Athlete"s heart and hypertrophic cardiomyopathy

Effects of 4-Week Low-Load Resistance Training with Blood Flow Restriction on Muscle Strength and Left Ventricular Function in Young Swimmers: A Pilot Randomized Trial

Low-load resistance training combined with blood flow restriction (BFR) is known to result in muscle hypertrophy and strength similar to that observed with higher loads. However, the effects of resistance training with BFR on cardiac structure and cardiac function remain largely unknown. Therefore, the purpose of this randomized study was to compare the effects of conventional high-load resistance training (HL-RT) with the effects of low-load resistance training with BFR (LL-BFR) on muscle strength and left ventricular function. Sixteen young swimmers (mean ± standard deviation: age = 19.7 ± 1.6 years, body mass = 78.9 ± 9.7 kg, body height = 180.8 ± 5.8 cm) were randomly allocated to a conventional HL-RT group (n = 8) or a LL-BFR group (n = 8) with a pressure band (200 mmHg) placed on both thighs of participants for 4 weeks (3 days•week-1). Outcome measures were taken at baseline and after 4 weeks of training, and included body composition, one-repetition maximum (1RM) back squat, and echocardiography measures. The 1RM back squat significantly improved (partial eta squared (Ƞ2) = 0.365; p = 0.013) in HL-RT (mean difference (Δ) = 6.6 kg; [95% confidence interval (CI) -7.09 to 20.27]) and LL-BFR groups (Δ = 14.7 kg; [95% CI 3.39 to 26.10]), with no main effect of group or group × time interaction (p > 0.05). Interventricular septum end-systolic thickness showed a slight but statistically significant increase in LL-BFR and HL-RT groups (Ƞ2 = 0.253; p = 0.047), yet there was no main effect of group or group × time interaction (p > 0.05). There were no statistically significant changes (p > 0.05) in other cardiac structure or function parameters (e.g., left ventricular (LV) mass, LV cardiac output, LV ejection fraction, LV stroke volume) after the training programs. Results suggest that 4 weeks of HL-RT and LL-BFR improve muscle strength similarly with limited effects on left ventricular function in young swimmers.

Echocardiographic Evaluation of the Athlete's Heart: Focused Review and Update

PURPOSE OF REVIEW

The athlete's heart exhibits unique structural and functional adaptations in the setting of strenuous and repetitive athletic training which may be similarly found in pathologic states. The purpose of this review is to highlight the morphologic and functional changes associated with the athlete's heart, with a focus upon the insights that echocardiography provides into exercise-induced cardiac remodeling.

RECENT FINDINGS

Recent studies are aiming to investigate the long-term effects and clinical consequences of an athlete's heart. The "gray-zone" continues to pose a clinical challenge and may indicate scenarios where additional imaging modalities, or longitudinal follow-up, provide a definitive answer. Echocardiography is likely to remain the first-line imaging modality for the cardiac evaluation of elite athletes. Multimodality imaging combined with outcome and long-term follow-up studies both during training and after retirement in both men and women may help further clarify the remaining mysteries in the coming years.

Assessment of Structure, Function, and Rhythm of the Heart with Echocardiography and Electrocardiography in Adolescent Swimmers

The aim of this study was to evaluate the cardiac parameters by using electrocardiography and echocardiography in adolescent swimmers. Twenty-two adolescent swimmers and 22 gender- and age-matched sedentary controls admitted to our center between November 2018 and May 2019 were included in this study. In addition to demographical characteristics, participants were assessed via a 12-lead electrocardiography and two-dimensional echocardiography for cardiac function. On the echocardiography, end-systolic and end-diastolic interventricular septum, end-systolic and end-diastolic left ventricular posterior wall thicknesses, left atrial width, Tricuspid E, left ventricular mass and left ventricular mass index were higher in the swimmers when compared to the sedentary controls (P < 0.05). On the electrocardiography, Tp-e duration which reflects ventricular transmural repolarization, and Tp-e/QT and Tp-e/corrected QT ratios were higher in the swimmers than the sedentary controls (P < 0.05). In conclusion, swimming exercise in children leads to concentric thickening of left ventricle and induces an increase in Tp-e duration, and Tp-e/QT and Tp-e/corrected QT ratios, which are the novel markers for risk of ventricular arrhythmias.

