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1.
EuroIntervention ; 14(2): 158-165, 2018 06 20.
Article in English | MEDLINE | ID: mdl-29488884

ABSTRACT

AIMS: Residual gradients >20 mmHg after transcatheter valve-in-valve (ViV) implantation are associated with worse survival. This study aimed to evaluate the feasibility of high-pressure post-dilation with a non-compliant balloon after transcatheter ViV implantation in small surgical valves to optimise haemodynamics. METHODS AND RESULTS: Thirty patients underwent ViV implantation in surgical valves with internal dimension ≤19 mm. High-pressure post-dilation to 16-20 atmospheres with a non-compliant balloon was performed in 12 patients and 18 patients underwent ViV without post-dilation. SAPIEN 3 and Evolut valves were used in 10 and two patients, respectively. The mean aortic valve (AV) gradient decreased by 11.3 mmHg following high-pressure post-dilation (18.7±7.9 mmHg immediately post ViV to 7.5±2.6 mmHg following high-pressure post-dilation, p<0.01). There were no cases of aortic root rupture. High-pressure post-dilation, compared to no post-dilation, was associated with lower invasive AV mean gradients at the end of the ViV procedure (8.2±3.5 mmHg vs. 17.3±7.9 mmHg, p=0.001) as well as lower day 1 (18.0±4.5 mmHg vs. 25.0±8.1 mmHg, p=0.016) and 30-day gradients (19.8±2.5 vs. 26.5±11.0, p=0.038) on transthoracic echocardiography. CONCLUSIONS: High-pressure post-dilation of small surgical valves following transcatheter ViV implantation results in a significant improvement in post-procedure haemodynamics.


Subject(s)
Aortic Valve Stenosis , Bioprosthesis , Heart Valve Prosthesis , Transcatheter Aortic Valve Replacement , Aortic Valve , Dilatation , Humans , Prosthesis Design , Treatment Outcome
2.
Circ Heart Fail ; 9(7)2016 07.
Article in English | MEDLINE | ID: mdl-27413036

ABSTRACT

BACKGROUND: There is no consensus within the heart transplant community about whether patients who use marijuana should be eligible for transplant listing, but several states have passed legislation prohibiting marijuana-using patients from being denied transplant listing based on their use of the substance. METHODS AND RESULTS: We conducted an independent, voluntary, web-based survey of heart and lung transplant providers to assess current practice patterns and attitudes toward marijuana use in patients with advanced heart failure being considered for transplant. A total of 360 heart transplant providers responded from 26 countries. Nearly two thirds of respondents (n=222, 64.4%) supported listing patients with advanced, end-stage heart failure for transplant who use legal medical marijuana. Significantly, fewer respondents (n=96, 27.5%) supported transplant listing for patients using legal recreational marijuana. The majority of providers currently make patients eligible for transplantation after a period of abstinence from marijuana (n=241, 68.3%). There were no differences between the proportion of respondents supporting transplant listing after stratification by profession or country/region. Most (78.4%) survey respondents from states with laws prohibiting marijuana-using patients from being denied transplant listing reported denying all marijuana-using patients or mandating abstinence before transplant listing. CONCLUSIONS: The majority of heart and lung transplant providers in our study sample supports the listing of patients who use medical marijuana for transplant after a period of abstinence. Communication and collaboration between the medical community and legislative groups about marijuana use in transplant candidates is needed to ensure the best patient outcomes with the use of scarce donor organs.


