, which can achieve low power consumption and high resolution. A novel switched-capacitor architecture is proposed to suppress the increasing in-band noise and alleviate the circuit sensitivity to capacitor mismatch in the high-pass integrator. The proposed HPSDM was fabricated in a 0.18-µm standard CMOS process. Measurement results reveal that the proposed HPSDM has a signal-to-noise and distortion ratio (SNDR) of 75.26/74 dB in 200 Hz bandwidth and consumes 1.52/0.8 µW under 1.2/1 V supply voltage, which can achieve a peak Schreier Figure-of-Merit of 156.45/157.98 dB and a peak Walden FoM of 0.802/0.488 pJ/conv.

HAT2CH2 score performance predicting neurologic events after cardiac implantable electronic device.

Objectives: The HAT2CH2 score has been evaluated for predicting new-onset atrial fibrillation in several clinical conditions, but never for adverse neurologic events. We aimed to evaluate the effectiveness of HAT2CH2 score in predicting neurologic events in patients with cardiac implantable electronic device (CIED), comparing with atrial high-rate episodes (AHRE). Methods: This case-control study enrolled 314 consecutive patients aged 18 years or older with CIED implantation between January 2015 and April 2021. Patient data were analyzed retrospectively. The primary endpoint was subsequent neurologic events (NE) after implantation. AHRE was defined as > 175 bpm (Medtronic®) lasting ≥ 30 seconds. Variables associated with independent risk of NE were identified using multivariate Cox regression analysis with time-dependent covariates. Results: Patients' median age was 73 years and 61.8% of them were male. During follow-up (median 32 months), 18 NE occurred (incidence rate 2.15/100 patient-years, 95% CI 1.32-4.30). Multiple Cox regression analysis showed that the HAT2CH2 score (HR 2.424, 95% CI 1.683 - 3.492, p < 0.001) was an independent predictor for NE. Optimal HAT2CH2 score cutoff value was 3 with highest Youden index (AUC, 0.923; 95% CI, 0.881-0.966; p < 0.001). Both AHRE ≥ 1 minute and HAT2CH2 score ≥ 3 had the highest AUC of the receiver-operating characteristic (0.898, 95% CI, 0.831-0.965, p < 0.001). Significant increase was observed in NE occurrence rates using the HAT2CH2 score (p < 0.001). Conclusion: The HAT2CH2 score and episodes of AHRE lasting ≥ 1 minute are independent risk factors for NE in patients with CIED.

The performance of five models compared with atrial high rate episodes predicts new atrial fibrillation after cardiac implantable electronic devices implantation.

AIMS: Several predicting models have been evaluated for new-onset atrial fibrillation (AF) in several clinical conditions, but never in patients with cardiac implantable electronic devices (CIED). We aimed to evaluate the five predicting models compared with atrial high rate episodes (AHRE) to predict new AF in patients with CIED. METHODS AND RESULTS: We retrospective enrolled 470 consecutive patients with CIED and without a history of AF. The five predicting models, including CHA2 DS2 -VASc score, C2 HEST score, mCHEST score, HAT2 CH2 score, and HAVOC score were used. The primary endpoint was new AF documented by 12-lead electrocardiography (ECG) or 30-s ECG strip. Multivariable Cox regression analysis was used to determine variables associated with independent factors of new AF. Patients' median age was 76 years and 58.7% were male. During follow-up (median 29 months), 34 new AF occurred (incidence rate 2.99/100 patient-years, 95% CI 1.67-6.20). Multivariable Cox regression analysis showed AHRE ≥6 min and 24 h, and HAT2 CH2 score were independent predictors for new AF. Optimal AHRE cutoff value was 9.3 min with highest Youden index (AUC, 0.806; 95% CI, 0.722-0.889; p < .001). The AF occurrence rate of AHRE ≥9.3 min was 7 times AHRE <9.3 min (p < .001). CONCLUSIONS: We compared 5 predicting models for new AF in patients with CIED and without a history of AF. AHRE ≥6 min and 24 h, and HAT2 CH2 score were independent predictors for AF.

Unexplained Left Ventricular Hypertrophy with Symptomatic High-Grade Atrioventricular Block in Elderly Patients: A Case Report.

Left ventricular hypertrophy (LVH) is common among older adults. Amidst all causes, Fabry disease (FD) should be considered when LVH occurs with family history, specific clinical manifestations, or cardiac alert signs. Here, we report a case of a 76-year-old male who presented late onset concentric LVH with symptomatic high-grade atrioventricular (AV) block. After dual-chamber pacemaker implantation, interrogation revealed frequent right ventricular (RV) pacing with a wide QRS duration. The patient developed heart failure symptoms with rapid deterioration of LV systolic function. Pacing-induced cardiomyopathy (PICM) was suspected, and the pacemaker was upgraded to biventricular pacing. Further FD surveys were performed, including biochemical examinations, cardiac biopsies, and genetic sequencing, and the patient was ultimately diagnosed with a cardiac variant of FD. Particularly, we strongly suggest that physiologic pacing should be initially considered for patients with FD who have symptomatic high-grade AV block, rather than traditional RV pacing to prevent PICM.

