Transient ascending ST-segment depression and widening of the S wave in 3-channel Holter monitoring-A sign of dromotropic disturbance in the right ventricular outflow tract in the Brugada syndrome: A report of five cases.

BACKGROUND: Brugada syndrome (BrS) is somewhat a challenging diagnosis, due to its dynamic pattern. One of the aspects of this disease is a significant conduction disorder located in the right ventricular outflow tract (RVOT), which can be explained as a consequence of low expression of Connexin-43. This decreased conduction speed is responsible for the typical electrocardiographic pattern. Opposite leads located preferably in inferior leads of the electrocardiogram may show a deep and widened S wave associated with ascending ST segment depression. Holter monitoring electrocardiographic (ECG) aspects is still a new frontier of knowledge in BrS, especially in intermittent clinical presentations. METHODS: We describe, as an exploratory analysis, five case series of intermittent type 1 BrS to demonstrate the appearance of ascending ST segment depression and widening of the S wave, during 3-channel 24h-Holter monitoring (C1, C2 and C3) with bipolar leads. RESULTS: In the five cases described, the ST segment depression was observed mainly in C2, but in some cases also in C1 and C3. Only case 1 presented concomitant intermittent elevation of the ST segment in C1. All cases were intermittent. CONCLUSION: The recognition of an ECG pattern with ascending ST-segment depression and widening of the S wave in 3-channel Holter described in this case series should raise a suspicion of the BrS and suggests the counterpart of a dromotropic disturbance registered in the RVOT and/or reciprocal changes.

Value of electro-vectorcardiogram in hypertrophic cardiomyopathy.

The electrocardiogram is an important tool for the initial diagnostic suspicion of hypertrophic cardiomyopathy in any of its forms, both in symptomatic and in asymptomatic patients because it is altered in more than 90 percent of the cases. Electrocardiographic anomalies are more common in patients carriers of manifest hypertrophic cardiomyopathy and the electrocardiogram alterations are earlier and more sensitive than the increase in left ventricular wall thickness detected by the echocardiogram. Nevertheless, despite being the leading cause of sudden death among young competitive athletes there is no consensus over the need to include the method in the pre-participation screening. In apical hypertrophic cardiomyopathy the electrocardiographic hallmarks are the giant negative T waves in anterior precordial leads. In the vectorcardiogram, the QRS loop is located predominantly in the left anterior quadrant and T loop in the opposite right posterior quadrant, which justifies the deeply negative T waves recorded. The method allows estimating the left ventricular mass because it relates to the maximal spatial vector voltage of the left ventricle in the QRS loop. The recording on electrocardiogram or Holter monitoring of nonsustained monomorphic ventricular tachycardia in patients with syncope, recurrent syncope in young patient, hypotension induced by strain, bradyarrhythmia, or concealed conduction are markers of poor prognosis. The presence of rare sustained ventricular tachycardia is observed in mid-septal obstructive HCM with apical aneurysm. The presence of complete right bundle branch block pattern is frequent after the percutaneous treatment and complete left bundle branch block is the rule after myectomy.

Congenital short QT syndrome: landmarks of the newest arrhythmogenic cardiac channelopathy.

Congenital or familial short QT syndrome is a genetically heterogeneous cardiac channelopathy without structural heart disease that has a dominant autosomal or sporadic pattern of transmission affecting the electric system of the heart. Patients present clinically with a spectrum of signs and symptoms including irregular palpitations due to episodes of paroxysmal atrialfibrillation, dizziness and fainting (syncope) and/or sudden cardiac death due to polymorphic ventricular tachycardia and ventricular fibrillation. Electrocardiographic (ECG) findings include extremely short QTc intervals (QTc interval ≤330 ms) not significantly modified with heart rate changes and T waves of great voltage witha narrow base. Electrophysiologic studies are characterized by significant shortening of atrial and ventricular refractory periods and arrhythmias induced by programmed stimulation. A few families have been identified with specific genotypes: 3 with mutations in potassium channels called SQT1 (Iks), SQT2 (Ikr) and SQT3 (Ik1). These 3 potassium channel variants are the "genetic mirror image" of long QT syndrome type 2, type 1 and Andersen-Tawil syndrome respectively because they exert opposite gain-of-function effects on the potassium channels in contrast to the loss-of-function of the potassium channels in the long QT syndromes. Three new variants with overlapping phenotypes affecting the slow inward calcium channels havealso been described. Finally, another variant with mixed phenotype affecting the sodium channel was reported. This review focuses the landmarks of this newest arrhythmogenic cardiac channelopathy on the main clinical, genetic, and proposed ECG mechanisms. In addition therapeutic options and the molecular autopsy of this fascinating primary electrical heart disease are discussed.

