Diagnostic yield and financial implications of a nationwide electrocardiographic screening programme to detect cardiac disease in the young.

AIMS: There is limited information on the role of screening with electrocardiography (ECG) for identifying cardiovascular diseases associated with sudden cardiac death (SCD) in a non-select group of adolescents and young adults in the general population. METHODS AND RESULTS: Between 2012 and 2014, 26 900 young individuals (aged 14-35 years) were prospectively evaluated with a health questionnaire and ECG. Individuals with abnormal results underwent secondary investigations, the costs of which were being based on the UK National Health Service tariffs. Six hundred and seventy-five (2.5%) individuals required further investigation for an abnormal health questionnaire, 2175 (8.1%) for an abnormal ECG, and 114 (0.5%) for both. Diseases associated with young SCD were identified in 88 (0.3%) individuals of which 15 (17%) were detected with the health questionnaire, 72 (81%) with ECG and 2 (2%) with both. Forty-nine (56%) of these individuals received medical intervention beyond lifestyle modification advice in the follow-up period of 24 months. The overall cost of the evaluation process was €97 per person screened, €17 834 per cardiovascular disease detected, and €29 588 per cardiovascular disease associated with SCD detected. Inclusion of ECG was associated with a 36% cost reduction per diagnosis of diseases associated with SCD compared with the health questionnaire alone. CONCLUSION: The inclusion of an ECG to a health questionnaire is associated with a five-fold increase in the ability to detect disease associated with SCD in young individuals and is more cost effective for detecting serious disease compared with screening with a health questionnaire alone.

Role of Doppler Diastolic Parameters in Differentiating Physiological Left Ventricular Hypertrophy from Hypertrophic Cardiomyopathy.

BACKGROUND: The association between athletic participation and alteration in diastolic function is not well established. The aims of this study were to determine the spectrum of Doppler parameters of left ventricular (LV) diastolic function in a large cohort of healthy athletes and to quantify the overlap between physiologic LV hypertrophy and hypertrophic cardiomyopathy (HCM). METHODS: A retrospective analysis of indices of LV diastolic function was performed in 1,510 healthy athletes (mean age, 22 ± 5 years; range, 13-33 years; 72% men). The results were compared with those from 58 young patients with HCM. RESULTS: Septal E' < 7 cm/sec and lateral E' < 10 cm/sec were found in five (0.3%) and eight (0.5%) athletes, respectively. Septal E' was >14.6 cm/sec in 170 (11%) and lateral E' was >19.9 cm/sec in 430 (28%) athletes. Athletes aged >25 years showed lower E' velocities compared with younger athletes (mean septal E', 11.8 ± 6.1 vs 12.9 ± 5.9 cm/sec [P < .001]; mean lateral E', 17.1 ± 3.6 vs 19.3 ± 4.1 cm/sec [P < .001]). Athletes with high indexed LV end-diastolic diameters (>32 mm/m2) exhibited lower septal E' compared with athletes with normal indexed LV end-diastolic diameters (mean septal E', 11.9 ± 6 vs 12.7 ± 6 cm/sec; P = .002). Septal E' < 10 cm/sec and lateral E' < 12 cm/sec showed the best accuracy in differentiating between HCM and athlete's heart. CONCLUSIONS: Reduced septal and lateral E' are rarely observed in young elite athletes. Tissue Doppler velocities tend to decrease with increasing age and LV size, and values representative of supernormal diastolic function are found in less than one-third of young athletes. Cutoff thresholds for Doppler parameters of diastolic function should be corrected for multiple demographic and clinical variables to differentiate cardiac adaptation to exercise from HCM in young individuals.

Left ventricular lead misplacement discovered a decade after cardiac resynchronization therapy-defibrillator implantation: a case report.

INTRODUCTION: Satisfactory left ventricular (LV) lead placement into the coronary sinus (CS) can be achieved in the majority of patients but there are still instances of acute failure most often due to anatomical differences, for example due to tortuous CS anatomy. Chronic LV lead misplacement and its delayed discovery is not a common scenario. It is unclear if chronic dual right ventricular pacing can hasten the progression of heart failure. CASE PRESENTATION: A 73-year-old lady presented to our cardiac centre with severe heart failure. She had non-ischaemic dilated cardiomyopathy with underlying left bundle branch block and a cardiac resynchronization therapy-defibrillator device in situ for the past decade. She also had a chronic pericardial effusion of unknown aetiology. Whilst the patient was being treated for acute heart failure, it was noted on patient telemetry that the QRS morphology for supposed bi-ventricular pacing was unusual. This led to a lateral chest radiograph and a CS venogram to be performed, both of which confirmed that the LV lead was in fact not in the CS. Plans were made to place a new LV lead but unfortunately the patient continued to clinically deteriorate despite maximal treatment and died before this could be performed. DISCUSSION: It is only with thorough review of the electrocardiographic data and chest radiography that led to the discovery of chronic LV lead misplacement. This case illustrates the importance of expert review of radiographic imaging and electrocardiographic data in patients with implanted cardiac devices.