Subject(s)
Heart Failure/surgery , Heart Transplantation , Marijuana Abuse , Marijuana Smoking , Medical Marijuana/therapeutic use , Patient Selection , Waiting Lists , Adult , Attitude of Health Personnel , Eligibility Determination , Health Care Surveys , Health Knowledge, Attitudes, Practice , Heart Failure/diagnosis , Heart Failure/physiopathology , Humans , Marijuana Abuse/complications , Marijuana Abuse/prevention & control , Marijuana Smoking/adverse effects , Marijuana Smoking/legislation & jurisprudence , Marijuana Smoking/prevention & control , Medical Marijuana/adverse effects , Middle Aged , Practice Patterns, Physicians' , Risk Assessment , Risk Factors
3.
Am J Cardiol ; 118(2): 195-7, 2016 07 15.
Article in English | MEDLINE | ID: mdl-27241835

ABSTRACT

Invasive coronary angiography (ICA) uses harmful x-ray energy. To date, there are no studies evaluating the effect of performing ICA at lower than the standard 15 frames per second (f/s) on radiation dose and image quality. In this study, we investigated the effect of performing ICAs at 7.5 f/s as opposed to the standard 15 f/s on radiation exposure and image quality. Thirty-nine patients referred for ICA for clinical indications were assigned to have their ICA performed at 7.5 f/s or 15 f/s in a 2:1 ratio, respectively. All studies were performed by one experienced operator in the same laboratory. Magnification, table height, collimation, number of images, and specific angles for image acquisition were kept constant to account for these variables that also effect radiation. Studies performed at 7.5 f/s had significantly less radiation exposure than those performed at 15 f/s (252.2 mGy vs 433.7 mGy, p <0.01). In addition, radiation per unit time was also significantly reduced in the 7.5 f/s versus the 15 f/s group (140.0 mGy/min vs 254.7 mGy/min, p <0.01). Image quality was evaluated by an experienced operator blinded to the goals of the study; allstudies were graded as good to excellent. In conclusion, performing ICA at 7.5 f/s versus 15 f/s significantly reduces x-ray exposure without compromising image quality. The results of this single-center study warrant a larger randomized clinical trial.


Subject(s)
Coronary Angiography/methods , Coronary Vessels/diagnostic imaging , Radiation Dosage , Radiation Exposure , Cardiac Catheterization , Female , Humans , Male , Middle Aged , Time Factors
4.
JACC Cardiovasc Interv ; 9(12): 1280-1288, 2016 06 27.
Article in English | MEDLINE | ID: mdl-27339846

ABSTRACT

OBJECTIVES: This study reports a novel transcatheter procedure for residual mitral regurgitation (MR) after MitraClip implantation using the Amplatzer Duct Occluder II (ADO II). BACKGROUND: Although the MitraClip procedure is a transcatheter treatment option for patients at high surgical risk with severe MR, management of significant residual MR after MitraClip implantation is still challenging. METHODS: We describe a case series of 9 consecutive patients who underwent transcatheter deployment of the ADO II plug for significant residual MR after MitraClip implantation from April to October 2015. RESULTS: The mean age was 79.3 ± 11.4 years. The deployment of the ADO II plug was performed at the initial MitraClip procedure in 7 patients and at the second procedure for recurrent symptoms in 2 patients. There were 2 types of residual MR seen after MitraClip implantation: residual commissural MR (n = 3) and residual intraclip MR (n = 6). The ADO II was successfully deployed with significant reduction of MR flow and left atrial pressure in all patients. The ADO II plug was retrieved in 1 patient because of device embolization to the ostial right coronary artery. However, all patients were discharged 1.8 ± 1.2 days after the procedure, with no significant MR on pre-discharge transthoracic echocardiography. In 8 patients who underwent 1-month symptomatic assessment, clinical symptoms were diminished to New York Heart Association functional class I or II. CONCLUSIONS: Transcatheter deployment of the ADO II plug was effective for the reduction of residual commissural MR and intraclip MR after MitraClip implantation. The potential role of this technique should be established for challenging cases.