Do patients with electrocardiographic Brugada type 1 pattern have associated right bundle branch block? A comparative vectorcardiographic study.

AIMS: Previous studies have reported right bundle branch block in Brugada syndrome. Subsequent analysis of electrocardiograms (ECGs) found one-third of cases classified as right bundle branch block did not meet criteria of a wide final S wave in the left leads. We aimed to study the role of the vectorcardiogram to characterize Brugada type 1 ECG pattern. METHODS AND RESULTS: Compare Frank-method vectorcardiogram in 11 patients with Brugada type 1 ECG pattern (BrS group) with vectorcardiogram of 20 healthy individuals with ECGs depicting incomplete right bundle branch block (IRBBB group) and 12 patients with complete right bundle branch block (CRBBB group). Initial 10-20 ms vector of the QRS loop in the horizontal plane (HP): BrS and IRBBB groups: Vector heading anterior and leftward. CRBBB group: Vector directed anterior and rightward. Right end conduction delay of the QRS loop: BrS group: Upper right quadrant of the frontal plane, right posterior quadrant of the HP. IRBBB group: Upper right quadrant of the frontal plane (30%) and right anterior quadrant of the HP (90%). CRBBB group: Upper right quadrant on the frontal plane (30%); all cases in the right anterior quadrant of the HP. 0 point (onset of QRS loop) and J point (end of QRS loop) relationship: BrS group: Not coincidental. IRBBB and CRBBB groups: Coincidental. T loop morphology, size, and appearance: BrS group: Circular, with symmetrical afferent and efferent limbs in 10 cases (90%). IRBBB and CRBBB groups: Elliptical or linear with slow inscription of efferent limb and rapid inscription of afferent limb. CONCLUSIONS: Vectorcardiograms in patients with Brugada type 1 ECG pattern have distinctive characteristics compared with healthy individuals with incomplete and CRBBB. These differences relate to the spatial location of the end conduction delay (right superior and posterior quadrant in the BrS group) and the morphology, size, and velocity of inscription of afferent and efferent limbs of the T loop (circular, small, of symmetrical limbs) and with a 1:1 length/width ratio.

Cardiorespiratory fitness and health-related quality of life in bariatric surgery patients.

Health-related quality of life (HRQOL) is impaired in severely obese individuals presenting for bariatric surgery. Little is known about the relationship between cardiorespiratory fitness (CRF) and HRQOL in these individuals. We hypothesized that better HRQOL would be reported by those with higher CRF. In 326 gastric bypass patients (mean BMI = 46.5 ± 7.0; mean age=40.9 ± 10.1; 83.4% female), pre-surgical CRF was quantified as duration (minutes) of a submaximal treadmill test to 80% of age-predicted maximal heart rate (MHR). Patients completed both a general measure of HRQOL [the Medical Outcome Short Form 36 (SF-36)] and a weight-specific measure of HRQOL [Impact of Weight on Quality of Life--Lite]. Mean HRQOL scores were examined, controlling for age, gender, and BMI. Mean treadmill duration was 9.9 ± 3.1 min, and percent age-predicted MHR was 81.2 ± 3.0%. Higher cardiorespiratory fitness tended to be associated with better physical and weight-specific HRQOL. Adjustment for differences in gender, age, and BMI attenuated the significance of associations between fitness and physical measures from the SF-36, whereas adjustment eliminated significance of associations between fitness and weight-specific HRQOL in most cases. Results suggest that CRF confers some HRQOL benefits in severely obese adults, though these benefits may largely be explained by differences in age, gender, and BMI.