Prevalence of Subclinical Coronary Artery Disease in Masters Endurance Athletes With a Low Atherosclerotic Risk Profile.

BACKGROUND: Studies in middle-age and older (masters) athletes with atherosclerotic risk factors for coronary artery disease report higher coronary artery calcium (CAC) scores compared with sedentary individuals. Few studies have assessed the prevalence of coronary artery disease in masters athletes with a low atherosclerotic risk profile. METHODS: We assessed 152 masters athletes 54.4±8.5 years of age (70% male) and 92 controls of similar age, sex, and low Framingham 10-year coronary artery disease risk scores with an echocardiogram, exercise stress test, computerized tomographic coronary angiogram, and cardiovascular magnetic resonance imaging with late gadolinium enhancement and a 24-hour Holter. Athletes had participated in endurance exercise for an average of 31±12.6 years. The majority (77%) were runners, with a median of 13 marathon runs per athlete. RESULTS: Most athletes (60%) and controls (63%) had a normal CAC score. Male athletes had a higher prevalence of atherosclerotic plaques of any luminal irregularity (44.3% versus 22.2%; P=0.009) compared with sedentary males, and only male athletes showed a CAC ≥300 Agatston units (11.3%) and a luminal stenosis ≥50% (7.5%). Male athletes demonstrated predominantly calcific plaques (72.7%), whereas sedentary males showed predominantly mixed morphology plaques (61.5%). The number of years of training was the only independent variable associated with increased risk of CAC >70th percentile for age or luminal stenosis ≥50% in male athletes (odds ratio, 1.08; 95% confidence interval, 1.01-1.15; P=0.016); 15 (14%) male athletes but none of the controls revealed late gadolinium enhancement on cardiovascular magnetic resonance imaging. Of these athletes, 7 had a pattern consistent with previous myocardial infarction, including 3(42%) with a luminal stenosis ≥50% in the corresponding artery. CONCLUSIONS: Most lifelong masters endurance athletes with a low atherosclerotic risk profile have normal CAC scores. Male athletes are more likely to have a CAC score >300 Agatston units or coronary plaques compared with sedentary males with a similar risk profile. The significance of these observations is uncertain, but the predominantly calcific morphology of the plaques in athletes indicates potentially different pathophysiological mechanisms for plaque formation in athletic versus sedentary men. Coronary plaques are more abundant in athletes, whereas their stable nature could mitigate the risk of plaque rupture and acute myocardial infarction.

Anterior T-Wave Inversion in Young White Athletes and Nonathletes: Prevalence and Significance.

BACKGROUND: Anterior T-wave inversion (ATWI) on electrocardiography (ECG) in young white adults raises the possibility of cardiomyopathy, specifically arrhythmogenic right ventricular cardiomyopathy (ARVC). Whereas the 2010 European consensus recommendations for ECG interpretation in young athletes state that ATWI beyond lead V1 warrants further investigation, the prevalence and significance of ATWI have never been reported in a large population of asymptomatic whites. OBJECTIVES: This study investigated the prevalence and significance of ATWI in a large cohort of young, white adults including athletes. METHODS: Individuals 16 to 35 years of age (n = 14,646), including 4,720 females (32%) and 2,958 athletes (20%), were evaluated by using a health questionnaire, physical examination, and 12-lead ECG. ATWI was defined as T-wave inversion in ≥2 contiguous anterior leads (V1 to V4). RESULTS: ATWI was detected in 338 individuals (2.3%) and was more common in women than in men (4.3% vs. 1.4%, respectively; p < 0.0001) and more common among athletes than in nonathletes (3.5% vs. 2.0%, respectively; p < 0.0001). T-wave inversion was predominantly confined to leads V1 to V2 (77%). Only 1.2% of women and 0.2% of men exhibited ATWI beyond V2. No one with ATWI fulfilled diagnostic criteria for ARVC after further evaluation. During a mean follow-up of 23.1 ± 12.2 months none of the individuals with ATWI experienced an adverse event. CONCLUSIONS: ATWI confined to leads V1 to V2 is a normal variant or physiological phenomenon in asymptomatic white individuals without a relevant family history. ATWI beyond V2 is rare, particularly in men, and may warrant investigation.