Subject(s)
Cardiac Catheterization/instrumentation , Heart Valve Prosthesis Implantation/instrumentation , Heart Valve Prosthesis , Hemodynamics , Mitral Valve Insufficiency/therapy , Mitral Valve/physiopathology , Septal Occluder Device , Aged , Aged, 80 and over , Cardiac Catheterization/adverse effects , Echocardiography, Doppler, Color , Echocardiography, Three-Dimensional , Echocardiography, Transesophageal , Female , Heart Valve Prosthesis Implantation/adverse effects , Humans , Male , Mitral Valve/diagnostic imaging , Mitral Valve Insufficiency/diagnostic imaging , Mitral Valve Insufficiency/physiopathology , Prosthesis Design , Radiography, Interventional , Retreatment , Severity of Illness Index , Time Factors , Treatment Outcome
8.
Ann Thorac Surg ; 97(1): 15-21, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24206971

ABSTRACT

BACKGROUND: Clopidogrel use post coronary artery bypass grafting (CABG) has become more popular under the assumption that it improves graft patency. The purpose of this sub-analysis from the Randomized On and Off-Pump Bypass (ROOBY) trial is to evaluate the role of clopidogrel use post CABG to improve graft patency when added to standard aspirin therapy. METHODS: The ROOBY trial was a multi-center, randomized, controlled clinical trial that compared on-pump versus off-pump coronary artery bypass grafting (CABG). Clopidogrel use post CABG was left at the discretion of the operator. Detailed data regarding the use and timing of clopidogrel post CABG were collected prospectively, along with 1-year angiograms to evaluate graft status. RESULTS: Of the 2,203 subjects undergoing CABG, 953 patient records had complete clopidogrel use and 1-year angiographic data. Of these, 345 (36.2%) received clopidogrel post CABG prior to discharge. Compared with patients with no post-CABG clopidogrel use, baseline characteristics were similar for the clopidogrel group except for the following: lower preoperative aspirin use (80.2% vs 86.7%, p = 0.009); higher preoperative clopidogrel use (23.5% vs 14.0%, p < 0.001), less on-pump (35.9% vs 55.9%, p < 0.0001); and lower endoscopic vein harvesting (30.8% vs 42.5%, p < 0.001) rates. Overall 1-year graft patency rates were not different between the clopidogrel and no-clopidogrel groups (86.5% vs 85.3%, p = 0.43). Multivariable analyses did not alter these findings. CONCLUSIONS: This study suggests that routine post-CABG clopidogrel use may not translate to improved 1-year graft patency. Future studies appear warranted to better define the role of more aggressive antiplatelet therapy post CABG on graft patency and clinical outcomes.


Subject(s)
Coronary Artery Bypass/methods , Coronary Disease/surgery , Graft Occlusion, Vascular/prevention & control , Platelet Aggregation Inhibitors/administration & dosage , Ticlopidine/analogs & derivatives , Adult , Aged , Aged, 80 and over , Clopidogrel , Coronary Angiography/methods , Coronary Artery Bypass/adverse effects , Coronary Artery Bypass, Off-Pump/adverse effects , Coronary Artery Bypass, Off-Pump/methods , Coronary Disease/diagnostic imaging , Coronary Disease/mortality , Dose-Response Relationship, Drug , Drug Administration Schedule , Education, Medical, Continuing , Female , Follow-Up Studies , Graft Occlusion, Vascular/drug therapy , Humans , Male , Middle Aged , Multivariate Analysis , Postoperative Care/methods , Prospective Studies , Reference Values , Regression Analysis , Ticlopidine/administration & dosage , Time Factors , Treatment Outcome , Vascular Patency/physiology
9.
Phys Sportsmed ; 41(3): 58-66, 2013 Sep.
Article in English | MEDLINE | ID: mdl-24113703