Improved heart rate recovery after marked weight loss induced by gastric bypass surgery: two-year follow up in the Utah Obesity Study.

BACKGROUND: Obesity is associated with significantly increased cardiovascular mortality that has been attributed, in part, to sympathetic activation. Gastric bypass surgery (GBS) appears to increase long-term survival in the severely obese, but the mechanisms responsible for this increase are still being sought. Heart rate (HR) recovery after exercise reflects the balance of cardiac autonomic input from the sympathetic and parasympathetic systems. Blunted HR recovery is a very powerful predictor of increased mortality, whereas enhanced HR recovery portends a good prognosis. OBJECTIVE: The purpose of this study was to evaluate the effect of marked weight loss achieved via GBS on HR recovery. METHODS: Severely obese patients underwent submaximal exercise testing (80% predicted maximum HR) at baseline and 2 years after GBS (n = 153) or nonsurgical treatment (n = 188). RESULTS: Patients in the GBS group lost an average of 100 ± 37 lb compared to 3 ± 22 lb in the nonsurgical group (P <.001, GBS vs nonsurgical). Resting HR decreased from 73 bpm to 60 bpm in the GBS group and from 74 bpm to 68 bpm in nonsurgical patients (P <.001). HR recovery improved by 13 bpm in the GBS group but did not change in the nonsurgical group (P <.001 GBS vs nonsurgical). In multivariable analysis, the independent correlates of HR recovery at the 2-year time point were resting HR, treadmill time, age, body mass index, and HOMA-IR (an index of insulin resistance). CONCLUSION: Marked weight loss 2 years after GBS resulted in a significant decrease in resting HR and an enhancement in HR recovery after exercise. These changes likely are attributable to improvement in insulin sensitivity and cardiac autonomic balance. Whether and to what extent this contributes to a reduction in cardiovascular mortality with GBS remains to be determined.

Health outcomes of gastric bypass patients compared to nonsurgical, nonintervened severely obese.

Favorable health outcomes at 2 years postbariatric surgery have been reported. With exception of the Swedish Obesity Subjects (SOS) study, these studies have been surgical case series, comparison of surgery types, or surgery patients compared to subjects enrolled in planned nonsurgical intervention. This study measured gastric bypass effectiveness when compared to two separate severely obese groups not participating in designed weight-loss intervention. Three groups of severely obese subjects (N = 1,156, BMI >or= 35 kg/m(2)) were studied: gastric bypass subjects (n = 420), subjects seeking gastric bypass but did not have surgery (n = 415), and population-based subjects not seeking surgery (n = 321). Participants were studied at baseline and 2 years. Quantitative outcome measures as well as prevalence, incidence, and resolution rates of categorical health outcome variables were determined. All quantitative variables (BMI, blood pressure, lipids, diabetes-related variables, resting metabolic rate (RMR), sleep apnea, and health-related quality of life) improved significantly in the gastric bypass group compared with each comparative group (all P < 0.0001, except for diastolic blood pressure and the short form (SF-36) health survey mental component score at P < 0.01). Diabetes, dyslipidemia, and hypertension resolved much more frequently in the gastric bypass group than in the comparative groups (all P < 0.001). In the surgical group, beneficial changes of almost all quantitative variables correlated significantly with the decrease in BMI. We conclude that Roux-en-Y gastric bypass surgery when compared to severely obese groups not enrolled in planned weight-loss intervention was highly effective for weight loss, improved health-related quality of life, and resolution of major obesity-associated complications measured at 2 years.

The diabetes prevention program: a worksite experience.

