275 research outputs found
Impaired aortic distensibility measured by computed tomography is associated with the severity of coronary artery disease.
Impaired aortic distensibility index (ADI) is associated with cardiovascular risk factors. This study evaluates the relation of ADI measured by computed tomographic angiography (CTA) with the severity of coronary atherosclerosis in subjects with suspected coronary artery disease (CAD). Two hundred and twenty-nine subjects,age 63 ± 9 years, 42% female, underwent coronary artery calcium (CAC) scanning and CTA, and their ADI and Framingham risk score (FRS) were measured. End-systolic and end-diastolic (ED) cross-sectional-area(CSA) of ascending-aorta (AAo) was measured 15-mm above the left-main coronary ostium. ADI was defined as: [(Δlumen-CSA)/(lumen-CSA in ED × systemic-pulse-pressure) × 10(3)]. ADI measured by 2D-trans-thoracic echocardiography (TTE) was compared with CTA-measured ADI in 26 subjects without CAC. CAC was defined as 0, 1-100, 101-400 and 400+. CAD was defined as luminal stenosis 0, 1-49% and 50%+. There was an excellent correlation between CTA- and TTE-measured ADI (r(2)=0.94, P=0.0001). ADI decreased from CAC 0 to CAC 400+; similarly from FRS 1-9% to FRS 20% + (P<0.05). After adjustment for risk factors, the relative risk for each standard deviation decrease in ADI was 1.66 for CAC 1-100, 2.26 for CAC 101-400 and 2.32 for CAC 400+ as compared to CAC 0; similarly, 2.36 for non-obstructive CAD and 2.67 for obstructive CAD as compared to normal coronaries. The area under the ROC-curve to predict significant CAD was 0.68 for FRS, 0.75 for ADI, 0.81 for CAC and 0.86 for the combination (P<0.05). Impaired aortic distensibility strongly correlates with the severity of coronary atherosclerosis. Addition of ADI to CAC and traditional risk factors provides incremental value to predict at-risk individuals
Re: Effects of energy drinks on blood pressure, heart rate, and electrocardiographic parameters: An experimental study on healthy young adults
Left ventricular mass index and pulmonary artery pressure in patients with the obstructive sleep apnea syndrome
Background: Sleep apnea is accompanied by some cardiovascular complications. It has even been hypothesized that sleep apnea, itself, can induce some of these complications. Given such controversies, we assessed the left ventricular mass index (LVMI) and systolic pulmonary artery pressure in patients with sleep apnea. Methods: Through convenience sampling, 56 patients with the obstructive sleep apnea syndrome (OSAS) were included in the present descriptive cross-sectional study. Patients with any past history of hypertension and diabetes mellitus were excluded. The apnea severity was assessed via the polysomnography-derived apnea-hypopnea index (AHI). All the patients underwent transthoracic echocardiography. In this cross-sectional study-data regarding age, gender, smoking, systolic and diastolic blood pressures, polysomnographic parameters (AHI, severity of disease, mean heart rate, mean oxygen saturation SaO2, lowest SaO2, and duration of SaO2 below 90% d.SaO2 < 90%), and echocardiographic parameters (systolic pulmonary artery pressure and LVMI) were accumulated and processed. Results: Fifty-two men and 14 women at a mean age of 49.29 ± 11.79 years participated in this study. Systolic and was significantly high in the severe group compared with the mild group (128.21 ± 9.73 mmHg vs. 119.23 ± 12.5 mmHg; p value = 0.007). The LVMI was increased parallel to an increase in the severity of the OSAS, but that increase was not statistically significant (p value = 0.161). The d.SaO2 < 90% was positively correlated with the LVMI, and this relationship remained true after adjustment for the body mass index (r = 0.27; p value = 0.042). Conclusion: Severe OSAS was accompanied by a higher blood pressure. The LVMI did not differ significantly between the patients with the OSAS and those who did not suffer from other risk factors of cardiac diseases. © 2016, Tehran Heart Center. All rights reserved
Right ventricular thrombus in a 36-year-old man with Factor v Leiden
