Keerthi Prakash

Interpretation of the Electrocardiogram in Athletes.

Regular intensive participation in sport results in electrical and structural alterations within the heart that can manifest on the surface electrocardiogram (ECG). In addition to the actual sporting discipline and the volume and intensity of exercise being performed, other factors play a role in the development of certain ECG patterns including sex, age, and ethnicity. In some instances, large male endurance athletes and those of African or Afro-Caribbean origin (black athletes), might exhibit ECG patterns that overlap with those seen in patients with cardiomyopathy and channelopathies, which are recognized causes of exercise-related sudden cardiac death. The ability to distinguish accurately between benign physiological electrical alterations and pathological ECG changes is crucial to prevent the unnecessary termination of an athletes career and to minimize the risk of sudden death. Several recommendations currently exist to aid the physician in the interpretation of the athletes ECG. In this review we discuss which ECG patterns can safely be considered benign as opposed to those that should prompt the physician to consider cardiac pathology.

Comparison of hypertrophic cardiomyopathy in Afro-Caribbean versus white patients in the UK

Background This study investigated the influence of African/Afro-Caribbean (black) ethnicity on the clinical profile and outcomes in hypertrophic cardiomyopathy (HCM). Methods 425 consecutive patients with HCM (163 black and 262 Caucasians (white); mean age 52.5±16.6 years) were assessed at three cardiomyopathy centres. Repeat assessments were performed every 6–12 months and mean follow-up was 4.3±3.0 years. The primary outcome was a composite of cardiovascular death, cardiac arrest or appropriate device therapy. Results A fortuitous diagnosis of HCM was more commonly made in black compared with white patients (31.3% vs 19.1%, p=0.004). An abnormal ECG at presentation was more frequent in black patients (98.2% vs 90.5%, p=0.002), with T-wave inversion being a common feature (91.4% vs 73.0%, p<0.001). Asymmetric septal hypertrophy was the predominant pattern in both ethnic groups; however, apical (22.2% vs 10.7%, p<0.001) and concentric (9.3% vs 1.5%, p<0.001) patterns were more prevalent in black patients. Hypertension was more frequent in black patients (58.3% vs 31.7%, p<0.001). There were no ethnic differences in risk factor profile or primary outcome. Independent predictors of the primary outcome were non-sustained ventricular tachycardia (HR 6.03, 95% CI 3.06 to 11.91, p≤0.001) and hypertension at presentation (HR 2.02, 95% CI 1.05 to 3.88, p=0.036), with an additive effect. Conclusion Black ethnicity is an important determinant of the phenotypic expression of HCM but does not adversely affect outcomes. Apical and concentric hypertrophy are common in black patients and may hinder the identification of HCM in this cohort. Hypertension has an adverse effect on outcome, irrespective of ethnicity.

The Electrocardiogram in Highly Trained Athletes.

Regular intensive exercise is associated with a constellation of several structural and functional adaptations within the heart that permit the generation of a large and sustained increase in cardiac output and/or increase in blood pressure. The magnitude with which these markers of physiological remodeling manifest on the surface electrocardiogram is governed by several factors and some athletes show electrical and structural changes that overlap with those observed in cardiomyopathy and in ion channel diseases, which are recognized causes of sudden cardiac death in young athletes. This article provides a critical appraisal of the athletes ECG.

133 Cardiopulmonary exercise testing: does ethnicity matter?

Introduction Hypertrophic cardiomyopathy (HCM) is the largest cause of sudden cardiac death in athletes. Differentiation between HCM and athletic cardiac adaptation is not always straightforward. Cardiopulmonary exercise testing (CPET) is useful in this context, with a peak VO2>120% predicted commonly used to differentiate athletes with HCM from those with physiological left ventricular hypertrophy. This value however is derived from a predominantly white population. Differences with ethnicity have been well documented on the ECG and echocardiogram of both athletes and individuals with HCM, however, ethnic differences in their physiology have not been well investigated to date. Purpose To assess if there is a significant difference on CPET in HCM patients of black and white ethnicity. Methods Cardiopulmonary exercise testing data was prospectively and retrospectively analysed from a cohort of 49 sedentary HCM patients assessed in a quaternary referral centre (36 white, 38 male; aged 15–65 years). Inclusion criteria: HCM patients of black or white ethnicity, NYHA 1, resting LVOT gradient<40 mmHg, no ICD in-situ and having completed a maximal CPET (defined as: R 1.1 and test terminated due to breathlessness/muscular fatigue). Results Statistical significance was assessed using the Mann-Whitney U test (for non-parametric data) and the Student’s T-test (for parametric data). Statistically significant differences between black and white HCM patients were noted in the% predicted peak power and% predicted peak VO2/kg. (Table 1) Abstract 133 Table 1 Mean values p-value (2-?sided) Black HCM White HCM Age (years) 45.08 45.47 0.9214* BMI (kg/cm2) 26.86 27.96 0.416* Peak R achieved 1.19 1.20 0.3576** % predicted VO2/HR 95.77 102.42 0.177** VE/VCO2 slope 31.72 29.43 0.3524** % predicted peak power (Watts) 80.92 104.89 0.0016** Peak VO2/kg (mls/min/kg) 25.93 27.53 0.7114** % predicted peak VO2/kg (mls/min/kg) 77.85 88.03 0.0434** VO2 at lactate threshold (% of peak V02/kg) 58.88 55.66 0.3472** Conclusion Black HCM patients achieve a significantly lower% predicted peak power on CPET (24% lower) compared with white HCM patients. Black HCM patients also demonstrate a significantly lower% predicted peak VO2/kg (10% lower) compared to white HCM patients. Larger studies are required to corroborate these ethnic differences, however, this study suggests that the current standard cut-off of a peak VO2>120% predicted may be too high for a black athlete resulting in a false positive diagnosis of HCM.