The purpose of this study was to determine if the U.S. National Institutes of Health Diabetes Prevention Program (DPP) could be successfully implemented in a worksite setting. Thirty-seven adult employees of BD Medical Systems of Sandy, Utah were enrolled in a single-group time-series study using the DPP. Two-hour oral glucose tolerance tests (OGTT) and other outcomes were measured at baseline, 6 months, and 12 months. Weight, body mass index, waist circumference, 2-hour OGTT, very low density lipoproteins, triglycerides, and aerobic fitness were significantly improved at 6 and 12 months and showed overall significant improvement across time. Fasting blood insulin, total cholesterol, low density lipoproteins, and total cholesterol/high density lipoproteins ratio were significantly improved at 6 months, but not at 12 months. Eighteen of the program participants (51%) were no longer in the pre-diabetes and diabetes categories after 1 year. Existing worksite health promotion and occupational health professionals can successfully offer the DPP and help employees improve glucose tolerance.

Design and rationale of the Utah obesity study. A study to assess morbidity following gastric bypass surgery.

PURPOSE: This paper details the design and baseline characteristics of a study on the morbidity associated with Roux-en-Y gastric bypass surgery (GBP) in severely obese adults. This study is designed to assess the effectiveness of GBP in reducing morbidity and maintaining weight loss. A wide array of clinical tests and psycho-behavioral questionnaires are included as part of the study. METHODS: Three groups (n=1156 severely obese) have been recruited for this study: cases who were approved for and participated in surgery (n=415), a control group of GBP seeking individuals who were denied surgery (n=420) and a control group that was randomly chosen from a population of severely obese participants who were not seeking GBP (n=321). Clinical measures include: a physician interview and detailed medical history, resting electro- and echocardiograms, a submaximal exercise treadmill test and electrocardiogram, pulmonary function, limited polysomnography, resting metabolic rate, anthropometrics, resting and exercise blood pressure, comprehensive blood chemistry and urinalysis and dietary, quality of life and physical activity questionnaires. Most participants (76%) were tested following an overnight stay in a clinical research center. Remaining participants underwent less extensive testing in an outpatient clinic. RESULTS: Baseline characteristics of the 1156 participants are available for selected measures. Mean+/-S.D. for BMI was 46+/-7.5 kg/m(2) (range=33 to 92) and for age was 44+/-11.4 years (range=18 to 72). The prevalence of diabetes and hypertension was 19% and 35%, respectively. Of the participants who had an echocardiogram or polysomnogram, 92% had left-ventricular hypertrophy and 85% had mild to severe sleep apnea. The two control groups were similar to the surgical group. At approximately 24 months, all participants will have a second clinical examination. Statistical comparisons of changes in morbidity variables will be made between the surgical and control groups. CONCLUSIONS: This study design facilitates assessment of risks and benefits of GBP to perform recommendations on whether or not to perform surgery on the severely obese patient. Baseline and 2-year exams provide valuable data for comparison to future long-term follow-up data that can be collected at 5 and 10 years.

An accurate VO2max nonexercise regression model for 18-65-year-old adults.

The purpose of this study was to develop a regression equation to predict maximal oxygen uptake (VO2max) based on nonexercise (N-EX) data. All participants (N = 100), ages 18-65 years, successfully completed a maximal graded exercise test (GXT) to assess VO2max (M = 39.96 mL x kg(-1) x min(-1), SD = 9.54). The N-EX data collected just before the maximal GXT included the participant's age; gender; body mass index (BMI); perceived functional ability (PFA) to walk, jog, or run given distances; and current physical activity (PA-R) level. Multiple linear regression generated the following N-EX prediction equation (R = .93, SEE = 3.45 mL x kg(-1) x min(-1), % SEE = 8.62): VO2max (mL x kg(-1) x min(-1)) = 48.0730 + (6.1779 x gender; women = 0, men = 1) - (0. 2463 x age) - (0.6186 x BMI) + (0.7115 x PFA) + (0.6709 x PA-R). Cross validation using PRESS (predicted residual sum of squares) statistics revealed minimal shrinkage (R(p) = .91 and SEE(p) = 3.63 mL x kg(-1) x min(-1)); thus, this model should yield acceptable accuracy when applied to an independent sample of adults (ages 18-65 years) with a similar cardiorespiratory fitness level. Based on standardized beta-weights, the PFA variable (0.41) was the most effective at predicting VO2max followed by age (-0.34), gender (0.33), BMI (-0.27), and PA-R (0.16). This study provides a N-EX regression model that yields relatively accurate results and is a convenient way to predict VO2max in adult men and women.

