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Concept: Cardiac cycle

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Regular exercise training improves maximal oxygen uptake (VO2max), but the optimal intensity and volume necessary to obtain maximal benefit remains to be defined. A growing body of evidence suggests that exercise training with low-volume but high-intensity may be a time-efficient means to achieve health benefits. In the present study, we measured changes in VO2max and traditional cardiovascular risk factors after a 10 wk. training protocol that involved three weekly high-intensity interval sessions. One group followed a protocol which consisted of 4×4 min at 90% of maximal heart rate (HRmax) interspersed with 3 min active recovery at 70% HRmax (4-AIT), the other group performed a single bout protocol that consisted of 1×4 min at 90% HRmax (1-AIT). Twenty-six inactive but otherwise healthy overweight men (BMI: 25-30, age: 35-45 y) were randomized to either 1-AIT (n = 11) or 4-AIT (n = 13). After training, VO2max increased by 10% (∼5.0 mL⋅kg(-1)⋅min(-1)) and 13% (∼6.5 mL⋅kg(-1)⋅min(-1)) after 1-AIT and 4-AIT, respectively (group difference, p = 0.08). Oxygen cost during running at a sub-maximal workload was reduced by 14% and 13% after 1-AIT and 4-AIT, respectively. Systolic blood pressure decreased by 7.1 and 2.6 mmHg after 1-AIT and 4-AIT respectively, while diastolic pressure decreased by 7.7 and 6.1 mmHg (group difference, p = 0.84). Both groups had a similar ∼5% decrease in fasting glucose. Body fat, total cholesterol, LDL-cholesterol, and ox-LDL cholesterol only were significantly reduced after 4-AIT. Our data suggest that a single bout of AIT performed three times per week may be a time-efficient strategy to improve VO2max and reduce blood pressure and fasting glucose in previously inactive but otherwise healthy middle-aged individuals. The 1-AIT type of exercise training may be readily implemented as part of activities of daily living and could easily be translated into programs designed to improve public health.

Concepts: Blood, Myocardial infarction, Atherosclerosis, Blood pressure, Artery, Pulse, Cardiac cycle, Systole

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OBJECTIVES: The purpose of this study was to examine the impact of yoga on atrial fibrillation (AF) burden, quality of life (QoL), depression, and anxiety scores. BACKGROUND: Yoga is known to have significant benefit on cardiovascular health. The effect of yoga in reducing AF burden is unknown. METHODS: This single-center, pre-post study enrolled patients with symptomatic paroxysmal AF with an initial 3-month noninterventional observation period followed by twice-weekly 60-min yoga training for next 3 months. AF episodes during the control and study periods as well as SF-36, Zung self-rated anxiety, and Zung self-rated depression scores at baseline, before, and after the study phase were assessed. RESULTS: Yoga training reduced symptomatic AF episodes (3.8 ± 3 vs. 2.1 ± 2.6, p < 0.001), symptomatic non-AF episodes (2.9 ± 3.4 vs. 1.4 ± 2.0; p < 0.001), asymptomatic AF episodes (0.12 ± 0.44 vs. 0.04 ± 0.20; p < 0.001), and depression and anxiety (p < 0.001), and improved the QoL parameters of physical functioning, general health, vitality, social functioning, and mental health domains on SF-36 (p = 0.017, p < 0.001, p < 0.001, p = 0.019, and p < 0.001, respectively). There was significant decrease in heart rate, and systolic and diastolic blood pressure before and after yoga (p < 0.001). CONCLUSIONS: In patients with paroxysmal AF, yoga improves symptoms, arrhythmia burden, heart rate, blood pressure, anxiety and depression scores, and several domains of QoL. (Yoga on Arrythmia Burden and Quality of Life in Paroxysmal Atrial Fibrillation; NCT00798356).

Concepts: Blood, Heart, Stroke, Atrial fibrillation, Blood pressure, Ventricle, Cardiac cycle, Systole

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Interstitial fibrosis plays a key role in the development and progression of heart failure. Here, we show that an enzyme that crosslinks collagen-Lysyl oxidase-like 2 (Loxl2)-is essential for interstitial fibrosis and mechanical dysfunction of pathologically stressed hearts. In mice, cardiac stress activates fibroblasts to express and secrete Loxl2 into the interstitium, triggering fibrosis, systolic and diastolic dysfunction of stressed hearts. Antibody-mediated inhibition or genetic disruption of Loxl2 greatly reduces stress-induced cardiac fibrosis and chamber dilatation, improving systolic and diastolic functions. Loxl2 stimulates cardiac fibroblasts through PI3K/AKT to produce TGF-β2, promoting fibroblast-to-myofibroblast transformation; Loxl2 also acts downstream of TGF-β2 to stimulate myofibroblast migration. In diseased human hearts, LOXL2 is upregulated in cardiac interstitium; its levels correlate with collagen crosslinking and cardiac dysfunction. LOXL2 is also elevated in the serum of heart failure (HF) patients, correlating with other HF biomarkers, suggesting a conserved LOXL2-mediated mechanism of human HF.