The HAT2CH2 score predicts neurologic events in patients with cardiac implantable electronic devices without atrial fibrillation.

BACKGROUND: The HAT2CH2 score has been evaluated for predicting new-onset atrial fibrillation (AF) in several clinical conditions but never for adverse neurologic events. We aimed to evaluate the HAT2CH2 score for predicting neurologic events in patients with cardiac implantable electronic devices (CIED). METHODS AND RESULTS: We retrospectively reviewed 470 consecutive patients who had CIED without a history of AF. The primary endpoint was a neurologic event, i.e. ischemic stroke or transient ischemic attack. Multivariate Cox regression analysis with time-dependent covariates was used to determine variables associated with independent factors of neurologic events. Patients' median age was 76 years, and 58.7% were male. During follow-up (median 29 months), 21 neurologic events occurred (incidence rate 1.85/100 patient-years, 95% CI 1.03-3.83). Multivariable Cox regression analysis revealed that the HAT2CH2 score (HR 3.397, 95% CI 2.357-4.895, p < 0.001) was an independent predictor for neurologic events. Optimal HAT2CH2 score cut-off value was 3, with highest Youden index (AUC, 0.923; 95% CI, 0.886-0.959; p < 0.001). The rate of neurologic events increased significantly with increasing HAT2CH2 score (p < 0.001). CONCLUSIONS: The HAT2CH2 score can predict the occurrence of neurologic events in patients with CIED with no history of AF. Further study of the utility of the HAT2CH2 score for the assessment of neurologic event risk and the selection of anti-thrombotic therapy in patients with CIED without prior AF is warranted.

HATCH Score and Left Atrial Size Predict Atrial High-Rate Episodes in Patients With Cardiac Implantable Electronic Devices.

Background: Patients with sustained atrial high-rate episodes (AHRE) have a high risk of major adverse cardio/cerebrovascular events (MACCE). However, the prediction model and factors for the occurrence of AHRE are unknown. We aimed to identify independent factors and various risk models for predicting MACCE and AHRE. Methods: We retrospectively enrolled 314 consecutive patients who had cardiac implantable electronic devices (CIEDs). The primary endpoint was MACCE after AHRE ≥3, 6 min, and 6 h. Atrial high-rate episodes was defined as >175 bpm (Medtronic®) lasting ≥30 s. Multivariate Cox and logistic regression analysis with time-dependent covariates were used to determine variables associated with independent risk of MACCE and occurrence of AHRE ≥3 min, respectively. Results: One hundred twenty-five patients (39.8%) developed AHRE ≥3 min, 103 (32.8%) ≥6 min, and 55 (17.5%) ≥6 h. During follow-up (median 32 months), 77 MACCE occurred (incidence 9.20/100 patient years, 95% CI 5.66-18.39). The optimal AHRE cutoff value was 3 min for MACCE, with highest Youden index 1.350 (AUC, 0.716; 95% CI, 0.638-0.793; p < 0.001). Atrial high-rate episodes ≥3 min-6 h were independently associated with MACCE. HATCH score and left atrial diameter were independently associated with AHRE ≥3 min. The optimal cutoff for HATCH score was 3 and for left atrial diameter was 4 cm for AHRE ≥3 min. Conclusion: Patients with CIEDs who develop AHRE ≥3 min have an independently increased risk of MACCE. Comprehensive assessment using HATCH score and echocardiography of patients with CIEDs is warranted.

Atrial high-rate episodes predict major adverse cardio/cerebrovascular events in patients with cardiac implantable electrical devices.

Patients with atrial high-rate episodes (AHRE) have a high risk of neurologic events, although the causal role and optimal cutoff threshold of AHRE for major adverse cardio/cerebrovascular events (MACCE) are unknown. This study aimed to identify independent factors for AHRE and subsequent atrial fibrillation (AF) after documented AHRE. We enrolled 470 consecutive patients undergoing cardiac implantable electrical device (CIED) implantations. The primary endpoint was subsequent MACCE after AHRE ≥ 6 min, 6 h, and 24 h. AHRE was defined as > 175 beats per minute (bpm) (Medtronic®) or > 200 bpm (Biotronik®) lasting ≥ 30 s. Multivariate Cox regression analysis with time-dependent covariates was used to determine variables associated with independent risk of MACCE. The patients' median age was 76 year, and 126 patients (26.8%) developed AHRE ≥ 6 min, 63 (13.4%) ≥ 6 h, and 39 (8.3%) ≥ 24 h. During follow-up (median: 29 months), 142 MACCE occurred in 123 patients. Optimal AHRE cutoff value was 6 min, with highest Youden index for MACCE. AHRE ≥ 6 min ~ 24 h was independently associated with MACCE and predicted subsequent AF. Male gender, lower body mass index, or BMI, and left atrial diameter were independently associated with AHRE ≥ 6 min ~ 24 h. Patients with CIEDs who develop AHRE ≥ 6 min have an independently increased risk of MACCE. Comprehensive assessment of patients with CIEDs is warranted.