The hypertriglyceridemic waist phenotype among women.

BACKGROUND: Elevated plasma triglycerides (TG) and waist girth (hypertriglyceridemic waist (HTGW)) has been associated with elevated insulin, small dense low-density lipoprotein (sLDL) particles, and Apo B in men. The HTGW has not been reported for women and the effect of cardiorespiratory fitness ("fitness") on associations between HTGW and coronary risk factors is unknown. PURPOSE: To determine the prevalence of HTGW and the influence of fitness on the relationship between HTGW and coronary risk among 137 healthy women (54+/-9 year; body mass index (BMI)=28+/-6 kg/m(2)). METHODS: HTGW was defined as waist girth >88 cm and TG >150 mg/dl. The metabolic triad was defined as insulin >31 pmol/l, Apo B >69 mg/dl and LDL-C >84 mg/dl. Fitness was assessed with a maximal treadmill exercise test. RESULTS: The sample prevalence of HTGW (n=15) was 11% (95% CI=5.7-16.0%). Apo B (P=0.04) and insulin (P=0.0001) increased across quintiles of waist girth, and LDL-C (P=0.004) increased across quintiles of TG. Metabolic triad prevalence was highest (67%, n=10) among HTGW women and lowest (22%, n=26) among non-HTGW women. A trend for higher coronary heart disease CHD risk factors was observed among HTGW compared with non-HTGW women. Among the HTGW group, a trend for lower CHD risk factors was observed among fit (>or=6.5 METs, n=7) versus unfit women (<6.5 METs, n=8). Sample size limitations prohibited meaningful tests of significant differences in CHD risk factors when stratified simultaneously on HTGW and fitness status. CONCLUSIONS: HTGW is associated with increased coronary risk factors similarly among women as reported for men. Higher fitness may improve the CHD risk profile among women with HTGW.

Cardiorespiratory fitness and C-reactive protein among a tri-ethnic sample of women.

BACKGROUND: Elevated C-reactive protein (CRP) is associated with increased coronary heart disease (CHD) risk. Cardiorespiratory fitness ("fitness") is related with lower CHD risk; however, its relationship with CRP is relatively unknown. METHODS AND RESULTS: Cross-sectional associations between fitness and plasma CRP were examined among 135 African American (AA), Native American (NA), and Caucasian (CA) women (55+/-11 year; 28+/-6 kg/m2). Fitness was assessed with a maximal treadmill exercise test. Plasma CRP concentrations were determined with the Dade Behring high-sensitivity immunoassay. Geometric mean CRP levels were 0.43, 0.25, and 0.23 mg/dL, and average maximal MET levels of fitness were 7.2, 9.1, and 10 METs for AA, NA, and CA, respectively. CRP decreased across tertiles of fitness (P=0.002), increased across tertiles of BMI (P=0.0007), and varied by race (P=0.002). After adjustment for covariates, lower CRP (P<0.05) was observed across tertiles of fitness among NA and CA, but not AA. Among all women, after adjusting for race and covariates, the odds of high-risk CRP (>0.19 mg/dL) were 0.67 (95% CI=0.19 to 2.4) among fit (>6.5 METs) versus unfit women. CONCLUSIONS: The health benefits from enhanced fitness may have an antiinflammatory mechanism.

Physical activity and health in the elderly.

Adults 65 years and older constitute the most rapidly growing segment of the US population. Sedentary lifestyle is a major risk factor for chronic disease and disability in the elderly. Physical activity levels among most older adults are insufficient to confer health benefits. This paper reviews recent evidence that physical activity and exercise training can positively modify the pathophysiology and outcomes of two leading causes of death and disability in the elderly: cardiovascular disease and fall-related injuries.