Publications by authors named "Victor F Froelicher"

Objectives: To compare the prevalence of training-related ECG findings in white, mixed-race, and black male Brazilian soccer players.

Design: Multicenter observational study.

Methods: This study involved athletes aged 15 to 35 years from 82 professional clubs across Brazil's five regions.

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Objective: ST segment deviations around the isoelectric line are common findings in manifest cardiovascular disease. In athletes, ST elevation is common, while ST depression is considered rare. However, clinical studies in athletes have associated ST depression with myocardial fibrosis and fatty infiltration and ST elevation with pericarditis and myocarditis.

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There is a growing body of literature focusing on the morphology, management, and outcomes of PVCs in athletes. This review summarizes this literature and establishes recommendations on management, treatment, and indications for specialist referral in this patient population. The sports medicine physician's responses and recommendation should be made in conjunction with the athletes wishes.

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Objectives: The 12-lead electrocardiogram (ECG) is used in the preparticipation screening examination for athletes. Despite known differences in ECG findings by sex, only QTc prolongation is given a sex-specific threshold. We hypothesize that our large dataset-with diversity in age, race, and sport participation-can be utilized to improve ECG screening in female student athletes.

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Although engaging in physical exercise has been shown to reduce the incidence of cardiovascular events, the molecular mechanisms by which exercise mediates these benefits remain unclear. Based on epidemiological evidence, reductions in traditional risk factors only accounts for 50% of the protective effects of exercise, leaving the remaining mechanisms unexplained. The objective of this study was to determine whether engaging in a regular exercise program in a real world clinical setting mediates cardiovascular protection via modulation of non-traditional risk factors, such as those involved in coagulation, inflammation and metabolic regulation.

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Background: Because sudden cardiac death (SCD) in the young mainly occurs in individuals with structurally normal hearts, improved screening techniques for detecting inherited arrhythmic diseases are needed. The QT interval is an important screening measurement; however, the criteria for detecting an abnormal QT interval are based on Bazett formula and older populations.

Objective: To define the normal upper limits for QT interval from the electrocardiograms (ECGs) of healthy young individuals, compare the major correction formula and propose new QT interval thresholds for detecting those at risk of SCD.

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Objective: While >20% of patients presenting to the cardiac catheterization laboratory with angina have no obstructive coronary artery disease (CAD), a majority (77%) have an occult coronary abnormality (endothelial dysfunction, microvascular dysfunction (MVD), and/or a myocardial bridge (MB)). There are little data regarding the ability of noninvasive stress testing to identify these occult abnormalities in patients with angina in the absence of obstructive CAD.

Methods: We retrospectively evaluated 155 patients (76.

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Background: Numerous methods have been proposed for diagnosing left ventricular hypertrophy using the electrocardiogram. They have limited sensitivity for recognizing pathological hypertrophy, at least in part due to their inability to distinguish pathological from physiological hypertrophy. Our objective is to compare the major electrocardiogram-left ventricular hypertrophy criteria using cardiovascular mortality as a surrogate for pathological hypertrophy.

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Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural, or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes.

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Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes.

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Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural, or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes.

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Purpose: Sudden cardiac death is the leading cause of death in athletes. Long QT syndrome (LQTS) is one of the most common cardiogenetic diseases that can lead to sudden cardiac death and is identified by QT interval prolongation on an ECG. Recommendations for QT monitoring in athletes are adopted from nonathlete populations.

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Background: Sudden cardiac death is often linked with hypertrophic cardiomyopathy in young athletes, but with a divergence of study results. We performed a meta-analysis to compare the prevalence of sudden cardiac deaths associated with hypertrophic cardiomyopathy vs sudden cardiac deaths associated with structurally normal hearts.

Methods: A structured search of MEDLINE was conducted for studies published from 1990 through 2014.

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Background: The prognostic value of early repolarization with J waves and QRS slurs remains controversial. Although these findings are more prevalent in patients with idiopathic ventricular fibrillation, their ability to predict cardiovascular death has varied across studies.

Objective: To test the hypothesis that J waves and QRS slurs on electrocardiograms (ECGs) are associated with increased risk for cardiovascular death.

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Objective: To examine the prevalence of athletes who screen positive with the preparticipation examination guidelines from the American Heart Association, the AHA 12-elements, in combination with 3 screening electrocardiogram (ECG) criteria.

Design: Observational cross-sectional study.

Setting: Stanford University Sports Medicine Clinic.

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Although extending the duration of ambulatory electrocardiographic monitoring beyond 24 to 48 hours can improve the detection of arrhythmias, lead-based (Holter) monitors might be limited by patient compliance and other factors. We, therefore, evaluated compliance, analyzable signal time, interval to arrhythmia detection, and diagnostic yield of the Zio Patch, a novel leadless, electrocardiographic monitoring device in 26,751 consecutive patients. The mean wear time was 7.

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Aims: Though early repolarization (ER) in the inferior leads has been associated with increased cardiovascular risk, its natural history is uncertain. We aimed to study the serial electrocardiographic behavior of inferior ER and understand factors associated with that behavior.

Methods: We selected electrocardiograms (ECGs) from patients with the greatest amplitude of ER in AVF from ECGs of 29,281 ambulatory patients recorded between 1987 and 1999 at the Palo Alto Veterans Affairs Hospital.

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Although it is known that the electrocardiographic pattern of early repolarization (ER) occurs most commonly in healthy young bradycardic men, its natural history is uncertain. We considered initial electrocardiograms (ECGs) at rest from 29,281 ambulatory patients recorded from 1987 through 1999 at Veterans Affairs Palo Alto Hospital. With PR interval as the isoelectric line and amplitude criterion as >0.

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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.

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Background: Cardiac repolarization adaptation to cycle length change is patient dependent and results in complex QT-RR hysteresis. We hypothesize that accurate patient-specific QT-RR curves and rate corrected QT values (QTc) can be derived through patient-specific modeling of hysteresis.

Method And Results: Model development was supported by QT-RR observations from 1959 treadmill tests, allowing extensive exploration of the influences of autonomic function on QT adaptation to rate changes.

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