ABSTRACT

In determining what is "abnormal"-in terms of cardiac electrical and morphologic remodeling in athletes-it is important to identify what is "normal" or expected. With specialization for each position in a football team lineup, we attempted to describe the association between the position played and the physiologic cardiac changes of designated players. We evaluated data from 85 National College Athletic Association football players from a single team. The participants were assigned to 1 of 3 groups based on position and training regimen: lineman (n = 34), mobility/power players (n = 13), and skill players (n = 38). Players underwent assessment with electrocardiography and echocardiography (ECHO), with results interpreted by reviewers blinded to players' positions. Linemen were found to have greater body mass index and body surface area (BSA), as well as longer QRS duration (102 ± 10 ms vs 101 ± 7 ms in mobility/power players, and 96 ± 7 ms in skill players; P < 0.007). Left ventricular (LV) voltage values were lower in linemen (27.7 ± 6.5 mV vs 28.8 ± 7 mV in mobility/power players, and 31.8 ± 7.6 mV in skill players; both, P < 0.05). No differences in ejection fraction between groups were revealed on ECHO, but ECHO did show greater calculated LV mass, LV end-diastolic diameter, aortic root diameter, and LV outflow tract diameter in linemen, whether adjusted for BSA or not, and the differences were statistically different. Multivariate analysis showed that position (P < 0.0004 and QRS duration (P = 0.03) predicted LV mass. Echocardiographic variables found to be associated with player position included LV mass adjusted for BSA (P < 0.0001), LV end-diastolic diameter adjusted for BSA (P < 0.0003), and QTc interval (P = 0.007). On multivariate analysis, racial identity did not demonstrate significant differences; however, differences existed on univariate analysis of electrocardiography and ECHO variables, mostly in skill players. In skill players, QRS duration was shorter in the African American (AA) subgroup compared with that in the white/other subgroup. Lateral ST elevation and LV end-systolic volume were greater in AA players after adjustment for BSA, and AA linemen had greater LV posterior wall thickness after adjustment for BSA. In summary, we found that football players who are linemen had greater heart mass than did other players, despite adjustments for body size.


Subject(s)
Athletes , Echocardiography/methods , Exercise/physiology , Football/physiology , Heart Atria/diagnostic imaging , Heart Ventricles/diagnostic imaging , Ventricular Remodeling/physiology , Adolescent , Adult , Electrocardiography , Follow-Up Studies , Humans , Male , Retrospective Studies , Young Adult
10.
Mayo Clin Proc ; 87(7): 614-9, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22766081

ABSTRACT

OBJECTIVE: To evaluate the prevalence of early polarization (ER) in a stable population and to evaluate the prognostic significance of the association or absence of Q waves or T-wave inversion (TWI). PATIENTS AND METHODS: In this retrospective study performed at the university-affiliated Palo Alto Veterans Affairs Health Care Center from March 1, 1987, through December 31, 1999, we evaluated outpatient electrocardiograms. Vital status and cause of death were determined in all patients, with a mean ± SD follow-up of 7.6±3.8 years. RESULTS: Of the 29,281 patients, 87% were men and 13% were African American. Inferior or lateral ER was present in 664 patients (2.3%): in inferior leads in 185 (0.6%), in lateral leads in 479 (1.6%) , and in both inferior and lateral leads in 163 (0.6%). Only when Q waves or TWI accompanied ER was there an increased risk of cardiovascular death (Cox proportional hazards regression model, 5.0; 95% confidence interval, 3.4-7.2; P<.001). CONCLUSION: Common patterns of ER without concomitant Q waves or TWI are not associated with increased risk of cardiovascular death; however, when either occurs with ER, there is a hazard ratio of 5.0. These findings confirm that ER is a benign entity; however, the presence of Q waves or TWI with ER is predictive of increased cardiovascular death.


Subject(s)
Arrhythmias, Cardiac/mortality , Arrhythmias, Cardiac/physiopathology , Cardiovascular Diseases/mortality , Cardiovascular Diseases/physiopathology , Electrocardiography , Heart Conduction System/physiopathology , Adult , Black or African American/statistics & numerical data , Aged , Arrhythmias, Cardiac/ethnology , Cause of Death , Coronary Disease/mortality , Coronary Disease/physiopathology , Female , Heart Rate , Humans , Male , Middle Aged , Predictive Value of Tests , Prognosis , Proportional Hazards Models , Retrospective Studies , Risk Assessment , Risk Factors , Time Factors , White People/statistics & numerical data
11.
Eur J Prev Cardiol ; 19(1): 126-38, 2012 Feb.
Article in English | MEDLINE | ID: mdl-21450619

