No description available.

No description available.

Background: Patients with left ventricular ejection fractions between 40% and 49% either discovered de novo, having declined from ≥50%, or improved from <40% have been described as heart failure (HF) with mid-range ejection fraction (HFmrEF). Though clinical signs and symptoms are similar to other phenotypes, possible prognostic differences and therapeutic responses reinforce the need for further understanding of patients’ characteristics especially in a rural community based population. The purpose of this study is to evaluate the clinical characteristics, comorbidities and prognosis of a rural patient population with HFmrEF. Materials and Methods: We queried the electronic medical record from a community based university practice for all patients with a HF diagnosis. We included only those patients with >3 months follow-up and interpretable Doppler echocardiograms. We recorded demographic, Doppler-echo, and outcome variables (up to 2,083 days). Results: There were 633 HF patients: 42.4% with preserved ejection fraction (HFpEF, EF ≥50%), 36.4% with HFmrEF, and 21.0% with reduced ejection fraction (HFrEF, EF <40%). HFmrEF patients were older, had greater coronary disease prevalence, lower systolic blood pressure, elevated brain natriuretic peptide, lower hemoglobin, and higher creatinine than HFpEF. All-cause mortality was intermediate between HFrEF and HFpEF but was not significantly different. Landmark analysis revealed a trend toward greater second readmission in HFmrEF as compared to HFpEF (hazard ratio: 1.43 [0.96-2.14],P = 0.0767). Conclusions: Rural patients with HFmrEF without an ambulatory HF clinic represent a higher percentage of HF patients than previously reported with greater coronary disease prevalence with comparable readmission rates and nonsignificantly different all-cause mortality.

