Ahmed Merghani

Exercise and the heart: the good, the bad, and the ugly

The benefits of exercise are irrefutable. Individuals engaging in regular exercise have a favourable cardiovascular risk profile for coronary artery disease and reduce their risk of myocardial infarction by 50%. Exercise promotes longevity of life, reduces the risk of some malignancies, retards the onset of dementia, and is as considered an antidepressant. Most of these benefits are attributable to moderate exercise, whereas athletes perform way beyond the recommended levels of physical activity and constantly push back the frontiers of human endurance. The cardiovascular adaptation for generating a large and sustained increase in cardiac output during prolonged exercise includes a 10-20% increase in cardiac dimensions. In rare instances, these physiological increases in cardiac size overlap with morphologically mild expressions of the primary cardiomyopathies and resolving the diagnostic dilemma can be challenging. Intense exercise may infrequently trigger arrhythmogenic sudden cardiac death in an athlete harbouring asymptomatic cardiac disease. In parallel with the extraordinary athletic milieu of physical performances previously considered unachievable, there is emerging data indicating that long-standing vigorous exercise may be associated with adverse electrical and structural remodelling in otherwise normal hearts. Finally, in the current era of celebrity athletes and lucrative sport contracts, several athletes have succumbed to using performance enhancing agents for success which are detrimental to cardiac health. This article discusses the issues abovementioned, which can be broadly classified as the good, bad, and ugly aspects of sports cardiology.

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.

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.

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

Cardiac Screening of Young Athletes Prior to Participation in Sports Difficulties in Detecting the Fatally Flawed Among the Fabulously Fit

539,888 (

91 Differentiating Physiological Left Ventricular Hypertrophy from Hypertrophic Cardiomyopathy in Athletes: Proposed Echocardiographic Protocol

110 per athlete and

103 Prevalence And Significance Of Anterior T Wave Inversion In Females

35,993 per serious diagnosis). The Seattle and refined criteria reduced the cost to

Hematocrit, iron and HDL-cholesterol explain 90% of variation in native blood T1

92 and

Native myocardial T1 and ECV with age and gender developing normal reference ranges - a 94 healthy volunteer study

87 per athlete screened and

Sudden cardiac death: detecting the warning signs

30,251 and