ABSTRACT

BACKGROUND: Broad criteria for abnormal electrocardiogram (ECG) findings, requiring additional testing, have been recommended for preparticipation exams (PPE) of athletes. As these criteria have not considered the sport in which athletes participate, we examined the effect of sports on the computerized ECG measurements obtained in college athletes. METHODS: During the Stanford 2007 PPE, computerized 12-lead ECGs (Schiller AG) were obtained in 641 athletes (350 male/291 female, age 19.5 ± 2 years). Athletes were engaged in 22 different sports and were grouped into 16 categories: baseball/softball, basketball, crew, crosscountry, fencing, field events, football linemen, football other positions, golf, gymnastics, racquet sports, sailing, track/field, volleyball, water sports, and wrestling. The analysis focused on ECG leads V2, aVF and V5 which provide a three-dimensional representation of the heart's electrical activity. As marked ECG differences exist between males and females, the data are presented by gender. RESULTS: In males, ANOVA analysis yielded significant ECG differences between sports for heart rate, QRS duration, QTc, J-amplitude in V2 and V5, spatial vector length (SVL) of the P wave, SVL R wave, and SVL T wave, and RS(sum) (p < 0.05). In females ECG differences between sports were found for heart rate, QRS duration, QRS axis and SVL T wave (p < 0.05). Poor correlations were found between body dimensions and ECG measurements (r < 0.50). CONCLUSIONS: Significant ECG changes exist between college athletes participating in different sports, and these differences were more apparent in males than females. Therefore, sport-specific ECG criteria for abnormal ECG findings should be developed to obtain a more useful approach to ECG screening in athletes.


Subject(s)
Athletes , Cardiovascular Diseases/diagnosis , Electrocardiography , Signal Processing, Computer-Assisted , Sports , Students , Adolescent , Analysis of Variance , California , Cardiovascular Diseases/etiology , Cardiovascular Diseases/physiopathology , Female , Heart Rate , Humans , Male , Predictive Value of Tests , Reproducibility of Results , Risk Assessment , Risk Factors , Sex Factors , Young Adult
12.
Heart Rhythm ; 9(4): 558-65, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22094072

ABSTRACT

BACKGROUND: Increased prevalence of classic early repolarization, defined as ST-segment elevation (STE) in the absence of acute myocardial injury, in African Americans is well established. The prognostic value of this pattern in different ethnicities remains controversial. OBJECTIVE: Measure association between early repolarization and cardiovascular mortality in African Americans. METHODS: The resting electrocardiograms of 45,829 patients were evaluated at the Palo Alto Veterans Affairs Hospital. Subjects with inpatient status or electrocardiographic evidence of acute myocardial infarction were excluded, leaving 29,281 subjects. ST-segment elevation, defined as an elevation of >0.1 mV at the end of the QRS, was electronically flagged and visually adjudicated by 3 observers blinded to outcomes. An association between ethnicity and early repolarization was measured by using multivariate logistic regression. We analyzed associations between early repolarization and cardiovascular mortality by using the Cox proportional hazards regression analysis. RESULTS: Subjects were 13% women and 13.3% African Americans, with an average age of 55 years and followed for an average of 7.6 years, resulting in 1995 cardiovascular deaths. There were 479 subjects with lateral STE and 185 with inferior STE. After adjustment for age, sex, heart rate, and coronary artery disease, African American ethnicity was associated with lateral or inferior STE (odds ratio 3.1; P = .0001). While lateral or inferior STE in non-African Americans was independently associated with cardiovascular death (hazard ratio 1.6; P = .02), it was not associated with cardiovascular death in African Americans (hazard ratio 0.75; P = .50). CONCLUSIONS: Although early repolarization is more prevalent in African Americans, it is not predictive of cardiovascular death in this population and may represent a distinct electrophysiologic phenomenon.