Factor V Leiden deficiency is the most common hereditary hypercoagulable disease in the United States and involves 5 of the Caucasian population. Up to 30 of patients who present with deep vein thrombosis (DVT) or pulmonary thromboembolism present with this condition. This is a case report of a 36-year-old man who experienced one episode of DVT within the previous year and was admitted to our hospital due to productive coughs and hemoptysis. Paraclinical studies demonstrated a right ventricular thrombus. Additional investigation was done to find the underlying cause. Laboratory tests were positive for Factor V Leiden mutation. Other factors for hypercoagulability states were normal. Given that Factor V Leiden mutation is a life-threatening condition with a relatively high prevalence and considering its thrombogenesis, screening tests are necessary in young patients without obvious reasons for recurrent thrombus formation. It seems that medical noninvasive treatments can be an alternative therapy to surgery when a ventricular thrombus is suspected in these patients. � 2015 Tehran Heart Center. All rights reserved
Comparing myocardial injury patterns and outcomes in cardiac magnetic resonance imaging between COVID-19- and non-COVID-19-related myocarditis
Purpose: Despite the low incidence of COVID myocarditis, its influence on outcomes is substantial. The pivotal role of cardiac magnetic resonance (CMR) in diagnosing myocarditis is considered to be associated with disease prognosis. The primary objective of this study was to conduct a comparative analysis of myocardial injury patterns, CMR pathologic features, outcomes, and their correlation with CMR findings in COVID- and non-COVID-related myocarditis. Material and methods: This historical cohort study involved 124 patients diagnosed with myocarditis (COVID-19 or non-COVID-19), who underwent CMR between 2018 and 2021. The COVID group consisted of 70 individuals with a definite history of COVID-19 infection within 4 weeks, and the non-COVID group comprised 54 individuals who had no prior exposure to the SARS-CoV-2 virus. All patients were monitored for one year to assess the incidence of major adverse cardiovascular events (MACE). Additionally, baseline and follow-up echocardiography data were obtained with a minimum 3-month interval. Results: In comparison between two groups regarding to indices of CMR, left ventricular (LV) ejection fraction (p < 0.001), right ventricular (RV) ejection fraction (p < 0.001) were significantly lower in non-COVID group, and significant LV and RV systolic dysfunction were meaningfully lower in the COVID group. Extension of late gadolinium enhancement (LGE) was significantly greater in COVID group. Finally, the incidence of MACE and mean event-free survival did not have significant difference between two groups. Conclusions: Although CMR findings differed between the 2 groups, there was no significant difference in the risk of MACE or survival during one-year follow-up. Notably, LV and RV dysfunction were more prevalent in the non-COVID group, while extension of LGE was greater in the COVID group
Successful closure of pulmonary artery aneurysm in a patient with Hughes-Stovin syndrome
Hughes-Stovin syndrome is a syndrome of unknown etiology characterized by thrombophlebitis and pulmonary aneurysms. Less than 40 cases have ever been reported in the English medical literature. We are reporting a 38-year-old man with a history of right ventricular thrombus and also deep vein thrombosis who presented with massive hemoptysis. Initial work-up revealed a round opacity on chest roentgenogram which later was diagnosed as a pulmonary artery aneurysm on subsequent imaging studies. Based on the history of thrombophlebitis with this newly diagnosed pulmonary artery aneurysm a diagnosis of Hughes-Stovin syndrome was made. The patient was treated with endovascular coiling of the aneurysm. A sixteen-month follow up was uneventful. To our knowledge, this is the first case of HSS ever reported from Iran and the fourth to have a cardiac chambers involvement in the course of the disease
Mineral potential mapping of porphyry copper deposit by translating the mineral system using soil geochemistry data at Kahang, Iran