Post cardiac injury syndrome successfully treated with medications: a report of two cases.

BACKGROUND: Post cardiac injury syndrome (PCIS) is induced by myocardial infarction or cardiac surgery, as well as minor insults to the heart such as percutaneous coronary intervention (PCI), or insertion of a pacing lead. PCIS is characterized by pericarditis after injury to the heart. The relatively low incidence makes differential diagnosis of PCIS after PCI or implantation of a pacemaker a challenge. This report describes two typical cases of PCIS. CASE PRESENTATION: The first patient presented with signs of progressive cardiac tamponade that occurred two weeks after implantation of a permanent pacemaker. Echocardiography confirmed the presence of a moderate amount of newly-formed pericardial effusion. The second patient underwent PCI for the right coronary artery. However, despite an uneventful procedure, the patient experienced dyspnea, tightness of chest and cold sweats, and bradycardia two hours after the procedure. Echocardiography findings, which showed a moderate amount of newly-formed pericardial effusion, suggested acute cardiac tamponade, and compromised hemodynamics. Both patients recovered with medication. CONCLUSION: These cases illustrated that PCIS can occur after minor myocardial injury, and that the possibility of PCIS should be considered if there is a history of possible cardiac insult.

A Portable Wireless Urine Detection System With Power-Efficient Electrochemical Readout ASIC and ABTS-CNT Biosensor for UACR Detection.

This work presents a portable wireless urine detection system which consists of an electrochemical readout application specific integrated circuit (ASIC) and a biosensor composed of 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and carbon nanotube (ABTS-CNT) for the detection of urine albumin-to-creatinine ratio (UACR). The ASIC includes a potentiostat, a digital circuitry and a power management circuit which can perform electrochemistry techniques with a dual-channel screen-printing carbon electrode (SPCE). Electrochemical experiments on the proposed biosensor (SPCE|ABTS-CNT|Nafion) have revealed promising sensing characteristics for creatinine and human serum albumin detection. Practical urine tests has demonstrated the capability of the proposed urine detection system for UACR detection with both the power-efficient readout ASIC and the ABTS-CNT biosensor. A user-friendly prototype has also been designed which can be useful for either personal health administrationor homecare.

The optimal cutoff of atrial high-rate episodes for neurological events in patients with dual chamber permanent pacemakers.

BACKGROUND: Patients with atrial high-rate episode (AHRE) are at higher risk of neurological events. This study aimed to identify the optimal cutoff threshold for AHRE duration in patients with dual chamber permanent pacemakers (PPM) without prior atrial fibrillation. METHODS: We included 355 consecutive patients receiving dual chamber pacemaker implantation. Primary outcome was composite endpoint of subsequent neurological events after various AHRE durations. AHRE was defined as >175 bpm (MEDTRONIC) or > 200 bpm (BIOTRONIK) for longer than 30 s. Cox regression analysis with time-dependent covariates was conducted. RESULTS: The mean age of included patients was 75.6 ± 11.3 years. Among 355 included patients, some had multiple AHREs; 125 patients (35.2%) developed AHRE ≥2 min, 107 (30.1%) had ≥5 min, 55 (15.5%) had ≥6 h, and 37 (10.4%) had ≥24 h. The mean follow-up was 42.1 ± 31.2 months. During follow-up, 19 neurological events occurred. After adjustment for CHA2 DS2 -VASc score and device type, multivariate Cox regression analysis indicated AHRE ≥2 min (HR 13.605, 95% CI 3.010-61.498), and AHRE ≥5 min (HR 5.819, 95% CI 2.056-16.470) were significantly associated with neurological events. Hence, the optimal AHRE cutoff value was 2 min with the highest Youden index (sensitivity, 89.5%; specificity, 67.8%; AUC, 0.823, 95% CI, 0.763-0.884; p < 0.001). CONCLUSIONS: Patients with dual chamber PPM who develop AHRE have increased risk of neurological events. Comprehensive assessment of the risks and benefits of prescribing anticoagulants should be considered in PPM patients with AHRE ≥2 min.