Subject(s)
Black or African American/statistics & numerical data , Coronary Artery Disease/diagnosis , Myocardial Infarction/diagnosis , Adult , Confidence Intervals , Coronary Artery Disease/epidemiology , Coronary Artery Disease/mortality , Female , Focus Groups , Humans , Logistic Models , Male , Middle Aged , Multivariate Analysis , Myocardial Infarction/epidemiology , Myocardial Infarction/mortality , Odds Ratio , Prognosis , Statistics as Topic , Time Factors , United States/epidemiology
13.
Circulation ; 124(20): 2208-14, 2011 Nov 15.
Article in English | MEDLINE | ID: mdl-21986288

ABSTRACT

BACKGROUND: The significance of early repolarization, particularly regarding the morphology of the R-wave downslope, has come under question. METHODS AND RESULTS: We evaluated 29 281 resting ambulatory ECGs from the VA Palo Alto Health Care System. With PR interval as the isoelectric line and amplitude criteria ≥0.1 mV, ST-segment elevation is defined at the end of the QRS, J wave as an upward deflection, and slur as a conduction delay on the QRS downstroke. Associations of ST-segment elevation patterns, J waves, and slurs with cardiovascular mortality were analyzed with Cox analysis. With a median follow-up of 7.6 years, there were 1995 cardiac deaths. Of 29 281 subjects, 87% were male (55±14 years) and 13% were female (56±17 years); 13% were black, 6% were Hispanic, and 81% were white or other. Six hundred sixty-four (2.3%) had inferior or lateral ST-segment elevation: 185 (0.6%) in inferior leads and 479 (1.6%) in lateral leads, 163 (0.6%) in both, and 0.4% had global elevation. A total of 4041 ECGs were analyzed with enhanced display, and 583 (14%) had J waves or slurring, which were more prevalent in those with than in those without ST-segment elevation (61% versus 13%; P<0.001). ST-segment elevation occurred more in those with than in those without J waves or slurs (12% versus 1.3%; P<0.001). Except when involving only inferior leads, all components of early repolarization were more common in young individuals, male subjects, blacks, and those with bradycardia. All patterns and components of early repolarization were associated with decreased cardiovascular mortality, but this was not significant after adjustment for age. CONCLUSIONS: We found no significant association between any components of early repolarization and cardiac mortality.


Subject(s)
Ambulatory Care , Arrhythmias, Cardiac/mortality , Arrhythmias, Cardiac/physiopathology , Electrocardiography , Adult , Aged , Ambulatory Care/methods , Arrhythmias, Cardiac/diagnosis , Electrocardiography/methods , Female , Follow-Up Studies , Humans , Male , Middle Aged , Retrospective Studies , Time Factors
14.
Clin J Sport Med ; 21(5): 433-40, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21892017

ABSTRACT

OBJECTIVE: To demonstrate the prevalence and patterns of ST elevation (STE) in ambulatory individuals and athletes and compare the clinical outcomes. DESIGN: Retrospective cohort study. ST elevation was measured by computer algorithm and defined as ≥0.1 mV at the end of the QRS complex. Elevation was confirmed, and J waves and slurring were coded visually. SETTING: Veterans Affairs Palo Alto Health Care System and Stanford University varsity athlete screening evaluation. PATIENTS: Overall, 45 829 electrocardiograms (ECGs) were obtained from the clinical patient cohort and 658 ECGs from athletes. We excluded inpatients and those with ECG abnormalities, leaving 20 901 outpatients and 641 athletes. INTERVENTIONS: Electrocardiogram evaluation and follow-up for vital status. MAIN OUTCOME MEASURES: All-cause and cardiovascular mortality and cardiac events. RESULTS: ST elevation in the anterior and lateral leads was more prevalent in men and in African Americans and inversely related to age and resting heart rate. Athletes had a higher prevalence of early repolarization even when matched for age and gender with nonathletes. ST elevation greater than 0.2 mV (2 mm) was very unusual. ST elevation was not associated with cardiac death in the clinical population or with cardiac events or abnormal test results in the athletes. CONCLUSIONS: Early repolarization is not associated with cardiac death and has patterns that help distinguish it from STE associated with cardiac conditions, such as myocardial ischemia or injury, pericarditis, and the Brugada syndrome.