Concepts: Physiology, Cardiology, Heart, Blood pressure, Interstitial fluid, Ventricle, Mitral valve, Cardiac cycle

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We aimed to evaluate the predictive value of pulse rate (PR), systolic blood pressure (SBP), diastolic blood pressure, respiratory rate (RR), oxygen saturation (SaO2), and the Glasgow Coma Scale (GCS) for cardiac arrest and death in critically ill patients.

Concepts: Medicine, Blood, Myocardial infarction, Blood pressure, Vital signs, Artery, Pulse, Cardiac cycle

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Central aortic systolic blood pressure (SBP-C) can be estimated from a cuff oscillometric waveform derived during the pulse volume plethysmography (PVP) by applying a device-specific aortic pressure-to-PVP waveform-generalized transfer function (A2P(GTF)). The present study compared the performance of an aortic-to-brachial pressure waveforms generalized transfer function (A2B(GTF)), which is independent of any PVP devices, with an A2P(GTF). Generalized transfer function of aortic-to-brachial (A2B(GTF)) and aortic-to-PVP (A2P(GTF)) were generated from the simultaneously obtained central aortic and brachial pressure waveforms recorded by a high-fidelity dual pressure sensor catheter, and the PVP waveform recorded by a customized noninvasive blood pressure monitor during cardiac catheterization in 40 patients, and were then applied in another 100 patients with simultaneously recorded invasive aortic pressure and noninvasively calibrated (using cuff SBP and diastolic blood pressures) PVP waveforms. The mean difference±s.d. between the noninvasively estimated and invasively recorded SBP-C was -2.1±7.7 mm Hg for A2B(GTF), which was not greater than that of -3.0±7.7 mm Hg for A2P(GTF) (P<0.01). In conclusion, SBP-C can be measured reliably using a noninvasive blood pressure monitor by applying either an A2P(GTF) or A2B(GTF) to a noninvasively calibrated PVP waveform. The performance of an A2B(GTF) is not inferior to that of an A2P(GTF).

Concepts: Blood pressure, Artery, Pulse, Ventricle, Cardiac cycle, Systole, Brachial artery, Sphygmomanometer

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BACKGROUND: A variety of β-blockers are used to control heart rate (HR) in atrial fibrillation (AF); however, there have been few quantitative assessments of HR and blood pressure reductions with β-blocker monotherapy. METHODS AND RESULTS: Seventy-eight patients with chronic (persistent or permanent) AF were administered bisoprolol (2.5mg/day) for 2 weeks. Subsequently, 48 patients judged to require a dose increase were either continued on 2.5mg/day (24 patients) or administered a higher dose (5mg/day; 24 patients) in a double-blind fashion for two further weeks. Change in mean HR as determined by Holter electrocardiogram was the primary endpoint. After 2 weeks of bisoprolol 2.5mg/day, mean HR was significantly lower than that before treatment (12.2±9.1beats/min, p<0.001). Mean HRs in the 5-mg and 2.5-mg continuation groups were also significantly decreased compared with those before treatment (17.3±12.9 and 11.4±7.4beats/min, respectively, both p<0.001), with a significant between-group difference (p=0.033). The HR reduction was greater during the day than at night. Although a greater reduction in systolic blood pressure was seen in the 5-mg group than in the 2.5-mg continuation group, the difference between groups was not significant. There were no serious adverse events. CONCLUSIONS: This is the first quantitative analysis of β-blocker monotherapy in AF patients. Bisoprolol exhibits a dose-responsive HR reduction when administered at sequential doses of 2.5mg/day and 5mg/day.