Elevated LV Mass and LV Mass Index Sign on the Athlete's ECG: Athletes' Hearts are Prone to Ventricular Arrhythmia

OBJECTIVES

Intense exercise elevates all heart chambers' dimensions, left ventricular mass (LV mass), and left ventricular mass index (LV mass index). The relationship between increased ventricular arrhythmias and sudden cardiac death with LV dilatation and elevated LV mass has been previously demonstrated. We investigated whether sports-related LV dilatation and elevated LV mass and LV mass index cause an increase in ventricular repolarization heterogeneity.

PATIENTS AND METHODS

This prospective observational study recruited 565 participants. There were 226 (female: 28) athletes and 339 (female: 45) healthy controls between 17 and 42 years of age. They were evaluated using 12-lead-electrocardiography and transthoracic echocardiography. Electrocardiograms were obtained at a rate of 50 mm/s and an amplitude of 10 mV, including at least 3 QRS complexes for each derivation. They were taken with 12 standard deviations. Transmural dispersion of repolarization indexes (TDR) (Tp-Te interval, Tp-Te/QT ratio and Tp-Te/QTc ratio, Tp-Te(d)) were measured from precordial derivations. Measurements weretakenwith a program which was generated with MATLAB codes.

RESULTS

Tp-Te interval, Tp-Te/QT ratio, Tp-Te/QTc ratio, Tp-Te(d), PW (posterior wall thickness), IVS (interventricular septal thickness), LVEDD (left ventricular end-diastolic diameter), LV mass (left ventricular mass), and LV mass index (left ventricular mass index) for the athlete group were significantly higher than for the control group. Correlation analyses revealed that TDR indexes significantly correlated with PW, IVS, LVEDD, LV mass, and LV mass index.

CONCLUSION

LV mass and LV mass index increase in well-trained athletes, and this increase leads to an increase in TDR indexes. The increased frequency of ventricular arrhythmia and sudden cardiac death may be explained with increasing ventricular repolarization heterogeneity in these individuals.

Hypertension in Athletes and Active Populations

Hypertension continues to be the most common cardiovascular disorder in the USA and worldwide. While generally considered a disorder of aging individuals, hypertension is more prevalent in athletes and the active population than is generally appreciated. The timely detection, diagnosis, and appropriate treatment of hypertension in athletes must focus on both adequately managing the disorder and ensuring safe participation in sport while not compromising exercise capacity. This publication focuses on appropriately diagnosing hypertension, treating hypertension in the athletic population, and suggesting follow-up and participation guidelines for athletes.

The Relationship Between Physical Activity and Risk of Atrial Fibrillation-A Systematic Review and Meta-Analysis

Aim: The aim of this systematic literature review and meta-analyses was to explore the relationship between physical activity and risk of new-onset atrial fibrillation (AF) or flutter (AFlu). Results: The search revealed 10 published studies that were eligible for three different meta-analyses. A meta-analysis of six case-control studies showed that risk of AF increased more than 5-fold in athletes compared to non-athletic controls, OR=5.3 [(3.6, 7.9; 95% confidence interval (CI)], p<0.0001. A second meta-analysis of three case-control studies showed a significantly higher prevalence of athletes among AF populations compared to their healthy controls, OR=4.7 (3.1-6.9; 95% CI), p<0.0001. A third meta-analysis of three prospective large-scale long-term studies showed that moderate/high habitual physical activity was associated with significantly reduced risk of AF compared with none or very low intensity physical activity OR=0.89(0.83, 0.96; 95% CI), p=002 Conclusions: Long-term vigorous physical training or lack of physical activity both are associated with increased risk of AF, while habitual moderate physical activity may be associated with reduced risk. Further large-scale prospective randomized controlled studies particularly in athletes are needed to further confirm these findings.

Primary hypertension and special aspects of hypertension in older children and adolescents

The prevalence of hypertension has increased at an accelerated rate in older children and adolescents. This has raised great concern about premature development of cardiovascular disease, which has major long-term health and financial implications. While obesity and sedentary habits largely explain this phenomenon, there are other social and cultural influences that may unmask genetic susceptibility to hypertension in the pediatric population. While it is essential to exclude numerous causes of secondary hypertension in every child, these disorders are not discussed in this review. Rather, the aim of this review is to familiarize pediatricians with casual and ambulatory blood pressure measurement, epidemiology, pathophysiology, and management of several common conditions that play a role in the development of hypertension in children and adolescents. Besides primary hypertension and obesity-related hypertension, emphasis is given to epidemiology, measurement of blood pressure, including ambulatory blood pressure monitoring, hypertension associated with drug use, teenage pregnancy, and video and computer games. Lastly, because pediatricians are increasingly confronted with special issues concerning the management of the hypertensive athlete, this topic is also addressed.