Effect of Sex and Sporting Discipline on LV Adaptation to Exercise.

OBJECTIVES: This study sought to investigate the effect of different types of exercise on left ventricular (LV) geometry in a large group of female and male athletes. BACKGROUND: Studies assessing cardiac adaptation in female and male athletes indicate that female athletes reveal smaller increases in LV wall thickness and cavity size compared with male athletes. However, data on sex-specific changes in LV geometry in athletes are scarce. METHODS: A total of 1,083 healthy, elite, white athletes (41% female; mean age 21.8 ± 5.7 years) assessed with electrocardiogram and echocardiogram were considered. LV geometry was classified into 4 groups according to relative wall thickness (RWT) and left ventricular mass (LVM) as per European and American Society of Echocardiography guidelines: normal (normal LVM/normal RWT), concentric hypertrophy (increased LVM/increased RWT), eccentric hypertrophy (increased LVM/normal RWT), and concentric remodeling (normal LVM/increased RWT). RESULTS: Athletes were engaged in 40 different sporting disciplines with similar participation rates with respect to the type of exercise between females and males. Females exhibited lower LVM (83 ± 17 g/m2 vs. 101 ± 21 g/m2; p < 0.001) and RWT (0.35 ± 0.05 vs. 0.36 ± 0.05; p < 0.001) compared with male athletes. Females also demonstrated lower absolute LV dimensions (49 ± 4 mm vs. 54 ± 5 mm; p < 0.001) but following correction for body surface area, the indexed LV dimensions were greater in females (28.6 ± 2.7 mm/m2 vs. 27.2 ± 2.7 mm/m2; p < 0.001). Most athletes showed normal LV geometry. A greater proportion of females competing in dynamic sport exhibited eccentric hypertrophy compared with males (22% vs. 14%; p < 0.001). In this subgroup only 4% of females compared with 15% of males demonstrated concentric hypertrophy/remodeling (p < 0.001). CONCLUSIONS: Highly trained athletes generally show normal LV geometry; however, female athletes participating in dynamic sport often exhibit eccentric hypertrophy. Although concentric remodeling or hypertrophy in male athletes engaged in dynamic sport is relatively common, it is rare in female athletes and may be a marker of disease in a symptomatic athlete.

Abnormal electrocardiographic findings in athletes: Correlation with intensity of sport and level of competition.

INTRODUCTION: Athletes can exhibit abnormal electrocardiogram (ECG) phenotypes that require further evaluation prior to competition. These are apparently more prevalent in high-intensity endurance sports. The purpose of this study was to assess the association between ECG findings in athletes and intensity of sport and level of competition. METHODS: A cohort of 3423 competitive athletes had their ECGs assessed according to the Seattle criteria (SC). The presence of abnormal ECGs was correlated with: (1) intensity of sport (low/moderate vs. at least one high static or dynamic component); (2) competitive level (regional vs. national/international); (3) training volume (≤20 vs. >20 hours/week); (4) type of sport (high dynamic vs. high static component). The same endpoints were studied according to the 'Refined Criteria' (RC). RESULTS: Abnormal ECGs according to the SC were present in 225 (6.6%) athletes, more frequently in those involved in high-intensity sports (8.0% vs. 5.4%; p=0.002), particularly in dynamic sports, and competing at national/international level (7.1% vs. 4.9%; p=0.028). Training volume was not significantly associated with abnormal ECGs. By multivariate analysis, high-intensity sport (OR 1.55, 1.18-2.03; p=0.002) and national/international level (OR 1.50, 95% CI 1.04-2.14; p=0.027) were independent predictors of abnormal ECGs, and these variables, when combined, doubled the prevalence of this finding. According to the RC, abnormal ECGs decreased to 103 (3.0%), but were also more frequent in high-intensity sports (4.2% vs. 2.0%; p<0.001). CONCLUSIONS: There is a positive correlation between higher intensity of sports and increased prevalence of ECG abnormalities. This relationship persists with the use of more restrictive criteria for ECG interpretation, although the number of abnormal ECGs is lower.

Cost Implications of Using Different ECG Criteria for Screening Young Athletes in the United Kingdom.