Concepts: Blood, Cardiology, Heart, Atrial fibrillation, Blood pressure, Artery, Ventricle, Cardiac cycle

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Esophageal stethoscope is less invasive and easy to handling. And it gives a lot of information. The purpose of this study is to investigate the correlation of blood pressure and heart sound as measured by esophageal stethoscope. Four male beagles weighing 10 to 12 kg were selected as experimental subjects. After general anesthesia, the esophageal stethoscope was inserted. After connecting the microphone, the heart sounds were visualized and recorded through a self-developed equipment and program. The amplitudes of S1 and S2 were monitored real-time to examine changes as the blood pressure increased and decreased. The relationship between the ratios of S1 to S2 (S1/S2) and changes in blood pressure due to ephedrine was evaluated. The same experiment was performed with different concentration of isoflurane. From S1 and S2 in the inotropics experiment, a high correlation appeared with change in blood pressure in S1. The relationship between S1/S2 and change in blood pressure showed a positive correlation in each experimental subject. In the volatile anesthetics experiment, the heart sounds decreased as MAC increased. Heart sounds were analyzed successfully with the esophageal stethoscope through the self-developed program and equipment. A proportional change in heart sounds was confirmed when blood pressure was changed using inotropics or volatile anesthetics. The esophageal stethoscope can achieve the closest proximity to the heart to hear sounds in a non-invasive manner.

Concepts: Artery, Anesthesia, Change, Cardiac cycle, Heart sounds, Auscultation, Stethoscope, Microphone

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Objective: The present study was planned to study comparative effects of telmisartan vs lisinopril on blood pressure in patients of metabolic syndrome Methods: The study was carried out on 62 patients of metabolic syndrome from Dec 2010 to Oct 2012 in OPD of Institute. There were two groups, A and B. Group A- Telmisartan (31 patients) and Group B- Lisinopril (31 patients) receiving Telmisartan 40 mg and lisinopril 5 mg orally once a day respectively for 12 weeks. The diagnosis of essential hypertension was made by the physician based on two measurement of blood pressure on two different occasions using auscultatory method and was done at initial stage and repeated after 6 weeks and 12 weeks of treatment in Group A and Group B patients. Key findings: Our study found that telmisartan or lisinopril treatment for 12 weeks leads to statistically significant (p<0.001) reduction in both SBP and DBP at 6 and 12 weeks when compared with baseline, whereas comparison between telmisartan and lisinopril treatment failed to show any statistically significant effect. Conclusion: Treatment of metabolic patients with telmisartan or lisinopril for management of hypertension reduced both Systolic blood pressure (SBP) as well as Diastolic blood pressure (DBP) statistically significantly during 12 weeks treatment. However, telmisartan and lisinopril treatment found effective.

Concepts: Atherosclerosis, Hypertension, Blood pressure, Artery, Orthostatic hypotension, Prehypertension, Cardiac cycle, Systole

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Increased vascular stiffness, endothelial dysfunction, and isolated systolic hypertension are hallmarks of vascular aging. Regular cocoa flavanol (CF) intake can improve vascular function in healthy young and elderly at-risk individuals. However, the mechanisms underlying CF bioactivity remain largely unknown. We investigated the effects of CF intake on cardiovascular function in healthy young and elderly individuals without history, signs, or symptoms of cardiovascular disease by applying particular focus on functional endpoints relevant to cardiovascular aging. In a randomized, controlled, double-masked, parallel-group dietary intervention trial, 22 young (<35 years) and 20 elderly (50-80 year) healthy, male non-smokers consumed either a CF-containing drink (450 mg CF) or nutrient-matched, CF-free control drink bi-daily for 14 days. The primary endpoint was endothelial function as measured by flow-mediated vasodilation (FMD). Secondary endpoints included cardiac output, vascular stiffness, conductance of conduit and resistance arteries, and perfusion in the microcirculation. Following 2 weeks of CF intake, FMD improved in young (6.1 ± 0.7 vs. 7.6 ± 0.7 %, p < 0.001) and elderly (4.9 ± 0.6 vs. 6.3 ± 0.9 %, p < 0.001). Secondary outcomes demonstrated in both groups that CF intake decreased pulse wave velocity and lowered total peripheral resistance, and increased arteriolar and microvascular vasodilator capacity, red cell deformability, and diastolic blood pressure, while cardiac output remained affected. In the elderly, baseline systolic blood pressure was elevated, driven by an arterial-stiffness-related augmentation. CF intake decreased aortic augmentation index (-9 %) and thus systolic blood pressure (-7 mmHg; Clinicaltrials.gov: NCT01639781). CF intake reverses age-related burden of cardiovascular risk in healthy elderly, highlighting the potential of dietary flavanols to maintain cardiovascular health.

Concepts: Blood, Myocardial infarction, Atherosclerosis, Hypertension, Blood pressure, Artery, Cardiovascular system, Cardiac cycle

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