<p>  </p> <p><strong>Background: </strong></p> <p>Torsades de pointes (TdP) is a polymorphic ventricular tachycardia (VT) associated with heart rate-corrected QT interval (QTc) prolongation on the electrocardiogram (ECG). TdP can cause sudden cardiac arrest (SCA), a catastrophic outcome. The antiarrhythmic drugs dofetilide and sotalol can cause QTc prolongation and arrhythmias, as can more than 200 other medications available on global markets. Heart failure (HF) with reduced ejection fraction (HFrEF) is a risk factor for drug-induced TdP, and HFrEF heightens sensitivity to drug-induced QTc lengthening. However, ~55% of patients with HF have preserved, rather than reduced, ejection fraction. It remains unknown whether patients with HF with preserved ejection fraction (HFpEF) are at increased risk for drug-induced VT/SCA. Assessment of the risk of drug-induced VT/SCA in HFpEF patients is important, so that recommendations can be made regarding the safety of QTc-prolonging drugs and need for enhanced ECG monitoring in this population. </p> <p><strong>Objective:</strong></p> <p>In aim 1, we sought to determine the risk of VT and SCA associated with dofetilide and sotalol in patients with HFpEF. In aim 2, we were able to use QTc interval to determine the odds of dofetilide/sotalol-associated QT interval prolongation in patients with HFpEF. In Aim 3, we investigated the influence of HFpEF on VT and SCA associated with a broader group of drugs known to cause TdP (“known “TdP drugs”), as designated by the QT drugs list at www.crediblemeds.org. </p> <p><strong>Methods:</strong></p> <p>In aim 1, we used Medicare claims (2014-2016) and ICD-9/10 codes to identify patients taking the QT interval-prolonging drugs dofetilide or sotalol, which are used commonly in patients with HF and atrial fibrillation, as well as non-dofetilide or sotalol users among 3 groups: HFpEF, HFrEF, and no HF. Multinomial propensity score-matching was performed. Cochran–Mantel–Haenszel statistics and standardized differences were used to compare baseline characteristics. A generalized Cox proportional hazards model was used to estimate hazard ratios (HRs) and test the association of VT and SCA among dofetilide/sotalol users, HFpEF, HFrEF, and no HF.</p> <p>In Aim 2, the data source was electronic health records from the Indiana Network for Patient Care (February 2010 to May 2021). After removing patients with overlapping diagnoses of HFpEF and HFrEF, no diagnosis code, absence of QT interval records, and no validated record of using dofetilide or sotalol, we identified patients taking dofetilide or sotalol among three groups: HFrEF, HFpEF, and no HF. Cochran–Mantel–Haenszel statistics were used to compare baseline characteristics. QT interval prolongation was defined as heart rate-corrected QT (QTc) > 500 ms during dofetilide/sotalol therapy. Unadjusted odds ratios (OR) of QT interval prolongation were determined by univariate analysis, and adjusted ORs were determined by generalized estimating equations (GEE) with logit link to account for an individual cluster with different times of hospitalization and covariates.</p> <p>In aim 3, we used Medicare enrollment in fee-for-service medical and pharmacy benefits (2014 to 2016) and ICD-9/10 codes, we identified patients taking drugs known to cause torsades de pointes (TdP drugs; www.crediblemeds.org) and non-TdP drug users among three groups: HFrEF, HFpEF, and no HF. Multinomial propensity score-matching was performed to minimize baseline differences in covariates (patient demographics, comorbidities, health care utilization and drug history). Cochran–Mantel–Haenszel statistics and standardized differences were used to compare baseline characteristics. A generalized Cox proportional hazards model was used to estimate HRs and test the association of VT and SCA among TdP drug users with HFpEF, HFrEF, and no HF.</p> <p><strong>Results:</strong></p> <p>In Aim 1, VT and SCA occurred in 166 (10.68%) and 16 (1.03%), respectively, of 1,554 dofetilide/sotalol users with HFpEF, 543 (38.76%) and 40 (2.86%) of 1,401 dofetilide/sotalol users with HFrEF, and 245 (5.06%) and 13 (0.27%) of 4,839 dofetilide/sotalol users with no HF. The adjusted HR for VT in patients with HFrEF was 7.00 (95% CI 6.12-8.02) and in patients with HFpEF was 1.99 (1.71-2.32). The risk of VT associated with dofetilide/sotalol was increased across the overall study population (HR: 2.47 [1.89-3.23]). Use of dofetilide/sotalol increased the risk of VT in patients with HFrEF (HR: 1.53 [1.07-2.20]) and in those with HFpEF (HR: 2.34 [1.11-4.95]). However, while the overall risk of SCA was increased in patients with HFrEF (HR: 5.19 [4.10-6.57]) and HFpEF (HR: 2.53 [1.98-3.23]) compared to patients with no HF, dofetilide/sotalol use was not significantly associated with an increased risk of SCA.</p> <p>In Aim 2, QTc prolongation associated with dofetilide/sotalol occurred in 51.2% of patients with HFpEF, 70.1% of patients with HFrEF, and 29.4% of patients with no HF. After adjusting for age, sex, race, serum potassium and magnesium concentrations, kidney function, concomitant drug therapy, and comorbid conditions, the adjusted odds of having QTc interval larger than 500ms during the hospital stay were 5.23 [3.15-8.67] for HFrEF and 1.98 [1.17-3.33] for HFpEF with no HF as the reference group. </p> <p>In Aim 3, of 23,910 known TdP drug users with HFrEF, VT and SCA occurred in 4,263 (17.8%) and 493 (2.1%) patients, respectively. In comparison, among 31,359 known TdP drug users with HFpEF, VT and SCA occurred in 1,570 (5.0%) and 340 (1.1%) patients. VT and SCA occurred in 3,154 (0.8%) and 528 (0.1%) of 384,824 known TdP drug users without HF. The overall HR of both VT and SCA was increased in patients with HFrEF (HR: 7.18 [6.13-8.40])  and in those with HFpEF (HR: 2.09 [1.80-2.42]). The risk of VT associated with known TdP drugs was increased across the overall population (HR: 1.34 [1.20-1.51]). Use of known TdP drugs significantly increased the risk of VT and SCA in patients with HFrEF (HR: 1.34 [1.07-1.67]), but not in patients with HFpEF.</p> <p><strong>Conclusion:</strong></p> <p>HFpEF may exhibit an enhanced response to drug-associated VT, and is associated with a higher risk of drug-associated QTc interval prolongation. Further study is needed to identify methods to minimize this risk for patients with HFpEF requiring therapy with dofetilide, sotalol, or drugs known to cause TdP. </p>