Identification of geochemical anomalies is a critical task in mineral exploration targeting. Decades of research and technology have resulted in new algorithms and techniques for recognizing anomaly detection methods at various scales and sample media. However, algorithms cannot always reveal the true nature of geological processes. The mineral system concept may contribute to a better understanding of the geological processes required to form and preserve ore deposits at all spatial and temporal scales. The mineral systems concept investigates the geochemical processes occurring within mineral subsystems in soil samples from the porphyry prospect area. The Cu/(Al + Ca) index was used to compare Cu, Mo, and (Pb* Zn)/(Cu*Mo) to highlight the region of interest for mineral potential mapping and pioneer borehole drilling based on fluid-rock interaction and secondary processes (e.g., alteration, weathering, and leaching). Exploratory boreholes validate a better performing Cu/(Al + Ca) index for detecting and refining soil geochemical anomalies
Effects of energy drinks on blood pressure, heart rate, and electrocardiographic parameters: An experimental study on healthy young adults
Objective: To evaluate the effects of the consumption of energy drinks on cardiovascular parameters in a group of healthy young individuals. Methods: In a quasi-experimental study, 44 healthy adult participants aged between 15 and 30 years were evaluated. The blood pressure (BP) as well as electrocardiographic indices, including heart rate (HR), PR interval, QRS duration, corrected QT (QTc) interval, and ST-T changes were recorded before consumption of a caffeine-containing energy drink and at the specific time points over a 4-h test duration. Results: We found statistically significant HR decline (p=0.004) and more frequent ST-T changes (p=0.004) after the participants consumed the energy drink. However, readings for systolic BP (p=0.44), diastolic BP (p=0.26), PR interval (p=0.449), QRS duration (p=0.235), and QTc interval (p=0.953) showed no significant change post-consumption. Conclusion: In conclusion, we demonstrated that the consumption of energy drinks could contribute to HR decline and ST-T change in healthy young adults. © 2016 by Turkish Society of Cardiology
Giant congenital left ventricular diverticulum associated with infective endocarditis: A diagnosis made by tissue Doppler echocardiography
Left ventricular (LV) diverticulum is a relatively rare condition, and it is important to differentiate it from pseudoaneurysm. The increasing use of noninvasive imaging modalities can help to demonstrate different types of ventricular outpouching structures. We report a case of congenital LV diverticulum that is much larger than the usual size and is diagnosed with tissue Doppler echocardiography and cardiac magnetic resonance imaging. Although a ventricular diverticulum is mostly asymptomatic, in the case of this particular patient, it has become complicated with infective endocarditis. © 2016 Japanese College of Cardiolog
Design and Implementation of a 16-bit Multi-Mode Delta-Sigma Digital-to-Analog Converter with Time-Interleaved Structure, Multi-Channel, and Compensation of Non-Idealities Based on FPGA
In this research, a 16-bit multi-mode second-order Delta-Sigma Modulator-Digital-to-Analog Converter (DSM-DAC) with a time-interleaved (TI) structure operating at a center frequency of 4 GHz and a bandwidth of 20 MHz has been implemented using VHDL on an FPGA platform. The proposed architecture utilizes a single clock frequency for generating RF signals. The second-order DSM is reconfigurable, offering three filter modes: LP, BP at Fs/4, and HP for signal synthesis. Since the coefficients remain simple for all modes, multiplication operations can be achieved using a shifter block. To investigate the effect of duty-cycle-error (DCE) and its compensation, various error values are applied to the modulator and compensation is performed. A novel solution is proposed to overcome the DCE by adjusting the filter and unilaterally narrowing the signal passband without adding extra hardware complexity. This approach significantly enhances the SNDR and SFDR of the DSM output, even for the BP mode. Another challenge is the mismatch error in DAC cells. This error is simulated and compensated using two methods: DWA and SDEM. Simulation results in ISE demonstrate that the SNDR values for LP, BP, and HP modes are 106.10, 105.65, and 104.95 dB, respectively.</p
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