BACKGROUND: High false-positive rates and cost of additional investigations are an obstacle to electrocardiographic (ECG) screening of young athletes for cardiac disease. However, ECG screening costs have never been systematically assessed in a large cohort of athletes. OBJECTIVE: This study investigated the costs of ECG screening in athletes according to the 2010 European Society of Cardiology (ESC) recommendations and the Seattle and refined interpretation criteria. METHODS: Between 2011 and 2014, 4,925 previously unscreened athletes aged 14 to 35 years were prospectively evaluated with history, physical examination, and ECG (interpreted with the 2010 ESC recommendations). Athletes with abnormal results underwent secondary investigations, the costs of which were based on U.K. National Health Service Tariffs. The impact on cost after applying the Seattle and refined criteria was evaluated retrospectively. RESULTS: Overall, 1,072 (21.8%) athletes had an abnormal ECG on the basis of 2010 ESC recommendations; 11.2% required echocardiography, 1.7% exercise stress test, 1.2% Holter, 1.2% cardiac magnetic resonance imaging, and 0.4% other tests. The Seattle and refined criteria reduced the number of positive ECGs to 6.0% and 4.3%, respectively. Fifteen (0.3%) athletes were diagnosed with potentially serious cardiac disease using all 3 criteria. The overall cost of de novo screening using 2010 ESC recommendations was $539,888 ($110 per athlete and $35,993 per serious diagnosis). The Seattle and refined criteria reduced the cost to $92 and $87 per athlete screened and $30,251 and $28,510 per serious diagnosis, respectively. CONCLUSIONS: Contemporary ECG interpretation criteria decrease costs for de novo screening of athletes, which may be cost permissive for some sporting organizations.

The prevalence and significance of a short QT interval in 18,825 low-risk individuals including athletes.

OBJECTIVES: The short QT syndrome is a cardiac channelopathy characterised by accelerated repolarisation which manifests as a short QT interval on the ECG. The definition of a short QT interval is debated, ranging from <390 to ≤320 ms, and its clinical significance in healthy young individuals is unknown. We assessed the prevalence and medium-term significance of an isolated short QT interval in a diverse young British population. METHODS: Between 2005 and 2013, 18 825 apparently healthy people aged 14-35 years underwent cardiovascular evaluation with history, physical examination and ECG. QT intervals were measured by cardiologists using 4 recommended guidelines (Seattle 2013, Heart Rhythm Society 2013, European Society of Cardiology 2010 and American Heart Association 2009). RESULTS: The prevalence of a short QT interval was 0.1% (26 patients, ≤320 ms), 0.2% (44 patients, ≤330 ms), 7.9% (1478 patients, <380 ms), 15.8% (2973 patients, <390 ms). Male gender and Afro-Caribbean ethnicity had the strongest association with short QT intervals. Athletes had shorter QT intervals than non-athletes but athletic status did not predict short QT intervals. Individuals with short QT intervals ≤320 ms did not report syncope or a sinister family history, and during a follow-up period of 5.3±1.2 years, there were no deaths in this group. CONCLUSIONS: The prevalence of a short QT interval depends on the recommended cut-off value. Even at values ≤320 ms, there was an excellent medium-term prognosis among 14 people followed. We conclude that a definition of ≤320 ms is realistic to prevent overdiagnosis and excessive investigations.

A young man presenting with paralysis after vigorous exercise.

Thyrotoxic periodic paralysis (TPP) is a rare metabolic disorder characterised by muscular weakness and paralysis in predisposed thyrotoxic patients. Although patients with TPP are almost uniformly men of Asian descent, cases have been reported in Caucasian and other ethnic populations. The rapid increase in ethnic diversity in Western and European nations has led to increase in TPP reports, where it was once considered exceedingly rare. Correcting the hypokalaemic and hyperthyroid state tends to reverse the paralysis. However, failure to recognise the condition may lead to delay in diagnosis and serious consequences including respiratory failure and death. We describe a young man who was diagnosed with hyperthyroidism who presented with acute paralysis. The clinical characteristics, pathophysiology and management of TTP are reviewed.

Unusual presentation of thyrotoxicosis as complete heart block and renal failure: a case report.

INTRODUCTION: Thyrotoxicosis is a clinical entity often very difficult to diagnose without biochemical confirmation as its clinical features can be highly varied. The most common cardiac manifestations of thyrotoxicosis are resting sinus tachycardia, supraventricular tachycardia including atrial fibrillation and atrial flutter with or without cardiac failure. Bradycardia and atrio-ventricular conduction defects are very uncommon in thyrotoxicosis. CASE PRESENTATION: We report the case of a 59-year-old Caucasian man presenting with progressive weight loss, abnormal liver function, acute renal failure and complete heart block due to thyrotoxicosis. CONCLUSION: Thyrotoxicosis should be considered as a possible diagnosis in patients with bradycardia and heart blocks associated with abnormal symptoms like weight loss. Nevertheless, the clinical, electrophysiological and biochemical abnormalities associated with thyrotoxicosis may be completely reversible restoring euthyroid state.