Magnetic resonance imaging in the assessment of ventricular remodeling and viability

Cardiovascular MRI has effectively become a reference standard for quantifying ventricular volumes and function and for measuring the myocardial scar burden after myocardial infarction. Imaging of late gadolinium enhancement and microvascular obstruction carries strong prognostic information for identifying patients who would benefit from anti-remodeling therapy. The combination of gadolinium enhancement, perfusion, and cine imaging should make MRI the modality of choice in the assessment of left ventricular dysfunction and remodeling. The use of MRI in clinical trials of heart failure could help reduce sample size requirements because of its accuracy and reproducibility. This review describes the use of MRI in assessing ventricular remodeling and viability and summarizes the few studies that have relied on MRI for image-based markers of ventricular remodeling.

Serum cardiac troponin T, troponin I, plasma BNP and left ventricular mass index in professional football players

Concentrations of cardiac troponins (cTn) in serum or plasma may be elevated in several disease states other than acute coronary syndromes. In heart failure and end stage renal disease, cardiac troponin T (cTnT) correlates positively with left ventricular mass index (LVMI). Exercise-induced elevation of cardiac troponins in well-trained athletes has been confirmed by several reports but the aetiology and clinical significance is unclear. In the present study, we measured baseline concentrations of cardiac markers and investigated whether or not serum cTnT is associated with left ventricular hypertrophy (LVH) in professional football players.

METHODS

Twenty-three male professional football players with a mean age of 23 years (range 18-32) were studied. Echocardiography and blood sampling were carried out approx 24h after a training session. Serum cTnT, other cardiac markers and plasma brain natriuretic peptide (BNP) were compared with LVMI.

RESULTS

cTnT was only detectable in one subject. The prevalence of elevated cardiac troponin I (cTnI), creatine kinase MB (CKMB) and creatine kinase was higher than for cTnT. cTnI concentrations were higher in football players than in controls. LVMI did not correlate with any of the cardiac markers. Plasma BNP concentrations were normal in all subjects.

CONCLUSION

Serum cTnT concentrations were not elevated in healthy professional football players with LVH. This argues against the hypothesis that LVH per se may cause increased cTnT. The finding of higher cTnI in football players than in non-athletic controls should be confirmed and the aetiology elucidated.

Cardiac alterations in cirrhosis: reversibility after liver transplantation

BACKGROUND/AIMS

Liver cirrhosis induces cardiac alterations. We aimed to define these alterations and assess their reversibility after transplantation.

METHODS

Cirrhotic patients (n = 40) and controls (n = 15) underwent echocardiography and stress ventriculography. Fifteen cirrhotics were reevaluated 6-12 months after transplantation.

RESULTS

Cirrhotics had higher left ventricular wall thickness (9.6+/-1.2 vs. 8.8+/-1.2 mm; P < 0.05) and ejection fraction (73+/-6 vs. 65+/-4%, P < 0.001) than controls. Basal diastolic function was similar. During stress, cirrhotics presented lower increases of heart rate, left ventricular ejection fraction, stroke volume and cardiac index (P < 0.05 for all), and diastolic dysfunction with lower ventricular peak filling rate (P = 0.001). Exercise capacity was reduced (48+/-21 vs. 76+/-24 W; P < 0.001). Ascitic patients exhibited more diastolic dysfunction at rest and during stress compared to non-ascitic patients. Liver transplantation caused regression of ventricular wall thickness (10.2+/-1.3 vs. 9.5+/-1.2 mm; P < 0.05), improvement of diastolic function, and normalization of systolic response and exercise capacity during stress (significant increases in heart rate, ventricular ejection fraction, stroke volume and cardiac index; P < 0.05 for all).

CONCLUSIONS

Cardiac alterations in cirrhosis present with mild increases in ventricular wall thickness, diastolic dysfunction that worsens with ascites and physical stress, and abnormal systolic response to stress limiting exercise capacity. Liver transplantation reverses these alterations.