Assessment of left ventricular (LV) function is one of the most common requests made to cardiac imaging services. This demand stems from a large body of evidence that shows abnormal LV systolic and, more recently, diastolic function has important prognostic and treatment related implications for patients with a wide range of cardiovascular diseases. The vast majority of information supporting the use of conventional measures of LV function, such as ejection fraction, originates from population studies and large clinical trials. However, the application of these measurements to individual patients is far less defined, especially when used for serial evaluation. Central to these concerns is the relative paucity of data surrounding the test-retest reliability of conventional measures in clinical settings. Newer measures of LV function have been developed over recent years, with several techniques becoming widely used in clinical practice (i.e. tissue Doppler imaging) and others remaining largely research tools (i.e. 3D echocardiography, tissue strain/strain rate). Possible benefits of new technologies include improved identification and early detection of myocardial disease, improved reliability for monitoring progression of disease, and the development of novel methods to assess response to therapy. Despite this potential, the application and clinical utility of these techniques above and beyond more conventional measures remains in many cases to be adequately characterized. This thesis addresses several of these issues: from variability of novel and conventional measures of LV function in clinical practice, to new applications of novel functional measures in clinical settings.

No description available.

Transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) imaging are two commonly used imaging modalities for evaluating the size and function of the heart. There are advantages and disadvantages associated with both modalities when examining the right ventricle (RV). The RV is positioned partly behind the sternum and lung, sometimes causing shadows in the TTE images. This along with the complex shape of the RV makes volume calculations challenging by 2D TTE. CMR is considered to be the reference method for volume calculations of the ventricles. The valve separating the RV from the right atrium is however often oblique compared to the valve separating the left ventricle from the left atrium. This complicates RV volume calculations using conventional CMR short-axis stack images. The aim of this thesis was to find ways to improve the RV stroke volume and ejection fraction calculations using TTE and CMR. A method, transferring the position of the tricuspid plane from RV long-axis images to short-axis images, was developed to improve the separation of the right atrium from the RV when calculating RV stroke volumes by CMR. The method provided calculations of RV stroke volumes with good agreement to reference volumes. Further, the movements contributing to the RV stroke volume was studied aiming to find new ways of calculating RV stroke volumes and ejection fraction by TTE. A model for RV stroke volume and ejection fraction calculations was evaluated showing underestimation of stroke volumes by TTE compared to CMR, which probably depend on differences in distance measurements using the two modalities. The model provided, however, promising results for ejection fraction calculations which was validated in a study of 37 participants that covered a wide range of EF.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22042号 / 医博第4527号 / 新制||医||1039(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 佐藤 俊哉, 教授 湊谷 謙司, 教授 稲垣 暢也 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Author: Bc. Michaela Tejnecká Title: The effect of regularly applied Nordic walking on selected cardiorespiratory parameters in adults after heart valve surgery. Aim: The aim of this work was to analyze the effect of six months of Nordic walking intervention on selected casrdiorespiratory parameters in adults after heart valve surgery. Methods: The study included ten individuals (mean age 62 years) who were at least five years apart after heart valve surgery. Blood pressure (BP) was measured using a pulsed wrist tonometer, blood oxygen saturation (BOS) and heart rate (HR) were measured using a pulse oximeter, and the ejection fraction of the heart (EF) was evaluated echocardiographically. Nordic walking training units took plaxe once a week for 6 months. During this intervention, the level of training gradually increased both in distance and elevation of the terrain. Results: In all probands there was an average reduction in systolic blood pressure during exercise by an average of 10,3 mmHg and a reductionin heart rate during exercise by an average of 24 beats per minute. The resting ejection fraction increased by an average of 5,5% after six month intervention. These changes were statistically significant (p<0,01). The results of the work point to the benefits of Nordic walking for cardiac...

Author: Bc. Michaela Tejnecká Title: The effect of regularly applied Nordic walking on selected cardiorespiratory parameters in adults after heart valve surgery. Aim: The aim of this work was to analyze the effect of six months of Nordic walking intervention on selected casrdiorespiratory parameters in adults after heart valve surgery. Methods: The study included ten individuals (mean age 62 years) who were at least five years apart after heart valve surgery. Blood pressure (BP) was measured using a pulsed wrist tonometer, blood oxygen saturation (BOS) and heart rate (HR) were measured using a pulse oximeter, and the ejection fraction of the heart (EF) was evaluated echocardiographically. Nordic walking training units took plaxe once a week for 6 months. During this intervention, the level of training gradually increased both in distance and elevation of the terrain. Results: In all probands there was an average reduction in systolic blood pressure during exercise by an average of 10,3 mmHg and a reductionin heart rate during exercise by an average of 24 beats per minute. The resting ejection fraction increased by an average of 5,5% after six month intervention. These changes were statistically significant (p<0,01). The results of the work point to the benefits of Nordic walking for cardiac...