Subject(s)
Electrocardiography , Heart Diseases/diagnosis , Sports/physiology , Adolescent , Adult , Age Factors , Aged , Chi-Square Distribution , Female , Heart Diseases/ethnology , Heart Diseases/physiopathology , Heart Rate , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Physical Examination , Proportional Hazards Models , Retrospective Studies , Young Adult
16.
Exerc Sport Sci Rev ; 39(2): 68-76, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21206280

ABSTRACT

Aging, vascular function, and exercise are thought to have a common link in oxidative stress. Both antioxidant supplementation and exercise training have been identified as interventions that may reduce oxidative stress, but their interaction in older humans is not well understood.


Subject(s)
Aging/physiology , Antioxidants/physiology , Exercise/physiology , Oxidative Stress/physiology , Vasodilation/physiology , Aged , Arteries/physiology , Blood Pressure/physiology , Humans
18.
Am J Physiol Heart Circ Physiol ; 298(2): H671-8, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19966056

ABSTRACT

Aging, vascular function, and exercise are thought to have a common link in oxidative stress. Of the 28 subjects studied (young, 26 +/- 2 yr; old, 71 +/- 6 yr), 12 took part in a study to validate an antioxidant cocktail (AOC: vitamins C, E, and alpha-lipoic acid), while the remaining 8 young and 8 old subjects performed submaximal forearm handgrip exercise with placebo or AOC. Old subjects repeated forearm exercise with placebo or AOC following knee-extensor (KE) exercise training. Brachial arterial diameter and blood velocity (Doppler ultrasound) were measured at rest and during exercise. During handgrip exercise, brachial artery vasodilation in the old subjects was attenuated compared with that in young subjects following placebo (maximum = approximately 3.0 and approximately 6.0%, respectively). In contrast to the previously documented attenuation in exercise-induced brachial artery vasodilation in the young group with AOC, in the old subjects the AOC restored vasodilation (maximum = approximately 7.0%) to match the young. KE training also improved exercise-induced brachial artery vasodilation. However, in the trained state, AOC administration no longer augmented brachial artery vasodilation in the elderly, but rather attenuated it. These data reveal an age-related pro-/antioxidant imbalance that impacts vascular function and show that exercise training is capable of restoring equilibrium such that vascular function is improved and the AOC-mediated reduction in free radicals now negatively impacts brachial artery vasodilation, as seen in the young.


Subject(s)
Aging/physiology , Antioxidants/pharmacology , Brachial Artery/physiology , Exercise Tolerance/physiology , Exercise/physiology , Vasodilation/drug effects , Vasodilation/physiology , Adolescent , Adult , Aged , Aged, 80 and over , Ascorbic Acid/pharmacology , Drug Therapy, Combination , Hand Strength/physiology , Humans , Male , Oxidative Stress/drug effects , Thioctic Acid/pharmacology , Vitamin E/pharmacology , Young Adult
19.
Clin Sci (Lond) ; 116(5): 433-41, 2009 Mar.
Article in English | MEDLINE | ID: mdl-18795893

ABSTRACT

Both antioxidant supplementation and exercise training have been identified as interventions which may reduce oxidative stress and thus improve cardiovascular health, but the interaction of these interventions on arterial BP (blood pressure) and vascular function has not been studied in older humans. Thus in six older (71+/-2 years) mildly hypertensive men, arterial BP was evaluated non-invasively at rest and during small muscle mass (knee-extensor) exercise with and without a pharmacological dose of oral antioxidants (vitamins C and E, and alpha-lipoic acid). The efficacy of the antioxidant intervention to decrease the plasma free radical concentration was verified via EPR (electron paramagnetic resonance) spectroscopy, while changes in endothelial function in response to exercise training and antioxidant administration were evaluated via FMD (flow-mediated vasodilation). Subjects were re-evaluated after a 6-week aerobic exercise training programme. Prior to training, acute antioxidant administration did not change resting arterial BP or FMD. Six weeks of knee-extensor exercise training reduced systolic BP (from 150+/-8 mmHg at pre-training to 138+/-3 mmHg at post-training) and diastolic BP (from 91+/-5 mmHg at pre-training to 79+/-3 mmHg at post-training), and improved FMD (1.5+/-1 to 4.9+/-1% for pre- and post-training respectively). However, antioxidant administration after exercise training negated these improvements, returning subjects to a hypertensive state and blunting training-induced improvements in FMD. In conclusion, the paradoxical effects of these interventions suggest a need for caution when exercise and acute antioxidant supplementation are combined in elderly mildly hypertensive individuals.


Subject(s)
Antioxidants/therapeutic use , Exercise/physiology , Hypertension/drug therapy , Aged , Antioxidants/administration & dosage , Antioxidants/adverse effects , Blood Pressure/drug effects , Combined Modality Therapy , Cross-Over Studies , Dietary Supplements/adverse effects , Double-Blind Method , Drug Administration Schedule , Endothelium, Vascular/drug effects , Endothelium, Vascular/physiopathology , Free Radicals/blood , Humans , Hypertension/physiopathology , Hypertension/rehabilitation , Male , Treatment Outcome , Vasodilation/drug effects
20.
Am J Physiol Heart Circ Physiol ; 292(3): H1516-22, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17114239

ABSTRACT

Originally thought of as simply damaging or toxic "accidents" of in vivo chemistry, free radicals are becoming increasingly recognized as redox signaling molecules implicit in cellular homeostasis. Indeed, at the vascular level, it is plausible that oxidative stress plays a regulatory role in normal vascular function. Using electron paramagnetic resonance (EPR) spectroscopy, we sought to document the ability of an oral antioxidant cocktail (vitamins C, E, and alpha-lipoic acid) to reduce circulating free radicals, and we employed Doppler ultrasound to examine the consequence of an antioxidant-mediated reduction in oxidative stress on exercise-induced vasodilation. A total of 25 young (18-31 yr) healthy male subjects partook in these studies. EPR spectroscopy revealed a reduction in circulating free radicals following antioxidant administration at rest ( approximately 98%) and as a consequence of exercise ( approximately 85%). Plasma total antioxidant capacity and vitamin C both increased following the ingestion of the antioxidant cocktail, whereas vitamin E levels were not influenced by the ingestion of the antioxidants. Brachial artery vasodilation during submaximal forearm handgrip exercise was greater with the placebo (7.4 +/- 1.8%) than with the antioxidant cocktail (2.3 +/- 0.7%). These data document the efficacy of an oral antioxidant cocktail in reducing free radicals and suggest that, in a healthy state, the aggressive disruption of the delicate balance between pro- and antioxidant forces can negatively impact vascular function. These findings implicate an exercise-induced reliance upon pro-oxidant-stimulated vasodilation, thereby revealing an important and positive vascular role for free radicals.


Subject(s)
Antioxidants/metabolism , Antioxidants/pharmacology , Brachial Artery/physiology , Exercise/physiology , Hand Strength , Vasodilation/physiology , Adolescent , Adult , Ascorbic Acid/blood , Blood Flow Velocity/drug effects , Brachial Artery/diagnostic imaging , Electron Spin Resonance Spectroscopy , Exercise Test , Forearm/blood supply , Free Radicals/metabolism , Humans , Male , Oxidative Stress , Reference Values , Ultrasonography, Doppler , Vasodilation/drug effects , Vitamin E/blood
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